poster - International Conference of Agricultural Engineering

POSTER 

SW: SOIL 

AND WATER 

ENGINEERING 

P-0012 

GROWING MORE WITH LESS IN THE WEST- 

LANDS WATER DISTRICT IN THE SAN JOAQUIN 

VALLEY, CALIFORNIA 

Presenter: James Ayars 

USA 

Authors: James Ayars 1 , Bakhodir Mirzaev 2 

1 

Agricultural Engineer, Water Management Research Unit, 

USDA-ARS 

2 

Water Resources Management Specialist, IWRM project, 

UNDP Uzbekistan 

P-0024 

DAILY PENMAN-MONTEITH SENSITIVITY 

ANALYSIS IN MANY SUBCLASSES CLIMATES OF 

KERMAN BASED ON EXTENDED-DE MARTONNE 

CLASSIFICATION 

Presenter: Bahram Bakhtiari 

Iran 

Authors: Bahram Bakhtiari 1 , Amin Baghizadeh 2 

1 

Shahid Bahonar University of Kerman 

2 

International Center for Science, High Technology & Environmental 

Sciences 

P-0025 

RECOGNITION AND ESTIMATION OF EFFECTIVE 

RAINFALL AS A DROUGHT MANAGEMENT STRA- 

TEGY IN RAINFED AGRICULTURE. 

Presenter: Jaber Rahimi 

Iran 

Authors: Jaber Rahimi, Jaber Rahimi 

M.Sc. Student of Irrigation and Reclamation Engineering 

Department, University of Tehran, Karaj University of Tehran 

P-0029 

SOIL MOISTURE AND TEMPERATURE MONI- 

TORING FOR SUSTAINABLE LAND AND WATER 

MANAGEMENT IN TRANSYLVANIAN PLAIN, 

ROMANIA 

Presenter: Teodor Rusu 

Romania 

Authors: Teodor Rusu, Paula Moraru, Mara Sopterean, Adrian 

Pop, Ileana Bogdan 

University of Agricultural Sciences and Veterinary Medicine 

Cluj-Napoca 

P-0030 

SOIL TILLAGE CONSERVATION AND ITS EFFECT 

ON SOIL MANAGEMENT AND CLIMATIC CHAN- 

GES 

Presenter: Paula Moraru 

Romania 

Authors: Paula Moraru, Teodor Rusu 

University of Agricultural Sciences and Veterinary Medicine 

Cluj - Napoca 

P-0062 

PRODUCTION OF HYBRID PAPAYA CULTIVATED 

UNDER DIFFERENT IRRIGATION LEVELS. 

Presenter: Juarez Pedroza Paz 

Brazil 

Authors: Juarez Pedroza Paz 

Campina Grande, Brazil 

P-0147 

THERMOFHYSICS PROPERTIES OF THE OIL EX- 

TRACTED OF THE GENOTYPES OF CASTOR BEAN 

Presenter: Mohammad Sharrifmoghaddasi 

Brazil 

Authors: Katcilanya Meneses De Almeida, Juarez Paz 

Pedroza 

Ufcg 

Eng. Agrícola UFCG 

P-0182 

EFFECTS OF THE NITROGEN FERTILIZER AND 

AZOTOBACTER ON FLOWER YIELD AND CARO- 

TENOID CONTENTS OF MARIGOLD (CALENDULA 

OFFICINALIS) 

Presenter: Mohammad Reza Haj Seyed Hadi 

Iran 

Authors: Mohammad Reza Haj Seyed Hadi 1 , Mohammad Taghi 

Darzi 1 , Zohreh Ghandeharialavijeh 2 , Gholamhossein Riazi 3 

1 

Agronomy Islamic Azad University, Roudehen Branch 

2 

Agronomy University of Tehran 

3 

IBB University of Tehran 

P-0211 

MORPHOLOGICAL RESPONSES OF EUCALYPTUS 

GRANDIS SEEDLINGS SUBMITTED TO DIFFERENT 

WATER STRESS LEVELS DURING HARDENING 

Presenter: Magali Ribeiro da Silva 

Brasil 

Authors: Magali Ribeiro da Silva 1 , Antonio Carlos Nogueira 2 , 

Carlos Marchesi de Carvalho 1 , Danilo Simões 1 

1 

Department at Natural Resources - Sector of Forestry Sciences 

Universidade Estadual Paulista 

2 

Forestry Engineering Universidade Federal do Paraná 

P-0215 

TRANSPIRATION OF EUCALYPTUS SPP SEE-

DLINGS SUBMITTED TO DIFFERENT FERTIGATION 

MANAGEMENTS 

Presenter: Magali Ribeiro da Silva 

Brasil 

Authors: Magali Ribeiro da Silva, Simone Fernandes Ciavatta, 

Danilo Simões 

Department at Natural Resources - Sector of Forestry Sciences 

Universidade Estadual Paulista 

P-0243 

AGRICULTURE AND WATER SOURCES PROTEC- 

TION ZONES 

Presenter: Petra Oppeltová 

Czech Republic 

Authors: Petra Oppeltová 

MENDELU, Zemdlská 1,Brno, 613 00, Czech Republic. 

P-0246 

BIOLOGICAL NITROGEN FIXATION IN GENOTYPES 

OF COWPEA UNDER SALT STRESS INCREASING 

THE STATE OF PARAÍBA, BRAZIL 

Presenter: Ronaldo Nascimento 

Brazil 

Authors: Ronaldo Nascimento, Jailma Ribeiro De Andrade, 

Francisco Valfisio da Silva Silva, Aryadne Ellen Vilar De Alencar, 

Daniele Ferreira Melo, José Wilson Da Silva Barbosa 

Universidade Federal de Campina Grande 

P-0255 

ADEQUACY OF THE PENMAN-MONTEITH 

METHOD TO IRRIGATED SURFACE WITH DIFFE- 

RENT EXPOSURES AND DECLIVITY 

Presenter: José Eduardo Pitelli Turco 

Brazil 

Authors: José Eduardo Pitelli Turco, Adhemar Pitelli Milani, 

Edemo João Fernandes 

Departamento de Engenharia Rural Faculdade de Ciências 

Agrárias e Veterinárias, UNESP - Univ Estadual Paulista 

P-0269 

SALT STRESS ON THE PHOTOSYNTHETIC PIG- 

MENT CONTENT COWPEA INOCULATED WITH 

RHIZOBIA 

Presenter: Ronaldo Nascimento 

Brazil 

Authors: Ronaldo Nascimento, Jailma Ribeiro De Andrade, 

Francisco Valfisio da Silva Silva, Aryadne Ellen Vilar De Alencar, 

Bruna Vieira De Freitas, José Wilson Da Silva Barbosa 


P-0272 

SOIL WATER MANAGEMENT STRATEGIES FOR 

ENHANCED CROP WATER PRODUCTIVITY IN 

DRY SEASON FARMING ON INLAND VALLEY 

SWAMPS OF THE TROPICS 

Presenter: Samuel Agele Ohikhena 

Nigeria 

Authors: Samuel Agele Ohikhena 

P-0409 

EVAPOTRANSPIRATION AND CROP COEFFICIENT 

OF ONION (ALLIUM CEPA L.) UNDER THE MULCH 

OF PLASTIC FILM IN AN ARID REGION, NOR- 

THWEST CHINA 

Presenter: Guanhua Huang 

China 

Authors: Jianhua Zheng, Guanhua Huang, Jun Wang, Quanzhong 

Huang 

Department of Irrigation and Drainage China Agricultural 

University 

P-0410 

NUTRIENT RETENTION IN WETLAND USING 

ORNAMENTAL PLANTS 

Presenter: Rojane M. Kletecke 

Brazil 

Authors: Rojane M. Kletecke, Michelle Piccolli, Jose Teixeira 

Filho 

Faculdade de Engenharia Agrícola/Universidade Estadual de 

Campinas (FEAGRI/UNICAMP) 

P-0415 

IMPORTANCE OF DRY GEAR MASS CULTURE OF 

SUNFLOWER 

INCORPORATED INTO THE SOIL 

Presenter: Rosa Helena Aguiar 

Brasil 

Authors: ROSA H. AGUIAR 1,2 , DURVAL R. P. JUNIOR 1 , ARTUR 

B. O. ROCHA 1,2 

1 

Universidade Estadual de Campinas (Unicamp)/ Faculdade 

de Engenharia Agrícola (Feagri) – Av. Marechal Candido 

Rondon, n.501, Barão Geraldo, Campinas, São Paulo State, 

postcode: 13083-875, Brazil. 

2 

PhD student in agriculture engineering 

P-0424 

IRRIGATION AND BIOFERTILIZER EFFECTS ON 

GROWTH OF GARLIC 

Presenter: João Galbiatti Antonio 

Brazil 

Authors: João Galbiatti Antonio, Aline Rombega Tito Rosa, 

Barbara Barofaldi Ariguchi 

UNIFAFIBE 

P-0509 

PHYSICAL, CHEMICAL AND MICROBIOLOGICAL 

EFFECTS OF SUSPENDED SHADE CLOTH COVERS 

ON STORED WATER FOR IRRIGATION 

Presenter: Victoriano Martínez-Alvarez 

Spain 

Authors: Victoriano Martínez-Alvarez 1 , José F. Maestre-Valero 

1 , Emilio Nicolas Nicolas 2 

1 

Agriculture Engineering E.T.S.I. Agronómica Universidad 

Politécncia de Cartagena 

2 

Riego Centro de Edafología y Biología Aplicada del Segura 

(CEBAS-CSIC) 

P-0514 

WATER TREATMENT USING POWDER OF MORIN- 

GA OLEIFERA SEEDS IN SACHS AS COAGULANT

Presenter: Jose Euclides Paterniani 

Brazil 

Authors: Gabriela Kurokawa Silva 1 , Camila Clementina Arantes 

1 , Jose Euclides Paterniani 1 , Ana Moreno de La Fuente 2 

1 

University of Campinas 

2 

Institute of Agricultural Science, CSIC 

P-0527 

ANALYSIS OF LEVELS OF LAND DEGRADATION 

USING LANDSAT-5, MUNICIPALITIES OF ARA- 

RIPINA (PE) CRATO AND BARBALHA (CE) AND 

MARCOLÂNDIA (PI), BRAZIL. 

Presenter: Maria De Fátima Fernandes Fátima 

Brazil 

Authors: Maria De Fátima Fernandes Fátima, Marx Prestes 

Barbosa, João Miguel Moraes 

Universidade Federal De Campina Grande-UFCG 

P-0559 

WATER TECHNOLOGY IMPROVEMENTS AND 

THEIR EFFECT ON THE PROFITABILITY OF MEDI- 

TERRANEAN WOODY CROPS UNDER DIFFERENT 

WATER PRICING POLICIES 

Presenter: María Dolores de Miguel Gómez 

Spain 

Authors: María Dolores de Miguel Gómez 1 , Alcon Provencio 

francisco José 1 , Fernández- Zamudio Mª Ángeles 2 

1 

Economía de la Empresa Universidad Politécnica de Cartagena 

2 

OF Horticulture IVIA 

P-0589 

LAND SUITABILITY EVALUATION BASED ON 

THE PARAMETRIC EVALUATION APPROACH IN 

DOSALEGH PLAIN 

Presenter: Mohammad Albaji 

Iran 

Authors: Saeed Boroomand Nasab, Mohammad Albaji 

Irrigation and Drainage Dept, Faculty of Water Science Eng, 

Shahid Chamran University, Ahwaz , Iran . 

P-0590 

LAND SUITABILITY EVALUATION FOR PRINCIPAL 

CROPS IN THE GARGAR REGION 

Presenter: Jabbar Hemadi 

Iran 

Authors: Jabbar Hemadi 1 , Saeed Boroomand Nasab 2 , Mohammad 

Albaji 2 

1 

KWPA 

2 

Irrigation and Drainage Dept, Faculty of Water Science Eng, 

Shahid Chamran University, Ahwaz , Iran. 

P-0675 

RAINFALL PATTERN AND STREAMFLOW VARIA- 

TION OF THE ATRAK CATCHMENT IN NORTH- 

EASTERN IRAN.? 

Presenter: Mokhtar Karami 

Iran 

Authors: Mokhtar Karami 1 , Sara Aliabadi 2 , Alireza Aliabadi 2 

1 

Department of Environmental Sciences, Tarbiat Moalem 

University 

2 

Department of Agriculture (Food engendering)? Department 

of Agriculture 

P-0710 

YIELD AND BEAN SIZE OF COFFEA ARABICA (CV CATUAÍ) 

CULTIVED UNDER DIFFERENT POPULATION ARRANGE- 

MENTS AND WATER AVAILABILITY 

Presenter: Eduardo Agnellos Barbosa Augusto 

Brazil 

Authors: Eduardo Agnellos Barbosa Augusto 1 , Emilio Sakai 3 , 

Jane Maria Carvalho Silveira 2 , Regina Célia de Matos Pires 3 

1 

Irrigation and Drainage Faculty of Agricultural Engineering of 

State University of Campinas 

2 

Pole experimental Northeast of São Paulo São Paulo’s Agency 

for Agribusiness Technology 

3 

Irrigation and Drainage Agronomic Institute of Campinas 

P-0756 

SUGARCANE FERTIRRIGATED WITH MINERAL FERTILIZER 

AND VINASSE UNDER SUBSURFACE DRIP IRRIGATION 

DURING FOUR YEARS 

Presenter: Eduardo Agnellos Barbosa Augusto 

Brazil 

Authors: Eduardo Agnellos Barbosa Augusto 1 , Flávio Bussmeyer 

Arruda 3 , Regina Célia de Matos Pires 3 , Tonny Jose de 

Araujo Silva 2 , Emilio Sakai 3 

1 

Irrigation and drainage Faculty of Agricultural Engineering of 

State University of Campinas 

2 

Irrigation and Drainage Federal University of Mato Grosso 

3 

Irrigation and Drainage Agronomic Institute of Campinas 

P-0765 

OPTIMAL RESERVOIR OPERATION MODEL WITH 

A STREAMFLOW NETWORK MODEL AND A 

GLOBAL OPTIMIZATION METHOD 

Presenter: Mingoo Kang 

South Korea 

Authors: Mingoo Kang 1 , Seung Woo Park 2 , Jooheon Lee 3 

1 

Future Resources Institute 

2 

Department of Rural Systems Engineering Seoul National 

University 

3 

Department of Civil Engineering Joongbu University 

P-0792 

CHARACTERISTICS OF HEAVY METAL CONTENTS 

IN MARINE SEDIMENT AND PADDY SOIL OF 

SOUTH KOREA 

Presenter: Jaesung Park 

Korea 

Authors: Jaesung Park, Young-Hwan Son, Sookack Noh, 

Tae-ho Bong 

Department of Rural Systems Engineering, Seoul Nation Univ., 

Seoul, Korea 

P-0826 

CALIBRATION OF HARGREAVES EQUATION FOR 

ESTIMATING THE REFERENCE EVAPOTRANSPI- 

RATION IN THE SOUTHEAST OF SPAIN 

Presenter: Antonio Ruiz Canales 

Spain 

Authors: Antonio Ruiz Canales 1 , José Miguel Molina Mar-

tínez 2 , DANIEL G FERNANDEZ-PACHECO 2 , Herminia Puerto 

Molina 3 , Ramón López Urrea 4 

1 

EPSO, UNIVERSIDAD MIGUEL HERNÁNDEZ 

2 

Grupo de Investigación en Ingeniería Agromótica y del Mar 

UNIVERSIDAD POLITÉCNICA DE CARTAGENA 

3 

Grupo AEAS. Departamento de Ingeniería Escuela Politécnica 

Superior de Orihuela. Universidad Miguel Hernández 

4 

Water Management Research Unit Instituto Técnico Agronómico 

Provincial (ITAP) y FUNDESCAM 

P-0851 

STOCHASTIC MODELLING OF CONTAMINANTS 

TRANSPORT THROUGH GROUND WATER USING 

A MOVING LEAST SQUARES RESPONSE SURFA- 

CE METHOD WITH HERMITE POLYNOMIAL 

Presenter: Tae-ho Bong 

korea 

Authors: Tae-ho Bong 1 , Young-Hwan Son 1 , Sookack Noh 1 , 

Jaesung Park 1 , Seong-Pil Kim 2 , Joon Heo 2 

1 

Department of Rural Systems Engineering, Seoul National 

Univ., Seoul 

2 

Rural Research Institute Korea Rural Community Corporation 

P-0854 

CHARACTERISTICS OF VEGETATIONS APPLIED 

ON VFS (VEGETATED FILTER STRIP) SYSTEMS 

Presenter: Kyung-Sook Choi 

South Korea 

Authors: Kyung-Sook Choi, Jeong-Ryeol Jang 

Dept. of Agricultural Civil Engineering Kyungpook National 

University 

P-0905 

EFFICIENCY OF WATER AND ENERGY USE IN 

THE CROP OF LACTUCA SATIVA VAR. CAPITATA 

L. SOME PREVIOUS RESULTS IN A PLOT IN THE 

SOUTHEST OF SPAIN. 

Presenter: Antonio Ruiz Canales 

Spain 

Authors: Antonio Ruiz Canales 1 , José Miguel Molina Martínez 

2 , Daniel G Fernández-Pacheco 3 , Francisco Javier Cánovas 

Rodríguez 4 , Herminia Puerto Molina 5 

1 

Epso, Universidad Miguel Hernández 

2 

Universidad Politécnica De Cartagena 

3 


Universidad Politécnica de Cartagena 

4 

Departamento de Ingeniería Eléctrica. Universidad Politécnica 

de Cartagena. 

5 

INGENIERÍA UNIVERSIDAD MIGUEL HERN´ÑANDEZ 

P-0913 

RELATIONSHIP BETWEEN COMPACTION, MOIS- 

TURE AND PENETRATION RESISTANCE IN HORTI- 

CULTURAL SOIL 

Presenter: Carlos Gracia 

Spain 

Authors: Carlos Gracia 1 , Estela Alemany 2 , Inmaculada Bautista 

3 

1 

Universidad Politécnica de Valencia 

2 

Universidad Politécnica de Valencia Unidad de Mecanización 

y Tecnología Agrária 

3 

Universidad Politécnica de Valencia Unidad de Edafología y 

Climatología Grupo REFOREST 

P-1041 

SIMULATION OF NITROGEN LEACHING WITH 

THE DSSAT MODEL UNDER DIFFERENT LEVELS 

OF NITROGEN AND WATER APPLICATION 

Presenter: Maliheh Rabie 

Iran 

Authors: Maliheh Rabie 1 , Mehdi Gheysari 1 , Seyed Majid 

Mirlatifi 2 , Gerrit Hoogenboom 3 

1 

Water Engineering Isfahan University Of Technology 

2 

Irrigation And Drainage Engineering Tarbiat Modares 

University 

3 

Washington State University 

P-1048 

IMPROVING MAIZE IRRIGATION MANAGEMENT 

BY CSM-CERES-MAIZE MODEL 

Presenter: Maliheh Rabie 

Iran 

Authors: Maliheh Rabie 1 , Mehdi Gheysari 2 , Seyed Majid 

Mirlatifi 3 

1 

Tarbiat Modares University 

2 

Water Engineering Isfahan University Of Technology 

3 

Irrigation And Drainage Engineering Tarbiat Modares 

University 

P-1053 

EUCALYPTUS IRRIGATION USING FACULTA- 

TIVE STABILIZATION POND EFFLUENT: POST 

TREATMENT EFFICIENCY OF THE SOIL-PLANT 

SYSTEM 

Presenter: Denis Roston Miguel 

Brazil 

Authors: Denis Roston Miguel 1 , Alex Henrique Veronez 2 , 

Bruno Coraucci Filho 3 , Ronaldo Stefanutti 4 

1 

Faculdade de Engenharia Agricola - UNICAMP 

2 

Dept. of Sanitary and Environmental Engineering Doctoral 

student in Civil Engineering - UNICAMP 

3 

Dept. of Sanitary and Environmental Engineering School of 

Civil Engineering - UNICAMP 

4 

Federal University of Ceará 

P-1063 

SIMULATION OF WATER FLOW WITH ROOT 

WATER UPTAKE PROPOSED THE NEW SOFT- 

WARE SWMRUM 

Presenter: Sina Besharat 

Iran 

Authors: Sina Besharat 

Water Engineering Department, University of Urmia, Urmia, 

Iran 

P-1070 

TREATMENT OF MILKING PARLOR EFFLUENT: 

STABILIZATION PONDS FOLLOWED BY CONS- 

TRUCTED WETLAND 

Presenter: Denis Roston Miguel 

Brazil 

Authors: Denis Roston Miguel 1 , Edu Max da Silva 2

1 

Faculdade de Engenharia Agricola - UNICAMP 

2 

Federal Institute Suldeminas - Inconfidentes - MG 

P-1089 

OPERATION AND ENERGY OPTIMIZATION MO- 

DEL FOR GHARAH-BAGH WATER CONVEYANCE 

SYSTEM 

Presenter: Sina Besharat 

Iran 

Authors: Mohsen Besharat 1 , Mohammad Taghi Aalami 2 , Avin 

Dadfar 3 , Sina Besharat 4 

1 

Islamic Azad University, Saghez Branch 

2 

Tabriz University, Iran 

3 

Islamic Azad University, Mahabad Branch 

4 

Urmia University, Iran 

P-1155 

APPLICATION OF SURFACE COVER AND SOIL 

AMENDMENT FOR REDUCTION OF SOIL ERO- 

SION FROM SLOPING FIELD IN KOREA 

Presenter: Suin Lee Soo 

Kangwon 

Authors: Suin Lee Soo, Chul-Hee Won, Min-Hwan Shin, Woon 

Ji Park, Yong-Hun Choi, Jae-Young Shin, Joongdae Choi 

Kangwon Univ. Agricultural And Bio. 1. 110 Hyoja 2 200-701 

Chuncheon 

P-1190 

THE EXPERIENCE OF USING PURIFIED WAS- 

TEWATER FOR IRRIGATION IN THE MARINA 

BAIXA COUNTY (ALICANTE, SPAIN). PROPOSAL 

OF FUTURE HYDRIC DESIGN PLANS. 

Presenter: Miguel Redon Santafe 

Spain 

Authors: Macarena Cavestany Olivares 3 , Jose Javier Ferran 

Gozalvez 1 , Carlos Manuel Ferrer Gisbert 1 , Modesto Perez 

Sanchez 3 , Miguel Redon Santafe 1 , Francisco Javier Sanchez 

Romero 1 , Juan Bautista Torregrosa Soler 1 , Elvira Santamaria 

Bravo 2 , Francisco J. Zapata Raboso 2 

1 

Universidad Politécnica de Valencia, Departamento de 

Ingeniería Rural y Agroalimentaria. Camino de Vera s/n 46022 

Valencia. 

2 

Conselleria de Agricultura, Pesca, Alimentación y Agua. 

Generalitat Valenciana, Alicante, Spain. 

3 

Vaersa, Alicante, Spain. 

P-1193 

RELATIONSHIP BETWEEN CITRUS PRODUCTIVITY 

AND INDICATORS OF UNIFORMITY IN TRICKLE 

IRRIGATION SYSTEM. 

Presenter: João Carlos Saad Cury 

Brazil 

Authors: João Carlos Saad Cury, Helio Moreira da Silva Junior 

Engenharia Rural FCA - UNESP 

P-1196 

INDIRECT REUSE OF RECLAIMED WASTEWATER 

FOR AGRICULTURE IN KOREA 

Presenter: Hanseok Jeong 

Korea 

Authors: Hanseok Jeong 3 , Taeil Jang 1 , Choung Hyun Seong 2 , 

Seung Woo Park 3 

1 

Department of Biological & Agricultural Engineering, University 

of Georgia 

2 

Virginia Tech. 

3 

Seoul national university 

P-1241 

COMPARISON BETWEEN CURVE NUMBER EMPI- 

RICAL VALUES AND CURVE NUMBER OBTAINED 

BY HANDBOOK TABLES AT BASIN SCALE IN 

SICILY, ITALY 


Italy 

Authors: Francesco D’Asaro, Giovanni Grillone, Giorgio 

Baiamonte 

SAgA University of Palermo 

P-1250 

EMPIRICAL METHODS TO DETERMINE AVERA- 

GE ANNUAL RUNOFF COEFFICIENT IN SICILIAN 

BASINS 


Italy 

Authors: Giorgio Baiamonte, Francesco D’Asaro, Giovanni 

Grillone 

SAgA University of Palermo 

P-1291 

ACCUMULATION OF THE CHLORIDE AND 

SODIUM IN PRECOCIOUS DWARF CASHEW 

IRRIGATED WITH SALINE WATER DURING THE 

FRUITING STAGE 

Presenter: Arlington Ricardo Ribeiro De Oliveira 

Brazil 

Authors: Arlington Ricardo Ribeiro De Oliveira, Ronaldo Nascimento, 

Maiene De Fátima Cordeiro Queiroga, Hugo Orlando 

Carvallo Guerra 

UFCG 

P-1328 

ENHANCEMENTS OF USING RTD INSTEAD 

OF THERMOCOUPLES FOR ESTIMATING EVA- 

POTRANSPIRATION BY MEANS OF ENERGY 

BALANCE METHOD 

Presenter: José Miguel Molina Martínez 

Spain 

Authors: David Escarabajal Henarejos 1 , José Miguel Molina 

Martínez 1 , Daniel Garcia Fernandez-Pachec 1 , Antonio Ruiz- 

Canales 2 , Ramón López Urrea 3 

1 



2 

Escuela Politécnica Superior de Orihuela Universidad Miguel 

Hernández 

3 

Sección de Investigación en el Manejo del Agua Instituto 

Técnico Agronómico Provincial de Albacete y FUNDESCAM 

P-1334 

IRRIGATION OF BRACHIARIA BRIZANTHA PASTU- 

RE WITH WASTEWATER OF CASSAVA INDUSTRY 

Presenter: Altair Bertonha

Brazil 

Authors: Altair Bertonha, Paulo Sérgio Lourenço De Freitas, 

Daiane De Cinque Mariano 

Agronomy University Of Maringá 

P-1365 

EVALUATING CLIMATE CHANGE IMPACT ON 

IRRIGATION VULNERABILITY IN SOUTH KOREA 

Presenter: Min-Won Jang 

Korea 

Authors: Min-Won Jang 1 , Soo-Jin Kim 2 , Dae-Sik Kim 3 , Sang- 

Min Kim 4 

1 

Institute of Ag. & Life Science Gyeongsang Nat’l University 

2 

Gyeongsang Nat’l University 

3 

Chungnam Nat’l University 

4 

Institute of Ag. & Life Science Gyeongsang Nat’l University 

P-1408 

RESPONSE OF SUGAR CANE CROP TO IRRIGA- 

TION SPROUTING AND USE OF ORGANIC MULCH 

IN SOIL COVER IN THE CERRADO REGION, 

BRAZIL. 

Presenter: José Alves Jr 

Brazil 

Authors: Patrick Francino CAMPOS 1 , José Alves Jr 1 , Pedro 

Henrique Pinto RIBEIRO 3 , Rogério Augusto Bremm SOARES 2 , 

Udo ROSENFELD 2 , Adão W. Pego EVANGELISTA 1 , Derblai 

Casaroli 1 

1 

Federal University of Goiás, College of Agronomy and Food 

Eng., Campus II Samambaia,74001-970. Goiânia-GO, Brazil. 

2 

Jales Machado S.A., Sugar Mill, Goianésia-GO, Brazil. 

P-1431 

EFFECT OF PRODUCTION SYSTEMS ON WATER 

QUALITY IN WATERSHEDS. 

Presenter: Rodrigo Brunini 

Brazil 

Authors: Michele Cláudia Silva, Teresa Cristina Tarlé Pissarra, 

Rodrigo Brunini 

Agricultural Engineering Paulista State University “Júlio de 

Mesquita Filho”, Faculty of Agriculture and Veterinary Sciences, 

Campus Jaboticabal-SP. 

P-1444 

IMPROVEMENT OF ICEBERG LETTUCE IRRIGA- 

TION IN THE \’CAMPO DE CARTAGENA\’ AREA 

Presenter: Herminia Puerto Molina 

Spain 

Authors: Herminia Puerto Molina 1 , Javier Juárez López 1 , Antonio 

Ruiz Canales 1 , José Miguel Molina Martínez 2 

1 

Universidad Miguel Hernández de Elche 

2 

Food Engineering and Agricultural Equipment Department 


P-1462 

MODELING OF WATER QUALITY PARAMETERS 

OF DISSOLVED OXYGEN AND BIOCHEMICAL 

OXYGEN DEMAND IN THE SUB-BASIN OF POXIM 

RIVER, BRAZIL 

Presenter: Antenor Oliveira Aguiar Netto 

Brazil 

Authors: Anderson Nascimento do Vasco 1 , Antenor Oliveira 

Aguiar Netto 1 , Marinoé Gonzaga da Silva 1 , Aderson Soares De 

Andrade Júnior 2 , Neylor Alves Calasans Rego 1 

1 

Department of Agronomy, University Federal of Sergipe, São 

Cristovão - Sergipe, Postal code: 49100-000, Brazil. 

2 

Embrapa Mid-North, PO Box 01, Teresina, PI, postal code 

64006-220. 

P-1465 

EFFECT OF RICE STRAW MULCH ON RUNOFF 

AND NPS POLLUTION DISCHARGES FROM A 

VEGETABLE FIELD 

Presenter: Joongdae Choi 

Korea 

Authors: Joongdae Choi, Min-Hwan Shin, Ji-Seong Yoon 

Regional Infrastructures Engineering Kangwon National 

University 

P-1517 

PAPAYA SEEDLINGS PRODUCTION FROM SOIL 

GROUP AND FORMOSA GENOTIPS UNDER 

WATER LEVELS IN SOIL 

Presenter: Lucia Helena Garofalo Chaves 

Brazil 

Authors: Evandro Franklin de Mesquita Mesquita 1 , Lucia 

Helena Garofalo Chaves 2 , Flaviana De Andrade Vieira 1 

1 

Universidade Estadual da Paraíba, Departamento de Agrárias 

e Exatas, Campus IV, Catolé do Rocha-PB, 

2 

Universidade Federal de Campina Grande, Campus I, Campina 

Grande-PB. 

P-1519 

DESORPTIONS, EXTRACTABLES AND BOUND 

RESIDUES OF ALACHLOR IN SOIL WITH THE 

ADDITION OF ORGANIC MATTER FROM SWINE 

WASTEWATER 

Presenter: Silvia Renata Machado Coelho 

Brazil 

Authors: Tatiane Cristina Dal Bosco 1 , Silvio Cesar Sampaio 2 , 

Silvia Renata Machado Coelho 2 , Natássia Jersak Cosmann 2 , 

Marcos Hiroiuqui Kunita 3 , Morgana Suszek Gonçalves 4 

1 

Universidade Tecnológica Federal do Paraná (Technological 

University of Paraná), Câmpus Londrina, Avenida dos Pioneiros, 

3131, Londrina 

2 

Universidade Estadual do Oeste do Paraná (State University 

of West Paraná), Câmpus Cascavel, Rua Universitária, 2069, 

Cascavel 

3 

Universidade Estadual de Maringá (State University of 

Maringá), Avenida Colombo 

4 

Universidade Tecnológica Federal do Paraná (Technological 

University of Paraná), Câmpus Francisco Beltrão, Linha Santa 

Bárbara, sem número, Francisco Beltrão-PR 

P-1559 

APPLICATION OF TREATED DOMESTIC SEWAGE 

IN THE SOIL FOR DESIGN THE SUBSURFACE DRIP 

IRRIGATION 

Presenter: Leonardo Nazário Silva dos Santos 

Brazil 

Authors: Marcelo Elaiuy Leite Conde 1 , Allan Charlles Mendes 

de Sousa, Leonardo Nazário Silva dos Santos, Edson Eiji

Matsura 

Department of hydraulic and irrigation State University of 

Campinas 

P-1576 

EFFECT OF MACHINE TRAFFIC ON SOIL COMPAC- 

TION DURING THE SEMI-MECHANIZED PLAN- 

TING PROCESS OF SUGAR CANE 

Presenter: Adriano Bastos Chaves 

Brasil 

Authors: Adriano Bastos Chaves 1 , Henrique Silveira 2 , Francelino 

Rodrigues Junior 2 , Marcelo José Silva 2 , Paulo S. Graziano 

Magalhães 2 

1 

Brazilian Bioethanol Science and Technology Laboratory 

(CTBE) 

2 

Agricultural Engineering College State University of Campinas 

P-1593 

A STUDY ON THE STREAM MANAGEMENT 

FLOW SUPPLY FOR THE RESTORATION OF RURAL 

STREAM ENVIRONMENT AND PREVENTION OF 

RURAL STREAM DRYING 

Presenter: Sang Min Kim 

South Korea 

Authors: Sang Min Kim 1 , Sung Jae Kim 2 , Sung Min Kim 2 

1 

Gyeongsang National University 

2 

Agricultural Engineering Gyeongsang National University 

P-1628 

WIND-INDUCED FLOW IN A CLOSED WATER 

BODY WITH FLOATING CULTURE SYSTEM 

Presenter: Kunihiko Hamagami 

Japan 

Authors: Kunihiko Hamagami 1 , Masayuki Fujihara 2 , Ken Mori 3 , 

Hidekazu Yoshioka 4 

1 

Iwate university 

2 

Faculty of Agriculture, Ehime University, Matsuyama city, 

Ehime, JAPAN 

3 

Former-Professor of Faculty of Agriculture, Kyushu University, 

Fukuoka city, Fukuoka, JAPAN 

4 

Graduate School of Agricultural Science, Kyoto University, 

JAPAN 

P-1712 

DRIP IRRIGATION BASED ON PAN EVAPORATION 

VALUES FOR MUSKMELON (CUCUMIS MELO L.) 

IN PLASTIC GREENHOUSE 

Presenter: Bao-Zhong Yuan 

China 

Authors: Bao-Zhong Yuan 1 , Jie Sun 1 , Zhi-Long Bie 3 , Yaohu 

Kang 2 

1 

Library of Huazhong Agricultural University 

2 

Key Lab of Water Cycle and Related Land Surface Process 

Institute of Geographic Sciences and Natural Resources 

Research,CAS 

3 

College of Horticulture and Forestry, Huazhong Agricultural 

University 

P-1790 

DEVELOPMENT OF A CONCEPTUAL MODEL FOR 

DROUGHT ANALYSIS 

Presenter: Hamid Babaei 

Iran 

Authors: Hamid Babaei 1 , Shahab Araghinejad 2 

1 

University Of Tehran 

2 

Deparetment Of Water Respurce Manegement University Of 

Tehran 

P-1861 

APPLICATION OF MECHANICAL SHAKERS FOR 

COFFEE HARVESTING 

Presenter: Duncan Mbuge Onyango 

Kenya 

Authors: Duncan Mbuge Onyango 1 , Philip Langat 2 

1 

JKUAT 

2 

INFRASTRUCTURE Tana and Athi River Development Authority 

(TARDA) 

P-1868 

VARIABILITY OF WATER QUALITY IN A LAKE 

RECEIVING DRAINAGE WATER FROM HETAO 

IRRIGATION SYSTEM, IN YELLOW RIVER BASIN, 

CHINA 

Presenter: Luis S. Pereira 

china 

Authors: Biao Sun 1 , Changyou Li 1 , Claudia M d S Cordovil 2 , Keli 

Jia 1 , Sheng Zhang 1 , Amarilis de Varennes 2 , Luis S. Pereira 2 , 

Paula Paredes 2 

1 

College of Water Conservancy and Civil Engineering Inner 

Mongolia Agricultural University 

2 

CEER, Biosystems Engineering, Institute of Agronomy Technical 

University of Lisbon 

P-1880 

SURFACE ENERGY BALANCE TO ESTIMATE 

EVAPOTRANSPIRATION OF IRRIGATED ORANGE 

ORCHARDS UNDER MEDITERRANEAN SEMI- 

ARID CONDITIONS 

Presenter: Rita Papa 

Italy 

Authors: Simona Consoli, Rita Papa 

Dept. di Gestione dei Sistemi Agro-alimentari e Ambientali 

(GeSA), University of Catania 

P-1882 

ON THE TRUE ORIGINS OF THE HEAT PROPAGA- 

TION MODEL FOR THE PREDICTION OF SUBTE- 

RRANEAN TEMPERATURES 

Presenter: Fernando Ruiz-Mazarrón 

SPAIN 

Authors: José Francisco Romero-García 1 , Ignacio Cañas 

Guerrero 1 , Fernando Ruiz-Mazarrón 2 

1 

Construction and Rural Roads Universidad Politécnica de 

Madrid 

2 

Rural Engineering Department. E.T.S.I.Agrónomos. Polytechnic 

University of Madrid 

P-1892 

FINDING LOCATION FOR NITRATE SOURCES 

ALONG KITAKAMI RIVER, JAPAN USING THE

NATURAL ABUNDANCE OF NITROGEN ISOTOPE 

Presenter: Kosuke Noborio 

Japan 

Authors: Kosuke Noborio 1 , Chitoshi Mizota 2 , Koji Harashina 2 , 

Mitsuomi Orisaka 3 

1 

Meiji University, School of Agriculture 

2 

Faculty of Agriculture Iwate University 

3 

Iwate Agricultural Research Center 

P-1897 

ASSESSMENT OF ANTIBIOTIC RESISTANCE IN 

WATER SYSTEMS 

Presenter: Paula Amador Pinto 

Portugal 

Authors: Paula Amador Pinto 1 , Ruben Fernandes 2 , Isabel 

Duarte 3 , Luisa Brito 4 , Mário Barreto 5 , Cristina Prudêncio 6 

1 

Departamento De Ambiente Da Escola Superior Agraria De 

Coimbra 

2 

Ciências Químicas E Das Biomoléculas Escola Superior De 

Tecnologia De Saúde Do Porto, Polytechnic Institute Of Porto 

3 

Ambiente / Agricultural College Of Coimbra, Polytechnic 

Institute Of Coimbra. 

4 

Laboratório De Microbiologia, Cbaa/Drat Instituto Superior 

De Agronomia, Technical University Of Lisbon 

5 

Eta Da Boavista Águas Mondego E Bairrada S.A. 

6 

Ciências Químicas E Das Biomoléculas Superior De Tecnologia 

De Saúde Do Porto, Polytechnic Institute Of Porto 

P-1898 

DEMAND SIDE MANAGEMENT IN IRRIGATED 

PERIMETER USING FREQUENCY INVERTER 

Presenter: André Luis Carvalho Mendes 

Brazil 

Authors: André Luis Carvalho Mendes, Jorge Henrique A. C. 

Damião, Maria Joselma Moraes, Delly Oliveira Filho, Gerson 

Ovidio Luz Pedruzi 

Agricultural Engineering Department Federal University of 

Viçosa 

P-1929 

INEFFICIENCY AN INDEX FOR DROUGHT ANALY- 

SIS 

Presenter: Hamid Babaei 

Iran 

Authors: hamid babaei, Shahab Araghinejad 

Deparetment of water respurce manegement University of 

Tehran 

P-1964 

GIS MAPPING OF SOIL COMPACTION AND 

MOISTURE DISTRIBUTION FOR TILLAGE AND 

IRRIGATION MANAGEMENT 

Presenter: Seif Salim Al-Adawi 

Oman 

Authors: Seif Salim Al-Adawi, Hemantha P W Jayasuriya 

Sultan Qaboos University 

P-1966 

FIELD CONSERVATION OF RAINWATER WITH 

ROCK FRAGMENTS 

Presenter: Majed Abu-Zreig 

Jordan 

Authors: Majed Abu-Zreig 

Jordan University of Science and Technology 

P-1996 

IDENTIFICATION OF FREE-FORM PARAMETE- 

RIZED SOIL HYDRAULIC PROPERTIES IN NON- 

ISOTHERMAL SUBSURFACE WATER FLOW 

USING INVERSE TECHNIQUE 

Presenter: Majed Abu-Zreig 

Japan 

Authors: Tomoki Izumi, Masayuki Fujihara 

Ehime University 

P-2014 

ENVIRONMENTAL PLANNING USE OF LAND RE- 

SOURCES IN WATERSHEDS, BATATAIS COUNTY, 

SAO PAULO STATE, BRAZIL 

Presenter: Teresa Cristina Pissarra Tarlé 

Brazil 

Authors: Teresa Cristina Pissarra Tarlé 1 , Marcelo Zanata 2 , 

Sergio Campos 3 , Kati White Migliaccio 4 , Christiano Luna 

Arraes 5 

1 

UNESP/FCAV/Dpto.Eng. Rural 

2 

Engenharia Rural UNESP/FCAVPostGrad. IF/Instituto Florestal 

3 

Engenharia Rural UNESP/FCA - Câmpus de Botucatu 

4 

Agricultural and Biological Engineering Department University 

of Florida, Institute of Food and Agricultural Sciences, 

Tropical REC 

5 

Geprocessamento UNICAMP/Campinas 

P-2018 

DEVELOP A SIMPLE ECONOMICAL EVAPORATION 

PAN 

Presenter: El-Sayed Omran Ewis 

Egypt 

Authors: El-Sayed Omran Ewis 1 , Mohamed A. Rashad 2 

1 

Suez Canal University 

2 

Agricultural Engineering Department Faculty of Agriculture 

P-2045 

TRANSNATIONAL AND NATIONAL ASPECTS OF 

THE ECOLOGICAL CATASTROPHE IN ARAL SEA 

REGION, ITS CAUSES AND SUGGESTIONS 

Presenter: Radek Malis 

Czech Republic 

Authors: Radek Malis 

University of life sciences in Prague 

P-2056 

COAGULATION USING MORINGA OLEIFERA AND 

FILTRATION TO REMOVE OOCYSTS OF CRYPTOS- 

PORIDIUM SPP THROUGH SIMULATION WITH 

POLYSTYRENE MICROESPHERES 

Presenter: Marcelo jacomini Moreira Silva 

Brazil 

Authors: Adriana Ribeiro Francisco, Marcelo jacomini Moreira 

Silva, Jose Euclides Paterniani 

Unicamp Feagro/Unicamp

P-2064 

MULTIVARIATE STATISTICAL OF PRINCIPAL 

COMPONENTS AND CLUSTER ANALYSIS IN THE 

STUDY SUPPORT OF REGIONALIZATION OF FLOW 

Presenter: Demetrius David Silva 

Brazil 

Authors: Abrahão Alexandre Alden Elesbon 1 , Demetrius David 

Silva 2 , Gilberto Chohaku Sediyama 2 , Carlos Antonio Alvares 

Soares Ribeiro 2 

1 

Instituto Federal do Espírito Santo 

2 

Universidade Federal de Viçosa 

P-2161 

WATER MONITORING AND CHARACTERIZATION 

OF WATERSHEDS AS REFLECTION OF SOIL USA- 

GE AND OCCUPATION 

Presenter: Michele Cláudia Da Silva 

Brazil 

Authors: Michele Cláudia Da Silva, Rodrigo Garcia Brunini, 

Teresa Cristina Tarlé Pissarra 

Engenharia Rural UNESP, Campus Jaboticabal 

P-2175 

DIMENSIONS AND PERFORMANCE OF THE 

CYLINDRICAL SPECIMENS USED IN UNIAXIAL 

CONSOLIDATION TESTS 

Presenter: Reginaldo da Silva Barboza 

Brazil 

Authors: Reginaldo da Silva Barboza 1 , Piero Iori 2 , Pedro 

Antonio Martins 1 

1 

UNESP - UNIVERSIDDE eSTADUAL pAULISTA 

2 

Soil Science Federal University of Lavras 

P-2198 

EMITTER CLOGGING UNDER LOW HEAD DRIP 

IRRIGATION WITH UNFILTERED NILE RIVER 

WATER 

Presenter: Mohamed A. Rashad 

Egypt 

Authors: Mohamed A. Rashad 1 , Mohmmed W. M. Elwan 2 , 

Khalid E. Abd El-Hamed 2 , Samy A. M. Abd El-Azeem 3 

1 

Agricultural engineering Dept. Faculty of Agriculture 

2 

Department of Horticulture Faculty of Agriculture 

3 

Soil and Water Dept. Faculty of Agriculture 

P-2201 

ASSESSMENT OF EMITTER DISCHARGE IN LOW 

HEAD DRIP IRRIGATION SYSTEM AS AFFECTED 

BY GREYWATER 

Presenter: Mohamed A. Rashad 

Egypt 

Authors: Mohamed A. Rashad 1 , Khalid E. Abd El-Hamed 2 , 

Mohmmed W. M. Elwan 2 , Samy A. M. Abd El-Azeem 3 

1 

Agricultural engineering Dept. Faculty of Agriculture 

2 

Department of Horticulture Faculty of Agriculture 

3 

Soil and Water Dept. Faculty of Agriculture 

IRRIGATION 

Presenter: El-Sayed Omran Ewis 

Egypt 

Authors: El-Sayed Omran Ewis, Gamal M. Elmasry, Mohamed 

A. Rashad 

Suez Canal University. Agricultural Engineering Department 

Faculty of Agriculture 

P-2273 

EVALUATION OF CROP CANOPY EFFECT ON 

THE MICRO-ADVECTIVE CONDITION AND SOIL 

WATER MOVEMENT IN MICRO- IRRIGATED 

FIELDS 

Presenter: Kozue Yuge 

Japan 

Authors: Kozue Yuge 1 , Mitsumasa Anan 2 , Yoshiyuki Shinogi 1 

1 

Kyushu University 

2 

Takasaki Sogo Consultant 

P-2278 

BENCHMARKING OF IRRIGATED AGRICULTURE: 

THE CASE OF THESSALY-GREECE 

Presenter: Constantinos Kittas 

Greece 

Authors: Constantinos Kittas 1 , Thomas Bartzanas 2 , Nikos 

Katsoulas 3 , Evagellini Kitta 2 , Adriano Batilliani 4 

1 

University of Thessalu 

2 

Center for Research and Technology-Thessaly 

3 

University of Thessaly 

4 

Canale Emiliano-Romagnolo 

P-2329 

POSSIBLE IMPACT OF CLIMATE CHANGE ON 

SOIL EROSION 

Presenter: Pall Rudra Ramesh 

Canada 

Authors: Pall Rudra Ramesh 1 , Trevor Dickinson 1 , Syed Imran 

Ahmed 1 , Greg Wall 2 

1 

School of Engineering University of Guelph 

2 

Soil Research Group Soil Research Group 

P-2344 

SIMULATION GEOLOGICAL ENVIRONMENTAL 

SHORTAGE WATER OF GROUNDWATER AND THE 

POSSIBILITY OF ACTIVITY EARTHQUAKE JAFA- 

RAH BASIN NW LIBYA 

Presenter: Elosta Fathi 

Libya 

Authors: Elosta Fathi 

Department Geological Section People’s Committee for Education 

and Scientific Research in Tripoli 

P-2256 

A NEW APPROACH TO DERIVE AND ASSESS 

SOIL WETTING FRONT MAP UNDER TRICKLE

Daily Penman-Monteith sensitivity analysis in many subclasses climates 

based on extended-De Martonne classification 

Bahram Bakhtiari 1* , Amin Baghizadeh 

1 Department of Water Engineering, College of Agriculture, Shahid Bahonar University of 

Kerman, Kerman, Iran 

2 

International Center for Science, High Technology & Environmental Sciences, Kerman, Iran 

Corresponding Author. Email: Drbakhtiari@uk.ac.ir 

Abstract 

ASCE daily Penman-Monteith model used in reference evapotranspiration (ET o ) estimation, 

has many climatic parameters. To get useful results from the model, every parameter is 

required to have a sensible value. In this study, a local sensitivity analysis of the 

standardized daily ASCE Penman-Monteith evapotranspiration equation to time variation of 

four climatic variables, net radiation (R n ), vapor pressure deficit (VPD), wind speed (U 2 ) and 

air temperature (T) have been realized. Four different types of subclasses of arid and 

semiarid climates in Kerman province (South east of Iran) have been studied using daily 

data over a 17-year period (1998-2005) database. The studied regions of Kerman province 

based on extended-De Martonne classification as follows: Baft (semiarid cool), Bam (arid 

moderate), Kerman (arid cool) and Jiroft (arid warm). The results showed that, sensitivity 

coefficients of studied climatic variables were positive in all stations. Net radiation was the 

most sensitive variable in general, followed by, vapor pressure deficit, wind speed and air 

temperature. The sensitivity of evapotranspimtion rates to changes in vapor pressure deficit, 

wind speed, and air temperature is less in arid warm area than in arid and semiarid cool 

regions. 

Keywords: Climate data, Daily Penman–Monteith, evapotranspiration, Sensitivity coefficients 

1. Introduction 

Precise quantifications of crop evapotranspiration (ET c ) in irrigated agriculture are 

consequential for scheduling irrigation. With increasing pressure on water resources from 

competing sectors, great emphasis has been placed on water use efficiency in irrigated 

fields (Hatfield et al., 1996), particularly in semiarid environment irrigation projects. Accurate 

estimation of ET c is also essential for optimizing crop production and management practices 

to minimize surface and groundwater degradation. The quantification of evapotranspiration is 

normally based on the determination of reference evapotranspiration (ET o ). Reference 

evapotranspiration is defined as ‘‘the rate of evapotranspiration from an extensive area of 

0.08–0.15 m high, uniform, actively growing, green grass that completely shades the soil and 

is provided with unlimited water and nutrients’’ (Allen et al., 1994). More recently, Allen et al. 

(1998) elaborated on the concept of ET o , referring to an ideal 0.12 m high crop with a fixed 

surface resistance of 70 s m-1 and an albedo of 0.23. ET o is widely used to estimate crop 

water use and water requirements by using appropriate crop coefficients (K c ). The crop 

coefficient is a dimensionless number that is multiplied by the ET o value to arrive at a crop 

ET (ET c ) estimate; ET c = K c ×ET o . The K c represents the integrated effect of changes in leaf 

area, plant height, irrigation method, rate of crop development, crop planting date, leaf area, 

canopy resistance, albedo, soil and climate conditions, and management practices 

(Doorenbos and Pruitt 1977). Different equations have been developed in attempts to model 

ET o , including water budget (e.g., Guitjens, 1982), mass-transfer (e.g., Harbeck, 1962), 

combination (e.g., Penman, 1948), radiation (e.g., Priestley and Taylor, 1972), and 

1

temperature-based (e.g., Thornthwaite, 1948; Blaney and Criddle, 1950) equations. The 

Penman-Monteith equation is the most frequently used and recommended model 

(Doorenbos and Pruitt, 1977; Allen et al., 1989; Jensen et al.1990) among actual 

evapotranspiration (ET) models taking into account both meteorological and physiological 

crop variables. Besides variables expressing the thermodynamic state of the atmosphere, it 

contains two kinds of parametric data: bulk canopy resistance, rc and aerodynamical 

resistance ra. The first one is the resistance that the canopy opposites to the diffusion of 

water vapour from inner leaves toward the atmosphere and is influenced by biological, 

climatological and agronomical variables. The second one is the aerial boundary layer 

resistance and describes the role of the interface between canopy and atmosphere in the 

water vapour transfer. The success of the Penman-Monteith evapotranspiration estimate 

depends on the modelling of these two parameters. A major disadvantage to apply the 

Penman-Monteith method is its relatively high data demand. The method requires, apart 

from site location, air temperature, wind speed, relative humidity, and shortwave radiation 

data. The number of meteorological stations where all of these parameters are observed is 

limited in many areas, especially in developing countries (Droogers and Allen, 2002). The 

American Society of Civil Engineers (ASCE) established a Task Committee on 

‘Standardization of Reference Evapotranspiration Calculation’ (Allen et al., 2000; Itenfisu et 

al., 2003). This Committee recommended the use of the ASCE–Penman–Monteith method, 

as simplified by FAO Paper No. 56 (Allen et al., 1998), to quantify the reference ET. Some of 

the most important advantages of using a standardized ET o equation are establishing a 

common methodology for using and evaluating ET o estimates (Allen et al., 2000) and the 

possibility of enhancing the transferability of K c values under different conditions (ASCE- 

EWRI, 2005). To understand the characteristics of this model, we must first understand each 

variable, and then know its relative role in the model. However, to understand the relative 

role of each variable requires a sensitivity analysis. To understand the relative role of each 

climate variable associated with computing ET o , sensitivity analysis is required (Saxton, 

1975). Results of these analyses make it possible to determine the accuracy required when 

measuring climatic variables used to estimate ET o (Irmak, et al., 2006). By definition, 

sensitivity analysis is the study of how the variation in the output of a model can be 

apportioned, quantitatively or qualitatively, to variation in the model parameters (Saltelli et 

al., 2004). A sensitivity analysis shows the effect of change of one factor on another (Mc 

Cuen, 1973). 

If the change of the dependent variable of an equation is studied with respect to change in 

each of several independent variables, the sensitivity coefficient will show the relative 

importance of each of the variables to the model solution. In the past, several papers of the 

sensitivity of Penman-Monteith ET o model have been devoted using single weather stations 

and different input and parametric data. Saxton (1975) derived sensitivity coefficients by 

differentiating the combination terms for the Penman (1948) method with respect to each 

variable. Results showed that the equation was most sensitive to net radiation. Beven (1979) 

carried out the most complete sensitivity analysis of a Penman-Monteith model for reference 

grass and forest in three sites of southern England, with respect to both climatic and 

parametric data. His study was limited to a humid climate, where the crops were generally in 

good water status conditions. He found that for dry canopy conditions, the sensitivity of 

Penman-Monteith estimates of ET o to differ input data and parameters is very dependent on 

the values of the aerodynamic and canopy resistance. The results of that analysis, in spite of 

their fundamental importance to the following research, were not completely applicable to 

Penman-Monteith estimation under different climates. Piper (1989) showed that errors in 

measurement of sunshine hours, wind speed and wet bulb temperature had the same 

relative effect on estimated ET o . In the same context, Ley et al. (1994) conducted sensitivity 

analysis for the Penman-Wright ET o model (same as Penman-Kimberly) to errors in 

parameters and weather data using a factor perturbation simulation approach for 

Washington State. This model was most sensitive to the error in maximum and minimum air 

temperatures. Rana and Katerji (1998) analyzed the sensitivity of the original Penman- 

2

Monteith equation to climatic and parametric factors in a semi-arid climate for a reference 

grass surface, grain sorghum and sweet sorghum in Italy. For grass, available energy and 

aerodynamic resistance played a major role. For sweet sorghum, the model was most 

sensitive to vapor pressure deficit. For grain sorghum under water stress, the most sensitive 

term was canopy resistance. Irmak et al. (2006) calculated the sensitivity coefficient of the 

standardized daily ASCE-Penman-Monteith equation in different climates of United States. 

Recently, Ali et al. (2009) calculated the sensitivity coefficient of the FAO Penman-Monteith 

equation under the environment of a semi-humid sub-tropic region of Bangladesh. The 

results showed that the ET o estimates are most sensitive to maximum temperature, relative 

humidity, sunshine duration, wind speed and minimum temperature, respectively. Estevez et 

al. (2009) calculated the sensitivity coefficients of the standardized ASCE-Penman-Monteith 

equation from 87 automatic weather stations in Spain. The results showed a large degree of 

daily and seasonal variability, especially for temperature and relative humidity. Also, the 

sensitivity of ET o to the same climatic variables showed significant differences among 

locations. Sensitivity of the daily standardized ASCE equation to meteorological variables 

has not yet been studied in Iran. Thus, the objective of this study was to investigate the 

sensitivity of the standardized daily ASCE ET o equation to climatic variables under different 

subclasses of arid and semiarid climatic conditions in Kerman province, southeast of Iran 

and to derive sensitivity coefficients for each one. 

2. Materials and Methods 

2.1. Study area and weather data source 

The study was carried out in Kerman province (Southeast of Iran), located between the 

latitudes 27° and 30° N and the longitudes 55° and 58° W. Site elevations range from 400 to 

2775 m above mean sea level. All agricultural productions in this area are irrigation-based. 

In this region irrigation water resources are supplied mostly from groundwater and slightly 

spring and Qanat. Surface irrigation is the most popular method of irrigation in this area, 

however, frequent droughts have led to switch over to pressurized irrigation systems to 

improve water use efficiency and prevent depletion of groundwater resources. 

Meteorological data used in this analysis were obtained over 4 stations in Kerman province 

from the Kerman Meteorological Department. These stations are located in different 

subclasses of arid and semiarid climates of the province based on extended-De Martonne 

classification (Khalili, 1997). Daily weather data were used in this study. Table 1 lists the 

annual average weather data of 4 meteorological stations in Kerman province, including the 

corresponding site elevations and coordinates. Average annual rainfall ranged from 61.3 mm 

at Bam to 261.6 mm at Baft; the range for the annual air temperature was 14.8-25.0 °C; 31- 

43 %, for relative humidity; and 0.5-1.6 m s-1 for wind speed at 2 m. 

TABLE 1: Summary of weather station sites characteristics used in the study 

2.2. ASCE standardized reference evapotranspiration equation 

The purpose of the standardized reference ET equation and calculation procedures is to 

bring commonality to the calculation of reference ET and to provide a standardized basis for 

determining or transferring crop coefficients for agricultural and landscape use (ASCE- 

EWRI, 2005). For the standardization, the ASCE-Penman-Monteith method was applied for 

3

two types of reference surfaces representing clipped grass and alfalfa, and for daily or hourly 

time step. This equation is simplified to a reduced form of the ASCE–PM. The equation is 

expressed as: 

900 

0.408 ( 

Rn 

G) 

U 

2 

( es 

ea 

) 

ET 

T 273 

o 

 

 

(1) 

(1 0.34U 

2 

) 

where ET o is standardized grass reference evapotranspiration (mm day-1), R n is calculated 

net radiation at the crop surface (MJ m -2 d -1 ), G is soil heat flux density at the soil surface 

(MJ m -2 d -1 ), T is mean daily air temperature at 2 m height (°C), U 2 is mean daily wind speed 

at 2 m height (m s-1), e s is saturation vapor pressure (kPa), calculated for daily time steps as 

the average of saturation vapor pressure at maximum and minimum air temperature, ea is 

mean actual vapor pressure (kPa), Δ is slope of the saturation vapor pressure-temperature 

curve (kPa °C -1 ), γ is psychrometric constant (kPa °C -1 ), Units for the 0.408 coefficient are m 2 

mm MJ -1 . All the calculations of daily values (R n , e s , e a ) and other parameters were made by 

ASCE-EWRI (2005). 

2.3. Sensitivity analyses and sensitivity coefficients 

In ecological and hydrometeorological studies (e.g., McCuen, 1974; Saxton, 1975; Beven, 

1979; Anderton et al., 2002) a number of sensitivity coefficients have been defined 

depending on the purpose of the analyses. For example, Saxton (1975) mathematically 

differentiated the equation under investigation to derive equations for the rate of change of 

the independent variable with respect to each dependent variable. Smajstrla et al. (1987) 

defined the sensitivity coefficient as the slope of the curve of ET o versus the climatic variable 

being studied. Slopes computed in this manner represented the rates of change in ET o with 

respect to change in the climatic variable. For multi-variable models (e.g., the Penman- 

Monteith equation), different variables have different dimensions and different ranges of 

values, which makes it difficult. In general, a model of evapotranspiration can be written as: 

ET f p p , p ,..., 

(2) 

 

o 1, 2 3 

p N 

where 

i 

 

p is input data variable and N is the number of parameters and input data variables. 

The error in ET o ( ETo 

) that results from errors in the pi 

can then be expressed as: 

ETo 

ETo 

f p1 p1, p2 

p2 

,..., pN 

p 

N 

 

(3) 

Expanding equation 3 in Taylor series and ignoring second-order terms and above, leads to: 

ETo 

ETo 

ETo 

ETo 

p1 

p2 

... pN 

(4) 

p 

p 

p 

1 

ET 

where the differential 

p 

2 

i 

o 

N 

is the absolute sensitivity of the estimation of 

p 

i 

, and 

pi 

is the 

individual error associated with p 

i (Beven, 1979). 

Following McCuen (1974) and Beven (1979), the partial derivative is transformed into a nondimensional 

form to display the sensitivity for the variables: 

ETo 

/ ETo 

ETo 

pi 

S lim 

 

 

/ 

 

P i 

pi 

pi 

pi 

ETo 

(5) 

Δp 0 

i 

 

where S 

P is the sensitivity coefficient represents the fraction of the change in p 

i 

i that is 

transmitted through to the estimate of ET o . However, the relative coefficients are sensitive to 

the values of p and ET o . p in this study represents air temperature, solar radiation, relative 

i 

i 

humidity and wind speed. Basically, a positive/negative sensitivity coefficient of a variable 

4

indicates that ET o will increase/decrease as the variable increases. The larger the sensitivity 

coefficient, the larger effect a given variable has on ET o . In graphical form, the sensitivity 

coefficient is the slope of the tangent at the origin of the sensitivity curve. A sensitivity 

coefficient of 0.1 for a variable would in this case mean that a 10% increase of that variable, 

while all other variables are held constant, may increase ET o by 1%. Many researchers have 

used this methodology to characterize sensitivity models (Saxton, 1975; Coleman and 

DeCoursey, 1976; Piper, 1989; Meyer et al., 1989; Rana and Katerji, 1998) using different 

variables and equations. In the present study, sensitivity coefficients for each station were 

calculated on a daily basis for air temperature, wind speed, relative humidity and solar 

radiation. Monthly and yearly average sensitivity coefficients were obtained by averaging 

daily values. 

3. Results and Discussion 

Global warming due to greenhouse effect is expected to cause major changes in climate of 

some areas (Goyal, 2004). The increase in temperature affects ET o primarily by increasing 

the capacity of air to hold water vapor. Daily sensitivity coefficients exhibit large fluctuations 

during the year at all locations. The same feature has also been reported by Hupet and 

Vanclooster (2001) and Gong et al. (2006). In general, net radiation (R n ) had large sensitivity 

coefficients thought the year at all cities. At all locations, the coefficients for temperature are 

systematically and significantly lower very close from zero to 0.15 than all other variables, 

but all variables exhibited large fluctuations during the year. Daily variation patterns of 

sensitivity coefficients for air temperature (S T ) agree with those of air temperature. ET o is 

insensitive to temperature in winter and the sensitivity gradually increases and achieves its 

maximum value in summer (Fig. 1). The similar patterns of ST and air temperature indicate 

that air temperature determines the extent of the seasonal variation of ST. Fig. 1 shows that 

ET o is most sensitive to wind in winter season in Baft, Bam and Kerman, but, the fluctuations 

of the sensitivity coefficients of wind speed (S U2 ) is large in all of the day in Jiroft (Fig. 1d). In 

general, temperature and wind speed were less influential to ET o and their sensitivities were 

similar to each other in warm months. Sensitivity coefficients of vapor pressure deficit (S VPD ) 

shows a pronounced seasonal cycle with a maximum value in January, February, March, 

October, November and December, similar to the seasonal cycle of the S U2 . The effects of 

VPD, which increases the evaporation, reached higher levels during the winter and cold 

months. As it shown in Figs. 1a, b, c, S U2 and S VPD had a similar pattern in all cities. In 

winter, 10% change in VPD could cause approximately a 5%, 3.7%, 3.8% and 1.8% change 

in ET o in Kerman, Baft, Bam and Jiroft, respectively. But in summer months, 10% change in 

VPD could cause a 3.5%, 2.7%, 2.5% and 1.7% change in ET o in these cities. There was 

also a considerable difference Between Jiroft from others. The sensitivity coefficients of U 2 , 

VPD and T are changes between zero to 0.4 in Jiroft. The sensitivity of evapotranspiration 

rates to changes in temperature and wind speed is less in Jiroft than in other study areas. In 

general, R n was the most sensitive variable at the daily scale in all of cities. Strong positive 

sensitivity coefficients indicated that increases in Rn greatly induce the potential 

evapotranspiration. In summer, 10% change in Rn could cause approximately a 6.5%, 7.4%, 

7.5% and 8.3% change in ET o in Kerman, Baft, Bam and Jiroft, respectively. In other words, 

The ET o estimates were very sensitive to R n , with an annual mean value of 0.58, 0.68, 0.70 

and 0.83 in Kerman, Bam, Baft and Jiroft, respectively (Table 2). This confirms that the 

radiation term in Penman-Monteith equation is generally dominant over the aerodynamic 

term in the prediction equation as reported by Beven (1979). 

5

(d) Baft 

(c) Bam 

(b) Kerma 

n 

(a) Jiroft 

FIGURE 1: Mean daily sensitivity coefficients for air temperature (S T ), wind speed (S U2 ), 

vapour pressure deficit (S VPD ), and net radiation (S Rn ) in (a) Baft, (b) Bam, (c) Kerman, and 

(d) Jiroft 

TABLE 2: Monthly and annual average sensitivity coefficients for individual climate variables 

6

4. Conclusions 

Sensitivity coefficients of reference crop evapotranspiration to mean air temperature, net 

radiation, Vapor pressure deficit and wind speed were calculated and analyzed by ASCE- 

Penman-Monteith method in Kerman, Baft, Bam and Jiroft (Southeast of Iran) using daily 

dataset. The study results show that on the whole, net radiation is the most and air 

temperature is the least sensitive meteorological factors for most of measurement locations. 

Our results are not directly comparable to those of other sensitivity analyses since the 

predictions for vegetation surfaces (Beven, 1979; Saxton, 1975) or open-water surfaces (Mc 

Cuen, 1974) were considered in the other available papers. However, all studies (Mc Cuen, 

1974; Saxton, 1975; Coleman and DeCoursey, 1976; Beven, 1979) showed that potential 

evaporation or evapotranspiration was much more sensitive to radiation and humidity. 

Therefore, accurate estimation of evapotranspiration rates in all the measurement stations 

depends primarily on the solar radiation. For highest S Rn (0.88), increase of 10% in net 

radiation may cause increase of 8.8% in ET o . We can conclude that vapor pressure deficit is 

the second controlling factor to ET o among the climate variables. The results provide a new 

approach for ET o estimation in Kerman province, and also can be used as a theoretical basis 

for future research on the response of reference evapotranspiration to climate change. 

References 

Ali, M. H., Adham, A. K. M., Rahman, M. M., & Islam, A. K. M. R. (2009). Sensitivity of 

Penman-Monteith estimates of reference evapotranspiration to errors in input climatic data. 

J. Agromet., 11(1), 1-8. 

Allen, R. G., Jensen, M. E., Wright, J. L., & Burman, R. D. (1989). Operational estimates of 

reference evapotranspiration. Agron. J., 81, 650-662. 

Allen, R. G., Smith, M., Pereira, L. S., & Perrier, A. (1994). An update for the calculation of 

reference evapotranspiration. ICID Bulletin, 43(2): 35–92. 

Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop Evapotranspiration. 

Guidelines for Computing Crop Water Requirements. FAO Irrigation and Drainage, Paper 

No. 56, FAO, Rome. 

Allen, R. G., Walter, I. A., Elliott, L., Itenfisu, D., Brown, P., Jensen, M. E., Mecham, B., 

Howell, T. A., Snyder, R., Echings, T. S., Spofford, T., Hattendorf, M., Cuenca, R.H., Wright, 

J. L., & Martin, D. L. American Society of Agricultural Engineers. (2000). Issues, 

requirements and challenges in selecting and specifying a satandardized ET equation. 

Proceedings of the 4th National Irrigation Symposium, St. Joseph, Michigan. 

Anderton, S., Latron, J., & Gallart, F. (2002). Sensitivity analysis and multi-response, multicriteria 

evaluation of a physically based distributed model. Hydrol. Processes, 16, 333–353. 

ASCE-EWRI. (2005). The ASCE Standardized Reference Evapotranspiration Equation. 

Technical Committee report to the Environmental and Water Resources Institute of the 

American Society of Civil Engineers from the Task Committee on Standardization of 

Reference Evapotranspiration. ASCE-EWRI, 1801 Alexander Bell Drive, Reston, VA 20191- 

4400, 173 p. 

Beven, K. (1979). A sensitivity analysis of the Penman- Monteith actual evapotranspiration 

estimates. J. Hydrol., 44, 169-190. 

Blaney, H. F., & Criddle, W. D. (1950). Determining Water Requirements in Irrigated Area 

from Climatological Irrigation Data, US Department of Agriculture, Soil Conservation Service, 

Techical, Paper No. 96, p. 48. 

Coleman, G., & DeCoursey, D. G. (1976). Sensitivity and model variance analysis applied to 

some evaporation and evapotranspiration models. Water Resour. Res., 12 (5), 873–879. 

Droogers, P., & Allen, R. G. (2002). Estimating reference evapotranspiration under 

inaccurate data conditions. Irrig. and Drain. Sys., 16, 33–45. 

Doorenbos, J., & Pruitt,W. O. (1977). Guidelines for Prediction of Crop Water Requirements. 

F.A.O. Irrig. and Drain. Paper No. 24. 2nd ed., FAO, Rome, Italy, 156 pp. 

7

Estevez, J., Gavilan, P., & Berengena, J. (2009). Sensitivity analysis of a Penman–Monteith 

type quation to estimate reference evapotranspiration in southern Spain. Hydrol. Processes, 

23, 3342–3353. 

Gong, L., Xu, C. Y., Chen, D., Halldin, S., & Chen, Y. D. (2006). SensitivityofthePenman- 

Monteithreference evapotranspirationtokeyclimaticvariablesinthe Changjiang(YangtzeRiver) 

basin. J. Hydrol., 329, 620- 629 

Goyal, R. K. (2004). Sensitivity of evapotranspiration to global warming: A case study of arid 

zone of Rajasthan (India). Agric. Water Management, 69(1): 1–11. 

Guitjens, J. C. (1982). Models of Alfalfa Yield and Evapotranspiration. Journal of the 

Irrigation and Drainage Division, Proceedings of the American Society of Civil Engineers, 

108(IR3), 212-222. 

Harbeck, Jr., G. E. (1962). A Practical Field Technique for Measuring Reservoir Evaporation 

Utilizing Mass-transfer Theory, US Geological Survey, Paper 272-E, 101–105. 

Hatfield, J. L., Prueger, J. H., & Reicosky, D. C. (1996). Evapotranspiration effects on water 

quality. In: Proceeding of the ASAE International Conference on Evapotranspiration and 

Irrigation Scheduling, 3–6 November, San Antonio, TX, 536–546. 

Hupet, F., & Vanclooster, M. (2001). Effect of the sampling frequency of meteorological 

variables on the estimation of the reference evapotranspiration. Journal of Hydrology, 243, 

192-204. 

Irmak, S., Payero, J. O., Martin, D. L., Irmak, A., & Howell, T. A. (2006). Sensitivity analyses 

and sensitivity coefficients of standardized daily ASCEPenman-Monteith equation. J. Irrig. 

Drain. Eng., 132(6), 564–578. 

Itenfisu, D., Elliot, R. L., Allen, R. G., & Walter, I. A. (2003). Comparison of reference 

evapotranspiration calculations as part of the ASCE standardization effort. J. Irrig. Drain. 

Eng., 129 (6), 440–448. 

Jensen, M. E., Burman, R. D., & Allen, R. G. (eds), (1990). Evapotranspiration and Irrigation 

Water Requirements. New York: ASCE, 332 pp. 

Khalili, A., 1997. Integrated water plan of Iran. Vol. 4: Meteorological studies, Ministry of 

Power, Iran. 

Ley, T. W., Hill, R. W., & Jensen, D. T. (1994). Errors in Penman-Wright alfalfa reference 

evapotranspiration estimates: Effects of weather sensor measurement variability. Trans. 

ASAE, 37(6), 1863-1870. 

Mc Cuen, R. H. (1973). The role of sensitivity analysis in hydrologic modeling. J. Hydrol. 18, 

37–53. 

Meyer, S. J., Hubbard, K. G., & Wilhite, D.A. (1989). Estimating potential evapotranspiration: 

the effect of random and systematic errors. Agric. For. Meteorol., 46, 285–296. 

Penman, H. L., 1948. Natural evaporation from open water, bare soil and grass. 

Proceedings of the Royal Society of London, 193, 120–145. 

Piper, B. (1989). Sensitivity of Penman estimates of evaporation to errors in input data. 

Agricultural Water Manage., 15, 279-300. 

Priestley, C. H. B., & Taylor, R. J. (1972). On the assessment of the surface heat flux and 

evaporation using large-scale parameters. Monthly Weather Review, 100, 81–92. 

Rana, G., & Katerji, N. (1998). A measurement based sensitivity analysis of the Penman- 

Monteith actual evapotranspiration model for crops of different height and in contrasting 

water status. Theoret. and Appl. Climatol., 60,141-149. 

Saltelli, A., Chan, K., & Scott, M. (2004). Sensitivity Analysis. John Wiley & Sons Publishers, 

N. Y. 

Saxton, K. E. (1975). Sensitivity analysis of the combination evapotranspiration equation. 

Agric. Meterol., 15, 343-353. 

Smajstrla, A. G., Zazueta, F. S., & Schmidt, G. M. (1987). Sensitivity of potential 

evapotranspiration to four climatic variables in Florida. Soil and Crop Sci. Soc. of Florida, 46, 

21–26. 

Thornthwaite, C. W. (1948). An approach toward a rational classification of climate. 

Geograph. Review, 38, 55–94. 

8

PRODUCTION OF HYBRID PAPAYA CULTIVATED UNDER 

DIFFERENT IRRIGATION LEVELS. 

Mônica Shirley Silva Souza, Av. Aprígio Veloso, 882, Campina Grande, PB, 58429- 

900, Brazil 

Alberto Soares de Melo, Av. Aprígio Veloso, 882, Campina Grande, PB, 58429-900, 

Brazil 

Juarez Paz Pedroza, Av. Aprígio Veloso, 882, Campina Grande, PB, 58429-900, 

Brazil 

Josivanda Palmeira Gomes Av. Aprígio Veloso, 882, Campina Grande, PB, 58429- 

900, Brazil 

moni_shirley@hotmail.com 

Abstract 

Wishing to know the potential production of hybrid papaya under irrigation, an 

experiment was conducted to evaluate their productivity under different irrigation levels, 

seeking subsidies for irrigated agriculture in semiarid region of Paraíba state. The work was 

done in the Campus IV, at the Center of Human and Agricultural Sciences, Universidade 

Estadual da Paraíba (UEPB), located in Catolé do Rocha – Paraíba (brazilian Northeast). It 

were tested four irrigation levels (50, 75, 100 and 125 % of ETo) and the reference 

evapotranspiration (ETo) calculated by Penman-Monteith model. It was used the papaya 

(Carica papaya L.) UENF/Caliman 01, planted in single rows, in the spacing 4.0 m x 2.0 m, 

irrigated by drip. The experimental design used was randomized blocks with six repetitions 

and three plants per plot. The variables studied were: fruit mass, number of fruits and 

productivity. In the level 2 (75 % ETo) obtained the maximum number of fruits (41.84 mg ha - 

1 ), showing that the hybrid UENF/Caliman 01 can be cultivated in the region of semiarid 

region of Paraíba state with this replacement rate, without compromising on growth 

performance of the crop. 

Keywords: Carica papaya L., irrigation management, productivity. 

1 Introduction 

Papaya (Carica papaya L.) is widespread in tropical and subtropical climate regions, 

and in 2005 was cultivated in 54 countries, and Brazil among the three largest producers. 

The country stood out as the largest producer, reaching 1,650,000 tonnes, followed by 

Mexico and Nigeria, with 955,694 and 755,000 tonnes respectively (FAO, 2010). 

The amount of water stored in the soil throughout the period of development of the 

papaya crop affects their productivity, being affected by both the excess and lack. 

Montenegro et al. (2004) said that the estimates of irrigation water to apply and the 

frequency of irrigation of crops are a great importance to avoid a decrease in income, caused 

by excess or deficit of soil moisture. 

It is known that water is a limited natural resource in semiarid region of Brazil, and its 

use in irrigated horticulture should stick to improving the efficiency of its use in farming 

systems in regions, especially in high evapotranspiration demand. In this sense, it becomes 

necessary to study that takes into account the productive potential of the papaya crop, 

specifically the hybrid UENF/Caliman 01 under different irrigation enabling the improvement 

in efficiency of water use.


2.1 The hybrid 

The hybrid used was developed by UENF (UNIVERSIDADE ESTADUAL NORTE 

FLUMINENSE) and CALIMAN FARM S/A, in Linhares town- ES resulting from crosses of 

'Sunrise Solo 72/12' with the 'JS12'. All characteristics of the hybrid meet the standards 

required by the foreign market (RJ-SETEC, 2007). 

2.2 Treatments and experimental design 

The studied treatments were four water irrigation levels (L1 = 50%, L2 = 75%, L3 = 

100% and L4 = 125% of ETo) and the reference evapotranspiration calculated by Penman- 

Monteith model standardized by Allen et al. (1998) (Equation 1). 

The applied quantities of water (Irrigation + effective Precipitation) in each treatment 

during the course studied was 986.7 mm; 1480mm; 1973.4mm and 2466.7 mm, respectively, 

for the treatment L1, L2, L3 and L4 as shown in Table 1. In Figure 1 there are a partial view 

of irrigation method and papaya cultivation field. The experimental design was randomized 

blocks with six replications, each plot consisted of three useful plants. 

ETo = 

0,48∆( 

R 

n 

⎛ 900U 

2 ⎞ 

− G) 

+ γ ⎜ ⎟( 

e 

⎝ T + 273 ⎠ 

∆ + γ (1 + 0,34U 

) 

2 

s 

− e 

a 

) 

Equation 1 

which: 

ETo = Reference evapotranspiration (mm day -1 ); 

Rn = net radiation at the culture surface (MJ m -2 day -1 ); 

G = heat flow in the soil (MJ m -2 day -1 ); 

∆= slope of vapor pressure curve versus air temperature (kPa. o C -1 ); 

U 2 = wind speed measured at two meters in height (m s -1 ); 

T = temperature ( o C); 

e s = saturation pressure of water vapor (kPa); 

e a = real pressure of water vapor (kPa); 

γ = psychrometric factor (MJ kg -1 ).

Table 1 - Reference evapotranspiration (ETo), total precipitation, usable precipitation 

and irrigation levels applied at different replacement rates evaluated. 

Treatment ETo * Total 

precipitation 

mm 

Usable 

precipitation 

mm 

Irrigation 

water depth 

50% of ETo 986,7 655,8 

75% of ETo 1480 

441,2 330,9 

1149,1 



a) b) 

Figure 1 - Operation of the emitter (a) and partial view of the hybrid UENF / Caliman 01 

papaya experiment (b). 

2.2 Fertilization and irrigation management 

Fertilization was made as indicated by Sobral et al, (2007), weekly using urea (44% 

N), potassium chloride (56%K 2 O) and phosphoric acid (50% P 2 O 5 ). 

The irrigation water depth, the amount of water application, and irrigation time was 

determined by equations 2, 3 and 4, respectively, as proposed by Mantovani et al. 2006. 

LB = 

ETo. 

Ks 

− Pe 

Ef 

Equation 2 

which: 

LB = gross water depth (mm day -1 ); 

ETo = reference evapotranspiration second Penman-Monteith method (mm 

day -1 ); 

Ks = percentage of wetted area by the issuer; 

Pe = effective precipitation, in the period (mm); 

Ef = irrigation efficiency.

Ia = 

n × v 

ec 

Equation 3 

which: 

Ia = intensity of application (mm h -1 ); 

n = number of emitters per plant; 

v = emitter flow (L h -1 ); 

ec = area occupied by the plant (m 2 ). 

Ti = 

LB 

Ia 

Equation 4 

which: 

Ti = Irrigation time (h); 

LB = gross water depth (mm day -1 ); 

Ia = intensity of application (mm h -1 ). 

The irrigation system used in the experiment was located, by dripping, consisting of 

two tapes per line with emitters with 1.3 L/h of flow, equidistants of 0.30m, equivalent to 12 

per plant. 

2.5 Analised Variables and Statistical Analysis 

Properly identified, for treatment, fruits were counted and weighed on digital scales of 

0,01g precision for determination of fruit weight, fruit number per plant and productivity. 

These measurements were made individually for each fruit. Analysis of variance for each 

variable for the F test, until 5% of significance and their respective regression models were 

adjusted according to the coefficient of determination (R 2 ) (STORCK et al., 2000). 


The irrigation depth had no consistent effect on the number of fruits per plant (NF) 

and productivity (P). For the variable fruit mass (MF) it showed significant differences at the 

1% level of probability for F Test. 

It can be seen in Figure 2 tendency of superiority of the mean weight of fruit of 0.92 

kg treated with 100% ETo, presenting a reduction after this level of 4.3%. The lowest mean 

weight (0.73 kg) was obtained by applying 50% of ETo, especially noting an increase of 

20.6% when the irrigation depth ranged from 50 to 100% of ETo.

Figure 2 - Fruit weight (kg) of hybrid papaya UENF / Caliman 01, grown under field 

conditions in water levels in the Catolé do Rocha microregion, Paraíba state, Brazil. 

Although the analysis of variance showed no significant effect on the number of fruits 

per plant and productivity, there were variations of these variables in different irrigation 

depths. The maximum amount of fruit occurred in the irrigation water depth corresponding to 

75% of ETo, providing an increase of 5.5% related to the level 1 (50% of ETo) and 8.3% 

when related to Level 4 (125% of ETo). The maximum productivity (41.84 Mg ha -1 year -1 ) was 

found by applying 75% of ETo, decreasing from that point (5.7%). The lowest value (32.81 

Mg ha -1 year -1 ) was obtained by applying 50% of ETo, indicating interference of moisture 

content on the available soil productivity. 


- The highest number of fruits per plant and maximum productivity is achieved in the 

rate of 75% of ETo. 

- The hybrid UENF/Caliman 01 can be cultivated in the semiarid region of Paraiba 

state with replacement rate of 75% ETo, without compromising the performance of crop 

yield.

5. References 

ALLEN, R.G.; PEREIRA, L.S.; RAES, D.; SMITH, M. Crop evapotranspiration: guidelines for 

computing crop water requirements. Roma: FAO, 1998. 300p. (Irrigation and Drainage 

Paper, 56). 

FAO. FAOSTAT. FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED 

NATIONS. Estatistical Databases Agriculture. Disponível em: . 

Acesso em: 26 de nov. 2010. 

MANTOVANI, E. C.; BERNERDO, S.; PALARETTI, L. F. Irrigação: Princípios e métodos. 

Viçosa: Editora UFV. 318p. 2006. 

MONTENEGRO, A. A. T.; BEZERRA, F. M.; LIMA, R. N. Evapotranspiração e coeficientes 

de cultura do mamoeiro para a região litorânea do Ceará, Revista Engenharia Agrícola, 

Jaboticabal, v. 24, n. 2, p. 464-472, 2004. 

SETEC-RJ, SECRETARIA DE CIÊNCIA E TECNOLOGIA DO RIO DE JANEIRO, Estudo 

da UENF eleva produtividade do mamão “calimosa”, 2007. Disponível 

em:. Acesso em 

13/11/2010. 

STORCK, L.; GARCIA, D.C.; LOPES, S.J.; ESTEFANEL, V. Experimentação agrícola. 

Santa Maria: Editora da UFSM, 2000. 198p.

THERMOFHYSICS PROPERTIES OF THE OIL EXTRACTED OF THE 

GENOTYPES OF CASTOR BEAN 

Katcilanya Menezes de Almeida 1 , Av. Aprígio Veloso, 882, Campina Grande, PB, 

58429-900, Brazil 

Juarez Paz Pedroza Av. Aprígio Veloso, 882, Campina Grande, PB, 58429-900, 

Brazil 

Napoleão Esberard de M. Beltrão, Av. Oswaldo Cruz, 1143, Campina Grande, PB, 

58428-095, Brazil 

katcilanya@yahoo.com.br 

Abstract: 

The objective of this work was to evaluate the possible changes in the thermophysics 

properties between the oil extracted from three different genotypes of castor bean, two 

modified cultivars (BRS Paraguaçu e BRS Energia) and other wild genotype caught in a 

vacant land, just for a standard comparison. The oil was characterized through analysis 

thermo-physics: density, point of minimum flow, viscosity and specific heat. The data were 

statistically analyzed and compared by analysis of variance for a randomized design using 

ASSISTAT program 7.0 version. The specific heat found to each genotype was: 0,2742 

cal/gºC to BRS Paraguaçu; 0,3653 cal/gºC to BRS Energia and 0,2792 cal/gºC to the wild 

one. The point of minimum flow ranged from -18,17 to -18,47 ºC. In relation to density 

variable there was no significant interaction between the genotypes, but it’s reduced 

significantly with the increase of the temperature. The viscosity showed significant 

differences between the genotypes and also reduced significantly with the increase of the 

temperature. 

Key-words: Ricinus communis L., oil, thermo-physics. 


The oil extracted from castor bean seeds has a high industrial value, due to versatility of 

applications constituting a raw material for the manufacture of plastics, synthetic fibers, 

enamels, resins and lubricants (Freire, 2001; O `Brien et al. 2000). 

In addition to the various uses of castor oil, it has been widely studied for biodiesel 

production, because of the specific characteristics: high productivity, it can be miscible in 

methanol and ethanol, it can be used as an additive until 10% (v/v) and high viscosity 

(Delgado et al., 2011). 

Although many applications recognized, there are still incipient technological information 

about the variability among genotypes of castor oil, which makes a more complete 

exploration of the industrial potential of this product for other applications (COSTA et al., 

2008). 


The seeds of castor beans Energy BRS, BRS Paraguaçu (produced by the Empresa 

Brasileira de Pesquisas Agropecuária – Embrapa/CNPA) and wild one were subjected to 

cold pressing in a mechanical press with manual pressure capacity of 30 tons without any 

pretreatment. After extraction the samples, it were subjected to centrifugation at a speed of 

3000 rpm during five minutes, to remove some impurities and waste.

The density analysis was performed with the aid of a 25 mL beaker where the sample was 

weighed and measured, then subjected to the desired temperature, -15, -10, -5, and 0 o C in 

vertical freezer, 20, 40 and 60 o C in B.O.D, 80 o C in an oven, monitored by a thermocouple, 

after get the temperature, the sample was weighed again and it was checked to made a 

relationship between the mass and volume (Equation 1) to obtain the density. 

m 

ρ = 

v 

(1) 

where: 

ρ = Density (g/cm 3 ); 

m = mass (g); 

v = volume (cm 3 ) 

Determination of the point of minimum flow was second 1149 NBR- Oil Product - The 

point of minimum flow is the lowest temperature at which the lubricating oil is still flowing. In 

the test, it cooled the oil sample within a tube and each decrease of 3 °C in temperature, it 

was observed whether or not the movement of the surface of the oil inside the tube and, after 

5 seconds is lacking movement that temperature, it will have reached the freezing point and 

a temperature of 3 °C above this temperature will be at the point of minimum flow. 

It was used to determine the viscosity, the B3 Hoppler viscosimeter. The viscosity of 

castor oil was determined in a temperature range of -15, -10, -5, 0, 20, 40, 60 and 80 0 C with 

the aid of a thermostated bath for obtaining the same. This is done through the time interval 

(Δt) that particular sphere of specific mass (ρ), constant (K) and diameter (D) known travels a 

distance (ΔL). The calculation is done by Equation 2: 

µ = K (δ 2 - δ 1 ) ∆t (2) 

which: 

μ = viscosity, mPas -1 

K = constant of the sphere, mPacm -3 

δ 2 = specific mass of the sphere, gcm -3 

δ 1 = density of sample, gcm -3 

∆t = fall time, s. 

The specific heat was determined using a handmade colorimeter constructed in a 

thermical bottle with a layer of glass fiber placed inside of a PVC tube, where a digital 

thermometer measures the temperature inside the calorimeter. 

To determine the heat capacity of the calorimeter are placed 100 g of water at 

environmental temperature (25 °C) within the calorimeter; this, in turn, it is sealed with a 

rubber coupled to a thermometer indicating a temperature T 1 within the calorimeter and then 

are placed in the container in 100 g of water at an average temperature of approximately 3 

°C, corresponding to the temperature T 2 ; stir the calorimeter at the time of 10 min until they 

reach the equilibrium temperature T 3 . The heat capacity was determined by Equation 3: 

C 1 m 1 (T 1 -T 3 ) + Ccal (T 1 -T 3 ) = C 2 m 2 (T 3 -T 2 ) (3)

where: 

C 1 = C 2 = specific heat of the alcohol at 45% NPm (0.6 cal/g °C) 

m 1 = mass of alcohol at 45% NPm in its natural state, 100g 

m 2 = mass of alcohol at 45% cold NPM, 100g 

T 1 = Temperature of the alcohol at 45% NPm in natural state, °C 

T 2 = Temperature of the alcohol at 45% PMn, cold °C 

T 3 = equilibrium temperature of the mixture, °C 

Ccal = calorimeter heat capacity (cal/ °C) 

Known heat capacity of the calorimeter (Ccal) and the equilibrium temperature T 3, there is 

a sample of oil at a temperature T 4 in the calorimeter and stirred for 10 min until a new 

equilibrium is achieved at a temperature T 5 . The specific heat of the oil was determined by 

the following energy balance of from Eq 4: 

where: 

moCo(T 4 -T 5 ) = C 1 m 1 (T 5 -T 3 ) + Ccal(T 5 -T 3 ) (4) 

m o = mass of the oil, (g) 

C o = specific heat of the oil, cal/g °C 

C 1 = specific heat of the alcohol at 45% PMn (0.6 cal/g °C) 

m 1 = mass of alcohol at 45% NPn in its natural state, 100g 

T 3 = equilibrium temperature of the mixture, °C 

T 4 = temperature of the oil sample, °C 

T 5 = equilibrium temperature of the mixture of oil, °C 

3 Results and Discussion 

Considering the variable density of the oil, very important for its use, including the 

production of biodiesel, it was found that the genotypes behave fairly, but there was a 

significant effect at 1% probability by the F test for the temperature factor which rises and 

decreases the density of the oil, as seen in Figure 1 and in equation 1, independent of the 

genotypes. When high temperature increases the kinetic energy of the molecules, as 

explained Rosenberg (1974) citing the law of Stefan, J = σT 4 , ruled to the relationship 

between temperature and energy emitted by a body, with I = energy, T = absolute 

temperature (273 + ºC) and σ = constant, corresponding to 5.67 x 10 5 energy -2 sec -1 o K -4 . 

Castor oil, despite being the most dense that nature has created, this property is reduced 

with increasing temperature. 

Equation: y = 1,1524 – 0,000642067x (1) 

R 2 = 0,948

Figure1 - Relationship between the castor oil density and the temperature, independent of the 

genotype tested, no significant interaction. Campina Grande, Paraíba, Brazil. 

Point of Minimum Flow 

The point of minimum value flow for each genotype were, respectively: BRS Paraguaçu, - 

18, 4667°C; BRS Energia, -18.1667°C and wild one, -18.2667°C, considering a low freezing 

point in a interval -18.17 to -18.47°C for the three genotypes. This result confirms those 

reported by Savy Filho et al. (1999) when said in which the hydroxyl carbon 12 and the 

double bond of ricinoleic acid in castor oil confer the characteristic of the lower solidification 

temperature. 

Viscosity 

With respect to the variable viscosity there was statistical significance at the 1% level of 

probability by the F test for the factors studied and the interaction between them, indicating 

varying behavior between genotypes with respect to different temperatures. 

For BRS Paraguaçu found that the effect of temperature on the viscosity of the oil was 

cubic nature, with high coefficient of determination, R 2 = 0.91, (Equation 2) indicating a 

strong relationship between the variables and explains well the phenomenon with high drop 

after 268.15 °K. 

Equation: y = 8074886 – 770010x + 243,8188x 2 – 0,2064x 3 (2) 

R 2 = 0,9184 

The BRS Energia, roughly 130 days earlier than the BRS Paraguaçu and BRS 

Nordestina, both cycled more than 240 days, showed a decrease in oil viscosity (Figure 2) at 

a lower temperature which, for the production of biodiesel is quite interesting. 

Equation: y = 8840041 – 84298x + 266,914x 2 – 0,28064x 3 (3) 

R 2 = 0,9305

Figure 2-Relationship between the viscosity of the castor oil plant genotype BRS Energia and 

temperature interaction significant at 1% significance level. Campina Grande, Paraíba, 

Brazil. 

The wild one material (Equation 4) suffered loss in viscosity at a temperature even lower, 

possibly because the lower content of fatty acids contained in oil of this genotype, although 

not measured. 

Equation: y = 8863445,00 – 84494,0x + 267,461x 2 – 0,2811x 3 (4) 

R 2 = 0,9366 

According CHIERICE NETO AND CLEAR (2001) the specific behavior of castor oil in the 

face of variable density and viscosity is due to the strong presence of ricinoleic acid 

(approximately 89.5%) in the oil composition, the molecule of this acid has 18 carbon atoms 

with three functional groups: the terminal carboxylic group, the double bond in the 9th carbon 

and the hydroxyl group at the 12th carbon. This structure of ricinoleic acid is also responsible 

for the solubility of castor oil in ethanol at normal temperature and pressure conditions 

(CNTP), it differing from the other vegetable oils. This high viscosity is interesting for some 

industrial applications, their use as lubricant, and is not good for others, their use as 

biodiesel, but this oil does not preclude such use, because now you can mix oils to obtain 

various types biodiesel that meets national specifications (ANP) and international oil and 

castor oil can enter up to 40% without problems in a mixture of mineral diesel. 

Specific Heat 

The average values of specific heat of genotype BRS Energia (0.3653 cal/g ºC) showed a 

significant difference at 5% probability by Tukey test, when compared to Wild genotypes 

(0.2792 cal/g °C) and BRS Paraguaçu (0.2742 cal/g °C), consisting higher heat capacity, to 

easily gain and heat loss without significant changes in temperature of the oil, which is 

important for industrial use. The larger the specific heat more heat energy can be retained 

without great increase in temperature.

4 Conclusions 

• The density obtained from castor oil was uniform and stable (ranging from 0.99 to 0.91 

g/cm ³) in the temperature range from -20 °C and 60 °C, almost independent of the genotype 

studied underscoring the high stability this oil; 

• The viscosity of castor oil in the range of -20 to 60 ° C has been reduced with the increase 

of its own energy content, in the same proportions between tested genotypes; 

• The highest specific heat was the genotype BRS Energia (0.3653 cal/g °C), indicating that 

this is oil accumulates greater amount of heat energy without a large increase in 

temperature; 

• The minimum flow point of the three genotypes was considered low within a range of -18.17 

to -18.47 ° C, confirming that the castor oil freezes at low temperatures. 

5 Reference 

CHIERICE, G.O.; CLARO NETO, S. Aplicação industrial do óleo. FIGUEIREDO NETO, A.; 

ARAÚJO, ALDERI EMÍDIO.; ARAÚJO, ALEXANDRE EDUARDO; AZEVEDO, D.M.P.; 

VIEIRA, D. J.; LEITE, E. J.; FREIRE, E. C. O agronegócio da mamona no Brasil. 1º Ed. 

Brasília, DF: Embrapa Informação Tecnológica. 2001. Cap.5, pág.89-119. ISBN.85-7383- 

116-2. 

COSTA, T. L.; MARTINS, M. E. D.; BELTRÃO, N. E. DE M.; MARQUÊS, L. F.; PAIXÃO, F. 

J. Revista da Pesquisa Aplicada e Agrotecnologia. Características do óleo de mamona da 

cultivar BRS-188 Paraguaçu. Set.-dez. 2008, v.1, n.1. 

DELGADO, A. E.; CHAPARRO, W. A.; GONZALEZ, J. R. S. Influencia del porcentaje de 

mezcla del aceite de higuerilla en la obtención de combustible alternativo para motores 

diesel: Infl uence of castor oil mix composition on the production of biofuel. Revista da. 

Faculdade. de Engenharia da. Universidade de. Antioquia. n.° 58 , pag. 46-52. Março, 2011. 

FREIRE, R. M. M. Em O Agronegócio da Mamona no Brasil. FIGUEIREDO NETO, A.; 

ARAÚJO, A. E.; ARAÚJO, A. E.; AZEVEDO, D. M. P.; VIEIRA, D. J.; LEITE, E. J.; FREIRE, 

E. C. Ed.; UNB, 2001, cap. 13. 

O`BRIEN, R. D.; FARR, W. E.; WAN, P. J.; Introduction to fats and oils technology, 2th ed., 

AOCS Press: Champaign, 2000. 

ROSEMBERG, N. J. Microclimate: the biological environment. John Wiley & Sons, New 

York. 1974. 315p. 

SAVY FILHO, A.; BANZATTO, N. V.; BARBOZA, M. Z. ; MIGUEL, A. M. R. O.; DAVI, L. O. 

de C.; RIBEIRO, F. F. Mamona. Campinas, SP. Coordenadoria de Assistência Técnica 

Integral, 1999. (CATI, Oleaginosas no estado de São Paulo: análise e diagnóstico. 

Documento Técnico, 107).

Morphological responses of Eucalyptus grandis seedlings 

submitted to different water stress levels during hardening 

Magali R. Silva 1* , Antonio C. Nogueira 2 , Carlos M. de Carvalho 1 , Danilo Simões 1 

1 Universidade Estadual Paulista - Sector of Forestry Sciences, Postbox 237, Postcode 

18610-307 - Botucatu, Sao Paulo, Brazil. 

2 

Universidade Federal do Paraná - Sector of Agricultural Sciences - Av. Pref. Lothário 

Meissner, 900, Postcode 80210-170 - Jardim Botânico - Curitiba - Parana – Brazil 

*Corresponding author. E.mail: magaliribeiro@fca.unesp.br 

Abstract 

Water stress, one form of seedling hardening, provokes morphological, physiological and 

nutritional alterations in the plant that influence its capacity to resist adverse field conditions 

and thus their quality. However, there are still some problems as to the manner of applying 

water stress since irrigation of forest seedlings, most markedly during the hardening phase, 

is done in a highly empirical manner in which only visual examination determines the 

moment and conduct of the irrigation (time and frequency). In this sense the present study 

aimed to verify the morphological responses of Eucalyptus grandis seedlings when submitted 

to different water stress levels during the hardening phase. The seedlings were produced in 

50 cm 3 plastic tubes with substrate based on pine bark and vermiculite. Until the 69th day, all 

seedlings experienced the same conditions. Starting on the 70th day, for a 30-day period, the 

seedlings received differentiated water managements that constituted the different 

treatments, which were chosen from results from the curve of tension-retention of water by 

the substrate, characterized as: T1 seedlings without suffering water deficit, in other words, 

permanently subirrigated, and T2, T3, T4 and T5 seedlings irrigated when reaching a tension 

of water retention at the substrate of -50, -100, -500 and -1500 KPa, respectively. The data 

were submitted to variance analysis and significant effects evaluated by Tukey’s test at 95% 

probability. The data revealed that the greatest seedling height was obtained under 

continuous subirrigation, which differed statistically from the other treatments. Both the 

greatest and least water stress produced statistically similar values for stem diameter and 

root dry mass. The highest shoot dry masses resulted from treatments with less water stress. 

Although the seedlings submitted to subirrigation continued to present greater height, the 

leaves were more widely spaced along the stem and presented smaller size resulting in leaf 

areas similar to seedlings submitted to greater water stress. The seedlings with greater water 

stress presented the lightest specific leaf weights. It is concluded that water management 

influenced the quality of Eucalyptus grandis seedlings given the alterations in morphological 

characteristics, although the greatest differences have occurred in seedlings produced under 

continuous subirrigation during the hardening phase. 

Key words: nursery, quality, water management, irrigation, subirrigation. 


The quality of the seedlings is one of the key factors for obtaining stands of high 

productivity. This quality is expressed by morphological, physiological and nutritional

characteristics resulting from of genetic factors as well as the management procedures of the 

nursery (SILVA, 1998). 

One of managements applied during hardening implies the application of water stress 

to acclimate the plants to field conditions. According Stape et al. (2001) the survival and 

development of seedlings in the field depend on the interactions between the morphological / 

physiological attributes and the environmental components of the site. The 

morphological/physiological attributes are more important under harsh field conditions. 

Acclimatization involves morphological, physiological and nutritional changes which 

reflect the efficiency of water use and, consequently, the plant's ability to resist adverse 

conditions, especially in the early post-planting. Coopman et al. (2008) reported that 

morphological changes allow the plants to maintain the balance between transpiration and 

absorption and increase the capacity to generate new roots. 

Morphological changes induced by water stress in seedlings were also studied by 

several authors who observed the reduction in shoot biomass, root and total (SILVA, 1998; 

COOPMAN et al, 2008), reduction in height (REIS et al., 1988, OLIVA et al., 1989; 

COOPMAN et al, 2008) and diameter (REIS et al., 1988), changes in the root / shoot 

(LANDSBERG & MYERS, 1989), reduction in the number of branches (COSTA E SILVA et 

al., 2004), number of leaves (Olive et al., 1989) and the leaf area (Stoneman et al. 1994 

LEMCOFF et al., 1997 and Silva, 1998; COOPMAN, et al., 2008; reduction of root growth 

(MCKERSIE & Ya'acov, 1994; COSTA E SILVA et al., 2004), an increase in the ratio dry 

weight / fresh weight (LI 1998). 

This study aimed to verify the morphological responses of Eucalyptus grandis 

seedlings when subjected to different levels of water stress during hardening. 

2. Material and methods 

The study was conducted in the Nursery Forestry Seedling Research, Faculty of 

Agronomic Sciences of UNESP, Botucatu, Sao Paulo – Brazil, located at the coordinates 22 

º 51'22'' south latitude and 48 ° 26'0'' West longitude, at an altitude of 810m and I Cwa type 

climate, Köppen classification of Wilhelm and average annual rainfall of 1524 mm. 

The seeds of Eucalyptus grandis were from a clonal seed orchard. The tubes used had 

55 cm ³ volumetric capacity and the substrate was a commercial product based on 

decomposed pine bark and expanded vermiculite with the following characteristics: 29.2% 

macropores, 46.8% micropores and 76.0% total porosity, retention of 2.2 g water/g of dry 

substrate. 

Two fertilization via subirrigation were carried out, one on the 35 th day after sowing 

(DAS) with ammonium nitrate and potassium nitrate at a concentration of 400 and 316 mg L -1 

of N and K respectively, and the other at 54 DAS, with Peters ® fertilizer (20:10:20) at a dose 

of 2 g L -1 . 

During the 70 th to 100 th DAS, the seedlings had different water managements. T1 

seedlings without suffering water stress or permanently subirrigated, T2, T3, T4 and T5 

seedlings irrigated when reaching a tension of water retention at the substrate of -50, - 

100, -500 and -1500 kPa, respectively, measured by gravimetric method. 

The morphological characteristics evaluated were height, stem diameter, leaf area, 

shoot dry mass, roots dry mass and leaf specific weight. 

The statistical design was completely randomized, with five treatments with four 

replications (trays) of 48 seedlings, which were considered useful for the morphological

evaluation, five central plants, amounting to 20 plants per treatment. The results were 

subjected to analysis of variance. Variables significant at Test F were subjected to the Tukey 

test at 5% probability. 

3. Results and discussion 

The water management affect with different intensities the morphological 

characteristics of Eucalyptus grandis seedlings (Table 1). Only the seedlings without stress 

treatment (T1) differed significantly from the others, with higher rates. 

The fact that the height was similar among stress treatments it can be attributed to the 

fact that during hardening, seedlings in tube have gone through the phase of rapid growth, 

since the size of the pack and hence the amount of substrate and nutrients are limiting (Silva 

et al., 2004). Therefore the seedlings that suffered water stress did not have higher growth 

rates than those subjected to high stress. 

Sasse et al. (1996) and Coopman et al. (2008) found a reduction of the height of 

Eucalyptus globulus subjected to water stress and Lopes et al. (2007) found an increase in 

height of of Eucalyptus grandis seedlings with increasing levels of irrigation. 

The stem diameter was not associated with the level of applied stress as found by 

Coopman et al. (2008) and different in Sasse et al. (1996) who concluded that diameter 

growth rates were reduced by water stress. 

The shoot dry masses, root dry masses and total dry masses had decreasing mean 

inasmuch water stress levels increased. Although the root dry masses of T1, considering 

only the root system contained in the tube (as seedlings are in constant contact with water, 

the root system grew out of the tube), had statistically similar values to those subjected to 

higher stress. These results confirm that the decrease of water promotes a slower growth 

which reflects in the total dry matter produced. 

The presence of water in the tissues of the leaves causes the stomatal cells to become 

turgid for longer and open capturing light energy and carbon to photosynthesize. Coopman et 

al. (2008) found a reduction in the biomass of leaf, stem and root of Eucalyptus globulus 

seedlings when subjected to water stress. Lima et al. (2005) observed that the increase of 

irrigation led to the linear increase in root biomass of Eucalyptus grandis seedlings. 

The results of the leaf area of seedlings showed that water stress also affected leaf 

area. In T1 it was observed that despite presenting greater height, the internodes were 

higher, with the leaves more spaced out contributing for a less high leaf area than others. 

The treatments with higher levels of stress (T4 and T5) showed the lowest values of leaf area 

did not differing from each other. 

Lopes et al. (2007) reported an increase in leaf area with increasing levels of irrigation. 

Stoneman et al. (1994) and Coopman et al. (2008) found a reduction in leaf area of 

Eucalyptus marginata and globulus respectively, when subjected to water stress. 

The most stressed seedlings (T5) had the lowest specific leaf weight. Treatment 1 

had the highest specific leaf weight and was statistically different from the other treatments. 

Farrell et al. (1996) in his research on physiological and morphological responses of 

seedlings of six clones of Eucalyptus camaldulensis grown in a greenhouse and subjected to 

water stress treatments found that clones that produced a large number of leaves had leaves 

with low specific weight, while clones that produced a few leaves had leaves with relatively 

high specific weight.

Table1. Morphological characteristics of Eucalyptus grandis seedlings, 100 days after 

sowing, under different irrigation management during hardening. 

Trat. H 

(cm) 

D 

(mm) 

SDM 

(g) 

RDM 

(g) 

TDM 

(g) 

LA 

(m 2 ) 

LSW 

(g m -2 ) 

T1 70.53 a 3.49 b 1.96 a 0.51 ab 2.47 a 0.0166 ab 101.30 a 

T2 52.15 b 3.63 ab 2.03 a 0.59 a 2.62 a 0.0173 a 87.74 b 

T3 48.95 b 3.79 a 1.83 ab 0.56 ab 2.39 ab 0.0182 a 84.45 bc 

T4 51.25 b 3.59 ab 1.61 b 0.50 b 2.12 b 0.0142 c 82.06 bc 

T5 50.95 b 3.46 b 1.56 b 0.50 b 2.06 b 0.0144 bc 73.43 c 

CV 7.75 8.87 18.24 16.61 16.88 16,32 16.31 

Means followed by same letters in the same column do not differ by the Tukey Test at 5% level of 

significance. CV = coefficient of variation. 

T1: Seedlings without suffering water stress (under continuous subirrigation), T2, T3, T4 and 

T5: irrigated seedlings up to reaching a tension of the substrate water retention at -50, -100, - 

500 and -1500 KPa, respectively. 

4. Conclusion 

It is concluded that water management influence on the quality of Eucalyptus grandis 

seedlings, as it altered morphological characteristics. Although the greatest differences 

occurred among the seedlings grown under continuous subirrigation and those which 

suffered some level of stress during hardening. 

Acknowledgements: This work was supported by CAPES (Coordenação de 

Aperfeiçoamento de Pessoal de Nível Superior), a Brazilian Government Agencies. 

5. References 

Coopman, R.E. et al. (2008). Changes in morpho-physiological attributes of Eucalyptus 

globulus plants in response to different drought hardening treatments. Electronic Journal of 

Biotechnology, 11, 1-10. 

Costa e Silva, F. et al. (2004). Responses to water stress in two Eucalyptus globulus clones 

differing in drought tolerance. Tree Physiology, 24, 1165–1172. 

Farrell, R.C.C., Bell, D.T., Akilan, K. & Marshall, J.K. (1996). Morphological and physiological 

comparisons of clonal lines of Eucalyptus camaldulensis. I. Responses to drought and 

waterlogging. Australian J ournal of Plant Physiology, 23, 497-507. 

Lemcoff, J.H., Garau, A., Guarnaschelli, A. & Prystupa, P. (1997). Water stress in seedlings 

of Eucalyptus camaldulensis clones and its efects on growth characteristics. In: IUFRO 

Conference on Silviculture and Improvement of Eucalypt. Proceedings. Colombo: 

EMBRAPA - Centro Nacional de Pesquisa de Florestas.

Li, C. (1998). Some aspects of leaf water relations in four provenances of Eucalyptus 

microteca seedlings. Forest Ecology and Management, 111, 303-308. 

Lopes, J.L.W., et al. (2005). Effects of irrigation depths on Eucalyptus grandis W. (Hill ex 

Maiden) seedlings in coconut fiber substrate . Revista Irriga, 10, 123-134. 

Lopes, J.L.W., et al. (2007). Quality of eucalyptus seedlings under different depths of 

irrigation and two substrastes. Revista Árvore, 31, 835-843. 

Sasse, J., Sands, R., Whitehead, D. & Kelliher, F.M. (1996). Comparative responses of 

cuttings and seedlings of Eucalyptus globulus to water stress. Tree Physiology, 16, 287- 

294. 

Mckersie, B.D. & Ya’acov, Y.L. (1994). Water and drought stress. In: _. Stress and stress 

coping in cultivated plants. Netherlands: Kluwer Academic Publishers, p.148-180. 

Myers. B.J. & Landsberg, J.J. (1989). Water stress and seedling growth of two eucalypt 

species from contrasting habitats. Tree Physiology, 5, 207-218. 

Oliva, M.A., Barros, N.F., Gomes, M.M.S. & Lopes, N.F. (1989). The development of dieback 

symptoms in Eucalyptus camaldulensis seedlings as related to moisture stress and mineral 

nutrition. Revista Árvore, 13, 19-33. 

Reis, G.G., Reis, M.G.F., Maestri, M. (1988). Growth and water relations of seedlings 

Eucalyptus grandis e E. camaldulensis in tubes under three irigation regimes. Revista Árvore, 

12, 183-195. 

Siddiqui, M. T., Shah, A. H. & Tariq, M. A. (2008). Effects of fertilization and water stress on 

Eucalyptus camaldulensis seedlings. Journal of Tropical Forest Science, 20, 205–210. 

Silva, M. R. (1998). Characterization morphological, physiological and nutritional of seedlings 

Eucalyptus grandis Hill ex.Maiden submitted to different levels of water stress during the 

hardening. Dissertation (Master of Forestry) - Division of Agricultural Sciences, Federal 

University of Parana, Curitiba, 105p. 

Silva, M. R.; Klar, A.E. & Passos, J.R. (2004). Effects of water management and potassium 

application on the morphophysiological characteristics of seedlings of Eucalyptus grandis W. 

(Hill ex. Maiden). Revista Irriga, 9, 31-40. 

Stape, J.L. & Gonçalves, J. L. de M. & Gonçalves, A.N. (2001). Relationships between nursery 

practices and field performance for Eucalyptus plantations in Brazil. New Forests, 22, 19-41. 

Stoneman, G.L., Turner, N.C. & Dell, B. (1994). Leaf growth, photosynthesis and tissue 

water relations of greenhouse-grown Eucalyptus marginata seedlings in response to water 

deficits. Tree Physiology, 14, 633-646.

Transpiration of Eucalyptus spp seedlings submitted to different 

fertigation managements 

Magali R. Silva 1* , Simone F. Ciavatta 1 , Danilo Simões 1 

1 Universidade Estadual Paulista - Sector of Forestry Sciences, Postbox 237, Postcode 

18610-307 - Botucatu, Sao Paulo, Brazil. 

*Corresponding author. E.mail: magaliribeiro@fca.unesp.br 

Abstract 

The transpiration of seedlings is an important parameter for evaluating physiological quality, 

as well as constituting a good indicator for definition of initial performance of seedlings after 

plantation in the field. Under identical conditions, transpiration differences can indicate a 

stomatic mechanism of greater or lesser efficiency, implying water savings by the plant. The 

tolerance of forest species seedlings to drought, is determined by several factors and can be 

modified by nutritional and water management. In this sense, the present work aimed to 

evaluate the influence of nutritional management, by means of fertigation, in the transpiration 

of seedlings of three species: Eucalyptus grandis, E.urophylla and the hybrid E. grandis x E. 

urophylla. The seedlings were produced in 50 cm 3 plastic tubes with substrate based on the 

bark of pine and vermiculite. The assay was conducted by a completely randomized 3x2 

factorial delineation (species and frequencies of fertigation). Fertigation during growth and 

hardening phase were parceled 1, 2, 3 and 6 times per week, maintaining application of the 

same total fertilizer quantity, and delivered by subirrigation. The results were submitted to 

variance analysis. The variables found significant by the F test were submitted to Tukey’s 

test at 5% probability. The data showed that E. grandis seedlings fertigated once or twice 

weekly, in other words, with more concentrated nutritive solutions, presented lower 

transpiration values. In relation to seedlings of E. urophylla and of E. grandis x E. urophylla, 

fertigation parceling produced no clear effect on transpiration. The E. urophylla seedlings 

fertigated twice weekly presented higher transpiration values while the other treatments were 

similar to each other. Seedlings of E. grandis x E. urophylla produced the lowest transpiration 

values when submitted to lesser and greater fertigation parceling, that is, both more 

concentrated and diluted nutritive solutions yielded statistically similar values. Species 

analysis revealed that all seedlings presented statistically similar results when fertigated 

once per week. The E. grandis seedlings fertigated twice weekly demonstrated the lowest 

transpiration values. Among seedlings submitted to greater parceling (3 and 4 times per 

week) the lowest transpiration values were obtained with E. urophylla. Thus, it is concluded 

that the species transpiration responds differentially to fertigation parceling. 

Key words: fertilization, nursery, physiology, cuttings. 


The transpiration of seedlings is a parameter to evaluate the physiological quality and, 

according to Silva (1998), it can be a good indicator to define the survival of seedlings after 

field planting. According to Inoue & Ribeiro (1988), transpiration is a phenomenon strongly

influenced by environmental conditions, especially by temperature and water vapor 

saturation. Under identical conditions, the differences in transpiration may indicate stomatic 

mechanism with greater or lesser efficiency, leading to the water savings by the plant. 

The efficiency in water use can be understood as an efficient evolutionary mechanism 

by which the plant acquires more elasticity to deal with possible water deficits (LIMA, 1995). 

The tolerance of seedlings of forest species for water deficits is determined by several 

factors and it can be temporarily modified by nutrition and water management. Regarding the 

seedlings of plants in the nursery, the hardening stage, the final period of the production, it is 

of great importance for the adjustment of the plants to field conditions and the way to adapt 

them is based on the application of one or more types of stress. Silva (1998) reports that, in 

the specific case of Brazil, the most important ones are water and nutritional stress. Both 

cause morphological and physiological changes that interfere with the ability to resist to the 

harsh conditions of the field, therefore affecting their quality. 

The hardening of the seedling through the handling of fertilization is based on the 

application of fertigation solutions with low N/K ratio in the range of 1/3 to 1/5 (HIGASHI & 

SILVEIRA, 2004). Increasing the concentration of K fertilization on hardening is due to their 

functions in the plant. The potassium cation is the most abundant cytoplasm and in 

conjunction with the accompanying anion has the largest contribution to the osmotic potential 

of cells and plant tissues (MARSCHNER, 1995), protein synthesis and maintenance of their 

stability, membrane permeability in the control of pH (MALAVOLTA al., 1997), activation of 

many enzymes and transport of sugars in the phloem (COLL et al., 1992), the mechanism of 

opening and closing of stomata (COLL et al., 1992 ; MALAVOLTA et al., 1997), increased 

plant resistance to drought and frost due to the increased water retention (SILVEIRA & 

MALAVOLTA, 2000). 

The levels of potassium, as suggested by some authors, for the nutrient solution 

applied daily as fertigation during the hardening phase are: 220 mg L-1 (SILVEIRA et al., 

2001), 249 mg L-1 (D'AVILA et al., 2011). However, studies are needed to verify the 

influence of fertigation parceling on the hardening of the seedlings. Thus, this study aimed to 

verify the effect of the concentration of potassium in the nutrient solution on the transpiration 

of seedlings in three Eucalyptus species. 


The study was conducted in the Nursery Forestry Seedling Research, Faculty of 

Agronomic Sciences of UNESP, Botucatu, Sao Paulo - Brazil, located at the coordinates 

22º 51' 22'' south latitude and 48° 26' 0'' West longitude, at an altitude of 810m and I Cwa 

type climate, Köppen classification of Wilhelm and average annual rainfall of 1524 mm. The 

experiment was carried out from December to March, 2009. 

The seeds of Eucalyptus grandis were derived from clonal seedling orchard F1 

generation and Eucalyptus urophylla from a seed orchard of F4 generation. The cuttings of 

the hybrid Eucalyptus grandis x Eucalyptus urophylla were purchased from a commercial 

nursery. We used tubes with a volume capacity of 50cm³, filled with commercial substrate, 

decomposed pine bark and expanded vermiculite fertilized with 300 mg of FTE BR 12 

("fritted Trace Elements") per m 3 . 

The seedlings remained for about 40 days in the greenhouse and 15 days in the shade 

house. Subsequently, the seedlings were transferred to a plastic covered greenhouse, where 

fertigation started.

The fertilization growth and hardening were identical for the quantity of fertilizer 

provided, but different in frequency of application, one, two, three or six times a week. Thus 

the experiment consisted of the treatments shown in Table 1. 

The fertilizers used in growing the seedlings were ammonium sulfate (20% N and 24% 

S); monoamoniofosfato (MAP) purified (60% P 2 O 5 and 12% N), potassium nitrate (Krista K © ) 

(45% K 2 O and 12% N), calcium nitrate (15% N and 20% Ca). For fertilization hardening was 

used potassium chloride (60% K 2 O). The fertilization of growth began 58 days after sowing or 

staking and remained for a period of 30 days, and the fertilization hardening started on day 

90 with 15-day duration. 

For irrigation, the system used was micro-sprinkling. For the fertirrigation it was used 

the subirrigation system to ensure uniformity of application of nutrient solution. Transpiration 

was obtained by the method of weighing as described by Silva (2003). 

Table 1. Concentration of fertilizer in nutrient solutions for different treatments. 

Treatments 

Fertilization growth 

(mg L -1 ) 

Fertilization 

hardening (mg L -1 ) 

N P K Ca S K 

F1 1560.0 420.0 1080.0 1020.0 507.0 600.0 

F2 780.0 210.0 540.0 510.0 253.5 300.0 

F3 520.0 140.0 360.0 340.0 169.0 200.0 

F6 260.0 70.0 180.0 170.0 84.5 100.0 

F1, F2, F3 and F6: fertigation one, two, three and six times a week, respectively. 

The experimental design was completely randomized, with four treatments, consisting 

of five plots of 48 plants each and three central plants of each plot considered useful for 

assessments, amounting to 15 plants per treatment. The results were submitted to variance 

analysis technique. For significant effects were tested medium, by the Tukey test at 5% 

probability. 

3. Results e discussion 

The species responded differently depending on the fertigation parceling (Table 2). For 

Eucalyptus grandis the lowest values of transpiration were obtained when more concentrated 

nutrient solutions (F1 and F2) were applied. Although statistically it was similar to the 

treatment with a more dilute solution applied six times a week (F4). Eucalyptus uropyhlla had 

an inverse to E. grandis, ie, the lowest values of transpiration were observed in plants 

fertigated with more dilute solutions (F3 and F4). Although it did not differ statistically from 

seedlings fertigated with the more concentrated solution (F1). Clonal seedlings E.grandis x 

E.urophylla, the lowest values of transpiration were found in extreme treatments, ie, in 

fertigated seedlings in solutions of lower and higher concentration (F1 and F4). The 

seedlings of the F2 and F3 treatments were similar and showed the highest water loss by 

transpiration. 

When comparing each species in a nutrient solution it was observed that when the 

plants were fertigated once a week, ie with more concentrated solution (F1), transpiration 

values were similar for all. In the treatment F2, the species with lowest transpiration was E. 

grandis, but it did not differ from clone E. grandis x E. urophylla, which in turn was similar to 

E. urophylla. In the treatment F3 E. urophylla had the lowest transpiration, and the E.grandis 

and the hybrid being statistically similar. With the treatment with the most diluted

concentration (F4), the E.urophylla showed the lesser transpiration followed by E. grandis x 

E. urophylla and E. grandis. 

Teixeira et al. (1995) also found differences between species, whereas the highest 

content of potassium in the nutrient solution increased the efficiency of water use more 

acutely in E. citriodora and E. camaldulensis. These species, when fertilized with low 

potassium content, were less efficient than E. tereticornis, E. saligna, E. urophylla and E. 

grandis. However, when fertilized with the highest dose of potassium they were more 

efficient. Therefore, for E. citriodora and E. camaldulensis higher doses of K are needed so 

that these species may have more efficient use of water. E. saligna presented a contrary 

behavior, as increased sweating when observed when applied with larger doses of 

potassium. 

Considering the mean values for each species, it appears that the three species were 

very similar with 9.1, 9.1 and 9.2 mg m -2 s -1 , respectively for E. grandis, and E.urophylla and 

E.grandis x E.urophylla. 

Silva et al. (2004) observed that for the seedlings of E. grandis subjected to high water 

stress (water potential of -1.5 MPa in the substrate), potassium had little effect in reducing 

transpiration. Whereas in the seedlings without stress (water potential of -0.01 MPa in the 

substrate) potassium was important to reduce water loss. Therefore, the impossibility of 

applying water stress to the plant, potassium is crucial for hardening. 

Teixeira et al. (2008) found that K deficient plants showed high transpiration and 

stomatal conductance and, in general, the maintenance of the open stomata plants that did 

not receive the K (thus allowing high exchange with the atmosphere of CO 2 ) was not 

sufficient to increase the photosynthesis. 

Table 2. Transpiration (mg m -2 s -1 ) of Eucalyptus grandis, Eucalyptus urophylla e E.grandis x. 

E.urophylla (E. urograndis) seedlings at final production process in the summer. 

Treatments 

Species 

E. grandis E.urophylla E. urograndis CV(%) 

F1 7.93 a B 9.20 aB 7.70 aC 15.5 

F2 8.59 bB 11.40 aA 10.10 abAB 15.1 

F3 10.41 aA 8.12 bB 10.61 aA 14.0 

F4 9.44 aAB 7.80 bB 8.39 abBC 12.1 

C.V. (%) 14.4 13.0 17.8 

- Means followed by same lowercase letters in the same row and uppercase letters in the 

same column do not differ by the Tukey Test at the 5% level of significance, CV = coefficient 

of variation, F1, F2, F3 and F6: fertigation one, two, three and six times a week, respectively. 


It can be concluded that for each type of Eucalyptus there is a need to differentiate 

fertigation management in order to obtain more hardened seedlings. 

Acknowledgements: This work was supported by CAPES (Coordenação de 

Aperfeiçoamento de Pessoal de Nível Superior), a Brazilian Government Agencies. 

References

Cool, J. B., Rodrigo, G. N., García, B. S., Tamés, R. S. (1992). Relaciones hídricas y 

nutrición. In: _. Fisiología Vegetal. 6.ed. (pp.59-167). Madrid: Ediciones Pirámide. 

Coopman, R.E. et al. (2008). Changes in morpho-physiological attributes of Eucalyptus 

globulus plants in response to different drought hardening treatments. Electronic Journal of 

Biotechnology, 11, 1-10. 

D’avila, F.S., et.al. (2001). Effect of potassium on the hardening phase of clonal seedlings of 

eucalypt. Revista Árvore, 35, 13-19. 

Higashi, E. N. & Silveira, R. L. A. Fertigation in nurseries of seedlings Eucalyptus and Pinus. 

In: Boaretto, A. E.; Villas-Boas, R. L.; Souza, W. F. & Parras, L. R. V. (Eds.) 1ed. 

Fertirrigação: teoria e prática.(pp. 677-725), Piracicaba : CD-ROM. 

Inoue, M.T. & Ribeiro, F.A. (1988). Photosynthesis and transpiration of clones of Eucalyptus 

grandis and E. saligna. Revista do IPEF, 40, p.15-20. 

Lima, W. P. (1995). Impactos da cultura do eucalipto. Revista Silvicultura, 64, 32-38. 

Malavolta, E., Vitti, G.C. & Oliveira, S.A. (1997) Avaliação do estado nutricional das plantas: 

princípios e aplicações. 2.ed. Potafós: Piracicaba (pp.55-105). 

Marschner, H. Functions of mineral nutrients: macronutrients. In: _. Mineral nutrition of 

higher plants. 2.ed. US: Academic Press: San Diego –, 1995. p.229-312. 

Silva, M. R. (1998). Characterization morphological, physiological and nutritional of seedlings 

Eucalyptus grandis Hill ex.Maiden submitted to different levels of water stress during the 

hardening. Dissertation (Master of Forestry) - Division of Agricultural Sciences, Federal 

University of Parana, Curitiba, 105p. 

Silva, M. R. (2003). Effects of water management and potassium application on the quality of 

seedlings of Eucalyptus grandis W. (Hill ex. Maiden). Thesis (Doutorado em Agronomia / 

Irrigação e Drenagem) - Universidade Estadual Paulista, Botucatu, 100p. 

Silva, M. R.; Klar, A.E. & Passos, J.R. (2004). Effects of water management and potassium 

application on the morphophysiological characteristics of seedlings of Eucalyptus grandis W. 

(Hill ex. Maiden). Revista Irriga, 9, 31-40. 

Silveira, R.L.V.A. & Malavolta, E. (2000). Nutrição e adubação potássica em Eucalyptus. 

Potafos: Piracicaba. 12 p. (Informações Agronômicas, 91). 

Silveira, R.L.V.A., Higashi, E.N., Sgarbi, F.& Muniz, M.R.A. (2001). Seja o doutor do seu 

eucalipto. Potafos: Piracicaba. 32p. (Arquivo do Agrônomo, 12). 

Teixeira, P.C.; Leal, P.G.L., Barros, N.F. & Novais R.F. (1995). Nutrición potásica y 

relaciones hídricas en plantas de Eucalyptus spp. Bosque,16, 61-68.

Teixeira, P. C., Gonçalves, J. L. M., Arthur Junior, J. C. & Dezordi, C. (2008). Eucalyptus sp. 

seedling response to potassium fertilization and soil water. Ciência Florestal, 18, 47-63.

Abstract 

Agriculture and water sources protection zones 

Petra Oppeltová 

MENDELU, Zemdlská 1,Brno, 613 00, Czech Republic. 

E-mail: oppeltova@mendelu.cz 

The question of contamination and protection of water source is a theme of great importance. 

Most drinking water is obtained from surface and ground water resources in the Czech 

Republic. For drinking water quality and quantity protection, it is necessary to establish 

protection zones. 

The area of interest is located in the South Moravia Region at the confluence of Jihlava, 

Oslava and Rokytná rivers. Ivanice spring area comprises a series of hydrologic boreholes - 

it is the main water source for water supply of Ivanice and Rosice cities and provides water 

for 30 000 inhabitants. The risk analysis was created on the basis of water quality monitoring, 

hydrogeological assessment and terrain exploration and revision of protection zones was 

proposed. The spring area is situated in nitrate vulnerable zones and recently nitrate 

concentrations have been decreasing. Water quality evaluation results: high concentration of 

manganese and iron, sometimes higher concentration of ammonium and COD. This area is 

intensively used for agriculture and it was necessary to make a compromise solution during 

protection zones proposal. The regime in protections zones can’t affect manganese and iron 

concentration (their origin is in the natural geological environment). Therefore, water 

treatment plant is in operation and its modernization is proposed. Further the paper deals 

with spring area intensification – construction of new hydrologic borehole and managed and 

unmanaged infiltration of surface water. The proposal of protection zones revision consists of 

reduction to 2nd level protection zone. 

Key words: water quality, ground water source of drinking water, good agricultural practice, 

nitrate vulnerable zones, Czech Republic 


1.1. European and Czech legislation 

There have been numerous changes regarding legislative framework for water during the last 

years. One of the reasons for these changes was the Czech Republic entering the European 

Union in 2004. The most important European Directives transposed to the national 

legislation are: Directive 2000/60/EC and Directive 91/676/EC. 

Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 

establishing a framework for Community action in the field of water policy (Water Framework 

Directive). By this Water Framework Directive, the European Union organizes management 

of surface water, continental water, transitional waters, coastal waters and groundwater in 

order to prevent and reduce its pollution, promote sustainable water use, protect and 

enhance the status of aquatic ecosystems and reduce the effects of floods and droughts 

(http://www.directivamarco.es/). Its fundamental principles are: 

• hygrographic basin as the management unit which corresponds to the unit with 

natural hydrological cycle. 

• cost recovery in the price of water that includes externalities. 

• achievement of good eco-biological, hydromorphological and physical-quimical 

status. 

• water and aquatic ecosystems recovery as a best guarantee of water quantity and 

quality – ecological aspect for sustainable water use.

• reduction of groundwater pollution and elimination of dangerous substances at 

source; 

According to this Directive, all bodies of water used for the abstraction of water intended for 

human consumption providing more than 10 m 3 a day as an average or serving more than 50 

person (http://www.directivamarco.es/) must be identified. 

The principles of the Water Framework Directive were adopted into Czech legislation by 

amending the Water Law 20/2004 Sb. (which came into force on January 23, 2004) and into 

the Drainage, sewers and public water supply law 274/2001 Sb. 

Another very important European legislation is the Directive 91/676/EC – referring to 

protection of waters against pollution by nitrate from agricultural sources. Its principles were 

adopted into Czech legislation in the Regulation 103/2003 Sb. and its amendment. According 

to this Directive, nitrate vulnerable zones are areas where surface waters or ground waters 

have nitrate concentrations of more than 50 mg.l -1 or are thought to be at risk of nitrate 

contamination. The purpose of this Directive is to protect water quality by preventing high 

nitrate concentrations polluting ground and surface waters and especially by reducing 

polluting effects of the intensive cultivation and reducing the use of chemical fertilizers. It also 

includes regulations for waste water treatment and good agricultural practice, such as 

nitrogen fertilizer use and storage, and livestock effluents. Action programmes should be 

implemented by farmers within the nitrate vulnerable zones in order to prevent and reduce 

pollution due to nitrates from agricultural sources and should be revised every 4 years. 

Water protection in the Czech Republic is divided into general, particular and special. The 

general protection is based on various legislative laws relating to the protection of individual 

environment components. It is obligatory for all and without any compensation. The particular 

protection includes CHOPAV, sensitive areas and nitrate vulnerable zones and for 

compliance with farming aren’t also compensation. The special protection includes protection 

zones of water resources. 

Protection zones have been defined in order to protect quality and quantity of drinking water 

sources (Water Law 254/2001 Sb.). Three water protection zones were established by 

previous legislation (level 1 protection zone; level 2 protection zone divided into outer 

protection zone and inner protection zone; and level 3 protection zone defined in surface 

water sources.). In the actual water legislation, only 2 levels of protection zone are defined: 

level 1 protection zone where more severe measures regime exists and level 2 protection 

zones. The actual tendency in water protection consists in determination of protection areas 

more defined, in result of which the water source area and the vulnerable area are not totally 

included in the established protection zone. It is also possible to establish more level 2 

protection zones. It is of great importance, especially for agricultures, to know and observe 

the regulation, especially with respect to the reduction of mineral and organic fertilizers use, 

as well as herbicides and pesticides use. Very often it is also necessary to elaborate special 

programmes for stock breeding prohibiting new constructions, establishment of new sewers 

and the use of chemicals for winter road maintaining within these zones (Oppeltová, Novák, 

2007). 

The owners whose land is within the protection zone receive subsidy to reduce 

disadvantages caused due to limitation they are subjected to. In view of the large initial area 

of protection zones and in view of the fact that the users of water sources did not want to pay 

high price for the subsidy paid to affected owners, new and more reduced protection zones 

have been gradually delimited (Oppeltová, Novák, 2007). 

1.2. Spring area Ivanice 

The area of interest is located in the South Moravia Region at the confluence of Jihlava, 

Oslava and Rokytná rivers. Ivanice spring area comprises a series of nine hydrologic 

boreholes - it is the main water source for water supply of Ivanice and Rosice cities and 

provides water for 30 000 inhabitants.

In 1985 and 1986 hygienic protection zones were established. Level 1 hygienic protection 

zone is common for all nine hydrologic boreholes (13,5 ha) and level 2 hygienic protection 

zone divided into outer protection zone (827 ha) and inner protection zone (57,8 ha). The 

whole Level 1 hygienic protection zone is fenced and there are permanent grasslands. The 

area of level 2 hygienic protection zone is agricultural and forestry used and there are 

municipalities although. The spring area is situated in nitrate vulnerable zones. 

2. Material and Methods 

The data on water quality and the reservoir flow values have been obtained from 

VODÁRENSKÁ AKCIOVÁ SPOLENOST, a.s., which operates the water supply. 

The following parameters were evaluated: iron, manganese, sulphates, chloride, nitrates, 

ammonia, DQO – permanganate, pH, cuprum, lead, cadmium, clostridium perfringens, 

thermotolerant bacteria, Enterococcus bacterias and Escherichia coli, 

The risk analysis was created on the basis of water quality monitoring, hydrogeological 

assessment and terrain exploration and revision of protection zones was proposed. 

3. Results 

3.1. Water quality evaluation 

Raw water complies with requirements for drinking water quality in most chemical, physical, 

microbiological, biological and radiological indicators. Between problematic indicators 

belongs manganese (the limit for drinking water is 0,05 mg.l -1 , but if the manganese 

concentration in groundwater has the origin in the natural geological environment, the limit is 

0,2 mg.l -1 ) and iron (the limit for drinking water is 0,2 mg.l -1 , but if the iron concentration in 

groundwater has the origin in the natural geological environment, the limit is 0,5 mg.l -1 ). The 

concentration limit of manganese and iron was exceeded in most boreholes at each analysis. 

Hydrogeological assessments confirm the natural origin of manganese and iron pollution. 

The regime in protections zones can’t affect high concentration of manganese (up to 2 mg.l -1 ) 

and iron (2 – 7 mg.l -1 ) because their origin is in the natural geological environment. The 

manganese and iron concentration is reduced in water treatment plant and after the 

treatment the values already comply Regulation No. 252/2004 Coll. for drinking water, as 

amended. Similarly with microbiological indicators - water disinfection is taking place in water 

treatment plant and in treated drinking water there aren’t free microorganisms. In three 

boreholes (marked HV 1, HV 2, HV 4) a high concentration of ammonium - up to 1 mg.l -1 - 

was regularly detected. For the future, it is recommended not to use these boreholes and to 

eliminate them gradually. 

In 2006 temporarily increased chloride, sulphate and COD concentrations. This could be the 

floods consequence that had been there in March 2006 and it was the exceptional condition. 

The agriculture in arable land surround the spring area could be an important source of the 

diffuse pollution. The processed results of drinking water samples show that in the last five 

years the maximum nitrate limit has not been exceeded. At present, agricultural management 

relies on the Nitrates Directive and it is necessary to respect the Action Programme 

principles of this Directive. 

Ground water in the spring area is subsidised by infiltration from the alluvial plain of Jihlava 

river and depends on precipitation distribution in the upper parts of the catchment. The spring 

area is located in the meadow and its surrounding is agricultural and forestry used. The 

nearest built-up area is located approximately 500 m from the spring area and the houses 

are connected to the waste water treatment plant. 

The old cow house is situated in the area of origin hygienic protection zone - level 2 - but 

currently is not operating. This object is used by small companies that don’t affect the water 

quality or quantity in the spring area. 

Former black dump consisted of building debris and excavated soil could be the potential 

source of drinking water contamination. There may be indefinite amounts of unknown 

harmful substances. Currently, the dump is covered and the old grass covers its surface. For

now, the influence of the dump on the water quality in the spring area has not been found. 

Due to ignorance of the exact dump composition, in order to protect the water sources it is 

necessary to include the dump in to the proposed protection zone of second level. In the 

future, it is possible to build several monitoring boreholes in the direction of groundwater 

flow. 

3.2. Protection zones propose 

The risk analysis was created on the basis of water quality monitoring, hydrogeological 

assessment and terrain exploration and revision of protection zones was proposed. Original 

hygienic protection zones were cancelled and new protection zones were established (Fig.1). 

Level 1 protection zone 

Level 1 hyg. protect. zone 

Level 2 protection zone 

Level 2 hygienic protection 

zone - inner 

Level 2 hygienic protection 

zone - outer 

M 1:10 000 

FIGURE 1: New protection zone and original hygienic protection zone 

Level 1 protection zone extension is the same like original level 1 hygienic protection zone 

(13,5 ha) and forms the immediate surroundings of collecting boreholes (Fig. 1). There are 

eight hydrologic boreholes (marked HV 1, HV 2, HV 4, HV 3, HV 7, St 1, S VII, HV 101), one 

collection well and water treatment plant in the level 1 protection zone. The entrance to the 

level 1 protection zone is restricted by fencing and protected against entry of foreign persons, 

and marked with warning boards. In three boreholes (marked HV 1, HV 2, HV 4) high 

concentrations of ammonium - up to 1 mg.l -1 - were regularly detected. It is recommended in 

the regime in protected zones not to use these boreholes and to eliminate them gradually. 

Water supply operator must regularly monitor the physico-chemical and microbiological 

parameters in all boreholes. In level 1 protection zone it is prohibited to carry out any 

activities not related to captation, transport, treatment and accumulation of ground water and 

not related to the maintenance of the surface and vegetation or technical support of the

spring area. It is also prohibited to build dumps, apply fertilizers and pesticides, pursue the 

pasture and drive with motor vehicles. It is necessary to cut the grass regularly and to 

remove it form protection zone. 

The extension of level 2 protection zone will be significantly reduced compared with the 

original level 2 hygienic protection zone (Fig. 1). The area of interest is located in nitrate 

vulnerable zones and the farmers must comply the regime according to the Nitrates Directive 

and good agricultural practice: 

• comply periods when the land application of fertilizer is inappropriate; 

• the land application of fertilizer to steeply sloping ground; 

• the land application of fertilizer to water-saturated, flooded, frozen or snow-covered 

ground; 

• the conditions for land application of fertilizer near water courses; 

• the capacity and construction of storage vessels for livestock manures, including 

measures to prevent water pollution by run-off and seepage into the groundwater and 

surface water of liquids containing livestock manures and effluents from stored plant 

materials such as silage; 

• procedures for the land application, including rate and uniformity of spreading, of both 

chemical fertilizer and livestock manure, that will maintain nutrient losses to water at 

an acceptable level. 

(http://ec.europa.eu/environment/water/water-nitrates/directiv.html) 

In the case of observe all conditions in nitrate vulnerable zones it isn’t necessary to include 

such a large territory to the level 2 protection zones and propose other special regime. Also 

the processed results of drinking water samples shows that in the last five years the 

maximum nitrate limit has not been exceeded. On the contrary, the black dump is included to 

the level 2 protection zone and this area must be regularly monitored. In level 2 protection 

zone is prohibited: 

• carry out large grading without previous hydrogeologists permission; 

• permit other collection objects for commercial purposes; 

• construct a waste dump, industrial and agricultural buildings and use the chemical 

road salting. 

It is possible to determine other level 2 protection zones in the case of water quality 

deterioration. Compliance with the Nitrates Directive conditions is required by law and there 

is no possibility to pay any compensation. The proposed conditions in protected zone aren’t 

although subject to refunds. 

3.3. Spring area intenzificacion 

In the future, the development and construction of residences is expected in the area of 

interest. At present, this trend is limited by the deficiency of water sources. The permitted 

ground water intake from the spring area is 30,9 l.s -1 . Another proposed project which deals 

with the intensification of spring area Ivanice is proposed. The owner and the operator of 

the water supply deal with this project. The aim is to obtain a subsides from European funds 

for the realization. The project substance is continue to use perspective intake objects (HV 3, 

HV 7, St 1, S VII, HV 101) and their yield increase by managed and unmanaged infiltration of 

surface water. 

The proposal of unmanaged infiltration: the movable weir is constructed in Jihlava river near 

the spring area, and it is possible to manipulate the water level in the river and subsequently 

groundwater level in the surrounding. The collection drain will be constructed around the 

spring area to the depth of groundwater level (affected by the weir in the river). 

The proposal of managed infiltration: two lagoons will be constructed near the spring area 

and the water from the river will be pumping there. The water in the lagoons will gradually 

infiltrate and enrich the ground water. In case of high contamination of surface water in the

iver, the surface water will be pumped to the pre-treatment plant, which will be constructed 

during treatment plant modernization. 

Spring area intensification is also related to the water treatment plant intensification - a 

capacity increase about 30 l.s -1 . Existing technology - single-stage filtration and ozone 

oxidation, will be preserved. 

Conclusions 

Agriculture and water supply belongs to the important landscape functions and during 

protection zones revision it was necessary to work closely together and create a compromise 

solution. 

The farmers have to comply with the Nitrates Directive conditions and no other measures in 

protection zones were necessary to propose. The cooperation between water managers, 

farmers and government control authorities is the current tendency when the protection 

zones are proposing. 

New level 2 protection zone is smaller than the original level 2 hygienic protection zone. 

Water supply operator must regularly monitor the physico-chemical and microbiological 

parameters in all boreholes. 

It is possible to determine other level 2 protection zones or more restrictive regime in the 

case of water quality deterioration. Currently, in the spring area we can find all types of water 

protection measures - preventive, technical and technological measures. Protection zones 

represent the preventive measures. Selection of perspective intake objects and the infiltration 

represent the technical measures and water treatment plant modernization and pre-treatment 

processes of surface water given up to infiltration represent the technological measures. 

Acknowledgements 

This work was created in the project QJ1230056 - The impact of the expected climate 

changes on soils of the Czech Republic and the evaluation of their productive functions. 

References 

Directiva Marco [online], [cit. 2012-02-10]. . 

Implementation of nitrates Directive. [online], [cit. 2012-03-12]. 

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Oppeltová, P., Novák, J. (2007). Zhodnocení problematiky ochrany vodních zdroj v R 

v období posledních let z pohledu právního i provozního (Evaluation of problematics of 

drinking water sources protection in the Czech Republic in terms of law). In Zborník 

prednášok z X. konferencie s medzinárodnou úasou Pitná voda 2007. Bratislava - REPRO 

PRINT, Bratislava, Slovaquia, 2007, pp. 63 - 70 (in Czech). 

Pitter, P. (2008). Hydrochemie (Hydrochemistry). VŠCHT Praga. ISBN 978-80-7080-701-9 

(in Czech). 

Vyhláška 103/2003 Sb. (National regulation 103/2003 Sb. On protection of waters against 

pollution by nitrate from agricultural sources ) (in Czech) 

Vyhláška MZDR R . 252/2004 Sb., kterou se stanoví hygienické požadavky na pitnou a 

teplou vodu a etnost a rozsah kontroly pitné vody (National Regulation 252/2004 Sb. On 

drinking water parameters and quality coontrol) (in Czech). 

Zákon . 254/2001 Sb. (Water Law 254/2001 Sb.) (in Czech). 

Zákon . 274/2001 Sb. o vodovodech a kanalizacích pro veejnou potebu v platném znní 

(Drainage, sewers and public water supply law 274/2001 Sb.) (in Czech).

Biological Nitrogen Fixation In Genotypes of Cowpea Under Salt 

Stress Increasing the State of Paraíba, Brazil 

Ronaldo do Nascimento 1* , Jailma R. de Andrade 2 , Francisco V. da Silva 3 , Aryadne 

Ellen V. de Alencar 4 , Daniele F. de Melo 4 , José Wilson Barbosa 2 

1 Teacher Associate of Academic Unit of Agricultural Engineering, CTRN / UFCG, Av Aprígio 

Veloso, 882, University District, Campina Grande, Paraíba, 58429-140, Brazil. 

2 Graduate in Agricultural Sciences, Ms in Agricultural Engineering, Academic Unit of 

Agricultural Engineering, CTRN / UFCG. 

3 Agronomist Engineer, PhD, Academic Unit of Agricultural Engineering, CTRN / UFCG. 

4 Graduate in Agricultural Engineering, Academic Unit of Agricultural Engineering, CTRN / UFCG. 

*Corresponding author. E-mail: ronaldo@deag.ufcg.edu.br 

Abstract 

The symbiosis between legumes and rhizobia can supply most or all of the nitrogen needed 

for growth and productivity of plant species. However, for this to occur satisfactorily, the plant 

must be effectively nodulated by bacteria. Nodulation is dependent on a number of factors 

involving the plant, bacteria and soil and the interaction of the three. The combined action of 

these factors may limit or stimulate nodulation, which will be reflected in the amount of fixed 

atmospheric nitrogen and productivity of the legume. Among the main environmental factors 

that affect the potential of biological nitrogen fixation in the northeast region of Brazil, there is 

the salinity of the soil, considering the use of low quality water and high evaporation due to 

climate conditions in the region. The objective of the research was to evaluate the potential 

for biological nitrogen fixation (BNF) for different cultivars of cowpea under conditions of 

increasing salinity in irrigation water. For this we used polyethylene pots containing neolithic 

regosols eutrophic fertilized as recommended for cultivation in specific vessels, except 

nitrogen, and protected environment. We used a completely randomized design in a 4x5 

factorial (salinity x genotype), with four repetitions. Treatments consisted of four levels of 

salinity of irrigation water (1.5, 3.0, 4.5 and 6.0 dS m -1 ) and genotypes (G) were used (G1) 

MNCO1-649F-1-3, (G2) BRS-Juruá, (G3) MNCO2-675F-4-9, (G4) MNCO3-736F-7 e (G5) 

MNCO2-684F-5-6, inoculated with rhizobium strain BR-3267, specially developed in Brazil 

for symbiosis this species legume. The FBN was estimated through the SPAD readings of 

the index and weight of the dry mass of nodules, 40 days after emergence (DAE). Analysis of 

variance showed that there were significant for levels of salinity on the parameters. 

Regression analysis showed a negative linear response for dry weight of nodules and SPAD 

index, which was negatively affected by salinity levels of irrigation water, showing a 

sensitivity of the symbiosis to salt stress. 

Key words: cowpea, salinity, nitrogen, nodulation. 


The cowpea constitutes the main subsistence crop in the north and northeast of Brazil, 

especially in the semiarid northeast. Irrigation is one of the technologies applied in agriculture 

that has most contributed to the increase in food production, however this practice should be 

used rationally, since the weather conditions in the northeast (high temperatures, low rainfall 

and high levels of salts in irrigation water), have caused problems of salinity in soils. The 

salinity of the soil is particularly important in semi-arid regions, in order to lower the 

precipitation rate and high evaporation. Most crop species subjected to salinity have reduced 

growth and metabolism affected (Lima et al., 1997). The growing need to increase food 

production, has significantly increased the expansion of cultivated areas, but this quest does 

not take into account only the expansion of agricultural areas, but also considered the use of

waters of inferior quality, and reuse drainage water with high salt contents and use of species 

able to produce high yields when irrigated with these types of water (Rhoades et al., 2000). 

The salinity tolerance is the ability of plants to maintain growth and metabolism remain 

unchanged, as photosynthesis depending on the content of chlorophyll in conditions of 

stress, so that the crop tolerant species presents itself as a viable choice for reuse of saline 

areas. Among the various processes affected by salinity, the reduction of photosynthesis is 

widely reported in the literature (Netondo et al., 2004a, 2004b; Praxedes et al., 2010; Silva et 

al., 2011) and has been attributed to stomatal limitations of origin and non-stomatal (Netondo 

et al., 2004b; Munns & Tester, 2008; Praxedes et al., 2010). According to FAO data, the 

cowpea tolerates irrigation with saline water with electrical conductivity of 3.3 dSm -1 (Ayers & 

Westcot, 1999). The objective of this study was to estimate the effect of increasing salinity of 

irrigation water on the chlorophyll content and nodulation of different genotypes of cowpea. 


The experiment was conducted in a greenhouse of the Federal University of Campina 

Grande (UFCG), on the premises of UFCG, Center for Technology and Natural Resources 

(CTRN), Academic Unit of Agricultural Engineering (UAEA), Brazil. The UFCG is located in 

central eastern state of Paraíba, in the Borborema Plateau, whose geographic coordinates 

are latitude 7 ° 13'11'', longitude 35 º 53'31'' west and altitude of 547.56 m (FIGURE 1). 

According to the National Institute of Meteorology (INMET), the city has an annual rainfall of 

802.7 mm, maximum temperature of 27.5 ° C, minimum 19.2 ° C and relative humidity of 83%. 

FIGURE 1: Aerial view of UFCG. Local greenhouse in focus.

We used a completely randomized in a factorial 5x4 (genotypes and salinity levels), with four 

replications. The treatments consisted of different levels of salinity of irrigation water (1.5, 

3.0, 4.5 and 6.0 dSm -1 ), each experimental unit was represented by one plant / pot, with a 

capacity of 1,5 kg soil Regossoil Neolithic eutrophic, fertilized according Novais et al. (1991). 

Were sown in each pot, three seeds, leaving only one plant per pot after thinning, which 

occurred five days after emergence (DAE). The genotypes (G) used in this experiment were: 

G1 (MNC01-649F-1-3), G2 (BRS-Juruá), G3 (-675F-MNC02 4-9), G4 (MNC03-736F-7) and 

G5 (MNC02-684F-5-6), assigned by Embrapa Mid-North, Center for reference in research 

with the improvement of cowpea, and production of new cultivars, located in the city of 

Teresina, Piauí State, and specially developed for cultivation in the climatic conditions 

prevailing in the semi-arid northeastern Brazil. The seeds were inoculated with rizobia strain 

BR-3267, especially developed in Brazil for symbiosis with this legume species. Irrigation 

was performed daily with water from the supply network's campus UFCG, to be pruned, if 

from this, the water used for irrigation had different levels of salinity, according to the 

treatments. Salinity levels evaluated were obtained by mixing the salts Ca, Na and Mg. The 

biological nitrogen fixation (BNF) was estimated through the SPAD readings of the index, 

using a chlorophyll meter SPAD-502 Minolta, the second fully expanded leaf from the apex to 

the base plant, and dry weight of nodules. Data were analyzed by F test and regression 

models adjusted with the regression coefficient. 


SPAD index in variable interaction between genotypes and salinity levels had no significant 

effect (FIGURE 2), significant effect (p

FIGURE 3: SPAD index in cowpea as a function of salinity of irrigation water. Campina 

Grande, Paraíba, Brazil, 2012. 

irrigation, where saline stress showed influence on the accumulation of chlorophyll in the 

leaves. According to these authors, the levels of biochemical constituents of the leaves as 

photosynthetic pigments, are reduced by salinity, and this effect is compounded by the length 

and level of exposure to stress condition. In response to conditions of high soil salinity, the 

plants develop various physiological and biochemical alterations (Munns & Tester, 2008). In 

plants subjected to salinity decreases in chlorophyll concentration can be attributed to 

increased activity of the enzyme that degrades the chlorophyll chlorophyllase (Sharma & 

Hall, 1991). Campbell et al. (2008) showed that the increase in the salinity significantly 

reduced levels of chlorophyll a, b and total. Under which of the biochemical point of view, 

observed reductions in chlorophyll content in plants under salt stress, appear to be related to 

reduced ability of plants to synthesize or further degradation of pigments. 

The number of nodules of all genotypes of cowpea plants submitted to increasing levels of 

salinity of irrigation water, was adversely affected, the largest decrease in the order of 75% 

and observed for genotype MNC01-649F-1-3 (data not shown). According to other authors, 

the effect of salt on nodulation varies depending on the host legume species (Cordovilla et 

al., 1999). In studies with pea and bean, Bohlool & Singleton, (1984) evaluated the effect of 

salt stress on nodulation and plant growth and observed that there was an inhibition of 

nodulation in both species. However, according to the authors, the pea had a higher 

sensitivity to salt stress than the beans. Previously, Singleton & Bohlool, (1984) evaluated 

the nodulation of soybean under different salinity levels and observed that the plants were 

sensitive to increasing salinity levels. 


No significant interaction between factors and between both genotypes, however there was a 

decrease in the values obtained in response to increasing salinity of irrigation water. Salt 

stress caused a decrease in pigmentation of the leaves and nodulation of cowpea.

5. References 

AYERS, R.S.; WESTCOT, D.W. Water quality for agriculture. Campina Grande, UFPB, 1999. 153p. 

CAMARGO, P.M.P.; COSTA, R.C.; BARRETO, A.G.T.; NETO, C.F.O.; CRUZ, F.J.R. 2008. 

Mechanisms of salt tolerance related to nitrogen metabolism in plants and osmotic 

adjustments sorghum (Sorghum bicolor (L.) Moench). VI Seminar on Scientific 

Initiation/UFRA and XII Seminary of Scientific Initiation of EMBRAPA. 

CORDOVILLA, M.D.P. LIGERO, F.; LLUCH, C. Effects of NaCl on growth and nitrogen 

fixation and assimilation of inoculated and KNO 3 fertilized Vicia faba L. and Pisum sativum L. 

plants. Plant Science, v.140, p. 127–136, 1999. 

LIMA, G.P.P.; ROSSI, C.; HAKVOORT, D.M.R. 1997. Activity of peroxidases (EC 1.11.1.7) 

and proline content in the embryo and cotyledons of common bean Phaseolus vulgaris L. 

grown under conditions of high salinity. Scientia. Agriculture, vol. 54, p.123-127. 

MUNNS, R.; TESTER, M. Mechanisms of salinity tolerance. Annual Review of Plant Biology, 

v.59, p.651-681, 2008. 

NETO, A.D.A. Salt stress, oxidative stress and cross-tolerance in corn. In: Environmental 

Stresses: Damage and benefits in plants. WALNUT, R.M.C.; Araujo E.L.; WILLADINO, L.G. 

et al. (Eds.) Recife: UFRPE, University Press, 2005. 500 p. 

NETONDO, G.W.; ONYANGO, J.C.; BECK, E. Sorghum and salinity: I. Response of growth, 

water relations, and ion accumulation to NaCl salinity. Crop Science, v.44, p.797-805, 2004a. 

NETONDO, G.W.; ONYANGO, J.C.; BECK, E. Sorghum and salinity: II. Gas exchange and 

chlorophyll fluorescence of sorghum under salt stress. Crop Science, v.44, p.806-811, 

2004b. 

NOVAIS, R.J.; NEVES, J.C.L.; BARROS, N.F. Testing in a controlled environment. In: 

Oliveira, AJ.; GARRIDO, WE, Araújo, JD, LORENZO, L. Research methods in soil fertility. 

Brasilia: Embrapa, p.189-254, 1991. 

PRAXEDES, S.C.; LACERDA, C.F. de; DAMATTA, F.M.; PRISCO, J.T.; GOMES-FILHO, E. 

Salt tolerance is associated with differences in ion accumulation, biomass allocation and 

photosynthesis in cowpea cultivars. Journal of Agronomy and Crop Science, v.196, p.193- 

204, 2010. 

RHOADES, J.P.; KANDIAH, A.; MASHALI, A.M. Use of saline water in agricultural 

production. Campina Grande: UFPB, 2000. 117p. 

SHARMA, P.K.; HALL, D.O. 1991. Interaction of salt stress and photoinhibition on 

photosynthesis in barley and sorghun. Journal of Plant Physiology, v.138, n.5, p.614-619. 

SILVA, E.N. da; RIBEIRO, R.V.; FERREIRA-SILVA, S.L.; VIÉGAS, R.A.; SILVEIRA, J.A.G. 

Salt stress induced damages onthe photosynthesis of physic nut young plants. Scientia 

Agricola,v.68, p.62-68, 2011. 

SINGLETON, P. W.; BOHLOOL, B. B. Effect of salinity on nodule formation by soybean. 

Plant Physiology, v. 74, p. 72-76, 1984.

ADEQUACY OF THE PENMAN-MONTEITH METHOD TO IRRIGATED 

SURFACE WITH DIFFERENT EXPOSURES AND DECLIVITY 

José Eduardo P. Turco 1* , Adhemar P. Milani 1 , Edemo J. Fernandes 1 

1 Faculdade de Ciências Agrárias e Veterinárias, UNESP - Univ Estadual Paulista, Via de 

acesso Prof. Paulo Donato Castellane, Km 5, Jaboticabal - SP, 14884-900, Brazil. 

* jepturco@fcav.unesp.br 

Abstract 

Among the methods used to estimate reference evapotranspiration (ETo) there are those that 

use as input variable the net radiation for example, the Penman-Monteith formula, widely used in 

project planning of hydric dotation for irrigated crops, which are recommended by FAO and used 

worldwide. Through this study aimed to determine the net radiation on a horizontal grassy 

surface and correlate it with the net radiation on grassy surfaces with different expositions and 

declivities to establish equations that can be used in the reference evapotranspiration estimates, 

considering the positioning of the site measured, for the four seasons of the year, in Jaboticabal- 

SP. The research was developed in a structure called "Experimental Hydrographic Basin", from 

the Department of Rural Engineering, FCAV/UNESP, Jaboticabal Campus, SP. In this structure 

was used 9 surfaces of 10.5 m 2 , being one horizontal, two with northern exposures, two with 

southern exposures, two with eastern exposures and two with western exposures, presenting 

each set two exposures of 10% and 20 % slope. In the experimental area surfaces Bahiagrass 

(Paspalum notatum Flügge) was planted in order to simulate the conventional weather station 

areas. For the determination of the net radiation on the surfaces studied, was installed on each 

surface a net radiometer, Kipp & Zonnen model NRLITE. The analysis of the results were made 

daily, using regression analysis and considering the linear model (y = ax + b), in which the 

dependent variable was the net radiation on the studied surface (Q * s) and the independent 

variable the net radiation at the horizontal surface (Q * H). In this analysis was considered the 

complete model and the one without intercept. It was analyzed the adjustments of the 

regression models, by means of the “t” test, at 1% and 5%. For the fall and the winter the more 

appropriate model for both surfaces with two northern exposition and the two eastern exposition 

and 10% and 20% slope was y = ax + b. In the spring and in the summer the more appropriate 

model for all surfaces was y = ax. 

Keywords: slope, reference evapotranspiration, Penman-Monteith. 

1. Introdution 

The determination of the evapotranspiration is a problem shared by several sciences that 

study the soil-plant-atmosphere system. Due to the necessity of knowing the water loss of 

vegetated surfaces, several researchers have developed methods for estimating 

evapotranspiration. A very used way of obtaining the reference evapotranspiration (ETo) in 

different situations and locations is by means of estimation methods. In 1990, the methods 

recommended by FAO in 1977 (FAO 24) underwent to a review by experts in 

evapotranspiration, which concluded that the Penman-Monteith parameterized method for 

grass with to 12 cm in height, aerodynamic resistance of surface of 70 sm -1 and albedo of 

0.23 showed better results being recommended by FAO as a standard method for estimating 

ETo. In Brazil there are several weather stations being used to manage irrigation by 

determining the ETo estimate by Penman-Monteith method, which is an indirect technique 

that leads in an estimate of the water needs by the plants, since using a culture coefficient. 

The Penman-Monteith formula (Allen et al., 1998) uses as input the net radiation. This 

method uses the solar radiation measured, in most weather stations, for horizontal surfaces.

2 

However, the cultures are not always installed on horizontal surfaces, there are variations in 

both the slope as the exposure field as a function of the solar declination. This fact may lead 

to significant errors in the estimates of evaporation, in order that differences in the radiation 

quantities received by various slopes can be quite high. Therefore, the study of the 

relationship between the radiation incident on horizontal and inclined surfaces is desirable to 

be able to minimize errors in the estimates of evapotranspiration through formulas that use 

this variable as input, with the objective of rationalizing water in agriculture without affecting 

productivity. To determine the radiation balance, when it does not have the necessary 

sensors, it is used the formula recommended by FAO which depends on the measurement of 

various parameters and coefficients that may not be suitable for the study area, occurring 

significant errors in estimated values. For this reason several researches (André & Volpe, 

1988; Marin et al., 2001; Alados et al. 2003; Silva et al. 2007) has sought to correlate the 

radiation balance with the global solar radiation, thus obtaining regression equations with only 

one input variable. Considering that the amount of incident solar radiation varies with the 

exposure and the slope of vegetated surface plots (Chang, 1968), with water in the soil 

sufficient to maintain the vegetation in conditions of maximum evaporation, logically will have 

different evaporation rates at different slopes for a single exposure or in different exposures 

to the same slope or when there is a combination of exhibitions and different slopes, as can 

occur normally in a watershed and often in an agricultural property. Studies were not found in 

the literature that analyzes comparatively the effect of exposure and the slope of vegetated 

surfaces on the balance of solar radiation. This fact seems to be connected to the great 

difficulty to be available, under natural conditions in the same place and with same type of 

soil, areas with equal slopes and varied exhibition and vice versa, that studies with the aim of 

determining the solar radiation balance in these situations can be realized. Research that 

makes possible this amount of information could only be developed on surfaces artificially 

arranged to simulate, in the same place, equal special conditions of soil, exposure and slope, 

and at the same time, maintaining the equality of soil, different conditions of exposure and 

slope. Therefore this study aimed to determine the radiation balance on a horizontal grassy 

surface and correlate it with the radiation balance on grassy surfaces with different 

expositions and declivities to establish equations that can be used in the reference 

evapotranspiration estimates, considering the positioning of the site measured. 


The research was developed in a structure called "Experimental Hydrographic Basin", from 

the Department of Rural Engineering, FCAV/UNESP, Jaboticabal Campus, SP, described 

with details by Turco et al. (1998). In this structure, an experiment was undertaken from 

March 2002 to March 2003, in which surfaces of 10.5 m 2 were used, characterized as H 

(horizontal), 10N (10% of slope and northern exposure), 20N (20% of slope and northern 

exposure), 10S (10% of slope and southern exposure), 20S (20% of slope and southern 

exposure), 10E (10% of slope and eastern exposure), 20E (20% of slope and eastern 

exposure) , 10W (10% of slope and western exposure) and 20W (20% of slope and western 

exposure), that simulates terrain with displays and slope commonly used in agriculture. In the 

experimental area surfaces Bahiagrass (Paspalum notatum Flügge) was planted in order to 

simulate the conventional weather station areas. The amount of water applied to each 

surface was in function of the ETo values obtained by Penman-Monteith method (Allen et al., 

1998), adjusted for each surface. Irrigation was performed in the late afternoon with an 

irrigation frequency of one day. The irrigation on each surface was performed through the 

installation of six hoses 3.5 m long, perforated every 20 cm, in its entire length. For the 

determination of radiation balance on the surface, was installed in the center area of each 

surface, a net radiometer (radiation balance sensor, model NRLITE of Kipp & Zonnen), 

parallel to the surface totalizing nine equipment. The sensor of each area was fixed in an 

aluminum frame, which remained at 1.0 m above the surface. The radiation balance on the 

surface was recorded by a data acquisition system, composed by a Datalogger CR10X, 

brand Campbell Scientific, Inc., being installed a data acquisition system in each basin. The

3 

analysis of the results were made daily, using regression analysis and considering the linear 

model (y = ax + b), in which the dependent variable was the radiation balance on the studied 

surface (Q * s) and the independent variable the radiation balance at the horizontal surface 

(Q * H). In this analysis was considered the complete model and the one without intercept. It 

was analyzed the adjustments of the regression models for the surfaces, by means of the‘t’ 

test, at 1% and 5%. The reference evapotranspiration accumulated on the surfaces studied 

was estimated for the period of March 2011 to March 2012, obtained daily by the Penman- 

Monteith method (Allen et al., 1998), corrected for each surface. The daily reference 

evapotranspiration was calculated by the equation: 

ETo 

( PM ) 

0,409 

 

900 

 

T 273 

1 

0,34 V 

Rn 

G 

 

Ves 

e 

 

where, ETo (PM) = reference evapotranspiration by the Penman-Monteith method, in grass, mm 

d -1 ; Rn = radiation balance on each surface, MJ m -2 day -1 ; G = heat flow in the soil, MJ m -2 day -1 ; 

T = average air temperature, ºC; V =average wind speed at 2 m height, m s -1 ; (e s -e) = vapor 

pressure deficit, kPa; = tangent to the curve of vapor pressure, kPa ºC -1 ; = psychrometric 

constant, kPa ºC -1 and 900 = conversion factor. The psychrometric constant was calculated 

using the Smith equations (1990). 

3. Results 

Tables 1 and 2 are shown the results of the average daily radiation balance (Q *) for the 

surfaces studied in the spring-summer and fall-winter periods. It was found that in the springsummer 

periods the values of the radiation balance to the surfaces were similar. According to 

Marin et al. (2001) the balance of radiation obtained on a vegetated surface represents the 

energy available to the system to perform its physiological functions, especially 

photosynthesis and perspiration, as well to processes for heating the air, the plants and the 

soil. Therefore, in the fall-winter period the surface that showed the highest available energy 

was 20N and the lowest 20S. 

 

(1) 

TABELA 1: Mean values of radiation balance in surfaces studied in the spring-summer 

period (2002-2003). 

Surface Average Q * (MJm -2 dia -1 ) 

H 13.1 

10N 13.6 

10S 13.1 

20N 13.6 

20S 12.7 

10E 13.4 

10W 13.3 

20E 13.1 

20W 13.0

4 

TABEL 2: Mean values of radiation balance in surfaces studied in the fall-winter period 

(2002). 

Surface Average Q * (MJm -2 dia -1 ) 

H 9.4 

10N 11.1 

10S 9.3 

20N 12.2 

20S 8.2 

10E 10.2 

10W 9.8 

20E 10.2 

20W 9.1 

Tables 3 and 4 show, for all surfaces in the spring-summer and autumn-winter period the 

values of the regression coefficients and correlations. According to the result of the‘t’ test, the 

cases where the linear coefficient was not significantly different from zero, they were 

despised and the angular coefficients of the equations estimated again. For the springsummer 

period the regression analysis shows that for all surfaces the linear coefficient (b) 

was not significantly different from zero, being used the model y = a x, where y represents 

radiation balance in the surfaces studied, and the x the balance radiation on the horizontal 

surface. For the spring-summer period the regression analysis shows that for the two 

surfaces with southern exposition and the two with western exposition, 10% and 20% of 

slope, the linear coefficient (b) was not significantly different from zero, being used the model 

y = a x, where y represents radiation balance in the surfaces studied, and the x the balance 

radiation on the horizontal surface. For the other surfaces, the most appropriate model was y 

= ax + b. The relationships presented in this study show that the radiation balance at each 

surface can be satisfactorily estimated from radiation balance on a horizontal surface. 

TABELA 3: Regressions between the daily values of radiation balance in the surfaces 

studied and radiation balance on horizontal surface (spring-summer). 

Regression 

y = a x 

Linear coefficient (b) Angular Coefficient 

(a) 

Correlation 

Coefficient (R 2 ) 

Q * 10N = a Q * H 1.0355 0.9671 

Q * 20N = a Q * H 1.0380 0.9098 

Q * 10S = a Q * H 0.9978 0.0021 

Q * 20S = a Q * H 0.9736 0.9820 

Q * 10E = a Q * H 1.0248 0.9906 

Q * 20E = a Q * H 1.0027 0.9332 

Q * 10W = a Q * H 1.0171 0.9951 

Q * 20W = a Q * H 0.9904 0.9614

accumulated ETo (mm dia -1 ) 

5 

TABELA 4: Regressions between the daily values of radiation balance in the surfaces 

studied and radiation balance on horizontal surface (fall-winter). 

Regression 

y = a x + b 

Linear coefficient (b) Angular Coefficient 

(a) 

Correlation 

Coefficient (R 2 ) 

Q * 10N = a Q * H + b 1.9166 (*) 0.9807 0.9599 

Q * 20N = a Q * H + b 3.4966 (*) 0.9299 0.8863 

Q * 10E = a Q * H + b 0.6142 (*) 1.0225 0.9915 

Q * 20E= a Q * H + b 0.7197 (*) 1.0136 0.9364 

y = a x 

Q * 10S = a Q * H 0.9897 0.9909 

Q * 20S = a Q * H 0.8715 0.9624 

Q * 10W = a Q * H 1.0463 0.9914 

Q * 20W = a Q * H 0.9751 0.9623 

Figures 1 and 2 show the estimation of reference evapotranspiration (ETo) accumulated in 

(mm d -1 ), in the surfaces studied, in the spring-summer and autumn-winter period, 

respectively. Note that the accumulated ETo on surfaces in the spring-summer periods were 

758.6, 781.3, 757.2, 782.9, 741.8, 774.5, 769.6, 760.4 and 752.5 mm, to H, 10N, 10S, 20N, 

20S, 10E, 10W, 20E and 20W, respectively. In the fall-winter period the accumulated Eto 

were 561.9, 643.8, 557.3, 695.8, 504.5, 601.0, 582.6, 602.0 and 550.8 to H, 10N, 10S, 20N, 

20S, 10E, 10W, 20E and 20W and 20W, respectively. The results obtained show the 

importance of such studies, which allow the correction of the Penman-Monteith for surfaces 

with different expositions and slopes. 

900 

800 

700 

600 

500 

400 

300 

200 

100 

0 

H 

spring-summer 

10N 10S 20N 20S 10E 10W 20E 20W 

FIGURA 1: Accumulated ETo on surfaces during spring-summer (2011-2012).

accumulated ETo (mm dia -1 ) 

6 

900 

800 

700 

600 

500 

400 

300 

200 

100 

0 

H 

fall-winter 

10N 10S 20N 20S 10E 10W 20E 20W 

FIGURA 2: Accumulated ETo on surfaces in the fall-winter period (2012). 

4. Conclussions 

The relationship between the radiation balances obtained will enable the correction of the 

Penman-Monteith methods for inclined surfaces, being an essential tool for planning projects of 

water budget of irrigated crops. 

5. References 

Alados, I.; Foyo-Moreno, I.; Olmo, F.J.; Alados-Arboledas, L. 2003. Relationship between net 

radiation and solar radiation for semi-arid shrub-land. Agricultural and Forest Meteorology, 

116, p.221-227. 

Allen, R. G. et al. 1998. Crop evapotranspiration: guidelines for computing crop water 

requirements. Rome: FAO, 300 p. (Irrigation and drainage paper, 56). 

André, R.G.B.; Volpe, C.A. 1988. Estimativa do saldo de radiação em Jaboticabal (SP). 

Revista de Geografia. v.7, p.1-8. 

Chang, J.H. 1968. Climate and agriculture: an ecological survey. Chicago, Aldine Publishing 

Co. 304p. 

Martin, F.R. et al. 2001. Relações entre saldo de radiação de pomar de lima ácida “tahiti”, 

saldo de radiação de gramado e radiação solar global. Revista Argentina de 

Agrometeorologia. Piracicaba, v.1, n.1, p.59-62. 

Silva, L.D.B.da. et al. 2007. Relações do saldo de radiação em grama batatais e capim 

tanzânia com a radiação solar global em Piracicaba, SP. Revista Brasileira de 

Agrometeorologia. v.15, n.3, p.250-256. 

Smith, M. et al. 1990. Expert consultation on revision of FAO methodologies for crop water 

requirements. Rome: FAO, 59 p. 

Turco, J.E.P. et al. 1998. Adequação de um modelo de crescimento da cultura de soja para 

terrenos com diferentes exposições e declividades. Engenharia Agrícola. v.17, n.4, p.25-34.

Salt Stress on the Photosynthetic Pigment Content Cowpea 

Inoculated With Rhizobia 

Ronaldo do Nascimento 1* , Jailma R. de Andrade 2 , Francisco V. da Silva 3 , Aryadne 

Ellen V. de Alencar 4 , Daniele F. de Melo 4 , José Wilson Barbosa 2 

1 Teacher Associate of Academic Unit of Agricultural Engineering, CTRN / UFCG, Av Aprígio 

Veloso, 882, University District, Campina Grande, Paraíba, 58429-140, Brazil. 

2 Graduate in Agricultural Sciences, Ms in Agricultural Engineering, Academic Unit of 

Agricultural Engineering, CTRN / UFCG. 

3 Agronomist Engineer, PhD, Academic Unit of Agricultural Engineering, CTRN / UFCG. 

4 Graduate in Agricultural Engineering, Academic Unit of Agricultural Engineering, CTRN / UFCG. 

*Corresponding author. E-mail: ronaldo@deag.ufcg.edu.br 

Abstract 

Soil salinity is an abiotic factor that can affect the Rhizobium-legume symbiosis, decreasing 

nodulation and consequently the fixation of atmospheric nitrogen. This can negatively 

influence the synthesis of chlorophyll and photosynthesis, a decrease in the growth and crop 

productivity. In the Northeast region of Brazil, cowpea, legume species capable of fixing 

atmospheric nitrogen through symbiosis with bacteria called rhizobial, is important for the 

subsistence families, because they are considered more resistant to adverse conditions the 

middle. This region has raised the problem of soil salinity due to the use of low water quality 

and intense evaporation. The objective of this study was to evaluate the effect of salt stress 

on the accumulation of photosynthetic pigments in differents cultivars of cowpea inoculated 

with rhizobium strain BR-3267, developed especially in Brazil for symbiosis with this legume. 

The study was performed using polyethylene pots containing Neolithic Eutrophic Regosols. 

We used a completely randomized design in a 4x5 factorial (salinity x genotype), with four 

repetitions. Treatments consisted of four levels of salinity of irrigation water (1,5; 3,0; 4,5 e 6,0 

dSm -1 ) and genotypes were used MNCO1-649F-1-3, BRS-Juruá, MNCO2-675F-4-9, 

MNCO3-736F-7 and MNCO2-684F-5-6. Evaluations were performed at 40 days after 

emergence (DAE), when samples were collected from leaf tissue of plants, brought to 

Irrigation and Salinity Laboratory (LIS) of the Center for Technology and Natural Resources 

(CTRN), Federal University of Campina Grande (UFCG), processed and determined the 

levels of chlorophyll a, chlorophyll b, total chlorophylls and carotenoids, and the relationship 

of chlorophyll a/b and total chlorophyll/carotenoids. Analysis of variance showed that there 

were significant for salinity levels on all variables. Regression analysis showed linear or 

quadratic response to the negative content of total chlorophylls and carotenoids, 

respectively. Regarding the contents of chlorophylls a and b, there was a negative linear 

response. The content of photosynthetic pigments were generally adversely affected by 

salinity levels of irrigation water, showing a sensitivity of the symbiosis to salt stress, which is 

reflected in the production of leaf pigments responsible for capturing light and CO 2 for 

photosynthesis. 

Keywords: salinity, chlorophyll, photosynthesis, cowpea, rhizobia. 


The irrigation is one of the technologies applied in agriculture that has most contributed to 

the increase in food production. Nevertheless this practice should therefore be used 

rationally, because the climate conditions of the Northeast (high temperature, low 

precipitation and the high salt contents in water used for irrigation), have been causing 

problem salinization in soils. The increasing need to enhance the food production, has 

increased significantly to expand of the cultivated areas but that search not take into account

only the expansion of agricultural lands but also regarded as of using water of lower quality 

as well as to reuse drain water with high levels of salts and use species able to provide high 

yields when irrigated with those types of water (Rhoades et al., 2000). 

Soil salinity is an abiotic factor that can affect the rhizobia-legume symbiosis, nodulation and 

consequently decreasing the fixation of atmospheric nitrogen. This can negatively influence 

the synthesis of chlorophyll and photosynthesis, a decrease in the growth and yield. In 

northeastern Brazil, cowpea, legume species capable of fixing atmospheric nitrogen through 

symbiosis with bacteria called rhizobia is important to the livelihoods of low income families, 

because they are considered more resistant to adverse conditions of the medium. This 

region has worsened the problem of soil salinity due to the use of low water quality and 

intense evaporation (Cordovilla, et al., 1999). The search for new sources of genes for 

tolerance to salinity must be constant. The identification of new genotypes as sources of 

tolerance, genetic variability in breeding genetically divergent groups represents an important 

strategy to gain selection. 

The aim of this work was to evaluate the effects of salt stress on accumulation of leaf 

photosynthetic pigments in various cultivars of the cowpeas inoculated with rhizobia strain 

BR-3267, especially developed in Brazil to a symbiosis with this leguminous. 


This experiment was conducted in a a greenhouse at the Federal University of Campina 

Grande (UFCG), in the dependencies of UFCG, Centre for Technology and Natural 

Resource (CTRN), Academic Unit the Agricultural Engineering (UAEA). A UFCG (FIGURE 1) 

is located in central east of the state of Paraíba, in the Borborema Plateau, which geographic 

FIGURE 1: Aerial view of UFCG. Local greenhouse in focus.

coordinates are latitude 7°13'11'', longitude 35º53'31'' west and altitude of 547.56 m. 

According to the National Institute of Meteorology (INMET), the city has an annual rainfall of 

802.7 mm, maximum temperature of 27.5 °C, minimum 19.2 °C and relative humidity of 83%. 

The search was performed using polyethylene vessel with a capacity of 1.5 kg of substrate 

Regossolo Neolithic Eutrophic fertilized according Novais et al. (1991). Were sown in each 

vessel, three seeds, leaving only one plant per pot after thinning, which occurred five days 

after emergence. We used a completely randomized design in a 4x5 factorial (genotype x 

salinity), with four replications. Treatments consisted of four levels of salinity of irrigation 

water (1.5, 3.0, 4.5 and 6.0 dSm -1 ), based on the results of Ayers and Westcot (1999) and 

genotypes (G ) were used (G1) MNCO1-649F-1-3 (G2) BRS-Juruá (G3) MNCO2-675F, 4-9, 

(G4) MNCO3-7-736F and (G5) MNCO2-5-684F 6, granted by Embrapa Mid-North, Center for 

reference in research with the improvement of cowpea, and production of new cultivars, 

located in the city of Teresina, Piauí State, and specially developed for cultivation in the 

climatic conditions prevailing in the Brazilian Northeast. Irrigation was performed daily with 

water from the supply network's campus UFCG, to be pruned, if from this, the water used for 

irrigation had different levels of salinity, according to the treatments. The salinity levels were 

evaluated salts obtained by mixing Na, Ca, and Mg. Evaluations were performed at 40 days 

after emergence (DAE), when samples were collected from leaf tissues of plants, brought to 

the Laboratory of Irrigation and Salinity (LIS) of the Center for Technology and Natural 

Resources (CTRN), Federal University of Campina Grande ( UFCG), processed and 

analyzed the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids, and 

the ratio chlorophyll a / b and total chlorophyll / carotenoids. Extractor as pigments used is 

80% acetone, and the absorbance readings determined at 470, 647 and 663 nm. The 

pigment content was determined by equations (Equations 1, 2, 3 and 4) conditions 

(Lichtenthaler & Welburn, 1983), and the data was analyzed by F test and adjusted 

regression models with the regression coefficient. 

Equation 1: Cl a = (12,25 x A 663 ) – (2,79 x A 647 ) 

Equation 2: Cl b = (21,50 x A 647 ) – (5,10 x A 663 ) 

Equation 3: Cl total = (7,15 x A 663 ) + (18,71 x A 647 ) 

Equation 4: Carotenoids = (1000 x A 470 – 1,82 x Cla – 85,02 x Clb) / 198 


Analysis of variance in showed significant interaction between the two limiting factors 

evaluated, genotype and salinity levels for any of the variables. Regarding the content of 

chlorophyll b, total chlorophyll and carotenoids, we obtained a significant response to the 

isolated factors. As for the content of chlorophyll a relative total chlorophyll / carotenoids, 

only the levels of salinity were significant, whereas the chlorophyll a / chlorophyll b, only the 

factor genotype was significant at 1%. Separately, there was significance (P ≤ 0.05) for 

salinity levels and genotypes on all variables. The content of chlorophyll a higher than were 

those of chlorophyll b, for all genotypes (FIGURE 2). The genotype-675F-MNCO2 4-9 

showed the smallest amounts of photosynthetic pigments, while the genotype MNCO1-649F- 

1-3 showed the highest levels of pigments, showing the differential sensitivity to salt levels. 

Regression analysis showed negative linear response to the levels of photosynthetic 

pigments (FIGURE 3), there was a gradual decrease in the levels of pigments with 

increasing salt concentration in irrigation water, showing likely that there was a symbiosis of 

sensitivity to salt stress, which is reflected in the N availability to plants and consequently in 

the production of pigments responsible for capturing CO 2 and light for photosynthesis. The 

content of chlorophyll a has been reduced linearly with increasing salinity of irrigation water 

(FIGURE 3). Comparing the values of that pigment in the higher salinity level (6 dSm -1 ) been

FIGURE 2: Content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in 

different genotypes of cowpea inoculated with strain BR-3267 rhizobia, under salinity in 

Paraíba State, Brazil. Campina Grande, December, 2011. 

. 

FIGURE 3: Content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in 

different genotypes of cowpea inoculated with strain BR-3267 rhizobia, under salinity in 

Paraíba State, Brazil. Campina Grande, December, 2011.

found in water with low salinity (1.5 dSm -1 ), there was a 40% reduction in levels of chlorophyll 

a. Analyzing the effect of levels of salinity on the content of chlorophyll b, it was found that 

increasing levels saline caused a reduction in the content of photosynthetic pigment. 

Comparing the lowest and the highest level of salinity, observed values of 302.2 and 153.9 

μg.mgMF -1 , respectively (FIGURE 3). Similar results were observed by other authors, who 

point out that decreases in chlorophyll content can be attributed to increased activity of the 

enzyme that degrades the chlorophyll, chlorophyllase (Neto, 2005; Berteli et al. In 1995, 

Rodriguez et al., 1997) besides the fact salt stress induces degradation of ß-carotene and 

the reduction in the formation of zeaxanthin, producing a decrease in carotenoids, pigments 

apparently involved in protection against photoinhibition (Sharma & Hall, 1991). 

Comparing the genotypes, we observed higher chlorophyll b (330.84 μg.mgMF -1 ) in G1 and 

G3 in lower (130.78 μg.mgMF -1 ). The total chlorophyll content decreased with increasing salt 

concentrations. For the highest electrical conductivity (EC) decreased slightly from 43.8% in 

pigment content. The content of carotenoids in the cowpea plants was negatively affected by 

increasing salinity in irrigation water (FIGURE 3), we observed a reduction of 36.1% from the 

lowest to the highest level of salt. One of the factors related to the photosynthetic efficiency 

of plants is chlorophyll content and carotenoids (Munns & Tester, 2008), which can be 

affected by soil salinity. 


The content of chlorophyll a, b and total carotenoids were not statistically different between 

genotypes. However, the contents of these pigments decreased with increasing salinity 

levels in all genotypes, with the largest decreases observed in salinity levels more 

pronounced. 

5. References 

AYERS, R.S.; WESTCOT, D.W. Water quality for agriculture. Campina Grande, UFPB, 1999. 153p. 

BERTELI, F.; CORRALES, E.; GUERRERO, C.; ARIZA, M.J.; PILEGO, F.; VALPUESTA, V. 

Salt stress increases ferrodoxindependent glutamate synthase activity and protein level in 

the leaves of tomato. Physiologia Plantarum, Copenhagen, v. 93, n. 2, p. 259-264, 1995. 

CORDOVILLA, M.D.P. LIGERO, F.; LLUCH, C. Effects of NaCl on growth and nitrogen 

fixation and assimilation of inoculated and KNO 3 fertilized Vicia faba L. and Pisum sativum L. 

plants. Plant Science, v.140, p. 127–136, 1999. 

MUNNS, R.; TESTER, M. Mechanisms of salinity tolerance. Annual Review of Plant Biology, 

v.59, p.651-681, 2008. 

NETO, A.D.A. Salt stress, oxidative stress and cross-tolerance in corn. In: Environmental 

Stresses: Damage and benefits in plants. WALNUT, R.M.C.; Araujo E.L.; WILLADINO, L.G. 

et al. (Eds.) Recife: UFRPE, University Press, 2005. 500 p. 

NOVAIS, R.J.; NEVES, J.C.L.; BARROS, N.F. Testing in a controlled environment. In: 

Oliveira, AJ.; GARRIDO, WE, Araújo, JD, LORENZO, L. Research methods in soil fertility. 

Brasilia: Embrapa, p.189-254, 1991. 

RHOADES, J.P.; KANDIAH, A.; MASHALI, A.M. Use of saline water in agricultural 

production. Campina Grande: UFPB, 2000. 117p. 

SHARMA, P.K.; HALL, D.O. 1991. Interaction of salt stress and photoinhibition on 

photosynthesis in barley and sorghun. Journal of Plant Physiology, v.138, n.5, p.614-619. 

RODRÍGUEZ, H.G.; ROBERTS, J.K.M.; JORDAN, W.R.; DREW, M.C. Growth, water elation, 

and accumulation of organic and inorganic solutes in roots of maize seedlings during salt 

stress. Plant Physiology, Rockeville, v.113, n.3, p.881-893, 1997. 

LICHTENTHALER, HK; WELBURN, AR. Determination of total carotenoids and chlorophylls 

a and b of leaf extracts in different solvents. Biochemical Society Transactions. v.11, p.591- 

592, 1983.

Evapotranspiration and Crop Coefficient of Onion (Allium cepa L.) 

under the Mulch of Plastic Film in an Arid Region, Northwest China 

Jianhua Zheng 1, 2 , Guanhua Huang 1, 2 *, Jun Wang 1, 2 , Quanzhong Huang 1, 2 

1 Center for Agricultural Water Research, China Agricultural University, Beijing, 100083, P. R. 

China 

2 Chinese-Israeli International Center for Research and Training in Agriculture, China 

Abstract 

Agricultural University, Beijing, 100083, P. R. China 

*Corresponding author. E-mail: ghuang@cau.edu.cn 

Field studies were carried out in 2008 and 2009 using nine weighing lysimeters to determine 

actual evapotranspiration (ET a ) of onion under surface irrigation with plastic mulch. Three soil 

water contents (SWCs) expressed as the percentage of field capacity (FC) were considered 

as thresholds for initiating irrigations at mid-season stage, i.e., 75%, 65% and 55% FC. ET a , 

crop coefficient (K c ), yield, irrigation water productivity (IWP) and water productivity (WP) were 

determined. The average seasonal ET a of 75% FC was 357 mm, 263 and 200 mm 

consequently for 65% and 55% FC, respectively. Results indicated that onion bulb yield was 

significantly affected by the irrigation depth. The highest average yield of 62.1 t ha -1 was 

obtained with irrigation threshold of 75% FC, and it was reduced by 33% and 65% for the 65% 

and 55% FC treatment, respectively. The WP increased as the increase of the irrigation 

thresholds. The estimated value of Kc during the initial, mid-season and late season was 0.73, 

1.28, and 0.70, respectively. Third-order polynomials were used to well predict K c as functions 

of days after transplanting (DAT) and cumulative growing degree-days (GDD), respectively. 

The estimated K c values of the present work can be used for irrigation scheduling of onion 

crop with similar agro-climatic conditions. 

Keywords: evapotranspiration, crop coefficient, onion, lysimeter 


Water scarcity became a bottleneck for the expansion and development of irrigated 

agriculture in the Shiyang River basin, an arid inland river basin in Northwest China. The 

groundwater is over exploited due to a dramatic reduction of surface water, which causes 

serious deterioration of ecological system (Kang et al., 2004). Thus, it is essential to develop 

agricultural water-saving strategies for promoting the sustainable utilization of water 

resources in the region and the development of the social economy. 

Onion (Allium cepa L.) is among the most important horticultural and cash crops in the arid 

Northwest China, due to its favoured long sunshine duration and the large day and night 

temperature differences. Although plastic mulch is widely applied for reducing soil evaporation, 

the water productivity for onion is still low. Therefore, to support precise irrigation scheduling, 

it is advisable to adapt the crop coefficient (K c ) values to local agronomic practices. 

Weighing lysimeter can provide dependable estimates of actual evapotranspiration (ET a ), 

but only if fundamental requirements concerning representativeness of vegetation and

environmental conditions are satisfied (Howell et al., 1985; Allen et al., 2011a, b). They are 

widely used, including for horticultural and fruit crops (Bryla et al., 2010; Flumignan et al., 

2011). However, few studies report on using lysimeters to determine ET a and K c of crops 

under plastic mulch; an exception is the study by Lovelli et al. (2005). 

Therefore, the objectives of this study are to estimate the K c of onion under plastic mulch, 

determine onion ET a under different soil moisture regimes, and investigate the response of 

onion bulb yield and water productivity to different irrigation levels in Northwest China. 


The field experiments were conducted during 2008 and 2009 at Shiyanghe Experimental 

Station for Water-saving in Agriculture and Ecology of China Agricultural University (latitude 

37°52′ 20″ N, longitude 102°50′50″ E, altitude 1581 m). The site is in a typical temperate 

semi-arid continental climate zone. 

Nine weighing lysimeters (0.5 m×0.8 m×0.95 m) were installed to determine actual 

evapotranspiration (ET a ) of onion by detecting changes in the mass of the soil/crop unit. 

The onion crop (Allium cepa L., cv. Babylon) were transplanted with plant and row spacing 

of 0.15 m, inside and outside the lysimeters, and irrigated with surface irrigation. White 

transparent plastic film was used as mulching material covered on the plot surfaces. 

Irrigation was initiated in terms of the soil water irrigation threshold in the root zone (0-30 

cm), which is corresponding to a percentage of field capacity (FC). Refilling to the field 

capacity was performed as the average soil water content in the root zone of each lysimeter 

approached the soil water irrigation thresholds. Three irrigation treatments were considered in 

both years with different soil water thresholds for initiating irrigation at the mid-season stage, 

i.e. 75%, 65% and 55% FC, namely T1, T2 and T3, respectively. The soil water irrigation 

threshold for initiating irrigation at the other three stages (i.e., initial, development and late 

season stages) was 75% FC. 

Reference crop evapotranspiration (ET o ) was calculated daily by the Penman-Monteith 

equation (FAO 56 method, Allen et al., 1998). The actual evapotranspiration (ET a ) of onion 

was determined based on mass balance of water in the lysimeters. Crop coefficient (K c ) was 

calculated as the ratio of ET a to ET o (Allen et al., 1998). The ET a values with the highest soil 

water irrigation threshold of 75% FC were used to calculate K c . 

The irrigation water productivity (IWP) and total water productivity (WP) were computed as 

the ratio of yield to the seasonal irrigation water use and total water use, respectively. 

Statistical analysis was done by standard analysis of variance (ANOVA) with the SPSS 

16.0 software (SPSS inc., Chicago, IL, USA). Least significant difference (LSD) method was 

used to determine whether differences existed. The probability level for determination of 

significance was 0.05. 

3. Results 

3.1. Actual evapotranspiration 

The depth of applied irrigation water is presented in Table 1 for each treatment in 2008 and 

2009. The total irrigation depths for treatments T1, T2 and T3 were, respectively, 337, 194 and 

134 mm in the first growing season and 326, 210 and 109 mm in the second growing season. 

The total irrigation depth in both seasons was significantly different. 60 mm and 50 mm water

were respectively applied in the first and second season during the first stage for better 

establishment of the transplanted onion seedlings. Deficit irrigation was imposed during the 

mid-season stage; water applied in this stage for T1, T2 and T3 accounted for 63%, 36.5%, 

20.4% and 56.7%, 54.6%, 11.8% of the total seasonal irrigation amounts in the first and 

second growing seasons, respectively. Significant differences were found in irrigation depth 

among treatments in both seasons. No water was applied in the late season stage due to the 

relatively short period and the senescence of leaves. 

Table 1 shows the actual evapotranspiration (ET a ) determined by lysimeters observations 

for each treatment in 2008 and 2009. Significant differences were found in the seasonal ET a 

among treatments, which were 357, 256 and 200 mm in 2008, and 358, 270 and 199 mm in 

2009 for T1, T2 and T3, respectively, but no significant difference was found in the seasonal 

ET a between the two growing seasons. The ET a values were small at the initial stage and then 

increased as the development of onion canopy and the increasing ET o ; it reached the peak 

value at the mid-season stage and decreased during the late season stage due to the 

termination of irrigation and the physiological deterioration of foliage. During both seasons, 

ET a increased significantly with the increase in irrigation depth and precipitation. The 

relationship between ET a and irrigation depth plus precipitation can be well fitted with a linear 

function as shown in Fig. 1. 

3.2. Crop coefficient 

The calculated 10-day K c of onion is shown in Fig. 2 (a). It can be observed that the K c 

consistently increased from 0.59 to 1.30 during 10-50 days after transplanting (DAT). This is 

due to the rapid crop development caused the increase in ET a which resulted in the increase 

of the K c value. During the mid-season, K c slightly increased from 1.30 to 1.32 and then 

decreased to 0.92. The highest K c value occurred at 60 DAT. K c declined rapidly from 0.92 to 

0.48 during the late season (80-90 DAT). This may be due to the fact that no water was 

applied in this stage, and the foliage began senescence which is usually associated with less 

efficient stomatal conductance of leaf surfaces due to the effects of ageing (Allen et al., 1998). 

The average K c values for the initial, mid-season and late season were 0.73, 1.28 and 0.70, 

respectively (see Table 2), which were slightly different from the values of 0.70, 1.05 and 0.75 

recommended by Allen et al. (1998) under the conditions without mulching. 

The variation in K c can be described as a function of days after transplanting (DAT) by 

using a polynomial equation with determination coefficient (R 2 ) of 0.984, as shown in Fig. 2 (a). 

Similarly, the variation in K c can also be expressed as a polynomial function of growing 

degree-days (GDD) with R 2 of 0.949, as shown in Fig. 2 (b). Better fits were obtained than that 

of similar researches elsewhere conducted by Al-Jamal et al. (1999) and Bossie et al. (2009), 

who presented third-order polynomials to estimate the onion K c from GDD with R 2 of 0.87 and 

0.89, respectively. The variation of K c for onion crop can be predicted from GDD was due to 

the fact that the growth rate of onion is related to the accumulated thermal time (Lancaster et 

al., 1996). 

3.3. Yield 

Onion fresh bulb yield of each treatment in both years are shown in Table 3. The highest yield 

in both seasons was obtained for the treatment with the highest soil water irrigation threshold

of 75% FC (T1). Statistical analysis showed significant differences among treatments in the 

onion fresh bulb yield. Onion bulb yield for the treatment with lower soil water irrigation 

threshold of 55% FC (T3) in 2008 was lower than that in 2009. This might be due to the 

difference of climatic conditions with higher solar radiation and lower rainfall in 2008 than 

those in 2009. On an average, the yield of treatment T1 was about 33% and 64% higher than 

those of treatment T2 and T3, respectively. 

3.4. Water productivity 

The results of IWP and WP in both seasons are presented in Table 3. The WP ranged from 

8.0 to 19.3 kg m -3 in 2008 and from 13.7 to 15.6 kg m -3 in 2009, respectively. Treatment T1 

had the highest WP while treatment T3 had the lowest WP in both seasons. The differences in 

WP among treatments were statistically significant in 2008, but no significant differences were 

found in 2009. 

In 2008, the highest value of IWP was 22.0 kg m -3 for treatment T2, while T3 had the 

lowest IWP value of 11.8 kg m -3 . The values of IWP in 2009 were in a range of 17.2 to 25.2 kg 

m -3 , which decreased with the increase in irrigation depth. No significant differences in IWP 

were found among treatments in both seasons. 

4. Conclusion 

The effect of different irrigation depths on onion ET a , bulb yield, WP and IWP of onion crop 

were investigated with weighing lysimeters in an arid climatic region for two consecutive 

growing seasons of 2008 and 2009, and finally the site specific crop coefficient was estimated 

for onion in this region. Main conclusions draw from the research are: 

(1) Irrigation depths significantly influenced ET a , bulb yield, and WP of onion. With 

irrigation depths increasing, the seasonal ET a , bulb yield, and WP increased. 

(2) The maximum average yield (62.1 t ha -1 ) and the highest average WP (17.5 kg m -3 ) 

were obtained by the treatment with soil water irrigation threshold of 75% FC with the most 

irrigation water (331 mm) and ET a (357 mm) in both seasons. The highest IWP was gained for 

treatment with soil water irrigation threshold of 65% FC (22.0 kg m -3 ) in 2008 and the 

treatment with soil water irrigation threshold of 55% FC (20.5 kg m -3 ) in 2009. There were no 

significant differences in IWP among treatments. 

(3) The estimated values of K c during the initial, mid-season, and late season were 0.73, 

1.28 and 0.70, respectively. It is 4% and 22% higher during the initial and mid-season, and 6% 

lower during the late season than the values suggested by FAO 56. K c can be well predicted 

by the fitted third-order polynomial functions expressed as DAT and GDD. The estimated K c 

values in this paper can be used to manage irrigation scheduling for onion crop under the 

similar agro-climatic conditions. 


We are grateful to the research grants from the Program 2007BAD88B07-3 supported by the 

Ministry of Science and Technology of China and the Program 200801104 supported by the 

Ministry of Water Resources of China.

TABLE 1: Irrigation depth and actual evapotranspiration of onion for each treatment. 

Irrigation depth (mm) 

Actual evapotranspiration (mm) 

Year Treatment 

P1 P2 P3 P4 Total P1 P2 P3 P4 Total 

2008 T1 78 46 212 a 0 337 a 25.0 112 199 a 21 357 a 

T2 63 60 71 b 0 194 b 25.9 105 108 b 18 256 b 

T3 47 60 27 c 0 134 c 23.0 84 77 b 17 200 c 

2009 T1 69 72 185 a 0 326 a 29.0 102a 204 a 23 a 358 a 

T2 47 49 115 b 0 210 b 30.0 77 ab 138 b 25 a 270 b 

T3 54 41 13 c 0 109 c 31.9 62 b 95 c 10 b 199 c 

*P1, P2, P3, P4 means different growth stages of onion, which were initial, development, 

mid-season, and late season, respectively. *Values in a column under the same year with 

different letters are statistically significant by Duncan’s multiple range test at p < 0.05. 

TABLE 2: Values of crop coefficient for onion at initial, mid-season and late season stages 

K c K c ini K c mid K c end 

2008 0.71 1.19 0.75 

2009 0.75 1.37 0.66 

Average 0.73 1.28 0.70 

FAO 56 suggested 0.70 1.05 0.75 

TABLE 3: ET a , bulb yield, WP, and IWP of onion under different irrigation treatments 

Treatment 

Irrigation (mm) ET a (mm) Yield (t ha -1 ) WP (kg m -3 ) IWP (kg m -3 ) 

2008 2009 2008 2009 2008 2009 2008 2009 2008 2009 

T1 337 a 326 a 357 a 358 a 68.2 a 56.0 a 19.3 a 15.6 20.5 17.2 

T2 194 b 210 b 256 b 270 b 41.9 b 40.8 b 16.3 a 15.3 22.0 20.5 

T3 134 c 109 c 200 c 199 c 15.8 c 27.2 c 8.0 b 13.7 11.8 25.2 

Values in a column with different letters are statistically significant by Duncan’s multiple range 

tests at p < 0.05. 

ETa (mm) 

500 

400 

300 

200 

100 

2008 2009 

Fitted 

y = 0.7306x + 118.7 

R 2 = 0.9995 

0 

0 100 200 300 400 

Irrigation depth + Precipitation (mm) 

FIGURE 1: Relationship between ET a and irrigation depth + precipitation in 2008 and 2009.

Crop coefficient (Kc) 

1.5 

1.2 

0.9 

0.6 

0.3 

0.0 

(a) 

y = -7E-06x 3 + 0.0005x 2 + 0.0049x + 0.5228 

R 2 = 0.984 

Crop coefficient (Kc) 

1.5 

1.2 

0.9 

0.6 

0.3 

0.0 

(b) 

y = -3E-09x 3 + 4E-06x 2 - 0.0007x + 0.669 

R 2 = 0.9487 

0 20 40 60 80 100 

Days after transplantation (DAT) 

0 300 600 900 1200 1500 

Growing degree-days (GDD) 

FIGURE 2: Crop coefficient (K c) as a function of (a) days after transplantation (DAT) and (b) 

cumulative growing degree-days (GDD) 

Reference list 

Allen, R.G., Pereira, L.S., Raes, D., & Smith, M. (1998). Crop evapotranspiration. Guidelines 

for computing crop water requirements. FAO Irrigation and Drainage Paper No.56, Rome, 

Italy. 

Allen R.G., Pereira L.S., Howell T.A., & Jensen M.E. (2011a). Evapotranspiration information 

reporting: I. Factors governing measurement accuracy. Agricultural Water Management, 98(6), 

899-920. 

Allen R.G., Pereira L.S., Howell T.A., & Jensen M.E. (2011b). Evapotranspiration information 

reporting: II. Recommended documentation. Agricultural Water Management, 98(6), 921-929 

Al-Jamal, M.S., Sammis, T.W., Ball, S., & Smeal, D. (1999). Yield based, irrigated onion crop 

coefficients. ASAE Applied Engineering in Agriculture, 15, 659-668. 

Bossie, M., Tilahun, K., & Hordofa, T. (2009). Crop coefficient and evapotranspiration of onion 

at Awash Melkassa, Central Rift Valley of Ethiopia. Irrigation and Drainage Systems, 23, 1-10. 

Bryla, D.R., Trout, T.J., & Ayars, J.E. (2010). Weighing lysimeters for developing crop 

coefficients and efficient irrigation practices for vegetable crops. HortScience, 45(11), 

1597-1604. 

Flumignan, D.L., Faria, R.T.D., & Prete, C.E.C. (2011). Evapotranspiration components and 

dual crop coefficients of coffee trees during crop production. Agricultural Water Management, 

98, 791-800. 

Howell, T.A., McCormick, R.L., & Phene, C.J. (1985). Design and installation of large weighing 

lysimeters. Trans ASAE, 28, 106-112. 

Kang, S.Z., Su, X.L., Tong, L., Shi, P.Z., Yang, X.Y., Abe, Y.K., Du, T.S., Shen, Q.L., & Zhang, 

J.H. (2004). The impacts of human activities on the water-land environment of the Shiyang 

River basin, an arid region in Northwest China. Hydrological Sciences Journal, 49, 413-427. 

Lancaster, J.E., Triggs, C.M., De Ruiter, J.M., & Gandar, P.W. (1996). Bulbing in onions: 

photoperiod and temperature requirements and prediction of bulb size and maturity. Annals of 

Botany, 78, 423-430. 

Lovelli, S., Pizza, S., Caponio, T., Rivelli, A.R., & Perniola, M. (2005). Lysimetric determination 

of muskmelon crop coefficients cultivated under plastic mulches. Agricultural Water 

Management, 72, 147-159.

NUTRIENT RETENTION IN WETLANDS USING ORNAMENTAL 

PLANTS¹ 

ROJANE KLETECKE²*; MICHELE PICCOLI² and JOSE TEIXEIRA FILHO ² 

¹Part of the thesis of first author; 

² College of Agricultural Engineering, Av. Candido Rondon, 501, Campinas, SP, CEP 13083- 

875, Brasil. *Corresponding author E-mail: rojane.kletecke@yahoo.com.br 

Abstract 

The treatment of sewage is of fundamental importance for the improvement and 

maintenance of the quality from water resources. The objective of this paper is to evaluate 

the retention capacity of nutrients Nitrogen (N) and Phosphorus (P) in constructed wetlands 

with ornamental plants, to treat domestic effluents after passing through compartmented 

anaerobic reactors (CAR). The ornamental plants used were Heliconia psittacorum (CW1) 

and Cyperus alternifolius (CW2). The water quality monitoring was made in an hourly scale 

and the evaluation was done in two periods: before pruning (BP) and after pruning (AP). The 

evaluation of retention capacity from the variables analyzed Ammonia nitrogen (NH³ + ), 

Nitrate (NO -3 ) and Total phosphorus (TP), was performed based on non-parametric statistics 

using the Mann-Whitney test at 5% significance. Statistical differences were registered only 

for the period BP, for the concentration and load of NO -3 , where CW1 was more efficient for 

the retention, with an average of 29.8% and 31.0% respectively. The ornamental plants 

contributed to the local landscape composition, reducing the rejection of persons to the 

sewage treatment, transforming this place in a flooded garden, appreciated for 

contemplation. 

Keywords: Constructed Wetlands; Water quality; Nutrients; Domestic effluents; Flooded 

garden. 

1.Introduction 

Water resources are being every time more degraded. Among the different factors which 

contribute for this degradation are the domestic effluents. Most effluents are disposed in 

natura in rivers, without any type of treatment. According to TUCCI et al. (2001), most rivers 

crossing Brazilian cities are deteriorated, which is considered one of the biggest 

environmental problems of the country. Within this frame, systems of constructed wetlands 

(CW) are a good option for sewage treatment in small communities, horizontal 

condominiums, small industries and agro-industries among others. It presents low 

implantation and operational costs, minimum mechanization indices (CHERNICHARO, 

2003). CWs are sustainable systems, indicated for tropical countries like Brazil. CWs are 

considered biological filters where aerobic and anaerobic microorganisms, which are fixed in 

the substrate and in the plants roots, are responsible for water purification reactions (WOOD, 

1995). The nutrients, mainly Nitrogen (N) and Phosphorus (P), available in domestic 

effluents, contribute to the eutrophication of water and CWs with ornamental plants improve 

the retention of these pollutants. 


The experiment was conducted at the Experimental Field of the Agricultural Engineering 

Faculty from University of Campinas (FEAGRI/UNICAMP). The geographical coordinates are 

S 22º48’57” and WGr 47º03’33”, average height is 640 m. The climate, according to the 

classification of Köppen, is a transition between types Cwa and Cfa, indicating that the 

climate is tropical in altitude with dry winter and humid summer. The temperature of the 

hottest month is above 22°C and below 18°C at the c oldest month (June). The average

annual rainfall is 1,382 mm and the rainy season is concentrated between October and 

March (1,048 mm), representing 75.8% of the total annual rainfall. The driest period occurs 

between June and September (SENTELHAS et al., 2009). 

The sewage originated from installations of FEAGRI/UNICAMP (bathrooms, laboratories and 

kitchen) present characteristics of domestic effluents. In the sewage treatment plant (STP) 

there is a box for the separation of the coarse material which is conducted to the Partitioned 

Anaerobic Reactor (PAR) and afterwards to the Subsurface Flow Constructed Wetlands 

(SFCW), with average dimensions of 3,17mx1,68mx0,53m, and useful volume of 

approximately 1.150 liter for each CW. The substratum used was gravel of size 1 and 

ornamental plants Heliconia psittacorum (CW1) and Cyperus altenifolius (CW2). The 

plantation of the macrophytes was in December 2008. The monitoring of water quality was 

done in two periods: before pruning (BP) at the beginning of May till Mid-August 2009, when 

pruning occurred, totaling 8 days monitoring. The sampling of affluent and effluents was 

done on an hourly scale (from 09:00 till 18:00 h, every hour). The flow was regulated 

manually, from the ball valves, in the morning before the first sampling. The flow 

measurements were performed by the volumetric method (direct measurement) (CALIJURI 

et al., 2009). The water collection for the analysis was made just after the flow 

measurements, being one affluent sample to the CWs and a sample for each effluent of 

CWs. The analysis of water quality parameters was done in a specialized lab, according to 

the methodology of Standard Methods (APHA, 1998). 

The calculus for the amount of variables was made by the multiplication of the concentration 

from each input and output variable by the effluent flow of input and output referring to each 

day. The efficiency of daily retention for the amount of each variable was obtained by the 

difference between the daily amount of input and the daily amount of expected output divided 

by the daily amount of input, times 100. 

The variables analyzed for the water quality were: Ammonia nitrogen (NH³ + ), Nitrate (NO -3 ) 

and Total Phosphorus (TP). 


The characterization of the PAR effluent can be observed at Table 1. The average values 

were obtained from the hourly collected samples, afterwards integrated in the daily scale, 

corresponding to the sampling days during the period monitored. 

Table 1. Average values and standard deviation of the principal characteristic of the effluent 

after anaerobic baffled reactor (ABR), and affluent of the CW. 

Sewage pH EC DO water temp NH³ + NO -3 TP 

effluent 7.9 ± 0.2 966.6 ± 151.0 2.06 ± 2.1 22.5 ± 1.8 41.0 ± 15.8 1.7 ± 0.4 3.4 ± 0.7 

PAR 

pH Hydrogen potential; EC Electrical Conductivity (µS.cm -1 ); DO Concentration of dissolved oxygen (mg.L -1 ); 

Water temperature (ºC); NH³ + ammonia nitrogen (mg.L -1 ); NO -3 nitrate (mg.L -1 ); TP total phosphorus (mg.L -1 ). 

Table 2 shows the minimum and maximum affluent concentrations during the total period 

under study. The affluent concentration of NH 3+ varied from 24.8 to 76.9 mg.L -1 . Authors like 

CALIJURI et al. (2009) and SOUSA et al. (2000) worked with domestic sewage and affluent 

averages of 43 mg.L -1 and 43.9 mg.L -1 , respectively. As for NO -3 the variation was of 1.1 to 

3.0 mg.L -1 , MAZZOLA (2003) worked with domestic sewage and affluent concentrations of 

NO -3 which varied from 0.4 to 1.3 mg.L -1 . The affluent concentration for TP during the period 

studied varied from 2.2 a 5.2 mg.L -1 . WU et al. (2010) and ZHANG et al. (2007) worked with 

domestic sewage and an average affluent concentration of TP 4.1 and 4.4 mg.L -1 , 

respectively. SILVA and ROSTON (2010) report an average affluent concentration of 5.1 

mg.L -1 in wash water at the milking parlor. The results found corroborate with the above 

mentioned authors.

Table 2. Daily affluent concentration of Ammonia nitrogen, Nitrate and Total Phosphorous with 

minimum and maximum in the CWs during the period studied. 

Minimum and 

NH³ + NO -3 TP 

maximum 

concentrations 

(mg.L -1 ) 

24.8 – 76.9 1.1 – 3.0 2.2 – 5.2 

At Table 3 one observes the average retention for the amount of NH³ + , NO -3 e TP, in 

accordance with the non-parametric statistics in the Mann-Whitney test, at 5% significance. A 

statistical difference was registered for the amount of NO -3 at CW1 with Heliconia 

psittacorum with 31.0% average retention in AP period. SIM et al. (2008) obtained an 

average Nitrate retention of 58.6% with hydraulic retention time (HRT) of 4 days. YOUSEFI & 

MOHSENI-BANDPEI (2010) observed that the highest efficiency the Nitrate retention, from 

53.5 to 62.5%, occurred with HRT of 4 to 5 days. The HRT of this CW was of 1.4 days, which 

could have influenced in this retention, when comparing to the authors mentioned. Heliconia 

psittacorum, (CW1) had a good recovery after pruning, which did not occur at Cyperus 

alternifolius (CW2) whose development was below expected, with smaller size and death of 

some plants. During the AP period all variables, in both CWs, presented positive efficiencies. 

During the AP period there were negative efficiencies, probably influenced by the plant 

senescence. 

Table 3. Average retention efficiency (%) for the amount of Ammonia nitrogen, Nitrate and Total 

Phosphorous during the period studied: before pruning (BP) and after pruning (AP) 

Period CW1 CW2 

NH³ + NO -3 TP NH³ + NO -3 P T 

BP 19.4 18.6 11.7 8.8 14.4 9.2 

AP -0.6 31.0 -1.8 -0.5 -7.0 -6.8 

CW1 – Heliconia psittacorum; CW2 – Cyperus alternifolius 


- Among the variables analyzed, the amount of Nitrate at CW1 vegetated with 

Heliconia psittacorum presented a statistical difference in the period after pruning, with an 

average retention of 31%; 

- In the period BP the CWs did not present a statistical difference, and all variables in 

both CWs obtained positive averages; 

- Macrophyte Cyperus alternifolius did not accept pruning. Its regrowth was below 

expected and there was death of some plants, unlike Heliconia psittacorum which had a 

good recovery after pruning; 

- Monitoring at an hourly scale allowed the data transference to longer temporal scales 

with higher security and efficiency, permitting to better understand the dynamics from the 

CWs; 

- The use of ornamental plants in the CWs reduced the public rejection to the sewage 

treatment, transforming this place in a “garden wetland”. 

5. References 

APHA; AWWA; WPCF. (1998). Standard methods for the examination of water and 

wastewater. Washington: American Public Health Association,. 20. ed.

Calijuri, M.L.; Bastos, R.K.X.; Magalhães, T.B.; Capelete, B.C. & Dias, E.H.O. (2009). 

Tratamento de esgotos sanitários em sistemas reatores UASB/wetlands construídas de fluxo 

horizontal: eficiência e estabilidade de remoção de matéria orgânica, sólidos, nutrientes e 

coliformes. Engenharia Sanitária Ambiental, v.14, n.3, 421-430. 

Chernicharo, C. A.L. (1997). Princípios do tratamento biológico de águas residuárias. 

Reatores anaeróbios. Depto. Engenharia Sanitária e Ambiental - UFMG, Belo Horizonte - 

MG, vol. 5, 246 p. 

Mazolla, M.; Roston, D M. & Valentim, M. A. A. (2005). Uso de leitos cultivados de fluxo 

vertical por batelada no pós-tratamento de efluente de reator anaeróbio compartimentado. 

Revista Brasileira Engenharia Agrícola e Ambiental, v.9, n.2, 276-283. 

Paulo, P.L.; Braga, A. F. M.; Maximovitch, A. C. & Boncz, M. A. (2007). Tratamento de água 

cinza em uma unidade residencial de banhados construídos. In: 24º Congresso Brasileiro de 

Engenharia Sanitária e Ambiental. Belo Horizonte/MG. 

Sentelhas, P.C.; Pereira, A.R.; Marin, F.R.; Angelocci, L.R.; Alfonsi, R.R.; Caramori, P.H. & 

Swart, S. (2009) BHBRASIL: Balanços hídricos climatológicos de 500 localidades 

brasileiras. Disponível em: http://www.lce.esalq.usp.br/BHBRASIL/BHBRASIL.DOC. Acesso 

em: 05 fev. 2009. 

Silva, E. M. & Roston, D. M. (2010). Tratamento de efluentes de sala de ordenha de 

bovinocultura: lagoas de estabilização seguidas de leito cultivado. Revista Brasileira 

Engenharia Agrícola e Ambiental, v.30, n.1, 67-73. 

Sim, C. H.; Yusoff, M. K.; Shutes,B.; HO, S. C. & Mansor, M. (2008) Nutrient removal in a 

pilot and full scale constructed wetland, Putrajaya city, Malaysia. Journal of Environmental 

Management 88, 307–317. 

Souza, J. T.; Haandel, A. C. & Cabral, R. P. B. (2000). Desempenho de sistemas wetlands 

no pós-tratamento de esgotos sanitários pré-tratados em reatores UASB. In: Simpósio lusobrasileiro 

de engenharia sanitária e ambiental, 9 a 14 de abr. 2000, Porto Seguro. 

Proceedings... Porto Seguro: ABES. 1 CD-ROM. 

Tucci, C. E. M.; Hespanhol, I. & Cordeiro Netto O. M. (2001) Gestão da água no Brasil. 

Brasília: UNESCO. 156p. 

Wood, A. (1995). Constructed wetlands in water pollution control, fundamentals to their 

understanding. Water Technology. 32 (3). 21-29. 

Wu, Y.; Hu, Z. & Yang, L. (2010). Hierarchical eco-restoration: A systematical approach to 

removal of COD and dissolved nutrients from an intensive agricultural area. Environmental 

Pollution 158, 3123-3129. 

Zhang, X.; Liu, P.; Yang, Y. & Chen, W. (2007). Phytoremediation of urban wastewater by 

model wetlands with ornamental hydrophytes. Journal of Environmental Sciences 19, 902– 

909. 

Yousefi, Z. & Mohseni-Bandpei, A. (2010). Nitrogen and phosphorus removal from 

wastewater by subsurface wetlands planted with Iris pseudacorus. Ecological Engineering 

36, 777–782.

IMPORTANCE OF DRY GEAR MASS CULTURE OF SUNFLOWER 

INCORPORATED INTO THE SOIL 

ROSA H. AGUIAR 1,2* ; DURVAL R. P. JUNIOR 1 ; ARTUR B. O. ROCHA 1,2 

1 Universidade Estadual de Campinas (Unicamp)/ Faculdade de Engenharia Agrícola (Feagri) 

– Av. Marechal Candido Rondon, n.501, Barão Geraldo, Campinas, São Paulo State, 

postcode: 13083-875, Brazil. 

2 PhD student in agriculture engineering 

* Corresponding author : rosahel@feagri.unicamp.br 

ABSTRACT 

Cover plants, incorporated or not the soil as green manure intercropped with crop practices 

is aimed at the sustainability of agricultural soil, in order to reduce erosion and restore 

physical, chemical and biological characteristics of soil from the incorporation of dry mass. 

The objective of this study was to evaluate the accumulation of dry matter and yield 

performance of sunflower grown using treated sewage by/for two reactors, Compartmented 

Anaerobic Reactor (RAC) and the Upflow Anaerobic Upflow Sludge Blanket and (Upflow 

Anaerobic Sludge Blanket - UASB). Assessments began at 21 days after emergence to the 

collection of leaves at regular intervals of 15 days, then dried and weighed to determine dry 

matter. The accumulation of dry matter of leaf followed a parabolic trend over the 

development of plants, with accumulation (15 g), 75 days after emergence. After this period, 

there is a decrease because of senescence. This is due to the strong mobilizing capacity of 

assimilates exerted by the chapter that metabolic drains are in constant development by the 

end of the cycle. 

Keywords: dry matter, reactor, sewage treated. 

1. INTRODUCTION 

The sunflower is a plant that presents important agronomic characteristics such as 

resistance to drought, cold and heat that most species grown in Brazil. Adaptability to 

different climatic conditions present and your income is little influenced by the photoperiod. 

Thanks to these characteristics, presents itself as an option in the systems of rotation and 

succession of cultures in grain-producing regions (Aeasa, 2008).The organic matter of the 

soil is an important factor in agricultural productivity and one of the ways to increase or 

preserve the organic matter content is the practice of green fertilization. Legumes are plants 

used in green fertilization primarily by incorporate large amounts of N the ground, through 

biological fixation of atmospheric N2 and make vigorous root system and branched. Physical 

properties also influences, chemical and biological properties of soil, structuring and 

stabilizing the soil particles, increasing the availability of nitrogen, phosphorus and sulfur 

through the process of digestion, increases water holding capacity, favouring the growth of 

plant roots and consequently the whole plant. The basis of this analysis is based on the fact 

that, on average, 90% of accumulated organic matter over plant growth resulting from 

photosynthetic activity and the rest of the absorption of minerals from the soil.Through 

sequential measures, quantifies the plant dry matter, thereby providing a basis for assessing 

the contribution of various bodies in total growth (Lessa et al., 2008). The goal of this work 

was to evaluate the mass of dry matter accumulation of sewage treated by sunflower planted 

using two Anaerobic Reactor, reactor Chambered (RAC) and bottom-up flow Anaerobic 

Reactor and sludge Blanket (UASB Upflow Anaerobic Sludge Blanket ).

2. MATERIAL AND METHODS 

The experiment was installed and conducted at Faculdade de Engenharia Agrícola 

(FEAGRI) / Universidade Estadual de Campinas, (UNICAMP)/Campinas/São Paulo 

State/Brazil. The soil experimental area was rated by Latossolo Vermelo Típico (Embrapa, 

1999). Cultural practices and the plant control were carried out in accordance with the 

recommendations for the conduct of commercial culture. The distribution of the effluent in the 

flower beds, sewage treatment system in the soil was made by means of a system of 

distribution by gravity from storage systems comprised of two reservoirs with a capacity of 

1000 liters each (total volume = 2000 litres). The distribution of water in flower beds was 

made as follows: a line along the gantry adutora toured; This water supply network has four 

branches, one for each module of the construction site; from water supply network line 

derivations was made a distribution module of the effluent in the quarry so that they reduce 

the speed, minimizing your possible erosive effect and monitoring to be provided a net 25 

mm blade distributed per turn each watering days. Distribution systems are schematized in 

Figure 1. 

Figure 1. Distribution systems and sewage water in flower beds 

The experimental plots were 4.0 x 20.0 meters and each plot were composed of 4 

lines of sowing, with 20.0 m long. The chosen spacing was spaced 1 m 0, 50 m between 

themselves and between plants in accordance with CATI (Coordenadoria de Assistência 

Técnica e Integral). Each parcel with the culture this subject to the following manipulations- 

Without distribution of effluent (witness); Distribution of water with sewage tank of 

Experimental field; Distribution of effluent water with soil fertilized field Experimental; 

Distribution of effluent with UASB effluent Anaerobic Filter set +; Distribution of effluent with 

the effluent RACINTERCONNECT + Anaerobic Filter set. In the experiment the delineation 

used was entirely casualizado, with five treatments and four repetitions, being dry treatments 

in an oven at 65° ± C to constant weight, being subsequently weighed for determination of 

dry matter mass balance of precision (Lessa et al., 2008). 

3. RESULTS AND DISCUSSION 

The accumulation of dry matter mass followed a parabolic trend sheet over development of 

plants, with greater accumulation (16.15 g) to 75 DAE (days after emergence). After this 

period occurs a decrease as a result of leaf senescence. This fact is due the strong ability

mobilizing assimilated exerted by chapter that are strong by its constant development 

metabolic drains until the end of the cycle (90 DAE). Similar changes occurred with the 

stems. Of the emergency to 15 days (DAE), the accumulation of dry matter mass is slow and 

depends on the reserves of the seed. After the 30 days (appearance of floral button), the 

buildup intensifies, increasing the consumption of water and nutrients. Castro & Farias 

(2005). Table 1 presents the results of the statistical analyses, where the variability of dry 

pasta production of leaves is much larger than the stem dry mass observed by CV%, 

332.45982 and 64.40239 respectively. 

TABLE 1. Medium dry mass analyses of the leaves and stems of sunflower, held for the five 

treatment.. 

Leaves treatment 

Stem treatment 

1 0.39822 a 1 0.15231 a 

2 1.17008 a 2 0.13579 ab 

3 0.26126 a 3 0.08798 ab 

4 0.32903 a 4 0.11562 ab 

5 0.28831 a 5 0.07585 b 

DMS 1.43187 DMS 0.06434 

MG 0.48938 MG 0.11351 

CV% 332.45982 CV% 64.40239 

* Means followed by the same letter in the column do not differ significantly from each other by the Tukey test 

(P

Physical, Chemical and Microbiological Effects of Suspended 

Shade Cloth Covers on Stored Water for Irrigation 

José F. Maestre 1* , Victoriano Martínez 1 , Belén Gallego 2 , Emilio Nicolás 3 

1 Universidad Politécnica de Cartagena, ETSI Agronómica, Paseo Alfonso XIII, 48, 30203 

Cartagena 

2 Institut National de la Recherche Agronomique UMR 114 EMMAH INRA-UAPV Domaine 

St Paul Site Agroparc 84914 Avignon cedex 9 FRANCE 

3 Centro de Edafología y Biología Aplicada del Segura CEBAS-CSIC, Campus Universitario 

de Espinardo, Espinardo, 20100 Murcia 

*Corresponding author. E-mail: josef.maestre@upct.es 

Abstract 

The aim of this study was to identify the effect of installing suspended shade cloth covers 

(SSCCs) on the water quality of agricultural water reservoirs (AWRs) for irrigation. Four 

AWRs located in south eastern Spain were monitored for a year. Two of the AWRs were 

covered with a black polyethylene SSCC, whereas the two others remained uncovered 

during the experimentation period. Monthly, a multi-parametric instrument OTT-DS5 was 

used and water samples were collected to determine and analyze the main physical, 

chemical and microbiological water quality parameters respectively. 

Results indicate a slight change in the thermal behaviour of the covered AWRs during the 

warmer months. Electrical conductivity presented a slow and progressive dismissing caused 

mainly by the frequent water renewals in the AWRs. The low transmitted solar radiation (1% 

transmission through the cover) reduced dramatically the photosynthesis activity and the 

algal bloom was highly limited. However, the oxygen levels were close to saturation 

regardless the installation of the SSCC. The chemical parameters were not affected by the 

installation of the cover and there was a significant reduction of E-coli and fecal coliforms in 

covered AWRs. Overall, the results show that the implementation of SSCCs in AWRs 

produces significant effects in the stored water quality, which are mainly beneficial for 

irrigation purposes, especially with drip irrigation systems and reuse of treated waste water. 

Keywords: Shade covers, water temperature, chlorophyll-a concentration, dissolved oxygen, 

E-coli. 


In arid and semiarid regions such as the south-eastern Spain, on-farm Agricultural Water 

Reservoirs (AWRs) which are used by many farmers and water agencies to manage irregular 

water allocation for irrigation (Martínez-Alvarez et al., 2008), are characterized by a large 

area to volume ratio, which implies substantial loss through evaporation, often representing a 

significant fraction of the total water managed during the irrigation season, especially in 

areas with a high evaporative demand (Craig et al., 2007; Martínez-Alvarez et al., 2008; 

Martinez-Granados, 2011). 

Besides, AWRs present a second substantial drawback; a high nutrient loading that induces 

frequent algal blooms, resulting in serious water quality problems that can be of particular 

concern for drip irrigation systems (Brainwood et al., 2004; Sperling et al., 2008). 

The installation of Suspended Shade Cloth Covers (SSCCs) is one of the most promising 

options since in addition to reduce evaporation (reduction factor = 75 to 90%; Craig et al., 

2005; Gallego-Elvira et al., 2011), it also improves water quality by (i) reducing algal 

photosynthesis and primary production, (ii) excluding wind-borne dust and debris and (iii) 

keeping or reducing the salinity of the stored water. 

1

This method consists of covering the AWR surface with a shade cover that is supported by a 

double reticulated frame structure made of steel or polyamide cables (Martínez-Alvarez et 

al., 2009). The cables are anchored either into the storage wall or to galvanised steel posts 

bolted to concrete footings. A black double polyethylene fabric, which is porous to water, but 

reduces light transmission and wind effect on the water by 99% and 92% respectively 

(Gallego-Elvira et al., 2011), is then attached between the frames and suspended over the 

AWR. 

Concerning the previous research, SSCCs have demonstrated to be an efficient water quality 

improving technique for AWRs without inlets or outlets of water (i.e. without flow regulation 

function; Maestre-Valero et al., 2011). However, they have not been evaluated so far for 

AWRs frequently used for irrigation subjected to ongoing water renewals, where the 

regulation of the reservoir is likely to smooth the effects of shading on water quality. 

Besides, as a result of increasing water shortages that mainly affect irrigated agriculture, the 

use of no-conventional water resources such as reclaimed water currently depicts an 

alternative option that complements the conventional water supply in intensive agricultural 

systems. However, irrigation with reclaimed water needs to settle some conditions that 

minimize the risk of contamination (pathogens or toxic substances) of agricultural products, 

soil and groundwater (Angelakis et al., 2003). Thus, both physical and chemical and 

microbiological water quality parameters need to be set up and evaluated. 

This study aimed at analyzing the changes in physical (water temperature, T w ; electrical 

conductivity, EC; chlorophyll-a, Chl-a; dissolved oxygen, DO; and turbidity, W t ), chemical 

(cations: B + , Ca + , K + , Mg + , Na + and S + and anions: Cl - , NO 3 - and SO 4 2- ) and microbiological 

(E-coli and fecal coliforms) parameters of water quality in uncovered and covered AWRs 

used for irrigation. 


2.1. AWRs characteristics 

Four AWRs that regulated flows for irrigation, located in the Segura River Basin, southeastern 

Spain, were monitored for a year (March-2011 to March-2012). Two of the AWRs 

were uncovered (named U 1 and U 2 ) whereas the two other were covered (named C 1 and C 2 ) 

with a SSCC made of double black polyethylene fabric. All AWRs, with similar geometric 

characteristics, were supplied with the same water sources: a large reservoir that feeds the 

entire irrigation area with surface water through a canal, in which is incorporated to a lesser 

extent reclaimed water from a water treatment plant wastewater. 

. 

2.2. Data collection and analyses 

During the one-year experimental period, physical, chemical and microbiological analyses 

were performed. Physical parameters were monthly determined using a multi-parametric 

instrument (OTT-DS5) placed in the middle of the reservoir to measure in situ T w , EC, Chl-a, 

DO and W t . Profiles were taken from the bottom to the surface and readings at depths of 0.2, 

0.5, 1.5, 2.5, 3.5 and 4.5 m were selected from such profile measurements. Additionally, 

chemical (cations: B + , Ca + , K + , Mg + , Na + and S 2+ and anions: Cl - - 

, NO 3 and SO 2- 4 ) and 

microbiological analyses (fecal coliforms and E-coli) were performed by taking water samples 

at 1 m depth and analyzing them in laboratory according to Spanish legal framework for 

water quality monitoring and sampling (UNE-EN 25667-1,2 and 3). 

Water quality data were interpreted using an analysis of variance and the Tukey’s range test, 

at a 95% confidence level was also applied (statistical software package Statgraphics Plus 

v.5.1). Statistical analysis results indicated that throughout the trial period, Chl-a, EC and DO 

did not vary significantly with depth in both covered and uncovered AWRs and hence those 

data were graphed as the average of all of the monitored depths. 

2

3. Results 

3.1. Effects of SSCCs on physical parameters 

Water temperature 

For uncovered AWRs, the thermal behaviour was discovered almost isothermal whereas for 

covered ones, water experienced some thermal stratification during the warmer months (Fig. 

1). 

Tw (ºC) 

30 

26 

22 

18 

14 

a: C 1 

0.2 m 

0.5 m 

1.5 m 

2.5 m 

3.5 m 

4.5 m 

Covered (C1 0,2) 






Tw (ºC) 

30 

26 

22 

18 

14 

b: C 2 

0.2 m 

0.5 m 

1.5 m 

2.5 m 

3.5 m 

4.5 m 







10 

10 

6 

Mar-11 

May-11 

30 

c: U 1 

26 

Jul-11 

Sep-11 

Nov-11 

Jn-12 Jan-12 

Mar-12 

Uncovered (B1) 

6 

Mar-11 

May-11 

30 

d: U 2 

26 

Jul-11 

Sep-11 

Nov-11 

Jn-12 Jan-12 

Mar-12 

Uncovered (B2) 

Tw (ºC) 

22 

18 

14 

Tw (ºC) 

22 

18 

14 

10 

6 

Mar-11 

May-11 

Jul-11 

Sep-11 

Nov-11 

Jn-12 Jan-12 

Mar-12 

FIGURE 1: Changes in water temperature (T w ) in covered (a) C 1 , (b) C 2 and uncovered (c) 

U 1 and (d) U 2 AWRs during the one-year experimentation period. Charts a and b show T w at 

different depths in the AWR whereas charts c and d present the average value of T w at all 

depths. The discontinuities observed in the curves of the charts a and b (covered AWRs) 

represent periods in which the reservoirs did not store water at that depth. 

In Uncovered AWRs, T w was affected by the short-wave radiation that shone through the 

water profile and the incoming and outcoming long-wave radiation at the water surface, 

whereas for covered ones, T w was affected by the long-wave radiation emitted by the SSCC 

(recorded maximum cover temperature of 60ºC at midday in summer) that did not shone 

through the water profile, hence heating the shallowest layers. 

Besides, other input and output energy fluxes that varied T w in both uncovered and covered 

AWRs were based on the regulation for irrigation function of the reservoir (water that enters 

and leaves the reservoir). However, such term was important only in covered AWRs, since 

the temperature of inlet water (water in the Tajo-Segura aqueduct) was always a few 

degrees higher than the temperature of the stored water. Such mentioned different thermal 

behaviour between uncovered and covered AWRs together with the wind effect on 

10 

6 

Mar-11 

May-11 

May-11 

Jul-11 

Sep-11 

Nov-11 

Jn-12 Jan-12 

Mar-12 

3

uncovered ones, that mixed the water layers, led covered AWRs to present a slight thermal 

gradient during the warmer months (maximum of 2ºC in September). The thermal gradient 

disappeared in the fall, when the first autumn rain cooled the upper layer inducing thermal 

mixing in the water. 

Such small thermal gradient registered on covered reservoirs does not match the results 

reported by Maestre-Valero et al. (2011) who observed a thermal gradient of 12ºC between 

the deeper and surface layers in water reservoirs no-regulated for irrigation. The use of 

reservoirs for irrigation, which implied the inlet and outlet of water and therefore a short time 

of permanence of the water in the AWR, was likely to soften the effect of the installation of 

the cover on the water thermal stratification. 

Electrical conductivity 

Unlike what happens in AWRs without regulation (Maestre-Valero et al., 2011), in this study, 

where AWRs were used for irrigation, changes in the EC are the result of a water and salt 

balance that involves both the water entries as storing and rainfall and the outputs as water 

used for irrigation and evaporation. Martínez-Alvarez et al. (2009) indicated that for an 

uncovered reservoir of about 12,000 m 3 which supplies an area of about 4 ha, the volume of 

water evaporated and rainfall with respect to the regulated water volume was 14.2% and 

2.8% respectively. Such values for the same AWR in covered conditions were about 4.0%. 

Accordingly, those low percentages indicate that in regulated AWRs, evaporation and rainfall 

play a minor role in EC reductions; being EC changes mainly due to water renewals. 

Chlorophyll-a (Algae) 

In covered AWRs, the cover did not allow the proliferation of algae and hence Chl-a was 

rather low during the experimental period (< 1 μg L -1 ). For uncovered AWRs, however, the 

incidence of the solar radiation in the water favoured the photosynthesis processes and 

hence the algae proliferation. A significant difference in algae concentration was also found 

between uncovered AWRs U 1 and U 2 . Water in U 1 remained stagnant for longer periods and 

renewals were also less frequent. U 1 reached a maximum of Chl-a of 52 μg L -1 . U 2 renewed 

water more frequently only reaching a maximum of 25 μg L -1 . For both uncovered AWRs, 

maximums of Chl-a were reached in September when the climatic conditions for algae 

growth were more suitable. W t followed the Chl-a trend during the experimental period. 

Dissolved oxygen 

Maestre-Valero et al. (2011) manifested that the oxygen concentration in the stored water in 

an AWR not used for irrigation was almost completely depleted in about two months after 

installing a SSCC. Unlike what happens with DO in that kind of AWRs, DO in covered AWRs 

with regulation for irrigation, where there is a short time of permanence of the water in the 

AWR, remained close to saturation during the whole experimentation period (Fig. 2). 

Renewals of water in covered AWRs increased the DO concentration, having this factor a 

more important effect in the DO concentration than the reduction of DO by the installation of 

the SSCC. DO in uncovered AWRs was slightly higher than DO in covered AWRs. The 

continuous renewals of water and the oxygation process by oxygen diffusion on the surface 

water and generation by photosynthesis allowed reaching such higher DO concentrations. 

3.2. Effects of SSCCs on chemical parameters 

The determination of chemical parameters of water for irrigation is of substantial importance. 

For instance, Na + , B + and Cl - are toxic to plants and in addition, high concentration of Na + 

- 

2- 

may cause problems of permeability in the soil. NO 3 and SO 4 are on the one hand, a 

natural source of nutrients for plants but, instead, present a risk of water eutrophication that 

can lead to a risk of clogging drip emitters during the irrigation. Covering AWRs hardly had 

consequences in the chemical water quality parameters and statistical analyses indicated 

4

that there were not significant differences between uncovered and covered reservoirs, except 

for NO 3 - where significant differences were found in C 2 . 

Dissolved oxygen (mg l -1 ) 

16 

12 

8 

4 

UB1 

1 

UB2 

2 

C1 

1 

C2 

2 

0 

Mar-11 

May-11 

Jul-11 

Sep-11 

FIGURE 2: Changes in dissolved oxygen (DO) for the four AWRs during the one-year 

experimentation period. DO data are presented as the average of readings taken at all 

depths, as there was no significant variation with depth. 

Nov-11 

Jn-12 Jan-12 

Mar-12 

3.3. Effects of SSCCs on microbiological parameters 

Throughout the one-year experimental period, the uncovered AWRs showed higher 

concentrations of fecal coliforms and E-coli than covered ones (reduction of 82% between 

uncovered and covered AWRs). The maximum concentration of fecal coliforms and E-coli in 

uncovered AWRs was found during the summer months, when the microbiological activity 

was higher as a result of a high water temperature. Even during this period, E-Coli 

concentration did not exceed the thresholds listed in the Royal Decree 1620/2007. 


Covered AWRs for irrigation show a slight thermal gradient, which is rather different from 

that observed in no-regulated covered AWRs. Variations in the EC are mainly due to water 

renewals for irrigation. The installation of the cover limits the incidence of solar radiation, 

reducing the algae growth and the frequent renewals of water for irrigation are not able 

to increase the concentration of Chl-a. Uncovered AWRs present a significant algae growth 

during the warmer months. Dissolved oxygen concentration in uncovered AWRs is slightly 

higher than the DO in covered ones, although both values are next to saturation during the 

experimentation. Chemical parameters are not affected by the installation of the cover. In 

covered AWRs, microbiological parameters were significantly reduced since the lower water 

temperature in covered AWRs hinders the development of microorganisms. 

In short, the installation of SSCCs on AWRs improves water quality, but in general their 

effects are smoothed as a result of frequent water renewals for irrigation. In spite of this, the 

water quality changes associated with the installation of SSCCs offer many advantages for 

drip irrigation. The reduction in suspended particles reduces filtering requirements and the 

risk of emitter clogging, significantly improving water and energy use efficiency especially 

when low quality water is stored. Besides, the cover reduces the concentration of fecal 

5

coliforms and E-coli that might have negative effects on health if statutory thresholds were 

exceeded. 

Aknowledgements 

The authors acknowledge the European Union (FP-VII) and the Ministry of Science and 

Innovation of Spain for the financial support of this study through the projects SIRRIMED and 

AGL2010-15001 (co-financed by FEDER) respectively. 

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Fellows C, Fitzmaurice L, Foley J, Hancock N, Lamb D, Morrison P, Misra R, Mossad 

R, Pittaway P, Prime E, Rees S, Schmidt E, Solomon D, Symes T, Turnbull D. (2007). 

Evaporation, Seepage and Water Quality Management in Storage Dams: A Review of 

Research Methods. Environmental Health, 7, 84-97. 

Craig, I., Green, A., Scobie, M., Schmidt, E. (2005). Controlling evaporation loss from water 

storages. NCEA Publication No. 1000580/1, Queensland, 207 pp. 

Gallego-Elvira, B., Baille, A., Martín-Górriz, B., Maestre-Valero, J. F., Martínez-Alvarez, V. 

(2011). Energy balance and evaporation loss of an irrigation reservoir equipped with a 

suspended cover in a semi-arid climate (south-eastern Spain). Hydrological 

Processes, 25, 1694-1703. 

Maestre-Valero JF, Martínez-Alvarez V, Gallego-Elvira B, Pittaway P. (2011). Effects of a 

suspended shade cloth cover on water quality of an agricultural reservoir for 

irrigation.. Agricultural Water Management, 100, 70-75. 

Martínez-Alvarez, V., González-Real, M.M., Baille, A., Maestre-Valero, J.F., Gallego- Elvira, 

B. (2008). Regional assessment of evaporation from agricultural irrigation reservoirs 

in a semi-arid climate. Agricultural Water Management, 95, 1056-1066. 

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Economic assessment of shade-cloth covers for agricultural irrigation reservoirs in a 

semi-arid climate. Agricultural Water Management, 96,1351-1359. 

Martínez-Granados, D., Maestre-Valero, J.F., Calatrava, J., Martínez-Alvarez, V. (2011). The 

economic impact of water evaporation losses from water reservoirs in the Segura 

6

asin, SE Spain. Water Resources Management, 25, 3153-3175. 

Sperling, E., Da Silva, A.C., Lodolf, L.N. (2008). Comparative eutrophication development in 

two Brazilian water supply reservoirs with respect to nutrient concentrations and 

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para conservación y la manipulación de muestras”. 

7

WATER TREATMENT BY COAGULATION WITH POWDERED SEEDS 

OF Moringa oleifera IN POUCHES 

Gabriela K e Silva1*, Camila C Arantes 1 ; Ana Moreno de la Fuente 2 ; José Euclides 

S. Paterniani 3 

1 Faculty of Civil Engineering, State University of Campinas, Av. Albert Einstein, 951 - CEP: 

13083-852, Campinas/SP, Brazil. 

2 

Institute of Agricultural Science, CSIC, Calle Serrano 115bis, 28006,Madrid, Espanha. 

3 Faculty of Agricultural Engineering, State University of Campinas, Av. Candido Rondon, 501 

– CEP: 13083 – 875, Campinas/SP, Brazil. 

*Correspoding author. E-mail: gabrielaks8@gmail.com 

ABSTRACT 

This study aims to evaluate the dissolution of the protein of powdered seeds of Moringa 

oleifera enclosed in pouches and apply this method to treat synthetic turbid water, comparing 

to the coagulant in its liquid form. Five types of materials for the manufacture of pouches 

were tested, inside of which was added 2 g of powdered seeds of Moringa oleifera. In the Jar 

Test unit, the protein was dissolved in deionized distilled water with stirring at a velocity 

gradient (G) 10 s -1 . Samples were collected for protein content and turbidity during 24 h of 

dispersion. A treatment with direct addition of the powdered seeds to water was also 

performed. After establishing the suitable pouch, tests were conducted to clarify the synthetic 

turbid water. Pouches were filled with 0.6 g, 0.8 g and 1.0 g of powdered seeds. After 

dispersion of the protein in water for 30 min at 10 s -1 , the stages of coagulation (400 s -1 30 s) 

and flocculation (20 s -1 10 min) were performed. At the same time, the coagulant solution (10 

ml L -1 at 2%) was tested. Sedimentation occurred in 60 min and during this period samples 

were collected for determination of turbidity and apparent color. Analysis of variance and 

Scott-Knott test at 5% significance level were conducted. The five types of pouches provided 

protein levels higher than the dose considered adequate for 30 min of sedimentation and the 

filter paper pouch presented lower turbidity levels for a longer period during the dissolution. 

In tests for clarification of turbid water, the turbidity reduction was 64.3%, 82.6%, 97.4 and 

97.9% for the filter paper pouches containing 0.6 g, 0.8 g, 1.0 g and for the coagulant 

solution, respectively, and the apparent color removal was, respectively, 99.1%, 71.9%, 

86.7% and 97.8%. The use of paper pouch is the best suited under the conditions proposed 

in this paper and the pouches containing 1.0 g and 0.8 g of powdered seeds are not 

significantly different than the coagulant solution used in the water treatment. 

Key words: natural coagulants, coagulation, reduction of turbidity, rural sanitation. 


The consumption of water free of contaminants is essential for maintaining the human 

health. Thus, the water quality is largely discussed on several studies. The use of coagulants 

in water treatment makes physical treatment systems more efficient, since the coagulant 

destabilize and aggregate impurities which are removed in the sedimentation / flotation or 

filtration processes. 

Synthetic coagulants are not always available at a reasonable price and can leave 

undesirable residues in treated water. For this reason, the use of coagulants of plant origin is 

an option for the clarification of turbid waters, especially in rural areas and small communities 

of developing countries. Moringa oleifera is a natural coagulant whose seeds are cationic 

proteins responsible for coagulation / flocculation of impurities (NDABIGENGESERE et al., 

1995; OKUDA et al., 1999). 

Arantes (2010) studied the use of Moringa oleifera seeds as an adjunct to direct 

filtration and suggests that this technology should be improved to reduce the solids loading of 

the coagulant solution, despite the effective turbidity and apparent color removal. Pritchard et

al. (2010) studied either the conventional method of dosing the coagulant solution and muslin 

pouches with powdered seeds of Moringa oleifera by the immersion of the pouch in the turbid 

water. The authors evidenced the necessity of optimization of pouches. 

Considering the recommendations of Arantes (2010) and Pritchard et al. (2010), the 

objective of this study was to develop a new method for applying the coagulant from the 

hypothesis that the powdered seeds in pouches provide the protein and retain part of the 

organic matter that remains in the water. 

2. METHODS 

2.1. Protein dissolution 

The dissolution behavior of the protein present in the powdered seeds of Moringa 

oleifera in pouches was evaluated to determine the pouch to be used for the clarification of 

synthetic turbid water. 

Five types of materials for the manufacture of pouches were tested: stitched nonwoven 

fabric; Mellita ® filter paper and 3 types of synthetic non-woven fabrics (white, gray and 

black). 

After addition of 2 g of not sieved powdered seeds of Moringa oleifera in each pouch, 

they were closed and locked in an acrylic strip as shown in Figure 1. The area for the 

Moringa oleifera powder in pouches was approximately 31 cm -2 . 

(a) (b) (c) (d) (e) 

FIGURE 1: Pouch used: (a) black fabric, (b) gray fabric, (c) white fabric, (d) non-woven 

fabric, (e) commercial filter paper for coffee. 

Two liters of deionized distilled water were added to each jar of the Jar-Test 

equipment. Two grams of prepared powder were directly added in a jar and each one of the 

5 pouches containing the powdered seeds were placed in each jar on the Jar-Test 

equipment. The assays were carried out during 24 h. Samples were collected at 0, 1, 5, 30, 

60, 120, 240, 1200 and 1440 min. The Jar-Test was kept with slow stirring, with a velocity 

gradient of approximately 10 s -1 . The turbidity was determined according to Standard 

Methods (APHA, 2005) and the protein content was quantified by spectrophotometer with the 

modified method of Lowry (1951) as described by Madrona (2010). Each experiment was 

carried out in triplicate. 

2.2. Clarification of synthetic turbid water 

After determining the appropriate pouch, it was assessed its efficiency in water 

clarification, as well as comparison with the coagulant solution. 

2.2.1 Preparation of synthetic turbid water 

The preparation of the raw water follows the method proposed by Mendes (1989) and 

adapted by Paterniani et al. (2010). The synthetic turbid water was prepared by adding 0.2 g 

L -1 of bentonite in deionized distilled water. This mixture was taken to the Jar-Test equipment 

under agitation with a gradient of 400 s -1 for 30 min. The suspension was left for 

sedimentation for 24 h. The supernatant was collected after this period, which presented a 

turbidity of 65 NTU and was used as raw water. 

2.2.2. Preparation of the coagulant solution and determination of the dose of 

powdered seed in pouches 

The preparation of the coagulant solution was based on Ramos (2005), with 

adjustments of Arantes (2010). Non-shelled Moringa oleifera seeds were ground to powder

in a grinder and passed through a 0.84 mm sieve opening. To the resulting powder was 

added distilled deionized water at 2% w / v. The suspension was homogenized by a 

magnetic stirrer for 3 min and passed through a 0.125 mm sieve opening, resulting in the 

coagulant solution used in the experiments. 

The determination of the dose of powdered seed to fill the pouches was made from 

the correlation between the protein content of the coagulant in solution and in pouches in the 

dispersing stage. Arantes (2010) recommends a dose of 10 ml L -1 of coagulant solution (2%) 

for a 65 NTU turbidity value. This dosage was adopted when the coagulant solution was 

used and as a reference for the calculation of the doses of powdered seed to be added in the 

pouch. 

2.2.3 Clarification process 

From the assays of dissolution of protein in distilled water, it was used the period of 

30 min to dissolve the protein with a gradient velocity of 10 s -1 during the clarification stage. 

Three different doses of Moringa oleifera powdered seeds in the pouches and one dosage of 

the coagulant solution were studied. 

After dissolution of the protein (only for the pouches) coagulation (30 s at a velocity 

gradient 400 s -1 ) and flocculation (10 min at 20 s -1 ) were carried out. Sedimentation took 

place for 60 min, and samples were collected at 0, 5, 15, 30, 45 and 60 min. Turbidity and 

apparent color parameters were determined according to the Standard Methods (APHA, 

2005). 


3.1. Tests for protein dissolution 

Table 1 shows that, for each time over 24 h, the turbidity values for the five pouches 

were statistically equal (A), differing from the direct application of the powdered seed of 

Moringa oleifera in distilled water (B), when such values were higher. When each pouch is 

studied over time, the one made of filter paper shows a significant variation in turbidity value 

only after 20 h, while in the other pouches such change occurs earlier (120 min for the 

stitched non-woven fabric and 240 min for pouches made of white, black and gray fabrics). 

Table 2 shows that the protein content values were statistically equal for the 5 

pouches studied and the direct application of the powder from 60 min to 24 h period. The 

analysis of the individual pouch over time shows significant differences in protein content 

after 30 min for the stitched non-woven fabric and filter paper pouches. For the other 

pouches, significant differences occurred after 60 min. 

According to the protein content of the coagulant solution of Moringa oleifera the 

suitable pouch must release about 21.33 mg of protein per liter of turbid water. All 2 g 

pouches provided higher content of protein than the required for 30 min of dispersion. The 

paper pouch was better for the clarification of synthetic turbid water, once it presented 

convenience of manufacture and availability and took longer to show an increased turbidity 

over the 24 h.

TABLE 1: Average Turbidity values (NTU) for the various applications of Moringa oleifera powder in distilled water during 24 h and result of the 

Scott-Knott test (*) 

Method of application 

Direct application of the 

powdered 

Time (min) 

0 1 5 30 60 120 240 1200 1440 

113.80 c B 88.73 b B 68.30 b B 46.10 a B 49.87 a B 64.27 b B 80.37 b C 22.27 a B 23.33 a B 

Non-woven fabric 0.50 a A 0.60 a A 0.58 a A 1.22 a A 1.71 a A 4.27 b A 11.87 c A 12.21 c A 13.97 c A 

Black fabric 0.56 a A 0.56 a A 0.64 a A 0.94 a A 1.35 a A 3.40 a A 9.89 b A 12.10 b A 9.97 b A 

Gray fabric 0.47 a A 0.43 a A 0.85 a A 1.25 a A 1.84 a A 7.05 a A 22.22 c B 13.37 b A 11.80 b A 

Filter paper for coffee 0.40 a A 0.42 a A 0.54 a A 1.14 a A 1.74 a A 2.17 a A 2.71 a A 7.65 b A 12.79 c A 

White fabric 0.47 a A 0.53 a A 0.60 a A 1.11 a A 1.29 a A 1.63 a A 3.65 b A 9.81 c A 9.83 c A 

(*) The same lowercase letters should be interpreted as statistical similarity of data in line. The same capital letters should be interpreted as statistical 

similarity of the data in column. 

TABLE 2: Average of protein content (mg L -1 ) for the various applications of Moringa oleifera powder in distilled water during 24 h and result of 

Scott-Knott test (*) 

Method of application 

Direct application of the 

powdered 

Time (min) 

0 1 5 30 60 120 240 1200 1440 

80.25 a B 77.39 a B 97.07 a B 153.42 b C 158.02 b A 169.62 b A 187,71 c A 223.10 d A 217.39 d A 

Non-woven fabric 0.00 a A 3.98 a A 26.67 b A 99.77 c A 127.71 d A 151.52 e A 169,93 e A 235.17 f A 223.74 f A 

Black fabric 0.00 a A 0.00 a A 22.79 a A 130.25 b B 156.44 c A 169.61 c A 188,34 c A 243.10 d A 231.67 d A 

Gray fabric 0.00 a A 0.00 a A 38.02 b A 151.67 c C 168.98 d A 180.56 e A 187,55 e A 241.52 f A 228.82 f A 

Filter paper for coffee 0.00 a A 0.00 a A 9.45 a A 112.15 b A 150.88 c A 163.58 c A 177,87 c A 266.28 e A 238.98 d A 

White fabric 0.00 a A 0.00 a A 19.29 a A 133.58 b B 153.58 b A 162.79 c A 182,31 c A 262.79 d A 251.67 d A 

(*) The same lowercase letters should be interpreted as statistical similarity of data in line. The same capital letters should be interpreted as statistical 

similarity of the data in column.

3.2. Determination of the required dose of powdered seeds in the pouches 

Considering jars of 2 L capacity, it would take 20 mL of 2% coagulant solution for 

each 2 L jar for 65 NTU turbidity values (ARANTES, 2010). Based on the protein content of 

the coagulant solution and the recommended dosage, each pouch must provide the 

equivalent of 42.66 mg of protein. Once the average protein content of the paper pouch with 

2 g of powder is 112.15 mg L -1 in 30 min of dispersion time and assuming that the 

relationship between protein content and powder dose is directly proportional, the powder 

dosing in each pouch must be approximately 0.76 g. 

Therefore, the doses of powdered seeds of Moringa oleifera in the pouches were 0.6 

g, 0.8 g and 1.0 g in the clarification tests. 

3.3. Clarification of synthetic turbid water 

The average results for turbidity and apparent color of the turbid synthetic water are 

shown in Tables 3 and 4, respectively. The results of Scott-Knott test with 5% significance 

concerning the comparisons for each dosage over time and between the dosages for each 

time are also shown. 

TABLE 3: Mean values of turbidity during the sedimentation and result of Scott-Knott test 

with 5% significance (*). Raw water turbidity = 65.5 NTU. 

Dosage 

Time (min) 

0 5 15 30 45 60 

10 mL L -1 ** 89.10 A b 9.42 A a 2.94 A a 2.00 A a 1.61 A a 1.37 A a 

Pouch 0,6 g 78.30 A b 30.23 B a 25.00 B a 23.90 B a 23.53 B a 23.37 B a 

Pouch 0,8 g 81.97 A b 14.00 A a 12.59 A a 11.91 A a 11.51 A a 11.38 A a 

Pouch 1,0 g 85.77 A c 26.00 B b 4.99 A a 2.70 A a 2.07 A a 1.71 A a 

(*) The same lowercase letters should be interpreted as statistical similarity of data in line. The same 

capital letters should be interpreted as statistical similarity of the data in column. (**) Coagulant 

solution. 

TABLE 4: Mean values of apparent color during the sedimentation and result Scott-Knott 

test with 5% significance (*). Apparent color of the raw water = 316 mg Pt-Co L -1 . 

Dosage 

Time (min) 

0 5 15 30 45 60 

10 mL L -1 ** 419.00 A b 42.00 A a 11.00 A a 6.00 A a 4.00 A a 3.00 A a 

Pouch 0,6 g 361.67 A b 124.67 B a 98.67 B a 91.33 B a 90.00 B a 88.67 B a 

Pouch 0,8 g 372.00 A b 69.00 A a 47.33 A a 44.67 A a 42.67 A a 42.00 A a 

Pouch 1,0 g 397.33 A c 120.67 B b 23.00 A a 11.67 A a 9.00 A a 7.00 A a 

(*) The same lowercase letters should be interpreted as statistical similarity of data in line. The same 

capital letters should be interpreted as statistical similarity of the data in column. (**) Coagulant 

solution. 

The statistical analysis of Tables 3 and 4 showed significant reductions of apparent 

color and turbidity in the initial 5 min for the coagulant solution and the powder pouches of 

0.6 and 0.8 g, with stability after this period until the end of sedimentation. The 1.0 g pouch 

presented significant difference with subsequent stabilization only after 15 min of 

sedimentation. After this period of sedimentation (when the turbidity and apparent color 

values did not vary over time for the 4 treatments), the comparison of dosages at each time 

demonstrates that the coagulant solution and the pouches of 0, 8 and 1.0 g did not differ. 

The 0.6 g pouch differs from the others and presented less reduction in the evaluated 

parameters. 

At the end of sedimentation (60 min), the efficiency of turbidity reduction compared to 

the raw water was 97.9%, 64.3%, 82.6% and 97.4% for the coagulant solution and pouches

of 0, 6 g, 0.8 g and 1.0 g respectively. The apparent color removal was 99.1% for the 

coagulant solution and 71.9%, 86.7% and 97.8% respectively for pouches containing 0.6 g, 

0.8 g and 1.0 g of powdered seeds. 

Regarding the protein content, the coagulant solution and the pouches of 0.6 g, 0.8 g 

and 1.0 g presented respectively: 47.07 mg L -1 , 29.53 mg L -1 35.17 mg L -1 and 47.47 mg L -1 , 

which shows that the turbidity and apparent color reduction is proportional to protein 

concentration. 

4. CONCLUSION 

The use of coagulant extracted from Moringa oleifera, as powdered seeds enclosed 

in pouches, was satisfactory. Although there was no significant difference between the 

coagulant solution and the 1.0 g and 0.8 g pouches, the indexes of turbidity and apparent 

color removal showed that the behavior of the 1.0 g pouch is closer to the coagulant solution 

than the 0.8 g pouch. The coagulant solution and the 1.0 g pouch presented 97% turbidity 

and apparent removal and the 0.8 g pouch presented efficiency below 87%. 

4. ACKNOWLEDGEMENTS 

The authors thank FAPESP (Processes: 10/16223-0, 10/09395-0 e 08/53066-0) for 

financial support for the research. 

5. REFERENCES 

American Public Health Association (APHA). (2005). Standard Methods for the Examination 

of Water and Wastewater. (21rd ed.). Washington: American Public Health 

Association/American Water Works Association/Water Environment Federation. 

Arantes, C.C. Utilização de coagulantes naturais à base de sementes de Moringa oleifera e 

tanino como auxiliares da filtração em mantas não tecidas. (2010). Dissertação (Mestrado) – 

Faculdade de Engenharia Civil, Universidade Estadual de Campinas, Campinas, 2010. 

Lowry, O. H., Rosebrough, N. J., Farr, A. L. & Randall, R. J. (1951) .Protein measurement 

with the folin phenol reagent. Journal Biological Chemistry, 193, 265-275. 

Madrona, G.S. Estudo da extração/purificação do composto ativo da semente da Moringa 

oleifera Lam e sua utilização no tratamento de água de abastecimento. Maringá (2010). 

Tese (Doutorado) – Universidade Estadual de Maringá, Maringá, 2010. 

Mendes, C. G. N. Estudo da Coagulação e Floculação de Águas Sintéticas e Naturais com 

Turbidez e Cor Variáveis. (1989) Tese (Doutorado) - Escola de Engenharia de São Carlos. 

Universidade de São Paulo, São Carlos, 1989. 

Ndabigengesere, A., Narasiah, K.S. & Talbot, B.G. (1995). Active agents and mechanism of 

coagulation of turbid waters using Moringa oleifera. Water Research, 29 (2), 703-710. 

Okuda, T., Baes, A. U., Nishijima, W. & Okada, M. Improvement of extraction method of 

coagulation active components from Moringa oleifera seed. Water Research, 33 (15), 3373- 

3378. 

Paterniani, J. E. S., Ribeiro, T. A. P., Mantovani, M. C. & Sant’anna, M. R. (2010). Water 

treatment by sedimentation and slow fabric filtration using Moringa oleifera seeds. African 

Journal of Agricultural Research, 5 (11), 1256-1263. 

Pritchard, M., Craven, T., Mkandawire, T., Edmondson, A. S. & O’neill, J. G. (2010). A 

comparison between Moringa oleifera and chemical coagulants in the purification of drinking 

water – An alternative sustainable solution for developing countries. Physics and Chemistry 

of the Earth, 35, 798-805, 2010 

Ramos, R. O. Clarificação de água com turbidez baixa e cor moderada utilizando sementes 

de Moringa oleifera. (2005). Tese (Doutorado) – Faculdade de Engenharia Agrícola, 

Universidade Estadual de Campinas, Campinas, 2005.

ANALYSIS OF LEVELS OF LAND DEGRADATION USING LANDSAT- 

5, MUNICIPALITIES OF ARARIPINA (PE) CRATO AND BARBALHA 

(CE) AND MARCOLÂNDIA (PI), BRAZIL. 

Abstrat 

Maria F. Fernandes 1 ; Marx P. Barbosa 2 ; João M. Moraes Neto 3 

1,2,3 


Rua Aprigio Veloso, 882, Campina Grande-PB - 58429-970, Brasil. 

fatima, marx, moraes (@deag.ufcg.edu.br) 

This study aimed to map the levels of land degradation in the municipalities of Araripina in 

the State of Pernambuco, Crato and Barbalha, State of Ceará and Marcolândia State of 

Piauí, and may also be considered as a basis for creation of public policy to combat 

desertification, taking into account that the realization of the comparative analysis of the 

evolution of the levels of land degradation for the periods between the years 1987, 2003 and 

2008, shows a local knowledge base about the installation of the process of land degradation 

in the municipalities. The paper focuses on the characterization, quantification and 

localization of areas at risk of desertification, using TM/Landsat-5 images. The comparative 

analysis of land degradation for the studied municipalities shows that the situation of land 

degradation in the municipalities in the considered period is worrying, therefore, this work 

constitutes a warning to local governments to adopt measures to combat land degradation. 

Key words: land degradation, desertification, digital processing 


The concept of desertification, as stated in Article 1º of the United Nations Convention to 

Combat Desertification (UNCCD, 2007) refers to: "desertification means land degradation in 

arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic 

variations and human activities". The Convention considers the arid, semi-arid and dry subhumid 

areas as “the areas, other than polar and sub-polar regions, in which the ratio of 

annual precipitation to potential evapotranspiration falls within the range from 0.05 to 0.65”. 

While establishing the definition of land degradation, as: "land degradation is the reduction or 

loss, in arid, semi-arid and dry sub-humid areas, of the biological or economic productivity 

and complexity of rain fed cropland, irrigated cropland, or range, pasture, forest and 

woodlands resulting from land uses or from a process or combination of processes, including 

processes arising from human activities and habitation patterns, such as: (i) Soil erosion 

caused by wind and/or water; (ii) Deterioration of the physical, chemical and biological or 

economic properties of soil; and long-term loss of natural vegetation” (UNCCD, 2007). 

In this sense, the Convention recognizes that desertification has its origin in the complex 

interactions of physical, biological, political, social, cultural and economic factors. (Brazil, 

2005). The consequences of the desertification can be of various natures, including: 

environmental and climate, social, economic, political and institutional (Cavalcanti, 2001). 

Thus, it may to list among others: reduction of water resources for both human consumption 

and for agriculture, increased water pollution, increased flooding, decreased productivity of 

agricultural areas and pastures, as well as biomass production of natural vegetation, 

destruction of fauna and flora. 

1.1. Characterization of the study area 

The study area comprises four municipalities, Araripina located in the State of Pernambuco, 

Crato Barbalha in the State of Ceará and Marcolândia in the State of Piauí (Fig. 1).

FIGURE 1: Location of the study area in the states of Ceará, Pernambuco and Piauí. 

The Table 1 shows the main characteristics of the municipalities of the study area. 

TABLE 1: Main characteristics of the studied municipalities. 

General data 

Municipalities 

Araripina Barbalha Crato Marcolândia 

Area (km 2 ) 1.893 599 1.158 144 

Altitude (m) 622 414 426 873 

Urban Population 46.908 38.022 100.916 6.707 

Rural Population 30.394 17.301 20.512 1.105 

Population density (in habitants/km 2 ) 40,84 92,31 104,87 54,30 

2. Methodology 

In support of the work was used the software SPRING (GIS and remote sensing image 

processing system), version 5.1.5., public domain, developed by the National Institute for 

Space Research (INPE), maps plani-altimetric from Northeast Development 

Superintendence (SUDENE) and multi-spectral TM/Landsat-5 images, orbit 217/65 dated 

September 12, 1987, August 23, 2003 and September 21, 2008, and orbit 218 / 65 dated 

August 18, 1987, June 27, 2003 and October 14, 2008. The digital image processing aimed 

to map the levels of land degradation in the studied municipalities. The initial phase of work 

consisted in processing and image classification, by means of computational techniques, and 

adopted the following procedures: preprocessing, enhancement techniques, arithmetic - ratio 

of bands in obtaining NDVI images (Normalized Difference Vegetation Index) Multispectral 

Adjusted Composition (MAC – RGB composition b3, NDVI, b1), image segmentation, pattern 

classification of the NDVI images and thematic maps publishing. 

The adopted methodology for the interpretation of TM/Landsat-5 images consisted of a 

deductive approach and a comparative analysis of the levels of land degradation based on 

visual interpretation which is based on the Systematic Method of Veneziani & Anjos (1982).

This methodology consists of a sequence of logical and systemathic steps that are 

independent of the knowledge of the study area and the use of photo interpretation keys. The 

fieldwork aimed to validate the results obtained from visual analysis and digital image 

processing of TM/Landsat-5 images, and collect information to compose the georeferenced 

database, based on the description of the visited places. The field work was recorded using 

digital camera, and places were georeferenced using a GPS. Regarding the legend for the 

mapping of land degradation levels were considered five levels of land degradation: very low, 

low, moderate, severe and very severe, based on Barbosa et al. (2005). 

3. Results 

Data on land degradation from visual analysis of TM/Landsat-5 images for the years 1987, 

2003 and 2008 (Fig. 2) indicate risks to desertification for the municipality of Araripina, State 

of Pernambuco. The results show that within two decades (1987-2008) the increase of areas 

under very serious level of degradation was significant and require urgent action to create 

public policies for the region, aiming the sustainability of the families living in areas where the 

process of desertification is occurring. 

FIGURE 2: Digital maps of the land degradation levels for the municipality 

of Araripina, State of Pernambuco. 

In the municipality of Araripina, the highest occurrence of the level very serious of land 

degradation has been identified especially where large mining companies are located. For 

example, in the area of extraction of gypsum the reject of mine is deposed without any 

environmental control, influencing the degradation of land and of the savanna vegetation 

already very impacted (Fig. 3 - A and B).

FIGURE 3: A – General view of the gypsum mine; B – area of the mine reject. 

The digital map of the land degradation levels for the municipalities of Barbalha and Crato in 

the State of Ceará, related to the years 1987, 2003 and 2008 (Fig. 4) clearly shows the risks 

to the process of desertification, with particular attention for the areas of the Araripe National 

Forest (FLONA) that even with low levels of degradation requires vigilance not to progress to 

more serious levels. In the municipality of Barbalha for the period of 1987/2008 the increase 

for the level serious of land degradation was 8.69%, and for the very serious corresponded to 

9.55%. In the municipality of Crato for the same period, the level serious of land degradation 

represented 16.50% and for the very serious level of land degradation corresponded to 

19.66%, representing a significant advance the process of land degradation in these 

municipalities. 

FIGURE 4: Digital maps of the levels of land degradation for the municipalities of: A) 

Barbalha B) Crato 

In the municipality of Barbalha, for example, the levels severe and moderately severe of land 

degradation are relating to clay extraction area. Fig. 5.A shows the appearance of these 

levels of land degradation along the highway CE-180. These levels also occur at the 

entrance to the Park Arajara in the municipality of Barbalha (Fig. 5. B and C), where is the 

largest source of fresh water in sandstone formation, with a flow rate of 240,000 l/h. 

The occurrence of the level serious of land degradation was observed at various places in 

the municipality of Crato, as near the urban area and the route to Arajara, in the village Ponta 

da Serra, where the slope of the mountain was cleared for pasture, and today has a high 

population density and presence of some quarries.

FIGURE 5. A – Area of exploitation of clay - level serious of land degradation. B and 

C – Partial view of slopes of the Araripe Mountain, showing areas of landslides. 

Municipality of Barbalha. 

In several places the exploitation of clay (Fig. 6 A and B), to supply the ceramic industries in 

the region, is present, as well as extensive areas explored in cattle raising that surpass the 

other agricultural activities, such as sugarcane. The mountain slopes are being cleared to 

supply as much the potteries of firewood as a cheaper source of energy and for use as 

pasture. The biomass burning was fairly observed during field work (Fig. 6 C). 

FIGURE 6: A – Area of exploitation of clay. B – Another view of area of exploitation of clay. 

C – Biomass burning 

Analyzing the land degradation in the municipality of Marcolândia, State of Piauí, and 

considering the years 1987, 2003 and 2008 (Fig. 7), the level very low of land degradation 

occurs only in 1987. 

FIGURE 7: Digital maps of the levels of land degradation. 

Municipality of,Marcolândia, State of Piauí.

When analyzing the data for the year 2008, it is possible to verify a deep modification of the 

local landscape, where the areas of occurrence of the levels serious and very serious of land 

degradation increased around 43.17% and 17.51% , respectively. The level very serious of 

land degradation was not identified between the years 1987 and 2003, however, in 2008, this 

level appears and represents 17.51% of the municipality. Activities that contributed to land 

degradation are related to the exploitation of material for construction, deforestation of 

savannah, livestock, cassava monoculture, forest fires and the presence of pests such as 

termites and ants. Given the diversity of use and occupation of land, part of the municipality 

is moving to the moderate to severe level, whose indicator is related to removal of material 

building construction, and natural vegetation has suffered environmental impacts in relation 

to the difficulty of regeneration, and in many places, due to impacts from activities of 

livestock, the land are like abandoned areas (Fig. 8. A and B). 

FIGURE 8: A – Areas of pasture in the lower part of the municipality - level moderate of land 

degradation, with characteristics of abandoned lands. B – Area of level moderate to serious 

of land degradation. Exploitation of the soil for civil construction. 

4. CONCLUSIONS 

The results indicated a strong tendency that natural resources in the municipalities 

studied, over time have suffered environmental imbalance, with areas at risk of 

desertification and with a strong impact in terms of land degradation on the one hand, and 

secondly the results point to the inefficiency of the government to create public policies to 

combat desertification and mitigating the effects of drought, which would allow the socially 

and environmentally sustainable development, with risk reduction. 

4. REFERENCES 

Barbosa, M. P.; Fernandes, M. F. de.; Silva, M. J. da.; Guimarães, C. L.; Costa, I. C. da. 

Diagnóstico Socioeconômico Ambiental da APA Chapada do Araripe: Ceará, Pernambuco e 

Piauí. Convênio ATECEL/GRUPO GESTÃO. Campina Grande, PB, 2005. 231p. 

BRASIL. Ministério do Meio Ambiente. Secretaria de Recursos Hídricos. Programa de Ação 

Nacional de Combate à Desertificação e Mitigação dos Efeitos da Seca: PAN - Brasil. 

Brasília, DF, 2005. 242p. il. 

Calvancanti, E. Para compreender a desertificação: uma abordagem didática e integrada. 

Instituto Desert: Teresina, 2001. Disponível em: 

http://ambientes.ambientebrasil.com.br/agropecuario/artigo_agropecuario/desertificaca.html 

UNCCD. Convención de las Naciones Unidas de Lucha contra la Desertificación y la Sequía. 

Proceso de implementación em América Latina y el Caribe (1994-2006). 2ª. Edición. 2007. 

Veneziani, P. a Anjos, C. E. Metodologia de interpretação de dados de sensoriamento 

remoto e aplicações em geologia. INPE. São José dos Campos. 1982. 61p.

Water technology improvements and their effect on the profitability 

of mediterranean woody crops under different water pricing 

policies 

Maria-Dolores de-Miguel 1 *, Francisco Alcon 1 , Maria-Angeles Fernandez-Zamudio 2 

1 Dpto. De Economia de la Empresa, Universidad Politecnica de Cartagena, Paseo Alfonso 

XIII, 48, Cartagena (Murcia), 30203, Spain 

2 Dpto. Horticultura, Instituto Valenciano de Investigaciones Agrarias, Ctra. Moncada- 

Naquera km 4.5, 46113, Moncada (Valencia) 

*Corresponding author. E-mail: md.miguel@upct.es 

Abstrat 

In this paper it is analyzed the impact of the Water Framework Directive on traditional woody 

crops that characterize the south-eastern Spanish Mediterranean region (olives, almonds, 

vineyards and table grapes). With the calculations of irrigation water demand curves, the 

maximum price that farmers can afford for water resources were obtained. Thus enabling us 

to deduce the effects that the irrigation water profitability and price have on the viability of 

these crops. Also, in this paper the impact of technological leap has been considered, 

moving from a more manual context to another more mechanized one. In the Results section 

it is discussed how the amount of water available is usually a key factor in the choice of crop. 

However, the price of water is relevant to decision-making due to a pricing policy that raises 

irrigation water costs can be expected to increase and speed up the abandonment of 

farmlands. There is evidence that technology provides more effective exploitation, improving 

the production process and enabling farmers to afford higher prices for irrigation water. 

Key words: Farm viability, demand curves, table grapes, olives, almonds, vineyards. 


Woody crops play a fundamental role in Mediterranean Spanish regions. Irrigated farmlands 

of citrus and a wide range of fruit-trees are characteristic of the Valencian Community and 

the Region of Murcia, for instance. These are intensively grown crops whose production is 

destined for fresh consumption, and are highly competitive due to the large proportion that is 

exported. However, there are other crops commonly grown in the inland areas which, 

although not weighty in economic terms, are of major importance. Examples are the irrigated 

table grapes, olives, almond trees and vines which are grown mostly under rainfed 

conditions. 

To encourage a sustainable use of water in agriculture, the recently entered into force 

European Water Framework Directive (WFD) proposes the full cost recovery related to water 

services under the polluter pay principle. For this end, a water pricing policy should be 

established by Member States and, it is foreseeable that the price of irrigation water will 

increase in such a way that the final price to be paid by the grower will cover all of the costs 

(economic and environmental) incurred in delivering it. But the prices of most agricultural 

products are increasingly lower, and any increase in production costs may seriously affect its 

profitability. 

In this context, the objective of this study is to analyze the potential trend of certain Spanish 

Mediterranean woody crops, on the establishment of water tariff policies that differ from 

those currently implemented. To achieve this goal, the water demand curves obtained for 

olives, vineyard, almond trees and table grapes have been analyzed. 

1.1 Background 

1

Numerous papers are found in scientific literature that determine the economic effects of the 

application of different water policies or the adoption of one type of irrigation system or 

another. Works related with irrigation water management in Mediterranean crops are: 

Gurovich (2002) studied the energy cost of irrigating the Chilean table grape; Bazzani et al. 

(2004) investigated the effects of putting into practice the Water Framework Directive in 

Europe; Jorge et al. (2003) carried out an economic evaluation of the consequences of 

drought on the Mediterranean crops; and Fernández-Zamudio et al. (2007) obtained 

irrigation water demand curves for the Spanish table-grape. 

Economic theory sets that farmers would respond to an increase in water prices by reducing 

their consumption, in accordance with a negative slope demand curve. The tariff policy 

applied must consider the specific conditions of each irrigation area, since its effect will be 

very different depending on their characteristics. Specifically, in south-eastern Spain, where 

the irrigation water demand curve is usually inelastic, a tariff policy would be valid only from 

the standpoint of cost recovery, but is not expected to be so from the water savings 

perspective (Sumpsi et al., 1998). 

1.2 Mediterranean tree crops 

Spanish Mediterranean dry-farming is predominant in the large inland extension, and the 

most traditional and characteristic crops are the olive (Olea europea), the vineyard (Vitis 

vinifera) and the almond (Prunus dulcis). All of them are shared in the farms in different 

proportions. These crops have helped in maintaining the countryside, which is one of the 

marks of the cultural identity of these regions, protect the soil from erosion, and they can also 

be considered an important promoter of human activity. 

The size of the farm also exerts an influence, but in contrast to the small-holding structure 

that is characteristic on the coast. In inland regions, the land is not considered as such a 

restrictive factor and, normally, it is rather the lack of family labour needed to cultivate the 

farm in optimum conditions. It leads to “Marginal management”, defined as semiabandonment 

non-definitive, in which these three tree crops survive left to the mercy of the 

climate. This is often the case in the regions under study and at specific periods of time 

when, due to the lack of labour or profitability, the farmers do not optimize crop care and limit 

it to a minimum (Fernández-Zamudio et al., 2006). 

Table grape is a very typical Mediterranean crop, accounting for 79.3% of the area and 

88.8% of the production between the Regions of Murcia and the Valencian Community 

(MARM, 2011). Both these regions are situated next to the Mediterranean, have a warm 

climate, but are greatly lacking in rainfall, with average precipitation of below 300 mm 

annually. Water is the scarcest and most valuable natural resource, given the overexploitation 

of aquifers or its low quality, and is the main reason why this crop is partially 

abandoned. The temporal marginal management are common in table-grape, that is to say, 

they are left to basic care for a certain amount of time, which habitually consist of 

maintenance pruning and minimum tillage. If the circumstances that have favoured this 

situation (scarcity of irrigation water, lack of personal and economic incentive of the 

agricultural producers, etc.) are longer lasting, then this abandonment becomes definitive. 

Rejecting optimum crop management is a common practice in these regions of production, 

and faced with the lack of irrigation water, the choice is to destine the one available to the 

most economically viable plots. 

2. Information and methodology 

In order to analyze the effects that irrigation water availability and price have on the 

profitability of the woody crops, several mathematical calculations have been used in this 

work. With the calculations of irrigation water demand curves, the maximum price that 

farmers can afford for water resources has been obtained. 

2

The Multiattribute Utility Theory (MAUT) has been used to derive water demand curves in 

rainfed crops In essence, MAUT consists of being able to establish a mathematical function 

U, which encompasses the utility resulting from a series of attributes, which are previously 

considered according to the importance each of them has for the decisor (Keeney and Raiffa, 

1976). In table grape, the demand curves have been obtained using a lineal mathematical 

programming model. 

2.1 Analysis approaches in rainfed crops 

The MAUT is obtained for two objectives: maximization of the net margin of the farm and 

minimization of total workforce. The mathematical expressions are: 

Max 

n 

∑ 

i= 

1 

NM i 

⋅ X i 

Min 

n 

∑ 

i= 

1 

TL i 

⋅ X i 

Where NM i is the net margin of the activity i, X i is the surface area, and TL i is total labour 

employed annually. 

Family farms predominate in the Mediterranean inland regions; therefore, the analysis is 

carried out choosing a representative farm, with 32 hectares of land and a full-time family 

Agricultural Work Unit (AWU). Within the Valencian Community, the study was located in the 

l'Alcoià area, in Alicante province. 

The calculations have been applied to two modelization scenarios that are real in these 

regions, and the differences are exclusively in the degree of mechanization existing on the 

farm. In the “manual-scenario” low-powered mobile equipment was used together with 

traditional harvesting and hand-picking, and in the “mechanized-scenario” higher-powered 

mobile equipment is considered. In this study the decision variables, or unknowns of 

optimization, are the surface area in farm for each crop-growing activity. To bring the models 

closer to the real conditions in the region, a number of restrictions have been taken into 

account, and have been introduced equally in both scenarios: 

- At maximum 30% of the available surface area can be subject to marginal management, 

concept already defined above. 

- The maximum surface area of each species is limited to its present value (32% in olive, 

8% in almond and 60% in vineyard). This restriction permits changes in variety within a 

species, changes in the type of irrigation, or for this to pass to marginal management. 

- It is established that only 10% of the available surface area can receive some kind of 

irrigation, the water supplied cannot exceed 600 m 3 monthly for the whole farm, and that 

the total amount allotted to the farm is of 5,000 m 3 annually. The current price of irrigation 

water is 0.15 €/m 3 . 

- The other restrictions are derived from manual labour. An AWU to be 2,160 hours a year, 

and hired labour is limited to complement what cannot be covered by family on a threemonthly 

basis. 

2.2 Analysis approaches in irrigated crops 

The Spanish table-grape farms are very small in size, 72% of those in Alicante (Valencian 

Community) and 66% of those in Murcia are smaller than 5 ha (INE, 2011). For this raison, in 

this study, a 5 ha family farm has been used as reference. The two cropped areas are Valle 

del Vinalopó (Alicante) and Valle del Guadalentín (Murcia), geographically next but 

technically and managerially different. 

In the Valle del Vinalopó there are 9,500 ha of grape. Its most defining feature is its 

“bagging”, by which the bunches of grapes are covered by a paper bag. Technology is found 

at an acceptable level, but it is possible to improve the mechanization. The varietal 

composition has undergone scarce variation over time, and is fundamentally based on the 

Italia and Aledo varieties, and seedless varieties will be introduced, which are still in minor 

representation. The situation is different in the Region of Murcia, where the surface area 

dedicated to grape has increased in recent years, reaching 5,200 hectares and where new 

3

production zones have appeared, with large business producers and a strong bid for 

seedless varieties. In general terms one can also talk about family farms, but the important 

investment in capital and technology mean that noticeable differences exist between Murcia 

and Alicante. There is intense activity concerning the introduction of new plant material, the 

traditional varieties like Italia and Ohanes have diminished, and instead there has been an 

increase in the surface area planted with seedless or early varieties, such as Superior and 

Crimson. 

Currently, in both regions, is bringing about massive implementation of drip irrigation. This 

type of irrigation covers 50% of the surface area at present, and it is foreseeable that it will 

reach 90% soon. The shortage of irrigation water in these zones, the irregularity of the 

supplies and the deficiencies in the quality, also encourage the grape-growers to construct 

water accumulation reservoirs, which is more widespread in the Murcia region. 

Therefore, the technological improvements that are being adopted more quickly in Spanish 

table-grape cultivation are: an increase in the average power of the machinery to carry out 

the labour and the phyto-sanitary treatments, use of tying machines for the summer pruning, 

use of pre-pruners (in espaliers), generalized use of shredders for the pruning remains and 

substitution of the traditional irrigation systems for programmed drip irrigation. Moreover, they 

are improvements that are beginning to spread to the new staking structures (higher espalier 

in Y in Alicante), and the use of mesh or plastic covering, which are common in Murcia. 

Two technological scenarios are analyzed. "Scenario-1", representing the traditional 

conditions of production of table grapes in the two areas, and the "scenario-2", which takes a 

series of technological improvements. 

The restrictions of the models are a maximum monthly and yearly irrigation allotments, 

maximum area of cultivation that will be subject to adoption of drip irrigation, change to Y 

trellises and covering with net screening, as well as those restrictions derived from the 

market (new varieties introduction). 

To obtain the demand curves a lineal mathematical programming has been applied, being 

the objective: 

Max 

n 

∑ 

i=1 

NM ⋅ X − Q ⋅ X ⋅ p 

i 

Where NM i is the net margin of the activity i, X i is the cultivated area, Q i its yearly quota of 

irrigation water. Also, p q is the price of irrigation water for each parameter (from zero to 4 

Euros per cubic meter). This is the real price that the grower pays for each cubic meter of 

water; this price includes administrative costs of delivery. 

i 

i 

i 

q 

3. Results 

The demand curves obtained for rainfed crops are shown in Fig.1 In the manual scenario, 

there is a first range of maximum demand, between 0 and 0.51 €/m 3 ; it continues with a drop 

to half the demand for tariffs of 0.52 to 0.55 €/m 3 and ends up with cropping plans in 

completely dry-farming when the water costs over 0.56 €/m 3 . In the mechanized scenario the 

demand is constantly at maximum until it reaches 0.91 €/m 3 , at which point the chosen 

cropping plan changes to one that is strictly dry-farming. The different response must be 

looked at in the different degree of mechanization. Technology improves management and 

enables farms to face more effectively the greater labour requirements that arise from 

irrigated crops. This limitation is accentuated if the labour (especially harvesting) is carried 

out manually, and for this reason the mechanized farms are better able to pay higher water 

prices. 

The results of the demand curves for table grape are Fig.2 where it is observed that the 

production units in Murcia demand more water than those of Alicante, up to 0.60 €/m 3 , a 

price at which Murcia would begin to reduce consumption. The curves of scenario-2 show a 

4

higher demand than those of scenario-1 since, if the grower has technology, other limitations, 

such as labour, can be compensated, and more productive varieties will be planted, but 

these consume more water. 

6000 

FIGURE 1. Demand functions for irrigation water for the two scenarios in 

Spanish dry-lands 

4,0 

FIGURE 2. Irrigation water demand curves in Spanish grape-table 

(Data for 5 ha production unit) 

5000 

3,5 

) 

34000 

(m 

n 

tio 

p 

3000 

m 

u 

s 

n 

o 

C 

2000 

1000 

0 

0 0,2 0,4 0,6 0,8 1 

Price of irrigation water (euros/ m3) 

3 ) 3,0 

/m 

s 

ro 

u 2,5 

(E 

e 

2,0 

ric 

p 

r 

te 1,5 

a 

W 

1,0 

0,5 

0,0 

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 

Yearly consumer (m3) 

manual-scenario 

mechanized-scenario 

Alicante scen-1 Alicante scen-2 Murcia scen-1 Murcia scen-2 

Since the demand for water only begins to decrease when prices are very high, availability of 

the resource is an even greater limitation than its price. Analyzing the repercussion of the 

price of water on net profit (Fig.3), it can be observed that with prices above 1.5 €/m 3 only a 

very low profit is obtained, or there may even be losses. If a first reference income is set at 

18,000 € to compensate the yearly work of the entrepreneur, the maximum price that small 

grape growers in Alicante can afford is 0.25 €/m 3 in scenario-1 and 0.60 €/m 3 in scenario-2. 

In Murcia, this reference income is achieved when prices are lower than 0.15 € per cubic 

meter in scenario-1, while the current price of water is 0.18 €/m 3 , meaning that only those 

growers with more technology are achieving profits. In the case of implementing the 

improvements of scenario-2, in Murcia it is possible to surpass the reference income when 

the price of water is not more than 1.1 €/m 3 . If proposing an income of farmer of 22,000 € 

(income ref-2), only are feasible for two regions the scenarios most technologically 

advanced. 

40000 

FIGURE 3. Repercussion of the price of water on net profit in Spanish grape-table 

(Data for 5 ha production unit) 

35000 

) 

s 

ro 

u 30000 

(e 

r 

m 

fa 25000 

in 

rg 

a 20000 

M 

t 

e 

N 

15000 

10000 

5000 

0 

0 0,5 1 1,5 2 2,5 3 3,5 

Water price (euros/m 3 ) 

Murcia scen-1 Murcia scen-2 Alicante scen-1 

Alicante scen-2 Income-ref-1 Income-ref-2 


With the goal to analyze the trends of the most important Mediterranean woody crops in the 

context of different tariff policies, water demand curves have been used. These calculations 

have been applied to olives, almonds and vineyards grown in the inland regions of the 

Valencian Community, and table grapes in the two main production areas in the southeast 

Spanish Mediterranean region. 

Technology can offset other agronomic technical limitations of the farm-holding, and 

optimizing the production process. Usually farmers believe that technology is their best 

strategy to improve farm viability, although, technological improvements allow more 

5

productive varieties to be grown, which typically require more water and more 

technologically. 

Irrigated crops with moderate irrigation requirements, such as table grapes, show highly 

inelastic demand curves, at least in the first price phases. As this resource becomes more 

expensive, demand falls while the surface area with marginal management increases, which 

may be the step prior to future crop abandonment. For the typical rainfed crops, the demand 

curves display strong inelasticity, demonstrating the huge value of having an extra cubic 

meter of water, this to be applied at specific moments and in low doses. In general, 

Mediterranean crops make very efficient use of the water supplied, even at doses below 

agronomic irrigation needs. Allocations should be supplied at the point in time most crucial to 

the crop, which often coincides with reduced water availability, and this availability becomes 

a more limiting factor than the price. This does not mean water high prices can be paid, since 

the real affordable price is much lower. 

Water prices to be paid can theoretically be very high, which does not indicate that sustained 

high prices are to be met. In fact, the first step taken by farmers is to increase the surface 

area with marginal management (prior step to abandonment) and concentrate investment in 

the more profitable fields or varieties. Therefore, it is foreseeable that a tariff policy 

implementing high prices would result in the gradual abandonment of Mediterranean crop 

cultivation and thereby reduce the economic activity in large tracts of land, especially in the 

inland regions. 

6. Acknowledgment 

We are grateful to the financial aid received from the Spanish Ministry of Science and 

Innovation and the ERDF through the GEAMED project "Gestión y eficiencia del Uso 

Sostenible del agua de Riego en la Cuenca mediterránea" (AGL2010-22221-C02-01). 

References 

Bazzani, G.M., Di-Pasquale, S., Gallerani, V. & Viaggi, D. (2004). Irrigated agriculture in Italy 

and water regulation under the European Union water framework directive. Water 

Resource Research, Vol. 40(7), W07S04. ISSN 0043-1397 

Fernández-Zamudio, M.A. & De-Miguel, M.D. (2006). Sustainable management for woody 

crops in Mediterranean dry-lands. Spanish Journal of Agricultural Research, Vol. 4(2), pp. 

111-123. ISSN: 1695-971-X 

Fernández-Zamudio, M.A., Alcón, F. & De-Miguel, M.D. (2007). Irrigation water pricing policy 

and its effects on sustainability of table grape production in Spain. Agrociencia, Vol. 41(7), 

pp. 805-845. ISSN: 1405-3195 

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for saving irrigation water and energy cost in Chile. International Water Irrigation, Vol. 

22(2), pp. 44-50. 

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la estructura de las explotaciones agrícolas. Available from 

http://www.ine.es/inebase/menu6_agr.htm 

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MARM (Ministry of Agriculture, Fisheries and Food of Spain). (March, 2011). Anuario de 

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Sumpsi, J.M., Garrido, A., Blanco, M., Varela, C. & Iglesias, E. (1998). Economía y Política 

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Ed. Mundi Prensa, ISBN: 84-7114-781-5, Madrid, Spain. 

6

YIELD AND BEAN SIZE OF COFFEA ARABICA (CV CATUAÍ) 

CULTIVED UNDER DIFFERENT POPULATION ARRANGEMENTS 

AND WATER AVAILABILITY 

Eduardo A. A. Barbosa 1 , Emilio Sakai 2 , Jane M. C. Silveira 3 , Regina C. M. Pires 2 

1 Ph.D. Student in Agricultural Engineering, FEAGRI/UNICAMP, Campinas – SP; 

2 Researcher, D.Sc, (IAC/APTA), Campinas –SP; 3 Researcher, D.Sc, APTA Regional 

Nordeste Paulista, Mococa –SP. 

Abstract: The purpose of this research was to evaluate the effect of drip irrigation under 

different population arrangements on coffee productivity and bean size classification 

according to sieve retention of two harvests (2008/2009 and 2009/2010). The experiment 

with Coffea arabica L. cv Catuaí was carried out in Mococa, São Paulo, Brazil. The 

experimental design was a 6 x 2 factorial scheme in randomized blocks, with four 

replications. The six densities of plantation were E1 (1.60 x 0.50); E2 (1.60 x 0.75); E3 (1.60 

x 1.00); E4 (3.20 x 0.50); E5 (3.20 x 0.75) and E6 (3.20 x 1.00), which were divided in 

irrigated and non-irrigated groups. Data were submitted to analysis of variance and averages 

compared by Tukey test at 1 and 5% of probability. In the first two years of Catuaí coffee 

crop cultivation, the adoption of irrigation was more advantageous in denser crops, ensuring 

higher production of processed coffee. In the first years the adoption of irrigation technique 

provided an increase in bean size. In this cycle the average temperatures during the grain 

filling stage, were lower than the observed temperatures in the 2009/2010 crop cycle. When 

there was high water availability due to the rain, irrigation did not affected grain size and 

grain type, but when there was low water availability, the adoption of irrigation technique 

increased grain size. In the first year, the cultivation without irrigation had a higher 

percentage of peaberry beans in relation to irrigate group. The production of peaberries is 

partially related to adverse environmental factors, mainly in the flowering and fruiting. So 

appropriate management of irrigation in these phases provided better conditions for the 

formation of beans, thus reducing the percentage of peaberries. 

Keyword: Drip irrigation, Plant density, Fertigation 


The adoption of irrigation in coffee crop is becoming increasingly common (Rezende et al. 

2006) due to increases in grain yield provided by the technique, since the soil water deficit is 

a main factor that affects the productivity of coffee (DaMatta & Ramalho, 2006). Other benefit 

of irrigation system is to allow a lower dependence on climatic factors. In Brazil, according to 

the study of Esperancini and Paes (2005), adoption of drip irrigation has been shown as 

economically viable. 

The adequate water supply to plants favors photosynthesis and therefore greater availability 

of assimilates to fill the coffee beans (Barros et al 1997). In the culture of coffee, studies on 

the use of irrigation show different effects on grain size. Rezende et al. (2006) and Silva et al. 

(2009) found effect on the average sieve with the use of irrigation and Custodio et al (2007), 

analyzing five seasons, found no effect of irrigation in four seasons. Another advantage of 

irrigation in coffee is the synchronization of flowering, allowing a more uniform ripening of the 

grains (Masarirambi, 2009).

Studies related to population arrangements in irrigated crops are essential for a greater 

maximization of production and use of natural resources. Esperancini and Paes (2005) found 

that the denser culture system, the best economic results when using drip irrigation. Thus, 

the purpose of this research was to evaluate the effect of drip irrigation under different 

population arrangements on coffee grain yield and grain size classification according to sieve 

retention of two harvests (2008/2009 and 2009/2010). 


The experiment was carried out in the Agribusiness Technological Development Cluster of 

Northeast of São Paulo State, located at latitude 21°28'S, longitude 47°00'W and altitude 663 

m. The climate according to Köppen is Cwa, featuring dry winters and warm and wet 

summers. Seedlings of Coffea arabica L. cultivar Yellow Catuaí were transplanted between 

March 6th and 7th, 2006, and the 2008/2009 and 2009/2010 crop cycles were assessed. 

The experimental design was a 6 x 2 factorial scheme in randomized blocks, with four 

replications. The six densities of plantation were E1 (1.60 x 0.50); E2 (1.60 x 0.75); E3 (1.60 

x 1.00); E4 (3.20 x 0.50); E5 (3.20 x 0.75) and E6 (3.20 x 1.00), corresponding to 12,500; 

8,333; 6,250; 6,250; 4,127 and 3,125 plants ha -1 , respectively, which were divided according 

to the availability of water (irrigated – I – or non-irrigated – NI – groups). 

Fertilization was performed according to Bulletin 200 of the Campinas Agronomic Institute 

(Fazuolli et al. 1998) based on the result of the soil chemical analysis. Fertirrigation was 

performed once a week, except during water restriction period (July-August). In the nonirrigated 

treatments, three applications were manually performed, along with the rainy 

months (October, November and January). 

Meteorological data were daily collected from the Automatic Weather Station located 

approximately 500 m from the experimental area. 

Precipitation (mm) 

300 

250 

200 

150 

100 

50 

0 

30 

25 

20 

15 

10 

5 

0 

Temperature (ºC) 

Precipitation 

Date (Month - years) 

Average air temperature 

Figura 1 - Monthly distribution of precipitation and average air temperature, during the two years of cultivation 

of coffee in Mococa-SP, Brazil. 

The amount of water applied depended on the irrigation interval, the climatic demand 

(reference evapotranspiration), undertaken by the Penman-Monteith method, and the 

estimated crop evapotranspiration, according to Allen et al. (1998). Irrigation was suspended 

for 60 days during July and August for the imposition of water deficit, in order to promote

uniformity of flowering. The irrigation system was surface drip irrigation, with emitter flow rate 

of 2.3 l h -1 and emitter spacing of 0.50 m. 

The harvest of irrigated coffee was performed on April and that of non-irrigated one on June. 

The early harvest in the irrigated group was due to the early fruit maturation. The crop was 

harvested in a sieve thus preventing fruit falling on the ground. The processing of freshly 

harvested coffee was done using the conventional terrace drying method. The production of 

coffee cherries from each plant was stored separately in nylon bags and let it dry in the sun, 

constantly revolving throughout the day. After 45 days of drying, the husk and parchment 

were removed. 

Values of the average sieve were determined in samples of 100 grams of processed coffee 

per treatment. After removal of the endocarp, the flat beans were separated through a set of 

sieves, with round opening between 23 and 12, and the peaberry beans were retained on 

sieve 11. The types of beans (flat and peaberry) retained on the sieves were weighed on 

precision balance for further statistic analysis. 

Data regarding production of processed coffee, average sieve and type of beans were 

subjected to analysis of variance followed by Tukey test at 1 and 5% of probability. 


The yield of processed coffee was significantly affected by different population arrangements 

(p> 0.05) and use of irrigation (p> 0.01) in the two cycles. In the cycle 2008/2009 the 

interaction between population arrangement x irrigation was statistically significant (p> 0.01), 

as shown in Table 1. 

Table 1 - Analysis of variance for yield of processed coffee cv. Catuaí, cultivated in different 

population arrangements (PA), with or without irrigation, in 2008/2009 harvest, in Mococa – SP, Brazil. 

Yield of processed coffee (kg ha -1 ) 

2008/2009 2009/2010 

E1 - 1.60 x 0.50 2979 a 4631 a 

E2 - 1.60 x 0.75 3173 a 4201 ab 

Population 

E3 - 1.60 x 1.00 2894 a 3590 ab 

arrangements 

(m) 

E4 - 3.20 x 0.50 1627 b 3463 b 

E5 - 3.20 x 0.75 1835 b 3287 bc 

E6 - 3.20 x 1.00 1373 b 2268 c 

F test for PA 25** 10.3** 

Irrigation 

With 3775 a 4162 a 

Without 853 b 2985 b 

F test for I 517** 32.3** 

F test for I x PA 10** 1.03 ns 

C.V.% 19.23 20.1 

General mean 2314 3574 

* Significant at 5% of probability; ** Significant at 1% of probability; ns – non 

significant. S.A.D = Significant average deviation; C.V. = Coefficient of variation. 

In cycle 2008/2009 the treatments with 1.60 m spacing between rows presented significant 

differences when compared with the treatments with spacing of 3.20 m, irrespective of 

spacing between plants. Coffee trees cultivated in 1.60 m spacing had a 46.5% higher 

average productivity than those cultivated in 3.20 m spacing. In this cycle, despite the similar 

planting density in E3 and E4 arrangements (6,250 plants ha-1), E3 treatment showed higher 

productivity of processed coffee (approximately 44%) when compared with E4, indicating that 

the spacing between rows has greater influence on productivity than the spacing among 

plants, in the cycle 2008/2009.

In the cycle 2009/2010 the treatment E1 had the highest yield of processed coffee (4,631 kg 

ha-1), differing from the yield obtained by the treatments E4, E5 and E6. The productivity of 

E1 was approximately two times higher than that obtained in E6. The treatments E6 showed 

small yield of processed coffee (2,268 Kg ha-1), and was not statistically different only from 

treatment E5. Moreira et al. (2004) found significant effects of the spacing between planting 

rows on Mundo Novo coffee tree productivity; the authors observed that the treatments with 

smaller spacing showed the highest productivity of processed coffee. 

In the irrigated crop, in the cycle 2008/2009 an average productivity of 3775 kg ha-1 was 

observed, representing an increase of 77% when compared to non-irrigated treatment. This 

value in productivity of processed coffee represented an increment of 49 bags ha-1 in the 

irrigated plants. In the cycle 2009/2010 the irrigated coffee showed higher production of 

processed coffee (4162 kg ha-1) in relation to rainfed cultivation (2985 kg ha-1), with an 

increase of approximately 19 bags ha-1 for irrigated crops. 

Increases in coffee yield by the use of irrigation have been reported by several authors in 

recent years as Silva et al. (2005) and Rezende et al. (2006). Soil water deficit decreases 

yield due to the reduction in steam flow and transpiration, and consequently the absorption of 

water and nutrients by the root system and CO 2 by leaves, thus affecting photosynthesis 

(DaMatta & Ramalho, 2006). 

The result of interaction between population arrangement and irrigation, in the cycle 

2008/2009, revealed that the irrigated coffee trees, cultivated at spacing of 1.6 m between 

planting rows, had higher productivity (47%) of processed coffee when compared with those 

cultivated at spacing of 3.2 m between rows (p 0.01). A 74-82% 

increase in productivity was observed with the irrigated plants when compared with the nonirrigated 

coffee trees. These findings highlight the benefit of irrigation in coffee plantation, 

improving productivity irrespective of the adopted spacing. 

Table 2 – Yield of processed coffee according to the adoption of irrigation in different population 

arrangement as well as of every population arrangement according to the adoption of irrigation in the 

2008/2009 harvest, in Mococa - SP. 

Productivity of processed coffee 

Population 

(kg ha -1 ) 

arrangement 

Irrigation 

F test 

(m) 

With Without 

F test 33.4** 1,8 ns 

E1 - 1.60 x 0.50 4995 a A 963 a B 164** 

E2 -1.60 x 0.75 5109 a A 1238 a B 151** 

E3 - 1.60 x 1.00 4675 a A 1113 a B 128** 

E4 - 3.20 x 0.50 2577 b A 678 a B 36** 

E5 - 3.20 x 0.75 2965 b A 706 a B 52** 

E6 - 3.20 x 1.00 2326 b A 421 a B 37** 

* Significant at 5% of probability; ** Significant at 1% of probability; ns 

– non significant. Lower cases represent average values in the column 

and upper cases represent average values in the row. 

The values of average sieve were not altered significantly (p> 0.05) by population 

arrangements in the crop cycles. The irrigation provided significant effect in grain size (p> 

0.05) in the crop cycle 2008/2009. The grains of irrigated group were higher than those of 

non-irrigated cultivation (Table 3). Rezende et al. (2006) and Silva et al. (2009) reported that 

there was increase in the size of the coffee beans through the use of irrigation. In the crop 

cycle 2009/2010, there was no effect of irrigation on average sieve of grains.

Table 3 – Analysis of variance for average sieve and type of Catuaí coffee bean (flat or peaberry), 

cultivated in different population arrangements (PA), with or without irrigation, in 2008/2009 harvest, in 

Mococa – SP. 

Cycles 

2008/2009 2009/2010 

Average Type of bean Average Type of bean 

Population 

arrangements (m) 

sieve Flat Peaberry sieve Flat Peaberry 

E1 18.4 66.6 ab 16.5 16.9 77.9 abc 8.5 ab 

E2 18.2 63.4 b 18.9 16.8 74.5 bc 11.0 a 

E3 18.1 63.8 ab 17.7 16.7 73.9 c 11.0 a 

E4 18.1 68.7 ab 16.9 16.8 80.0 a 7.2 b 

E5 18.2 69.8 a 15.6 16.8 79.9 ab 7.7 ab 

E6 17.6 67.4 ab 16.9 16.7 76.9 abc 8.9 ab 

F test – PA 2.47 ns 2.98* 0.78 0.19 ns 4.2* 4.4* 

Irrigation With 18.8 a 67.6 12.3 b 16.8 76.0 b 9.3 

Without 17.4 b 65.7 21.8 a 16.8 78.3 a 8.7 

F test – I 99.7* 2.57 ns 83.5* 0.19 ns 5.2* 0.92 ns 

Teste F - I x AP 0.65 ns 0.62 ns 1.21 ns 1.08 ns 0.40 ns 0.79 ns 

CV % 2.72 6.28 21.1 1.47 4.66 24.2 

General mean 18.1 66.6 17 16.8 77.2 9.0 

** Significant at 1% of probability by Tukey test. * Significant at 5% of probability by Tukey test.. SAD = Significant 

average deviation; CV = Coefficient of variation. 

The amount of water available by precipitation, in the phase of grain formation, was higher 

during cycle 2009/2010, with a rainfall of 886 mm, while in the previous cycle it rained 461 

mm. The largest volume of water made available by the rains, certainly promoted a grain 

filling of plants cultivated without irrigation similar to irrigated plants. To DaMatta & Ramalho 

(2006) water deficit in the pellet-like berries (October-December) delays fruit growth, 

resulting in smaller sieve. The good water supply provides better conditions for plant growth, 

reflecting a greater capacity for grain filling, obtaining a higher grain formation, because the 

water is directly involved in cell expansion and also the transport of assimilates from leaves 

to fruits, causing an increase of the grains. There was no effect of the interaction between 

irrigation and population arrangement in the average sieve in both years. 

The type of flat bean was significantly altered by the arrangement of population (p> 0.05) in 

both crop cycles. In general, the plants cultivated in a 1.60 m between the rows had lower 

values than the flat bean plants cultivated in a 3.20 m (Table 3). The use of drip irrigation in 

2008/2009 cycle was not significant for flat bean, in contrast to the cycle 2009/2010, when 

there was a significant effect (p> 0.05) of the use of irrigation on flat type grain. There was no 

effect of irrigation, or the interaction of irrigation and population arrangement on the formation 

of flat bean. 

Peaberry bean was not influenced by the population arrangement in the cycle 2008/2009 

(Table 3). The percentage of peaberry beans in the population arrangements is above the 

acceptable values for exports (12%), and may be related to the adverse environmental 

effects, such as the high temperature during flowering. Pezzopane et al. (2007) verified that 

an average air temperature close to 24ºC provided high productivity of peaberry beans, 

which affected the quality of beans. In the experiment, flowering occurred at 25º C during 

September/October, as illustrated in Figure 1. In the cycle 2009/2010 the population 

arrangement provided effect significantly in the peaberry bean, with less percentage in 

treatment E4 when compared with treatment E2 and E3. 

In the cycle 2008/2009 the coffee irrigated showed the production of peaberry beans was 

very close to the accepted values for exports (Table 3), and differed significantly (p> 0.01) 

from the non-irrigated group, which presented great amounts of peaberry beans (21.8%). As 

previously stated, the production of peaberries is partially related to adverse environmental 

factors, mainly in the flowering and fruiting. In the cycle 2009/2010 the irrigation and the 

interaction of irrigation and population arrangement did not provide significant effect in the

peaberry beans. Custódio et al. (2007) did not observe effect in the peaberry beans of coffee 

during five years of irrigation . 


In both years of Catuaí coffee crop cultivation, the adoption of irrigation was more 

advantageous in denser crops, ensuring higher production of processed coffee. 

The population arrangement did not affect the average sieve of coffee in both cycles, and the 

adoption of irrigation technique provided an increase in grain size in 2008/2009 crop cycle . 

5. Reference list 

Allen, R. G.; Pereira, L. S.; Raes, D.; Smith, M. Crop evapotranspiration – guidelines for 

computing crop water requirements. Irrigation and Drainage, Roma: FAO. 1998. 300p. 

Barros, R. S.; MOTA, J. W. S.; DaMatta, F. M.; MAESTRI, M. (1997). Decline of vegetative 

growth in Coffea arabica L. in relation to leaf temperature, water potential and stomatal 

conductance. Field Crops Research, 54, 65-72. 

Custódio, A. A. P.; Gomes, N. M.; Lima, L. A. (2007). Irrigation effect on coffee beans 

classification. Engenharia Agrícola, 27, 691-701. (In Portuguese, with abstract in English). 

Esperancini, M. S. T.; Paes, A. R. (2005). Investment analysis for the production of coffee 

irrigated and conventional systems, in region of Botucatu, State of São Paulo. Informações 

Econômicas, 35, 52-60. (In Portuguese) 

Fazuolli, L.C.; Gallo, P.B.; Cervellini, G.J.; Barros, I.; Van Raij, B. (1998). Coffee. In: J. I. 

Fahl.; M. B. P. Camargo; M. A. P. Pizzinato; J. A. Betti; A. M. Melos; I. C. de Maria; A. M. C. 

Furlani (Eds.). Instructions to the Principal Agricultural Crops - Bulletin 200. (396p.) 6° ed. 

Campinas: Agronomic Institute of Campinas. (In Portuguese). 

Masarirambi, M. T., Chingwara, V., Shongwe, V. D. (2009). The effect of irrigation on 

synchronization of coffee (Coffea arabica l.) flowering and berry ripening at Chipinge, 

Zimbabwe. Physics and chemistry of the earth, 34, 786-789. 

Moreira, R. C.; Furlani Junior, E.; Hernandez, F. B. T.; Furlani, R. C. M. (2004) Spacing to 

coffee (Coffea arábica L.) with and without use of irrigation. Acta Scientiarium Agronomy, 26, 

73-78. (In Portuguese, with abstract in English). 

Pezzopane, J. R. M.; Pedro Júnior, M. J.; Gallo, P. B.; Camargo, M. B. P.; Fazuoli, L. C. 

(2007). Phenological and agronomic evaluations in a coffee crop grown under unshaded and 

shaded by 'Prata Anã' banana plants. Bragantia, 66, 527-533. (In Portuguese, with abstract 

in English). 

Rezende, F. C.; Oliveira, S. R.; Faria, M. A.; Arantes, K. R. (2006) Productivity 

characteristics of pruned drip irrigated arabica coffee plants (Coffea arabica L., cv. topázio 

MG -1190). Coffee Science, 1, 103-110. (In Portuguese, with abstract in English). 

Silva, A. M.; Coelho, G.; Silva, R. A. (2005). Irrigation timing and split application of fertilizer 

on productivity of the coffee plant in 4 harvests. Revista Brasileira de Engenharia Agrícola e 

Ambiental, 9, 314-319. (In Portuguese, with abstract in English). 

Silva, E.A.; brunini, O.; Sakai, E.; Arruda, F.B.; Pires, R.C.M. (2009). Influence of controlled 

water deficits on flowering synchronization and yield of coffee under three distinct edaphoclimatic 

conditions of São Paulo State, Brazil. bragantia, 68, 493-501. (In Portuguese, with 

abstract in English).

SUGARCANE FERTIRRIGATED WITH MINERAL FERTILIZER AND 

VINASSE UNDER SUBSURFACE DRIP IRRIGATION DURING FOUR 

CYCLES 

Eduardo A. A. Barbosa 1 , Flavio B. Arruda 2 , Regina C. M. Pires 2 Tonny J. A. Silva 3 

Emilio Sakai 2 

1 Ph.D. Student in Agricultural Engineering, FEAGRI/UNICAMP, Campinas – SP. 

2 Researcher, D.Sc, IAC/APTA, Campinas –SP 

3 Teacher and Researcher, D.Sc, UFMT, Rondonopolis –MT 

Corresponding author. E-mail: eduardo.agnellos@gmail.com 

Abstract: The subsurface drip irrigation provides less consumption of water through 

irrigation, improving the efficiency in fertigation, because the water and nutrients are applied 

in roots zone and has the advantage of the safe usage of wastewater, what we can also see 

in the case of vinasse. The objective of this work was to evaluate the effect of fertigation and 

application of vinasse by subsurface drip irrigation in stem yield, as the technological 

characteristics of sugarcane and yield of theoretical recoverable sugar. The field work was 

carried out in randomized blocks, with four treatments and five replications. The treatments 

were: T1NI – non-irrigated with conventional mineral fertilization, T2I - subsurface drip 

irrigation and fertigation with mineral fertilizers, T3Iv - subsurface drip irrigation and 

fertigation with a low dose of vinasse supplemented with mineral fertilizers, T4IV - subsurface 

drip irrigation and fertigation with high dose of vinasse supplemented with mineral fertilizers 

when necessary. Four cycles of cultivation were analyzed. Data were submitted to averages 

compared by Duncan test at 5 and 10% of probability. The irrigation and fertigation with 

vinasse by subsurface drip irrigation did not cause significant effect in the sucrose's content 

of the sugarcane in all cycles, not affecting the quality of its juice. In the first, third and fourth 

cycles, there was significant response to stem yield, of one or more irrigated treatments. The 

sugar yields were affected in the first and third cycle: in these cycles the crop 

evapotranspiration was similar or higher to the precipitation. In the second cycle, whereas 

there was no effect of irrigation and fertigation in the stem and sugar yield. In these cycles, 

the crop evapotranspiration was lesser that to precipitation (-1150 mm). In the final 

computation, the treatments with vinasse were higher in the stems and sugar yield. 

Keywords: Localized irrigation, sucrose, stem yield, wastewater, Saccharum officinarum L. 


The adoption of irrigation in the cultivation of cane sugar provides improvements in the 

production environment (Carr & Knox, 2011), resulting in increases in the yield of stem and 

sugar (Dalri & Cross, 2008). On the other hand, agricultural irrigation is a major source of 

consumption of water, so, the search for more efficient methods of irrigation is required to 

obtain more sustainable production environments (IPCC 2007). 

An irrigation technique that promotes more efficient use of water is the subsurface drip 

irrigation (SDI). Lamm et al. (1995) evaluated the volume of water consumed by the irrigation 

of corn using the SDI technique, found out that water consumption was reduced by 25% 

when compared to surface drip irrigation. The SDI is characterized by being a localized and 

direct application of water in the root zone of the crop (Trooien & Lamm, 2003; Lamm & 

Camp, 2007) favoring the efficiency of water use. 

Due to the high uniformity of water application by the SDI (Gil et al., 2008) and the direct 

application of water in the root zone of culture, the usage of fertilizers throughout the

fertigation is favored in the SDI (Trooien & Lamm, 2003). The usage of fertigation generally 

has the characteristic of bettering the efficient use of nutrients, since they are applied 

fractionated, according to the uptake of nutrients of culture (Roberts, 2008). Another positive 

aspect of SDI is the safe usage of wastewater by the farmers (Lamm & Camp, 2007), e.g.: 

the application of vinasse in the sugar cane. 

The fertigation with vinasse, when used in addition to mineral fertilization in the cultivation of 

sugar cane, provides increases in the stem yield, and in some cases resulting in an increase 

in the yield of sugar (Simabuco Birth & Son, 1994; Oliveira et al., 2009). 

The objective of this work was to evaluate the effect of fertigation and application of vinasse 

by subsurface drip irrigation in stem yield, technological characteristics of sugarcane and 

yield of sugar. 


The experiment was installed at Colorado Mill, Guaira-SP, Brazil. The geographic 

coordinates of the experimental area are: latitude 20°16'S, longitude 48°10'W and altitude 

594 m. The climate, according Köeppen, Aw is classified as tropical dry winter and 

temperature of the coldest month is less than 18°C. The sugar cane was planted on May 16, 

2005 with the variety RB855536. The planting was done manually at a depth of 0.20 m 

above the soil surface, after planting 50 mm of water were applied in 30 days, by sprinkler to 

promote uniform germination in all treatments. The space between the rows of sugarcane 

was 1.5 m. 

The experiment was carried out in randomized blocks, with four treatments and five 

replications: T1NI - witness non irrigated with mineral NPK fertilization at planting; T2I - 

treatment irrigated by SDI and application of NPK nutrients through fertigation; T3Iv - 

treatment irrigated by SDI and fertigation with vinasse, supplying the K, and 

complementation of NP with fertilizers mineral by fertigation T4IV - treatments irrigated by 

SDI and fertigation with vinasse, supplying the NK, and complementation of P with fertilizer 

mineral by fertigation. 

The fertilization was carried out in accordance to the recommendation of Raij et al. (1996) 

from the chemical analysis of the soil. In the first cycle it was applied 90 kg ha -1 N, 100 kg ha - 

1 P 2 O 5 and 80 kg ha -1 K 2 O. In the second cycle, the fertilization of reference was of 150 kg 

ha -1 N, 40 kg ha -1 P 2 O 5 and 150 kg ha -1 K 2 O, although, in the third cycle at fertilization of 

reference was 150 kg ha -1 N, 25 kg ha -1 P 2 O 5 and 300 kg ha -1 K 2 O. In the fourth cycle, the 

fertilization of reference was 120 kg ha -1 N, 80 kg ha -1 P 2 O 5 and 160 kg ha -1 K 2 O. 

Irrigation was performed three times a week, while the fertigation was held once in a week. 

The irrigation and fertigation were stopped 45 days before harvest. The irrigation depth 

applied was in function of irrigation interval, crop evapotranspiration (Etc) and irrigation 

efficiency of 90%. The estimation of reference evapotranspiration was performed by 

Penman-Monteith, and later the ETc as Allen et al. (1998), the crop coefficient (Kc) followed 

the recommendation of Doorembos & Pruitt (1984). The flow and the distance between the 

emitters of the dripper tube were respectively 1.3 L h-1 and 0.40 m. The climatic elements 

were obtained from an automatic weather station located 500 m from the experimental area. 

The harvest in the first cycle was held on August 16, 2006. The harvest in the second cycle 

was held on June 12, 2007. While in the third cycle, it was held on July 2, 2008 and in the 

fourth in August 12, 2009. For the technological analysis, five stems were collected in each 

plot, immediately after harvest. 

The methodology adopted for technology analysis followed the recommendations of 

Consecana (2006), and for this type of analysis, it was determined the content of sucrose, 

Brix and total recoverable sugar (TRS). From the values of TRS and yield stem, the sugar 

yield per hectare was calculated. The data were submitted to ANOVA and means were 

compared with each other by Duncan test at 5% probability.


The values of the water depth precipitated, crop evapotranspiration of sugarcane (ETc) and 

average air temperature during the experiment, are shown in Figure 1. The irrigation depth 

applied after the planting, in all plots, was inserted into in the water precipitated depth. 

600 

30 

Precipitation and Etc (mm) 

500 

400 

300 

200 

100 

25 

20 

15 

10 

5 

Mean air temperature (°C) 

0 

May-05 

Jul-05 

Sep-05 

Nov-05 

Jan-06 

Mar-06 

May-06 

Jul-06 

Sep-06 

Nov-06 

Jan-07 

Mar-07 

May-07 

Jul-07 

Sep-07 

Nov-07 

Jan-08 

Mar-08 

May-08 

Jul-08 

Sep-08 

Nov-08 

Jan-09 

Mar-09 

May-09 

Jul-09 

Date (Month-year) 

0 

Precipitation Etc Temperature (°C) 

Figura 1 - Valores da temperatura média do ar, precipitação mensal e evapotranspiração mensal da 

cultura (ETc) em durante os ciclos de cultivo da cana-de-açúcar. Guaíra (SP). 

The average air temperature, during the four cycles, in the experimental area was 

approximately 23.4°C. The highest temperature occurred in October 2005, with the average 

value of 27°C and the lowest temperature was recorded in June 2009, with the average 

value of 19°C. During the second cycle of sugarcane was recorded higher rainfall (2100 mm) 

and lower crop evapotranspiration (949 mm). The rainfall recorded in this cycle was higher 

than those recorded in the first, third and fourth cycle in 36.5%, 46% and 29.3% respectively. 

The third agricultural cycle of sugarcane showed the lowest rainfall, the total value of 1147 

mm. Analyzing the difference between the precipitation and crop evaporation (Etc) by Figure 

1, checks that in the third cycle the difference was negative (-128 mm). In the first, second 

and fourth cycles the difference between the precipitated and ETc depth were 1.22, 1150 

and 192 mm respectively. 

In the four crop cycles there was not any significant effect of treatments on the sucrose 

content of the juice, as noted in Table 1. By means of Figure 1, checked that no long periods 

of drought, causing no steep water deficit in soil. According Du et al. (1998), moderate water 

deficit in the cultivation of sugarcane, causes no effect on sucrose content compared to 

plants well hydrated, these authors found changes in sucrose content when the water deficit 

was severe, ie thet causing water potential sheet of -0.9 MPa. 

By means of technologic analysis verified that the treatments T4IV and T2I caused a 

significant effect on Brix (Table 1) in the first cycle, when compared to the cultivation without 

irrigation. In the remaining cycles of cultivation there was no effect of treatments on this 

variable. The weekly application of vinasse, from August to November, in clay soil, did not 

cause deleterious effects on the quality of the sugarcane. This result is in agreement with 

those presented by Tasso Júnior et al. (2007) and Oliveira et al. (2009) and differs from that 

observed for Robaina et al. (1983), the authors said the vinasse applied in a single 

application per cycle in the early development of culture in the conventional manner.

Table 1 - Analysis of variance for content of sucrose (%), soluble solids content (Brix) and total 

recoverable sugar (TRS, Kg Mg -1 ) of sugarcane, during four cycles in Guaíra-SP, Brazil. 

Content of sucrose (%) Brix TRS (Kg Mg -1 ) 

Treatments 

Cycle 

1 st 2 nd 3 th 4 th 1 st 2 nd 3 th 4 th 1 st 2 nd 3 th 4 th 

T1NI 16,3 14,2 15,6 18,8 19,6 b 17,4 18,1 21,2 143 126 136 159,5 

T2I 16,7 14,6 16,3 17,8 20,8 a 17,3 18,8 20,4 147 129 141 152,2 

T3Iv 16,5 14,3 16,5 17,7 19,9 ab 17,3 18,9 20,1 144 127 143 150,7 

T4IV 17,5 13,6 16,7 18,3 20,9 a 16,6 19,0 20,8 153 123 144 155,7 

Test F 1,2 ns 1,6 ns 1,0 ns 1,0 ns 4,5* 0,5 ns 0,5 ns 0,7 ns 1,6 ns 1,4 ns 1,1 ns 1,3 ns 

C.V. (%) 6,6 5,3 7,3 6,0 3,3 4,9 5,4 4,99 5,0 4,1 5,9 4,9 

* Significant at 10% of probability; ** Significant at 5% of probability by Duncan’s test; ns – non significant; C.V. = 

Coefficient of variation. T1NI - non irrigated with mineral fertilization of NPK; T2I - irrigated by SDI and application 

of NPK by fertigation; T3Iv - irrigated by SDI and fertigation with vinasse, supplying the K; T4IV - irrigated by SDI 

and fertigation with vinasse, supplying the NK. 

As observed for the sucrose content of juice, there was no effect of treatment on the total 

recoverable sugar (TRS) in the four crop cycles. The information about content of sucrose in 

the juice and TRS (Table 1) allow us to state that the water applied through SDI, with a 

stopped 45 days before harvest, did not provided deleterious effect on the quality of the juice 

when compared to cultivation non-irrigated, reporting that the usage of irrigation and 

application of vinasse via subsurface drip until the fourth sugarcane cycle, does not affect the 

maturation of the culture. 

In the first cycle, the stem yield was significantly affected (p> 0.05) by the use of SDI and 

fertigation, with the dose of vinasse supplying the K (T3Iv), this treatment had the highest 

stem yield when compared to rainfed cultivation (T1NI), the average production of stem 

obtained by T3Iv was higher by 16.6 Mg ha-1 obtained in the T1NI (Table 2). 

Table 2 - Analysis of variance for Stem yield (Mg ha -1 ) and Sugar yield (Kg Mg -1 ), during four cycles of 

sugarcane in Guaíra-SP, Brazil. 

Stem yield (Mg ha -1 ) Sugar yield (Kg Mg -1 ) 

Treatments 

Cycle 

1 st 2 nd 3 th 4 th Total 1 st 2 nd 3 th 4 th Total 

T1NI 215 a 173 160 a 140 a 684 a 31 a 21 22 b 22 96 a 

T2I 225 ab 165 166 ab 151 b 708 ab 33 ab 21 24 ab 23 101 ab 

T3Iv 231 b 167 175 ab 151 b 724 b 33 ab 21 25 a 23 102 b 

T4IV 224 ab 172 180 b 149 ab 724 b 34 b 21 26 a 23 104 b 

Teste F 2,91* 0,52 ns 3,32* 2,35* 4,54 3,16* 0,04 ns 5,17** 0,23 ns 0,21 

C.V. (%) 4,46 4,46 4,46 4,94 3,50 6,76 6,68 7,11 9,64 3,81 

* Significant at 10% of probability; ** Significant at 5% of probability by Duncan’s test; ns – non significant; C.V. = 

Coefficient of variation. T1NI - non irrigated with mineral fertilization of NPK; T2I - irrigated by SDI and application 

of NPK by fertigation; T3Iv - irrigated by SDI and fertigation with vinasse, supplying the K; T4IV - irrigated by SDI 

and fertigation with vinasse, supplying the NK.. 

The stem yield in the second cycle of cultivation with sugarcane, did not differ significantly 

among treatments, as shown in Table 2. The precipitations that occurred during the 

development of culture in the second, (Figure 1) provided a good water supply in soil, 

providing favorable conditions for plants grown without irrigation. In the third crop cycle, the 

effect of treatments was significant, with the treatment T4IV different from the treatment 

without irrigation. The stem yield T4IV treatment was 20 Mg ha-1 higher than the yield 

obtained by the treatment T1NI. The treatment T4IV did not differ in the amounts of stem 

yield when compared to treatments T2I and T3Iv. 

For the stems yield in the fourth crop cycle had a significant effect (Table 2). Treatments T2I 

and T3Iv produced more stem with increased production of 11.1 and 10.6 Mg ha-1,

espectively, compared to that observed in T1NI. The period of water deficit in the crop cycle 

(2008/2009) was not sharp as the observed in the previous cycle (third cycle), but even so 

there is an increase in stem yield. 

The total stem yield, of four cycles, in the treatments that received doses of vinasse (T3Iv 

and T4IV) differed significantly from the control without irrigation (Table 2). The treatments 

T3Iv and T4IV had the same total production of stems, and the final computation of these 

treatments showed an increase of 40 Mg ha-1 compared to non-irrigated crop (T1NI). The 

treatment T2I did not differ significantly from other treatments, getting an intermediate 

production, between the non-irrigated and those who received vinasse. Increased production 

of stem through the usage of irrigation has been reported by several studies over the years, 

such as Inman-Bamber (2004) and Cruz and Dalri (2008). Several of these studies highlight 

the importance of using irrigation on sugarcane, to promote the vertical growth of production, 

reducing the horizontal expansion. 

In the first and third cycle of sugarcane, the sugar yield was significantly different between 

the treatments, as shown above. The crop evapotranspiration in these cycles was similar or 

higher than the precipitation said before. In the first cycle, there is a superiority of T4IV (p> 

0.05), with a sugar yield about 3.3 mg h -1 to more than in the non irrigated treatment. The 

treatments T2I and T3Iv did not differ significantly of T1NI. In the third cycle, the treatments 

with application of vinasse (T3Iv and T4IV), had higher sugar production when compared to 

non irrigated treatment (T1NI). The gain achieved in the sugar yield by treatments T4IV and 

T3Iv when compared to non irrigated treatment was 3 and 4 Mg ha-1 respectively. Pancelli & 

Prado (2006) found that often the highest sugar productions are due the higher yield of 

stems, and not in increase in the technological quality of the stems. According to the results 

shown in Table 2, noted that the increase in the sugar yield on first and third cycle, was 

caused primarily by increased production of stems. 

The sugar yield did not showed significant difference between treatments in the second crop 

cycle (Table 2), certainly this occurred due to the rainfall which occurred in this cycle. In the 

fourth cycle in spite of differences in the production of stem, there was no effect on the 

production of sugar, and the cycle precipitation was above of ETc in 192 mm, reduced the 

effect of irrigation when compared to non-irrigated crop 

The total sugar production in the four cycles was significant among treatments (Table 2), with 

higher yield of treatments with vinasse. If compared to T1NI, the T4IV showed an increase of 

8 Mg ha-1 when compared to T1NI, whereas the treatment T3Iv showed a significant 

increase of 6 Mg h-1. As noted for the stems yield, the treatment T2I did not differ to the 

other treatments. The vinasse fertigation in the four cycles yielded presented improvements 

in the productive system and promoted an increase in the total sugar yield. 


The disposal of vinasse in the production of sugarcane by subsurface drip irrigation did not 

alter the technological quality. In the final computation, the application provided increases in 

stem and sugar yield in comparison to traditional cultivation without irrigation. 

There was a strong influence of climate in the production level and response irrigation. In the 

cycles that the crop evapotranspiration was higher or similar the precipitation, the usage of 

drip irrigation subsurface provided significant increases in the production of stems and 

theoretical yield of sugar recoverable by at least one treatment. The final sum the treatments 

fertirrigated with vinasse had a greatest yield of stalks and sugar compared to the nonirrigated 

crop. 

5. Reference list 

Allen, R. G.; Pereira, L. S.; Raes, D.; Smith, M. (1998) Crop evapotranspiration – Gidelines 

for computing crop water requirementes. Rome: FAO. (Irrigation and Drainage – 56).

Carr, M. K. V.; Knox, J. W. (2011). The water relations and irrigation requirements of 

sugarcane (Saccharum officinarum): a review. Experimental Agriculture, 47,1–25. 

CONSECANA - Council of the producers of cane sugar, sugar alcohol in the State of Sao 

Paulo. (2006). Manual Instruction. (5 th ed.). Piracicaba: CONSECANA. (In Portuguese) 

Dalri, A. B.; Cruz, R. L. (2008). Productivity of sugarcane fertigation with NK by subsurface 

drip Engenharia Agrícola, 28, 516-524. (In Portuguese, with abstract in English). 

Doorenbos, J.; Pruitt, W.O. (1984). Crop water requirements. Rome: FAO. (FAO, Irrigation 

and Drainage Paper, 24). 

Du, Y. C.; Nose, A.; Wasano, K.; Uchida y. (1998). Responses to water stress of enzyme 

activities and metabolite levels in relation to sucrose and starch synthesis, the Calvin cycle 

and the C 4 pathway in sugarcane (Saccharum sp.) leaves. Australian Journal of Plant 

Physiology, 25, 253 – 260. 

Gil, M.; Rodriguez-Sinobas, L.; Juana, L.; Sanchez, R.; Losada, A. (2008). Emitter discharge 

variability of subsurface drip irrigation in uniform soils: effect on water-application uniformity. 

Irrigation Science, 26, 451-458. 

INMAN-BAMBER, N.G. (2004). Sugarcane water stress criteria for irrigation and drying off. 

Field Crops Research, 89, 107-122. 

IPCC - Intergovernmental Panel on Climate Change. (2007). Climate change 2007 - The 

Physical Science Basis. Contribution of working group I to the fourth assessment report of 

the IPCC. Cambridge: Cambridge University Press. 

Lamm, F.R.; Camp, C. C. (2007). Subsurface drip irrigation. In: F. R, Lamm; J. E, Ayars; F. 

S, Nakayama. Microirrigation for crop production: design, operation, and management. (pp. 

473-551). Amesterdam: Elsevier. 

Lamm, F. R.; Manges, H. L.; Stone, L. R.; Khan, A. H.; Rogers, D.H. (1995). Water 

requirement of subsurface drip-irrigated corn in northwest Kansas. ASAE, 38, 441-448. 

Lamm, F. R.; Trooien, T. P. (2007). Subsurface drip irrigation for corn production: a review of 

10 years of research in Kansas. Irrigation Science, 22, 195-200. 

Roberts, T. L. (2008). Improving nutrients use efficiency. Turkish Journal of Agriculture and 

Forestry, 32,177-182. 

Oliveira, E. L.; Andrade, L. A. B.; Faria, M. A.; Custódio, T. N.(2009). Alembic vinasse and 

nitrogen in sugar cane in irrigated and non-irrigated áreas. Revista Brasileira de Engenharia 

Agrícola e Ambiental, 23, 694-699. (In Portuguese, with abstract in English). 

Prado, R. M.; Pancelli, M. A. (2006). Nitrogen Nutrition in ratoon and technological quality of 

sugarcane. STAB, v.25, 60-63. (In Portuguese, with abstract in English). 

Raij, B. van; Cantarella, H.; Quaggio. J.A.; FurlanI, A.M.C. (1996). Liming and fertilization 

recommendations for the state of Sao Paulo. (2nd ed). Campinas: IAC. (In Portuguese, with 

abstract in English). 

Tasso Junior, L. C.; Marques, M. O.; Franco, A.; Nogueira, G. A.; Nobile, F. O.; Camilotti, F.; 

Silva, A. R. (2007). Yield and quality of sugar cane cultivated in sewage sludge, vinasse and 

mineral fertilization supplied soil. Engenharia Agrícola, 27, 276-283. (In Portuguese, with 

abstract in English) 

Robaina, A. A.; Vieira, J. R.; Azeredo, D. F.; Bolsanello, J.; Manhães, M. S. (1983). Doses 

and mineral supplementation of vinasse in clogs of cane sugar. Brasil Açucareiro, 102, 26- 

33. (In Portuguese). 

Simambuco, S. M.; Nascimento Filho, V. F. (1994). Study on vinasse dynamics in soil using 

energy dispensive x-ray fluorescence with radioisotopic excitation. Scientia Agricola, 5, 207- 

215.

Optimal Reservoir Operation Model with a Streamflow Network 

Model and a Global Optimization Method 

Mingoo Kang 1* , Seungwoo Park 2 , and Jooheon Lee 3 

1 

Research Fellow, Future Resources Institute, Woolim Lions Valley C-405, 371-28, 

Gasan-dong, Keumcheon-gu, Seoul, South Korea, 153-786 

2 Professor, Department of Rural Systems Engineering, Research Institute for Agriculture 

and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, 

599 Gwanak-ro, Gwanak-gu, Seoul, South Korea, 151-742 

3 

Professor, Department of Civil Engineering, Joongbu University, 101 Daehak-ro, 

Chubu-myeon, Geumsan-gun, Chungnam, South Korea, 312-702 

* 

Corresponding author. E-mail: kmg1218@gmail.com 

Abstract 

In this study, an optimal reservoir operation model is presented, featuring a nonlinear, 

multiple-objective function and a global optimization method. In order to verify the 

model’s applicability, the model is applied to optimal water allocations of both Balan 

Reservoir and Seomjin Dam in South Korea that are an irrigation reservoir and a 

multi-purpose, multi-outlet dam, respectively. For Balan Reservoir’s optimal operations, 

a streamflow network model is used to simulate daily inflows, and a water demand 

computation sub-model is developed, taking into account the amounts of water required 

by irrigated rice paddy fields. The operation results show that optimal release patterns 

are similar to those of the observed. For the optimal operations of Seomjin Dam, a 

hydro-electric power outputs computation sub-model is developed and calibrated. The 

results of the optimal operations for Seomjin Dam show that, during a wet term, the 

hydro-electric power outputs increase by -7.52 to 10.04 %, varying with target water 

stages; during a dry term, they increase by -5.94 to 3.98 %; and during a normal term, 

they increase by 4.53 to 10.37 %. To solve an operation problem at Seomjin Dam that is 

the result of the increase of water demand downstream of the dam, the model is applied to 

various cases, considering the amounts of additional water supply. The results show that 

in these cases that the amounts of additional water supply are less than 0.70 m 3 /sec with 

target water stages lower than 194.0 m, the hydro-electric power outputs are more than 

the historical average, and the total amounts of water supply are less influenced by the 

amounts of additional water supply. Consequently, it is concluded that the model is 

useful for evaluating the water supply capacities of water resources facilities and to 

suggest amounts of additional water supply and new operation rules appropriate to the 

changes in the circumstances related to water management of systems. 

Key words: Optimal water allocation; Global optimization method; Streamflow network 

model; Non-linear, multiple-objective function; Water supply capacity evaluation. 


In South Korea, on average, the annual rainfall amounts to 1,245 mm, that is 1.4 times 

larger than the average in the world. However, the amount of the annual rainfall per 

capita is 13.2 % of the average in the world. Since there are large gaps in rainfalls 

among regions and seasons, water resources have been developed inequitably. 

Particularly, because, during summer seasons, about two-thirds of the annual rainfalls 

have been concentrated, non-effective runoffs have been generated, and floods have 

occurred frequently. In order to resolve these problems that result from geographic and

topographic features and hydro-meteorological characteristics and to stably supply water 

and effectively control flooding, water resources development projects have been carried 

out. 

Most recently, due to urbanization and industrialization, as well as population 

pressures, the amounts of water usage have increased, and the states of water quality in 

rivers have degraded. Thus, it has been requested to secure water resources 

abundantly enough to upgrade the water-friendliness of rivers and rehabilitate the 

environment and ecosystems. Also, due to the prevalence of irrigation farming, the 

amount of agriculture water usage has increased. Besides, in rural areas, more water 

needs to be supplied than in the past, because the population wants to enjoy their 

prosperity under civilized circumstances. According to this information about water 

resources, it is predicted that, in 2020, about 0.82 billion m 3 would be deficient in South 

Korea. 

To secure water resources under the aforementioned circumstances, structural 

and non-structural measures are to be developed, and it is apparent that they need to go 

into effect in the near future. Particularly, to maintain the environment and ecosystems 

from the perspective of sustainability, non-structural measures, such as joint-operations of 

multi-reservoir systems and water demand management, are to be determined and 

implemented consistently. Moreover, due to the changes in climate, socio-economic 

systems, and eco-systems, the operation rules of existing water resources facilities should 

be reviewed and adapted to the changes. To achieve these management objectives, 

tools for evaluating water supply capacities of systems, such as water-budget models, 

simulation models, and optimization models, are to be prepared, and appropriate 

scenarios are to be created to determine efficient operation rules for the systems (Yeh, 

1985; Wurb, 1993). 

In this study, an optimal reservoir operation model is developed through integration 

of a nonlinear, multiple-objective function, a global optimization method, and a streamflow 

network model, and it is then applied to simulating the operations of two study reservoirs 

to verify the model’s applicability. 

2. Optimal Reservoir Operation Model 

In general, reservoir operation revenues are evaluated using simulation models, 

optimization models, and simulation-optimization models (Dandy et al., 1997). 

Particularly, simulation-optimization models have been employed to consider peculiar 

objective functions and operation conditions of specific operation periods through using 

simulation models and optimization models alternatively. Fig. 1 shows the flowchart of 

the presented model, which is grouped into the simulation-optimization models category 

and takes one of the simulation and optimization modules, taking into account the 

condition of each operation period of reservoirs. 

2.1 Reservoir Operation Sub-model 

A reservoir operation sub-model is developed to compute reservoir storage amounts and 

hydro-electric power outputs, considering inflows, releases, overflows during operation 

periods. During the simulation, in the case that the quality assurance of the data 

pertaining to observed inflows is confirmed, the historical inflow data is employed, and in 

other cases, the inflow data is generated using the SSARR hydrologic model. The 

amounts of municipal and industrial water usages and in-stream flow are determined 

before reservoir operations, considering the demand of each. On the other hand, 

agricultural water demands of all periods are simulated using the modified Penman 

method, considering the situations of rice paddy fields. Hydro-electric power outputs of

all periods are computed using Eq. (1), taking into account discharge for hydro-electric 

power generation, water stage of the reservoir, operation time, and turbine efficiency. 

(1) 

where GE = actually computed hydro-electric power outputs during the period t, E G = 

generating efficiency, O L = (1 - rate of operating loss), E t = turbine efficiency, Q t = 

discharge for hydro-electric power generation, H t = effective head drop, H L = (1 - rate of 

head loss), and T = operation time, respectively. 

Start 

Simulation model 

control data 

Input data 

Optimization model 

control data 

Computation of inflow and water demand 

No 

Optimization 

model 

Reservoir operation period ? 

Yes 

SCE -UA Method 

Reached optimum 

value ? 

No 

File with 

Variables’ values 

Yes 

Computation of reservoir storage 

Computation of hydropower product 

Computation of water requirement 

Computation of objective function 

Computation of reservoir storage 

Yes 

No. of period

eleases at period t; I(t) = reservoir inflow at period t; R i (t) = release at ith outlet at time 

period t; n = number of total outlets; S LS and S max = lower and upper bounds on reservoir 

storage amount; R i 

min 

and R i 

max 

= lower and upper bounds on reservoir release at ith outlet; 

and T p = number of total periods, respectively. 

2.2.2 Optimal value searching method 

Among optimization algorithms, global search methods have been reported to efficiently 

discover the minimum of multi-modal functions, irrespective of where in the variable space 

the search procedure is started. There are well known global optimization methods, such 

as Uniform Random Search (URS), Adaptive Random Search (ARS), Multiple Start 

Simplex (MSX), Genetic Algorithm (GA), simulated annealing method, Annealing-Simplex 

(A-S) method, and SCE-UA method. Particularly, the SCE-UA method has been tested 

by comparing it with other methods, and it proved to be consistent, effective, and efficient 

in locating the globally optimal variables (Duan et al., 1994). In this study, the SCE-UA 

method is employed to search for optimal variables during reservoir operation periods. 

3. Application and Results 

The model’s applicability is evaluated through the reviews of the results from its 

applications to optimal water allocations of both Balan Reservoir and Seomjin Dam in 

South Korea that are an irrigation reservoir and a multi-purpose, multi-outlet dam, 

respectively. 

3.1 Single-Purpose, Irrigation Reservoir Operations 

The model is applied to the optimal operation of a single-purpose reservoir. The case 

study reservoir is Balan Reservoir in the Balan watershed, which is 2,649ha in area and 

includes two irrigation reservoirs, as shown in Fig. 2. To simulate daily inflows for the 

reservoir, the streamflow network model, SSARR, is utilized using the system 

configuration as shown in Fig. 3. In this study, to generate the demand for agricultural 

water, a water demand computation sub-model is used, taking into account the amounts 

of water required by irrigated rice paddy fields and the application efficiency of irrigation 

districts. During the optimal operations, the differences in amounts of total water 

releases between the observed and simulated range from -2.6 % to 10.5 %, varying with 

each simulation case, and the operation results indicate that optimal release patterns are 

similar to those of the observed as shown in Fig. 4. 

HS#5 

1 

Kicheon 

reservoir 

A-4 

IG#4 

2 

A 

A4 

R-4 RT#4 

Figure 2: Watershed boundary of 

the Balan watershed 

RT#1 

IG#1 

Balan 

reservoir 

R-1 

A-1 

A1 

HS#1 

3 

6 

C 

7 

HS#4 

5 B 4 

HS#2 

HS#3 

Legend 

Reservoir 

Watershed 

Transfer 

point 

Channel 

reach 

Figure 3: Configuration of the study 

watershed system

(a) Calibration 

(b) Verification 

Figure 4: Comparison of observed and optimal releases of Balan reservoir 

3.2 Multi-Purpose, Multi-outlets Reservoir Operations 

The model is applied to the optimal operation of a multi-purpose reservoir, Sumjin Dam, 

having a watershed size and effective storage amount of 763.0 km 2 and 347 million m 3 , 

respectively. The purposes of the dam operation include the following: to supply 

irrigation water and municipal water, to generate hydro-electricity, and to control flooding; 

the elevation of its outlets vary with the purposes for which the water is released, as 

shown in Fig. 5. For the optimal operations of Seomjin Dam, the hydro-electric power 

outputs computation sub-model is employed, and, during the calibration and verification of 

the sub-model, the relative errors between the observed and computed range from -2.0 % 

to 2.0 % and -1.74 % to -0.23 %, respectively. The results of the optimal operations for 

Seomjin Dam show that, during a wet term, the hydro-electric power outputs increase by 

-7.52 to 10.04 %, the amounts of municipal and agricultural water usages increase by 

-0.83 to 2.69 %, varying with target water stages; during a normal term, the hydro-electric 

power outputs, 4.53 to 10.37 %, the amounts of municipal and agricultural water usages, 

1.86 to 17.54 %; and, during a dry term, the hydro-electric power outputs, -5.94 to 3.98 %, 

the amounts of municipal and agricultural water usages, 1.35 to 7.79 %. Fig. 6 shows 

there are the differences in water stages among the simulation cases and the observed 

during a dry term. It means that target water stages primarily influence the reservoir 

operation results. Fig. 7 shows that the comparison results of hydro-electric power 

outputs, varying with flow regimes of the simulation cases. It indicates that hydro-electric 

power outputs depend on flow regimes and target water stages of the simulations. 

Figure 5: Location of outlets of Seomjin Dam, varying with purposes of water releases 

3.3 Assessment of additional water supply capacity of Seomjin Dam 

To solve the operation problem of Seomjin Dam that results from the increase of water 

demand downstream, the model is applied to the cases, varying with the amounts of

Storage( EL. m) 

additional water supply, such as 0.17, 0.50, 0.70, 1.00, 1.50, and 3.00 m 3 /sec. The 

cases in which the amounts of additional water supply are less than 0.70 m 3 /sec with 

target water stages lower than 194.0 m show that the hydro-electric power outputs are 

more than the historical average, and the total amounts of water supply are less 

influenced by the amounts of additional water supply. 

200 

190 

180 

170 

Obs. 

188.68 m 

160 191.50 m 

194.00 m 

196.50 m 

150 

0 20 40 60 80 100 

Time (10days) 

Figure 6: Comparison of water stages, 

varying with operation conditions 

during a dry term 

Figure 7: Comparison of hydro-electric power 

outputs, varying with operation 

conditions and flow regimes 


The objective of the study is to develop an optimal reservoir operation model and to 

suggest the appropriate amount of additional water supply and optimal operation rule of 

reservoirs. The model uses a non-linear, multiple objective function and a global 

optimum search method, the SCE-UA method. The objective function is to establish 

ways to maintain target reservoir storage amounts, to satisfy the demand for water, and to 

maximize the hydro-electric power outputs. To evaluate the model's applicability, the 

model is applied to operations of an irrigation reservoir and a multi-outlet reservoir. In 

addition, the model is used for assessing an additional water supply project to satisfy 

increasing water demand downstream. The results after comparing optimal operations 

and historical data in three case studies show that the model can provide reasonable 

results and, consequently, it can be used for assessing water supply capacities of 

reservoirs. 

References 

Duan, Q., Soroooshian, S., & Gupta, V. K. (1994). Optimal use of the SCE-UA global 

optimization method for calibrating watershed models. Journal of Hydrology, 158, 

265-284. 

Dandy G. C., Connarty, M. C., & Loucks, D. P. (1997). Comparison of methods for yield 

assessment of multiple reservoir systems. Journal of Water Resources Planning 

and Management, 123(6), 350-358. 

Wurbs, R. A. (1993). Reservoir-system simulation and optimization models. Journal of 

Water Resources Planning and Management, 119(4), 455-472. 

Yeh, W. W-G. (1985). Reservoir management and operation models: A state-of-art review. 

Water Resources Research, 21(12), 1797-1818.

Characteristics of Heavy Metal Contents in Marine Sediment 

and Paddy Soil of South Korea 

Jaesung Park 1 , Younghwan Son 2 *, Sookack Noh 1 , Taeho Bong 1 

1 Gratuate Student of department of rural systems eng. of Seoul National Univ., Seoul, Korea 

2 Professor of department of rural systems eng. of Seoul National Univ., Seoul, Korea 

*Corresponding author. E-mail: syh86@snu.ac.kr 

Abstract 

This paper was aimed to characterize the behavior of heavy metals in soil particle and pore 

water. Pore water is an element of three phases of a soil system with soil particle and air. It 

has become important to collect pore water and to analyze properties of pore water in 

various environmental engineering fields such as sediment quality assessment, soil physics 

and geo-environmental studies. The analysis of pore water contamination is also very 

important in agricultural research because most plants are grown in the vadose zone 

(unsaturated zone). In this study, two kinds of samples were used to measure and compare 

the concentrations of heavy metal content. One was marine sediment soil, which was 

obtained from Young-il Bay, Southeastern coastal part of South Korea. The other was paddy 

soil sample, which was taken from a farm in Suwon, Gyeonggi-do, South Korea. Each 

specimen was separated into three types - oven dried soil particles, dilution sample 

(soil:water=1:3) and pore water. Pore water was extracted from each soil sample by the 

squeezing method (ASTM D4542). The concentrations of heavy metal including Cd, Cu, Pb, 

As, Zn, Ni, Hg and Cr were measured by the atomic absorption spectrometry (AAS) method 

and the inductively coupled plasma mass spectrometer (ICP) method. In soil particles, the 

concentrations of most heavy metals in paddy soil were 2~6 times greater than those of 

marine sediment. This is probably due to paddy site is located near metropolitan area where 

is most likely to be polluted. In pore water and dilution samples, heavy metal concentrations 

of pore water were detected while those of dilution water samples were below detection limit 

for most heavy metals. This may indicate that it is not appropriate to use dilution water for the 

assessment of soil heavy metal contamination. Especially, the copper ion was higher than 

any other heavy metals in pore water as compared with soil particles. The copper tends to be 

ionized more readily and thus it could affect the growth of crops. Therefore, it is important to 

measure the concentrations of copper in pore water as well as soil solid in order to 

understand their relationship each other. This study will help estimate the level of soil solid 

contamination using the analysis of heavy metal contents in pore water. 

Key words: heavy-metals, pore-water, soil-contamination, paddy-soil, marine-sediment 


Soil is the most basic environmental factor as water and air. Recently, it has become an 

important research area in environmental fields to research about heavy metal contamination 

of soil. Because the soil contaminant is very low fluidity, it has characteristic which is cause 

long-term contamination in soil systems. So, when the soil is polluted, it is costly and timeconsuming 

in order to recover. Also, the polluted soil can be harm to humans through the 

food chain as shown in Fig. 1

FIGURE 1: The migration pathways of soil contamination 

On the other hands, South Korea has various laws and regulations related to heavy metals 

contaminations. They are Soil Environmental Conservation Act(for soil), the Framework Act 

on Environmental Policy(for river water and lake water) and Act on Underground water(for 

underground water). There are applicable laws and regulations depending on the target of 

each pollution, however, there are some problems which a lack of consideration for crops. 

Currently, the surface soil and groundwater are the object where is measured contaminations. 

But since crops are grown in the unsaturated zone as shown in Fig. 2 where water and air 

are mixed together with soil particles, it is important to figure out the contamination 

characteristics of pore water which is actually absorbed by crops. Recently, many 

researchers have concerned this problem.(Huynh et al. 2008, Ye et al. 2011, Zhu et al. 2011, 

Khim et al. 2001) 

FIGURE 2: Characteristics of the soil systems considering the crops 

Therefore, in this study, degree of contamination of pore water is measured and is compared 

with contamination of soil particles and dilution water (wetted soil : water = 1 : 3).

2. Materials and Method 

2.1. Study area 

Two specific samples are used in this study – marine sediment and paddy field soils. The 

marine sediment soil samples (PH) are collected from seabed sediment in Young-il Bay, 

Pohang, southeastern coastal part of South Korea. And the paddy field soil samples (SW) 

are obtained from a farm in Suwon, Gyeonggi-do, South Korea. 

The sampling locations are shown in Fig. 3 

Suwon 

Pohang 

FIGURE 3: Locations of sampling sites 

2.2. Sample collection and pretreatment 

The samples taken from each site were prepared by three different types - soil particles, 

dilution water and pore water – to measure the concentrations of heavy metals. Pretreatment 

methods for each of the sample are as follows. 

Soil Particles 

The soil particles sample was dried while more than 24hr in oven which can be kept inner 

temperature constant about 110℃ to remove moisture. And then the dried soil is passed 

through a sieve #100 (150μm) and is taken 10g in passing. 

Dilution water 

The dilution water sample was prepared by passing through the filter paper after mixing with 

distilled water and wetted soil(wetted soil : water = 1:3). 

Pore water 

There are many methods to obtain of pore water as shown Table 1. And many researchers 

have tried to develop device obtaining pore water more easily. (Hesslein 1976, Robbins and 

Gustinis 1976, Bottomley and Bayly 1984, Bertolin, Rudello and Ugo 1995, Bufflap and Allen 

1995a, Bufflap and Allen 1995b, Teasdale et al. 1995, Angelidis 1997, Patrick H 2002) In this

study, pore water was extracted by squeezing method which is quickly and effectively 

according to the ASTM D4542. 

Name 

TABLE 1: Devices for collecting of pore water in soil 

Squeezing device 

Centrifuge Soil water extraction kit 

(ASTM D4542) 

Figure 

2.3. Measurement of heavy metals content 

The prepared samples of various types are measured heavy metals content which is 

managed legally. The heavy metal items are measured are Cd, Cu, Pb, As, Zn, Ni, Hg, Cr+6. 

The method to measure of heavy metal content is the inductively coupled plasma mass 

spectrometer (ICP) method and the atomic absorption spectrometry (AAS) method. The 

sequence of measurement is shown in Fig. 4. 

FIGURE 4: The measurement process of heavy-metal concentration 


The results of heavy metal content for each sample are shown in the following Table 2 

As shown in the Table 2, the percentage of Zn, Cu, Pb and Ni was higher in common both 

samples. The heavy metal contamination of the SW samples was higher than that of PH. In 

particular, the concentrations of most heavy metals in SW were 2~6 times greater than those 

of PH in soil particles. This is probably due to paddy site is located near metropolitan area 

where is most likely to be polluted. On the other hand, the dilution water samples were below 

detection limit for most heavy metals while the heavy metal concentrations of pore water 

samples were detected above the detection limit. This may indicate that it is not appropriate 

to use dilution water for the assessment of soil heavy metal contamination.

TABLE 2: Devices for collecting of pore water in soil 

Site Type Cd Cu Pb As Zn Ni Hg Cr6+ Unit 

SP 0.17 5.63 4.83 8.77 25.8 4.77 - - 

PH PW - 3.12 - - 0.15 0.25 - - 

D - 0.02 - - 0.02 - - - 

SP 1.11 14.7 15.79 4.06 99.83 11.29 - - 

mg/kg(l) 

SW SP 0.01 6.55 0.07 0.06 1.03 0.35 - - 

D - - - - 0.13 0.03 0.009 0.29 

SP : soil particles ; PW : pore water ; D : dilution water 

The values in the Table 2 are expressed as the graph in Fig. 5. 

(a) PH 

(b) SW 

FIGURE 5: The graphs of degree of contamination 

The copper ion was higher ratio than any other heavy metals in pore water as compared with 

soil particles as shown in Fig. 5. The copper tends to be ionized more readily and thus it 

could affect the growth of crops. Therefore, it is important to measure the concentrations of 

copper in pore water as well as soil solid in order to understand their relationship each other. 


The pore water was sampled from two site soil samples by squeezing method, measured 

heavy metals contents by AAS and ICP method in lab and compared heavy metals contents 

with soil particle and dilution water. As a result, it was found that copper ions were higher 

ratio detected than any other heavy metal in pore water. It seems that the copper ions are 

more hydrophilicity matter than other metals. This result shows that concentration of copper 

ion in pore water can estimate concentration of copper in soil. This study will help estimate 

the level of soil solid contamination using the analysis of heavy metal contents in pore water.


Angelidis, T. N. (1997) Comparison of sediment pore water sampling for specific parameters 

using two techniques. Water Air and Soil Pollution, 99, 179-185. 

Bertolin, A., D. Rudello & P. Ugo (1995) A new device for in-situ pore-water sampling. Marine 

Chemistry, 49, 233-239. 

Bottomley, E. Z. & I. L. Bayly (1984) A Sediment Porewater Sampler Used in Root Zone 

Studies of the Submerged Macrophyte, Myriophyllum spicatum. Limnology and 

Oceanography, 29, 671-673. 

Bufflap, S. E. & H. E. Allen (1995a) Comparison of Pore-Water Sampling Techniques for 

Trace-Metals. Water Research, 29, 2051-2054. 

Bufflap, S. E. & H. E. Allen (1995b) Sediment pore water collection methods for trace metal 

analysis: a review. Water Research, 29, 165-177. 

Hesslein, R. H. (1976) An in situ sampler for close interval pore water studies. Limnology and 

Oceanography, 21, 912-914. 

Huynh, T., W. Laidlaw, B. Singh, D. Gregory & A. Baker (2008) Effects of phytoextraction on 

heavy metal concentrations and pH of pore-water of biosolids determined using an in 

situ sampling technique. Environmental Pollution, 156, 874-882. 

Khim, J. S., K. T. Lee, K. Kannan, D. L. Villeneuve, J. P. Giesy & C. H. Koh (2001) Trace 

Organic Contaminants in Sediment and Water from Ulsan Bay and Its Vicinity, Korea. 

Archives of Environmental Contamination and Toxicology, 40, 141-150. 

Patrick H, J. (2002) A new rechargeable dialysis pore water sampler for monitoring subaqueous 

in-situ sediment caps. Water Research, 36, 3121-3129. 

Robbins, J. A. & J. Gustinis (1976) A Squeezer for Efficient Extraction of Pore Water from 

Small Volumes of Anoxic Sediment. Limnology and Oceanography, 21, 905-909. 

Teasdale, P. R., G. E. Batley, S. C. Apte & I. T. Webster (1995) Pore water sampling with 

sediment peepers. TrAC Trends in Analytical Chemistry, 14, 250-256. 

Ye, S. Y., E. A. Laws, X. G. Ding, H. M. Yuan, G. M. Zhao & J. Wang (2011) Trace metals in 

porewater of surface sediments and their bioavailability in Jiaozhou Bay, Qingdao, 

China. Environmental Earth Sciences, 64, 1641-1646. 

Zhu, H., B. Yan, X. Pan, Y. Yang & L. Wang (2011) Geochemical characteristics of heavy 

metals in riparian sediment pore water of Songhua River, Northeast China. Chinese 

Geographical Science, 1-9.

Calibration of Hargreaves Equation for estimating reference 

evapotranspiration in the Southeast of Spain 

A. Ruiz-Canales 1 ; J.M. Molina Martínez 2 ; D.G. Fernández-Pacheco 2 ; H. 

Puerto Molina 1 , R. López-Urrea 3 

1 Agua y Energía para una Agricultura Sostenible (AEAS). Departamento de Ingeniería. 

Escuela Politécnica Superior de Orihuela. Universidad Miguel Hernández, Crtra. de Beniel, 

km 3,2, 03312 Orihuela (Alicante), Spain. 

2 Grupo de Investigación en Ingeniería Agromótica y del Mar. Universidad Politécnica de 

Cartagena, Paseo Alfonso XIII 48, 30203 Cartagena (Murcia) Spain. 

3 Water Management Research Unit, Instituto Técnico Agronómico Provincial (ITAP) y 

FUNDESCAM (Albacete). Spain. 

* Corresponding author. E-mail: acanales@umh.es 

Abstract 

This study calibrates Hargreaves equation in order to estimate daily evapotranspiration 

(ETo) in semiarid conditions at the Southeast of Spain. Firstly, the Hargreaves equation 

determined by using meteorological data registered daily from several agrometeorological 

stations of the Irrigation Advisory Service for Farmers (SIAR) of several nearby autonomous 

regions of Spain during period 2005-2009 (Comunidad Valenciana, Región de Murcia and 

Castilla-La Mancha) is obtained. Next, these obtained values were compared with the ones 

calculated by using the Penman-Monteith FAO56 equation. ETo estimations obtained by 

both methods were later compared with a simple regression analysis, and several 

comparative statistics were calculated. According to the obtained results, the Hargreaves 

equation is precise enough to obtain daily estimations of ETo in the studied zone without a 

previous calibration. It would be necessary to extend this study to a biggest number of 

agrometeorological stations in order to obtain a local or regional scale calibration. 

Keywords: reference evapotranspiration, Hargreaves equation, Penman-Monteith equation, 

calibration, semiarid conditions. 


Crop water consumption must be adjusted to the atmospheric demand, which depends on 

climatic conditions. Doorenbos and Pruitt (1975) proposed a methodology for computing crop 

evapotranspiration (ETc) based on reference evapotranspiration (ETo) and crop coefficients 

(Kc). One of the methodologies to estimate ETo is by using empirical equations from 

metheorological data. The most extended indirect methodology is the FAO56 Penman- 

Monteith method (Allen et al., 1998), which requires a great availability of metheorological 

data to calculate ETo. Parameters such as relative humidity, air temperature, solar radiation 

and wind speed, among others, are required. While air temperature is available in the 

majority of metheorological stations all over the world, the rest of data is collected only in few 

occasions and their reliability is doubtful. For this reason, the use of standard methods to 

estimate ETo when a direct method is not available is required. The need of a precise and 

simple method to estimate ETo has been pointed out by numerous authors. 

One of the most simple equation to determinate ETo is Hargreaves equation (Hargreaves 

and Samani, 1985). This equation only requires average, maximum and minimum daily 

values of temperature and extraterrestrial radiation. Previous works have demonstrated that 

Hargreaves equation provides precise estimations of ETo (López-Urrea et al., 2006). 

However, this method usually overestimates ETo in humid regions, and underestimates it in 

very dry zones. For these reasons, Hargreaves equation has to be evaluated and, if it is 

necessary, calibrated for being used with a required precision in a determined zone. 

Methodologies that use an equation to calibrate another one have been used by other 

authors (Allen et al., 1998). If a direct measuring method, e.g. for lysimeter measurements, is 

not available, then these methodologies are needed. In previous works carried out near the

location of the study, López-Urrea et al. (2006) indicated that FAO56 P-M equation is the 

most accurate method to estimate ETo in semiarids conditions. For these reasons, this 

equation has been chosen to calibrate the Hargreaves equation. 

This paper aims to calibrate the Hargreaves equation for estimating ETo, comparing it with 

daily average estimations obtained through the FAO56 P-M equation in a zone of the 

Southeast of Spain. 


Weather data sets were obtained from agrometeorological stations in the provinces of Murcia 

and Albacete (Spain). These stations are integrated in the irrigation advisory service in the 

Spanish autonomous regions of Murcia and Castilla-La Mancha. Data were daily registered 

during period 2005-2009. 

From these climatic data, and by using the Penman-Monteith FAO56 equation, ETo was 

calculated (Allen et al., 1998). The used Penman Monteith equation is the next: 

ET 

0 

900 

0,408· ∆(Rn 

− G) + γ u2(e 

= 

T + 273 

∆ + γ(1+ 

0.34·u ) 

Where: 

ET o = reference evapotranspiration (mm·day -1 ) 

Rn = crop surface net radiation (MJ·m -2 day -1 ) 

Ra = extraterrestrial radiation (mm·day -1 ) 

G = soil heat flux (MJ·m -2 día -1 ) 

T = average air temperature at 2 m height (ºC) 

u2 = wind speed at 2 m height (m·s -1 ) 

e s = saturated vapor pressure (kPa) 

e a = real vapor pressure (kPa) 

e s - e a = vapor pressure deficit (kPa) 

∆ = slope of the vapor pressure curve (kPa·ºC -1 ) 

γ = psicrometric constant (kPa·ºC -1 ). 

2 

s 

− e 

a 

) 

Moreover, and by using the same climatic data, estimations of ETo values by means of 

Hargreaves equation were obtained (Hargreaves and Samani, 1985). 

ET 

0.5 

0 

= 0.0135·(t 

ave 

+ 17.78)·R 

0·KT·(t 

max 

− tmin) 

ET o = referente evapotranspiration (mm·day -1 ) 

t ave = daily average temperature (ºC) 

R o = extraterrestrial radiation (MJ·m -2 day -1 ) 

KT = coefficient (0.162 for inner regions and 0.19 for coastal regions) 

In order to transform MJ·m -2 day -1 to mm·day -1 , the value has to be multiplied by 0.408. 

Several comparisons were obtained through the simple linear regression analysis technique 

and a set of statistics. These statistics are: 

Root mean square error (RMSE): 

⎡ 

⎢ 

RMSE = ⎢ 

⎢ 

⎢⎣ 

n 

∑ 

i= 

1 

2 ⎤ 

(yi 

− xi) 

⎥ 

⎥ 

n0 

⎥ 

⎥⎦ 

0,5

Relative error (RE): 

Index of agreement (IA): 

IA = 1− 

n 

RMSE 

RE = ·100 

y 

∑ 

i= 

1 

∑ 

i= 

1 

i 

n 

(x − y ) 

((x − x) + (y 

Where: 

x i = ET o Hargreaves (ET o H) value for the i day. 

y i = ET o Penman Monteith (ET o PM) value for the i day. 

n = number of data. 

x = average ET o H value. 

y = average ET o PM value. 

i 

i 

i 

2 

− y)) 

Relation between ET o PM and ET o H values for the studied period has been graphically 

represented, and regression lines for every station have been calculated. 

3. Results 

In this study, data from two specific agrometeorological stations were analysed, concretely 

from the 2.5 (Villena, Alicante) and 3.4 (Yecla, Murcia) stations. In Fig. 1 a linear regression 

between the ETo values estimated by Hargreaves and the values calculated by using FAO56 

P-M equation is presented for every station. In 3.4 station (Fig. 1, left), the daily values 

obtained by Hargreaves neither overestimate nor underestimate the values calculated by 

FAO56 P-M equation, with a RMSE of 0.67 mm day-1, a RE near 20 % and a IA value of 

0.97. Otherwise, in 2.5 station (Fig. 1, right), Hargreaves has a good fit with values between 

0.5 and 4.5 mm day-1, but over these values the ETo calculated by FAO56 P-M equation is 

lightly underestimated (6%). 

2 

ETo Hargreaves (1985) 

(mm day -1 ) 

12 

10 

8 

y = 0.99x + 0.03 

R 2 = 0.90 

6 

4 

2 

0 

0 2 4 6 8 10 12 

ETo Hargreaves (1985) 

(mm day -1 ) 

12 

10 

8 

6 

4 

2 

0 

y = 0.86x + 0.31 

R 2 = 0.91 

0 2 4 6 8 10 12 

ET o Penman-Monteith FAO56 (mm day -1 ) 

ETo Penman.Monteith FAO56 (mm day -1 ) 

ETo PM 1:1 Regression 

ETo PM 1:1 Regression 

FIGURE 1. Daily ETo comparison between FAO56 P-M and Hargreaves equations during the 

studied period (2005-2009) in two stations: 3.4 (Yecla) station (left) and 2.5 (Villena) station (right). 

TABLE 1. Evaluation of Hargreaves equation to estimate daily ETo comparing with FAO56 Penman- 

Monteith equation for two different locations. 

N Xi yi yi/xi A B R 2 RMSE ER IA 

Station (mm day -1 ) (mm day -1 ) (%) (mm day -1 ) (mm day -1 ) (%) 

ET o (Har.)=A+B*ET o (P-M FAO56) 

Yecla (Murcia) 1816 3,41 3,40 100 0,03 0,99 0,90 0,67 19,61 0,97 

Villena (Alicante) 1825 3,67 3,46 94 0,31 0,86 0,91 0,70 18,96 0,97 

Results indicate that Hargreaves equation is precise for daily estimations in this zone. It is 

not necessary to previously calibrate data. The rest of stations present a similar performance 

with some exceptions.


Hargreaves equation can provide relatively accurate estimations of daily ET 0 at 

weather stations where only air temperature acquisition is available and under the 

semiarid conditions of the studied zone (SE Spain). 

Because of the empirical nature of the Hargreaves equation, a single universal 

calibration of this equation would be difficult to achieve. However, the approach 

outlined in this paper could likely be applied in other semiarid regions to obtain 

appropriate local calibrations of the Hargreaves equation. 

Obtained results indicate that Hargreaves equation is precise enough for daily 

estimations of ETo in the studied zone, without the requirement of a previous 

calibration. 

It would be necessary to extend this study to a higher number of stations in order to 

calibrate at local or regional scale. 

References 

Allen, R.G., Pereira, L.S., Raes, D. Smith, M., 1998. Crop evapotranspiration. Guidelines for 

computing crop water requirements. FAO Irrigation and Drainage, paper nº. 56, FAO, 

Rome. 

Doorenbos, J., Pruitt, W.O., 1975. Crop water requirements. FAO Irrigation and Drainage 

Paper nº 24. Roma. 

Hargreaves, G.H., Samani, Z.A., 1985. Reference crop evapotranspiration from temperature. 

Appl. Eng. Agric. 1(2), 96–99. 

López-Urrea, R., Martín de Santa Olalla, F., Fabeiro, C., Moratalla, A., 2006. An evaluation 

of two hourly reference evapotranspiration equations for semiarid conditions. Agric. Water 

Manage. 86, 277-282. 


This work has been partially supported by the PPII10-0319-8732 project “Determinación de 

las funciones de producción y necesidades hídricas de los cultivos utilizando radiometría de 

campo, imágenes de satélite y el modelo Aquacrop” (Ministry of Education and Science from 

the Government of Castilla la Mancha, Spain).

Stochastic modelling of Contaminants Transport through 

Groundwater Using a Moving Least Squares Response Surface 

Method with Hermite Polynomials 

T. H. Bong 1 , Y. H. Son 1 *, S. K. Noh 1 , J. S. Park 1 , S. P. Kim 2 , J. Heo 2 

1 Department of Rural Systems Engineering, Seoul National University, Gwanak-ro, Gwanakgu, 

Seoul, 151-921 Korea 

2 Rural Research Institute Korea Rural Community Corporation, Haean-ro Sangrok-gu, Ansan, 

426-908 Korea 

*Corresponding author. E-mail: syh86@snu.ac.kr 

Abstract 

It is important to understand contaminants transport through groundwater. To obtain reliable 

result, uncertainties of parameter should be considered. In this study, uncertainty in Benzene 

concentration at various distances is analyzed. Two parameters ( K and K 

oc 

) are 

considered as random variables and probability density distributions of random variables are 

estimated using Hermite polynomials. MLS-RSM is performed to improve the efficiency of 

uncertainty analysis and can achieve results close to accuracy of MCS with a sample size of 

100,000. In conclusion, considering the actual probability density distributions by Hermite 

polynomials, more accurate results can be obtained. 

Key words: contaminants transport, MLS-RSM, stochastic modelling, Hermite Polynomials 


The groundwater pollution load has been increased as a result of human activities related to 

industrial and agricultural production on water resources. Thus understanding contaminants 

transport through groundwater is important for water management and remedial action plans. 

However, groundwater modelling is not an easy task. To get reliable results, input data 

should be accurate and representative of the reality of the field and uncertainties in model 

input data including chemical, physical and hydrogeological parameters also needs to be 

considered (Baalousha & Köngeter, 2006). Several recent studies have been conducted on 

the modelling of contaminants transport though ground water considering uncertainties 

(Datta & Kushwaha, 2011; Isukapalli, 1999; Jim yeh, 1992; Ranade et al., 2010). 

Probabilistic uncertainty propagation methods available fall into three categories: (a) Monte 

Carlo simulation (MCS), (b) analytical method, (c) response surface method (Phoon & Huang, 

2007). The MCS is a universal method regardless of the complexities underlying the physical 

model and/or input uncertainties. However, when the models are complex, or when there are 

numerous parameters, the MCS can be costly and time-consuming. Therefore, a variety of 

variance reduction techniques have been proposed to reduce the number of runs. 

Among these, the response surface method (RSM) has been used in probabilistic modeling 

for various fields. However, the RSM requires transformation of input variable from the 

original space (X) to the standard normal space (U). To do this, probability density function 

(PDF) of input data is assumed by common PDF (e.g., normal distribution or lognormal 

distribution) and transformed using equivalent mean and standard deviation. It is difficult to 

estimate PDF from empirical data, especially when sample sizes are small. The reliability of 

result relies on input variable, and therefore, a realistic PDF should be considered by actual 

measurement rather than assumed probability distributions. Phoon (2003) proved that any 

random variable can be expanded as a sum of Hermite polynomials. The remaining issue is 

how to improve the efficiency of the calculation. Compared with traditional methods, the RSM

is computationally more efficient. But, the RSM require many approximation when problems 

are strongly nonlinear and sometimes shows large errors in the calculation of the sensitivity 

of the reliability index. In order to overcome these problems, Kang et al.(2010) proposed an 

efficient RSM applying a moving least squares (MLS) approximation. 

In this study, for reliable risk assessment of groundwater pollution, stochastic modelling was 

performed for the flow of Benzene considering dispersion, advection and retardation using a 

moving least squares response surface method (MLS-RSM). Two parameters are 

considered as input random variables and transformed into standard normal distribution 

using Hermite polynomials. The accuracy of analysis results are evaluated in comparison 

with MCS results. 

2. Theory and Background 

2.1. Hermite polynomials 

Hermite Polynomials utilizes a series of orthogonal polynomials to facilitate stochastic 

analysis. These polynomials are used as orthogonal basis to decompose a random process. 

One-dimensional Hermite polynomials are given by: 

H ( ) 1 

H 

0 

H ( ) 

1 

2 

H ( ) 1 

2 

3 

H ( ) 3 

3 

k 1 

( ) H 

k 

( ) kH 

k 1 

( ) 

(1) 

where is a standard Gaussian random variable (mean=0 and variance=1). Hermite 

polynomials over [- , ] satisfy the following orthogonal relation: 

 

 

 

1 

e 

2 

1 

u 

2 

2 

H 

m 

( u) 

H 

n 

( u) 

du 

mn 

n! 

(2) 

where 

mn 

is the Kronecker delta function. Any random variable can be approximated by 

Hermite polynomials expansion as follows (Phoon, 2003): 

Y a H ( i i 

) 

(3) 

i0 

where a 

i 

is the deterministic Hermite polynomials expansion coefficient which depends on 

the distribution of Y . H ( ) is multi-dimensional Hermite polynomials of degree i . 

i 

2.2. MLS-RSM 

The RSM is a collection of mathematical and statistical techniques for the approximation and 

optimization of stochastic models that was developed by Box and Draper(1987). The RSM is

widely used for various fields such as physics, engineering, biology, medical and food 

sciences. But, as a mentioned above, the RSM has limitations of efficiency and errors in the 

sensitivity of the reliability index. In this study, MLS-RSM was performed for modelling of 

contaminants transport. 

A limit state function was approximated by response surface function (RSF), given by: 

~ 

G( 

x) 

a 

0 

 

n 

 

a x 

 

n 

 

i i 

i1 i1 

a 

ii 

x 

2 

i 

(4) 

~ 

where G ( x ) is the approximated RSF, n is the number of random variables, and a 

0 

, a i 

, aii 

are unknown coefficients. The approximated RSF can be defined in terms of basis functions 

p (x) and coefficient vector a (x) 

: 

~ 

T 

G( 

x) 

p( 

x) 

a( 

x) 

(5) 

The vector of unknown coefficients, a (x) 

, is determined by minimizing the error between the 

observations and approximations by the limit state function: 

n 

i1 

2 

T 

p( 

x ) a( 

x) 

G( 

x ) 

E ( x) 

w( 

x xi 

) 

i 

i 

(6) 

where n is the number of experimental points, w( x xi 

) is a weight function depending on 

the distance between x and the observation points x 

i 

, given by: 

2 3 4 

x xi 

1 

6r 

8r 

3r 

for r 1 

w( 

x xi ) w( 

r ) 

(7) 

d 

mi 0 

for r 1 

The coefficient vector a (x) 

can be estimated by: 

T 

1 T 

a( 

x) 

( P W ( x) 

P) 

P W ( x) 

G 

(8) 

The most probable failure point (MPFP) is determined using by first order reliability method 

(FORM) and the MPFP was used as additional input point until the difference between MFPF 

and next MPFP is acceptably small (or converge). 

3. 1-D Transport of chemical contaminants though groundwater 

The transport of contaminants model cosidering dispersion, advection and retardation is 

given by (Van Genuchten & Alves, 1982):

R 

f 

C 

t 

D 

L 

2 

C 

V 

2 

x 

w 

C 

x 

(9) 

where 

C : concentration of the dissolved chemical species (contaminant) 

R : retardation factor ( ( K / ) ) 

f 

1 

d e 

: bulk density of the soil, 

e 

: effective porosity of the soil 

K : distribution coefficient of the soil ( K ) 

d 

oc 

foc 

K 

oc 

: organic carbon partition coefficient, 

oc 

* 

D : longitudinal dispersion coefficient ( V D / ) 

L 

 

L 

: longitudinal dispersivity, 

c 

w 

f 

L 

V V / R , 

f : fraction of organic carbon content 

c 

e 

* 

D : diffusion coefficient 

V 

w 

: pore water velocity in the x-direction ( ( K / e 

) /( dh / dx) 

) 

K : hydraulic conductivity, dh / dx : hydraulic gradient 

Analytical solution to the governing equation can be written as: 

x V t V x x V t 

c 

c 

c 

C x t C erfc 

 

erfc 

 

( , ) 0.5 

 

 

0 

exp 

t T 

 

D t 

 

D 

 

, 0 (10) 

L L DLt 

4 

4 

where and T is a period of injection. In this paper, Benzene is considered as contaminant. 

Model parameters of contaminant Benzene are given in Table 1 and 2. 

TABLE 1: The deterministic parameters of Benzene 

C 

0 

Chemical 

 

* 

dh / dx D 

 

L 

species (mg/L) (g/cm 3 ) (m/m) (m 2 /s) (%) (%) (m) 

Benzene 100 1.8 -0.008 0 1.6 25 5.0 

f 

oc 

 

e 

Chemical 

species 

TABLE 2: The uncertainty parameters of Benzene 

K 

Mean (cm/s) 

Standard 

Mean (cm 3 /g) 

deviation 

Benzene 0.001 0.0002 58.9 5.0 

K 

oc 

Standard 

deviation 

4. Results and Discussions 

The 50 samples of random variables are generated by combining of three different 

distributions (Normal, Log-Normal and Uniform). If sample size of a random variable is small, 

it is impossible to estimate the exact PDF. In order to compare results from using probability 

distributions by Hermite polynomials and results from using estimated well-known PDF, Chisquare 

goodness-of-fit test is performed for generated samples of K and K . The results 

oc

show that Extvalue and Logistic distribution are most appropriate in compared with other 

distributions (Fig 1). 

(a) distributions of K (b) distributions of K 

oc 

FIGURE 1: Estimated probability density functions of input data 

Fig. 2 shows the results of probabilistic analysis for contaminant concentration-distance 

profiles with the elapse time of 800 days by MCS with a sample size of 100,000. 

(a) distributions by Chi-square test (b) distributions by Hermite polynomials 

FIGURE 2: Profiles of concentration-distance for distributions of random variables 

Although the average profiles of concentration-distance are almost same, range of 

probabilistic concentration is different for the same distance. The probability of concentraion 

of greater than 1 mg/L at distance 80, 90, 100 m and elapsed time of 800 days are shown in 

Table 3. 

MCS 

MLS-RSM 

TABLE 3: Comparison of results by estimation method of PDF 

The probability of concentration 

Method 

of greater than 1 mg/L (%) 

80 m 90 m 100 m 

Chi-square test 44.9 26.4 13.4 

Hermite polynomials 48.6 29.5 14.6 

Chi-square test 44.6 26.6 13.5 

Hermite polynomials 48.8 29.8 14.5

The probability of concentration of greater than 1 mg/L decreased with distance and shows 

almost the same value between MCS results and MLS-RSM results. Comparing the results 

by estimation method of PDF, the results show different value at each distance. 


In this study, to reliable risk assessment of groundwater pollution, the flow of Benzene 

through groundwater considering uncertainties of K and Koc 

is analyzed. The PDF of 

random variables can easily be estimated using Hermite polynomials and transformed into 

space of standard normal random variable. To uncertainty analysis of Benzene transport, 

MLS-RSM is performed and the results are compared with MCS results. MLS-RSM gives the 

improvemant in computational efficiency of probability analysis and can achieve results close 

to accuracy of MCS with a sample size of 100,000. The probability analysis results are 

directly influenced by PDF of random variables and therefore by estimating the actual PDF 

using Hermite polynomials could derive a more accurate analysis results. 

References 

Baalousha, H. & Köngeter, J. (2006). Stochastic modelling and risk analysis of groundwater 

pollution using FORM coupled with automatic diffrentiation. Advances in Water Resources, 

29, 1815-1832. 

Box, G.P. & Draper, N.R. (1987). Empirical model-building and response surface. New York: 

Wiley. 

Datta, D. & Kushwaha, H.S. (2011). Uncertainty quantification using stochastic response 

surface method case study-Tansport of chemical contaminants through groundwater. 

International Journal of Energy, Information and Communications, 2(3), 49-58. 

Isukapalli, S. S. (1999). Uncertainty analysis of transport-tranformation models. New Jersey: 

New Brunswick. 

Jim yeh, T.-C. (1992). Stochastic modelling of groundwater flow and solute transport in 

aquifers. Hydrological Processes, 6, 369-395. 

Kang, S.C., Koh H.M. & Choo, J.F. (2010). An efficient response surface method using 

moving least squares approximation for structural reliability analysis. Probabilistic 

Engineering Mechanics, 25, 365-371. 

Phoon K.K. (2003). Representation of random variables using orthogonal polynomials. 

Proceedings Ninth International Conference on Applications of statistics and Probability in 

civil Engineering, San Francisco, 1, 97-104. 

Phoon, K.K. & Huang, S.P. (2007). Geotechnical probabilistic analysis using collocationbased 

stochastic response surface method. Applications of Statistics and Probability in Civil 

Engineering. London:Taylor & Francis, 45-51. 

Ranade, A.K., Pandey, M. & Datta, D. (2010). Stochastic response surface based simulation 

of ground water modeling, International Conference on modeling, Optimization and 

Computing, 213-218. 

Van Genuchten, M.Th. & Alves, W.J. (1982). Analysis solution of the One-dimensional 

convective-dispersive solute transport equation. United Stated Department of Agriculture, 

Agricutural Research Service, Technical Bulletin 1661.

Efficiency of water and energy use in the crop of Lactuca Sativa L. 

cv. Capitata. Some previous results in a plot in the Southern of 

Spain 

A. Ruiz-Canales 1* , J.M. Molina 2 , D.G. Fernández-Pacheco 2 , 

F.J. Cánovas-Rodríguez 3 , H. Puerto Molina 1 

1 Agua y Energía para una Agricultura Sostenible (AEAS). Departamento de Ingeniería. 

Escuela Politécnica Superior de Orihuela. Universidad Miguel Hernández, Crtra. de Beniel, 

km 3,2, 03312 Orihuela (Alicante), Spain. 

2 Grupo de Investigación en Ingeniería Agromótica y del Mar. Universidad Politécnica de 

Cartagena, Paseo Alfonso XIII 48, 30203 Cartagena (Murcia) Spain. 

3 Departamento de Ingeniería Eléctrica. Universidad Politécnica de Cartagena. Campus 

Muralla del Mar. C/ Doctor Fleming s/n. C.P. 30202 Cartagena (Murcia), Spain. 

* Corresponding author. E-mail: acanales@umh.es 

Abstract 

In the Southern of Spain, where water resources are limited, it is of primary importance 

an adequate management of irrigation water and energy. Agriculture must maximize water 

and energy use efficiency in irrigation by controlling these resources in order to permit a 

more efficient management. In this paper, a case study of a commercial plot of 98.93 ha 

located in Cartagena (Murcia, Spain) and cultivated with Iceberg lettuce (Lactuca sativa L. 

cv. Capitata) with trickle irrigation is carried out. The study was partially based in the 

methodology employed for Water Users Associations (WUA), but adapted to the specific 

conditions of a concrete farm. Concretely in this case, the irrigation station is considered as 

an independent hydraulic-functioning sector with an independent energy contract. Some 

energy parameters were calculated and monthly energy bills along the season 2010-2011 

were collected. Energy and water data were also contrasted, obtaining some descriptive, 

performance and energy efficiency indicators. Finally, these indicators were utilized for the 

proposal of measures to improve the use of water and energy. These measures were also 

financially and energetically valued. A potential energy efficiency improvement with a cost 

saving of 27% could be achieved after the implementation of the proposed courses of 

actions, what demonstrates the suitability of adapting the methodology used for WUA to 

irrigation systems in a farm. 

Keywords: lettuce, energy, water, costs, irrigation. 


Patterns of food production, distribution and consumption have undergone major 

transformations over the last years. One of the consequences of these changes is that the 

majority of consumers in developed countries expect to be able to purchase fresh vegetables 

at any time of the year. In order to overcome the natural seasonality of supply in these 

countries, one of the basic strategies has been the importation of fresh produce from 

countries where it is in season (Hospido et al., 2009). 

A good example of fresh vegetable which is offered along the year in the European Northen 

countries is the lettuce. Its consumption has increased regularly during the last two decades 

and the supply chains of these countries import this vegetable during the cold months from 

warmer countries like Spain. 

There is some discussion around the quantification of the environmental impacts of these 

crops that are far away from the supply points. Society is looking for environmentally 

sustainable supply chains in order to maintain the variety offer of fresh food throughout the 

year (Hospido et al., 2009). 

In order to guarantee the environmental sustainability of resources it is necessary to evaluate 

the use of them. Concretely in irrigation of lettuce, water and energy resources are utilized.

Measuring of resources employed for crop irrigation in general, and for lettuce in particular, 

will let to set the fundaments for the quantification of the environmental impact of their 

exploitation, and advance in the knowledge about the sustainability of resources employed in 

crop production. 

This paper is focused in the evaluation of water and energy use to produce lettuce in 

alternative countries during the winter season in Europe. The case study is located in a farm 

in the Southern of Spain, a warm country where there are zones in which is possible to 

cultivate lettuce in winter. The main objective was to evaluate the efficiency of water and 

energy used in the irrigation of lettuce crops during a typical season. 


The analysis of water and energy efficiency was performed during the 2010-2011 season in 

a commercial Iceberg lettuce orchard (Lactuca sativa, L. cv. ‘Capitata’) under trickle 

irrigation, located at Cartagena, Murcia (Spain). 

2.1. Description of the irrigation system of the experimental farm. 

The irrigated surface of the experimental farm is around 98.93 ha. Irrigation water comes 

from Tajo-Segura transfer and close wells, and it is stored in a private regulation reservoir at 

the East of the irrigation station of the farm. The capacity of the reservoir is 13,975 m 3 . 

Irrigation water is supplied by gravity from the regulation reservoir to the irrigation station. In 

this irrigation station energy is consumed by a horizontal pump where water is distributed to 

several plots under trickle irrigation. Moreover, the pump supplies the adequate pressure to 

different plots of the irrigation system. Additionally, the pump incorporates a frequency speed 

drive in order to adapt the operation point to the demand of the system along the operational 

period of the pump. The pump level is under the water level of the reservoir (around 5 

meters). Water must be raised approximately from a level of 25 meters over the sea level, 

where the pump is located, to a maximum level of 45 meters over the sea level (at the most 

unfavourable point of the farm), what supposes an elevation of around 20 meters. Due to the 

operation pressure of the trickle emitters, an additional pressure of 10 meters has to be 

added to this geometric level. Moreover, in specific times (e.g. in the beginning of the 

seedling phase in lettuce crops) is necessary an adicional pressure for sprinklers. If some 

additional losses (friction and located losses) are also considered, a maximum total pressure 

of 44 to 56.7 meters of water column (mWC) is required. The unitary flow of the pump 

installed is 90 m 3·h -1 . In the studied farm, an autoclean mesh filter and a fertilized dosage 

system are installed after the pump. 

The only meter that registers the volume that is flowing in the irrigation system network is 

located at the exit of the irrigation station. Due to the flow and store capacity of the reservoir 

are not enough for irrigating all the plots at the same time, a rotational scheduling water 

distribution network is needed to be used. For this reason, water distribution network is 

sectored and every sector irrigates a plot by means of manual opening valves. 

2.2. Methodology and equipment for data adquisition. 

The study was partially based in the methodology employed for Water Users Associations 

(WUA) (Abadía, et al., 2008a), but adapted to the specific conditions of a concrete farm. 

Concretely in this case, the irrigation station is considered as an independent hydraulicfunctioning 

sector with an independent energy contract. Some energy parameters (Abadía, 

et al., 2008b) were calculated and monthly energy bills along the season 2010-2011 were 

collected. During the study, the following parameters were simultaneously measured: 

Flow: it was measured by using an ultrasonic flowmeter, with a nominal diameter from 

12.7 mm to 7.6 mm and a measure error of ±1% to 2%. 

Energy consumption and other energy parameters: a net analyser that measures 

voltage, intensity, active and reactive power, power factor and frequency was used. All 

the obtained values had a precision level minor or equal to 1%.

Pressure: it was obtained by means of two pressure gauges. One gauge was installed 

in the suction circuit, and the other was placed in the discharge circuit. Value ranges 

were between 0-6 and 0-10 bars, respectively. 

These measurement instruments are required to be installed in the pump in a representative 

measurement period (e.g. during the crop highest water demand period). In this study, 

instruments were installed from March 16th to 23rd of 2011. Although the period in which the 

measurements were obtained did not coincide with the maximum demand period of the 

installation, it permitted to compare the demand measured in situ (by using the measurement 

instruments) with its electric bill. For this purpose, the electric bills of the irrigation station 

along the 2010-2011 season were compiled, what made possible to study its evolution and 

possibilities of improvement. In this comparison, the electricity and irrigation water 

consumption parameters were contrasted, taking into account the water consumption 

estimations and the irrigation calendars for every plot of the studied farm. These data were 

supplied by the managing enterprise of the farm. 

Some of the more representative indicators of the WUA were calculated. Finally, from 

calculated indicators and obtained measurements, some corrective actions to improve the 

energy efficiency of the system were proposed and valued financially and energetically. 

3. Results 

Descriptive 

Performance 

Efficiency 

TABLE 1. Indicators applied to the case study irrigation system. 

Value in the 

Indicators 

irrigation 

station 

Irrigated area (Sr, ha) 98.93 

Annual irrigation water supply per unit irrigated area (V TSr, m 3·ha -1 ) 3,480 

Total annual volume of irrigation water supply (V T, m 3 ) 344,277 

Maximum total contracted active energy (kWh) 19.8 

Annual consumed active energy (Eac, kWh) 68,123 

Annual consumed reactive energy (Er, kVArh) 36,802 

Power Factor (FP) 0.89 

Consumed Energy per unit irrigated area (kWh·ha-1) 688.60 

Consumed active Energy per unit irrigated area (EacSa, kWh·ha -1 ) 681.27 

Consumed active energy per unit irrigation delivery (EacV T, kWh·m -3 ) 0.20 

Energy cost per unit irrigated area (CENSr, €·ha -1 ) 123.07 

Energy load index (ICE, m) 56.7 

Average energy efficiency of the pumping system (EEB, %) 55.6 

Efficiency of the energy supply (ESE, %) 91.2 

General energy efficiency (EEG, %) 50.7 

The main energy efficiency indicators that were obtained in this study for the 2010-2011 

season are presented in Table 1. These indicators coincide with the ones used for collective 

irrigation systems that, with some peculiarities, can be also extended to individual irrigation 

systems. Energy consumption data used in this study included only from June of 2010 to 

March of 2011 (Table 2), being considered as representatives of a full year. Water 

consumption data along the irrigation season of lettuce crops began in December of 2009 

(first seedlings grown) and finished in April of 2010. The next season began again in 

September of 2010 in order to finish in April of 2011 (see Table 2). For this reason, only a 

simultaneous comparison of water and energy consumption data from October of 2010 to 

March of 2011 was able to be performed. In this study it has been taken into account that 

irrigation water consumption between May and September is low or inexistent. 

Total annual volume of irrigation water supply has been obtained from seasonal irrigation 

water consumption data. These data have not been contrasted with in situ values because, 

-1 

in this case, no devices were available for that purpose. The calculated value of 3,480 m 

3·ha 

is an estimated average value obtained from the average consumption of lettuce in the 

studied farm according to the estimated data provided by the management enterprise.

Maximum total contracted active energy is a data supplied by the energy supply company. 

The energy cost per unit irrigation supply (CENV T ) is 0.044 €·m -3 . The average values 

obtained in the studied farm were very similar to the average WUA values in this area (from 

0.025 to 0.129 €·m -3 , according to the WUA data in the province of Alicante, Spain). 

The value of energy load index (ICE) corresponds with the maximum operating pressure 

value of the pump, which is the highest value of the piezometric level of the irrigation 

network. The average energy efficiency of the pumping system (EEB) was obtained by the 

aid of the simultaneously measurements of the water and energy parameters cited in chapter 

2.2. Efficiency of the energy supply (ESE) quantifies the energy supply according to the 

topology of the irrigation network, and relates the energy demanded by the irrigation network 

with the energy supplied by the pump. The product of EEB and ESE presents the general 

energy efficiency (EEG) of the irrigation system. 

According to the calculated parameters and the protocol for WUA, the studied irrigation 

system was classified as a consumer system, into the forth group of energy consumption 

(600

them cover similar percentages. During the highest energy consumption (February-March 

and October-November) this percentage increases considerably. 

Nevertheless, and according to the results, it can be observed that the use of the cheaper 

periods (P3 and P2) could be increased in the studied irrigation station. For this reason, it is 

possible to move consumptions from P1 period, and even from P2, to P3 (cheapest period), 

what would suppose a decrease in energy costs of about 27%. 

A recommended general measure is to study the offers of the different companies annually, 

since most of them offer great discounts in the first year. 

TABLE 2. Energy consumption for lettuce irrigation in the studied farm (2010-2011 season). 

Consumption period 

Active Energy 

Consumption (kWh) 

Reactive Energy 

Consumption (kVAr) 

Average 

Cosine of phi 

Monthly Bill (€) 

June 2010 9,049 3,982 0.92 1,708.44 

July 2010 2,660 2,068 0.79 561.36 

August 2010 247 227 0.74 141.63 

October 2010 11,670 5,857 0.89 2,032.33 

November 2010 10,735 3,491 0.95 1,723.95 

December 2010 5,018 0 0.95 1,708.44 

January 2011 5,688 7,598 0.60 1,845.23 

February 2011 11,816 6,632 0.87 2,071.15 

March 2011 10,515 6,947 0.83 2,091.63 

TOTAL 67,398 36,802 0.89 12,175.71 

Another feature to be taken into account is the correction of the power factor to values over 

0.95 in order to decrease the reactive energy consumption. For this purpose, an automatic 

capacitor bank is installed in the electric circuit. This way, a low value in the power factor or 

cosine of phi (see Table 2) may be due to the next reasons: 

Bad design of the automatic capacitor bank, since every month a surcharge depending 

on the reactive energy is applied. In this study, the power factor values were under 

0.95 except in December of 2010. Concretely, the surcharge for a power factor value 

between 0.8 and 0.95 is 0.041554 €·kVArh-1. 

Bad system maintenance. In this study, decreases of the power factor, and 

consequently an increment of the penalization, were registered in the monthly bills. 

This could be caused by the failure of one of the condensers. During January, a power 

factor of 0.6 was registered, what involves a penalization of 0.062332 €·kVArh-1. This 

supposed a surcharge of 132.3 € in a bill of 1,845.23€. 

The budget to repair the automatic capacitor bank is around 125€, whose cost could be 

recovered in a month. If a redesign of the automatic capacitor bank is chosen instead, the 

return period of the investment can increase up to 18 months. This measure will only 

decrease the costs produced by the reactive energy, but not the energy consumption costs. 

Maximum values of energy consumption (see Table 3) were registered during October of 

2010 (seedling phase in three plots and beginning of rosette formation in one plot), January 

of 2011 (beginning of rosette formation in three plots, rosette formation phase in a plot and 

seedling phase in two plots), February of 2011 (rosette formation phase in four plots, 

beginning of rosette formation phase in two plots and seedling phase in one plot) and March 

of 2011 (heart formation phase and harvesting in two plots and rosette formation phase in 

five plots). During these months, highest demands of lettuce crops were registered. The total 

water volume was estimated for every cited month: 58,630 m 3 (October 2010), 28,724 m 3 

(January 2011), 59,671 m 3 (February 2011) and 53,100 m 3 (March 2011).

TABLE 3. Seasonal water amount (2010-2011) for lettuce irrigation in the case study. 

SURFACE 

(ha) 

DEC 2009 

JAN 2010 

FEB 2010 

MAR 2010 

APR 2010 

SEP 2010 

OCT 2010 

NOV 2010 

DEC 2010 

JAN 2011 

FEB 2011 

MAR 2011 

APR 2011 

Irrigation 

water 

amount 

(m 3 ) 

9.6821 

38,118.43 

25,928.66 

1.4690 2,798.45 

9.0481 

4.2680 

24,927.52 

27,551.47 

11,237.64 

13,892.34 

15,575.04 

5.4080 

21,388.64 

20,761.31 

7.6500 

30,079.80 

42,036.75 


The methodology employed for WUA can be perfectly adapted to irrigation systems in farms. 

In this paper this methodology has been applied to a commercial plot of 98.93 ha cultivated 

with Iceberg lettuce (Lactuca sativa L. cv. Capitata) and endowed with trickle irrigation, 

obtaining the following conclusions: 

Consumed irrigation water volumes per irrigated area are under crop water needs. 

The energy cost per unit irrigation supply (CENV T , €·m -3 ) is within the average values 

measured in the zone. 

The studied pumping system has a normal energy efficiency value and does not need 

urgent measures for its improvement, although an adequate adjusting would help to 

reach values over 60%. 

The studied irrigation system can be classified as consumer, energy consumption 

group 4, according to consumed active energy per unit irrigated area (EacSa, kWh·ha -1 ). 

Regarding general energy efficiency value (EEG), the system is classified as A 

(excelent energy efficiency), and the pumping station as C (normal energy efficiency). 

A change of energy tariff has not been considered since 3.1A is already the most 

adequate. However, energy consumption in more economical periods is 

recommended, being able to reach a cost saving around 27%. Study of annual offers 

from the companies is also proposed. 

The substitution of a automatic capacitor bank is an adequate measure to avoid 

surcharges for reactive energy, and is recovered in a short period of time. 

By means of the simultaneous control of monthly energy and water consumptions it is 

possible to improve the energy system efficiency and predict anomalous consumptions. 

Energy cost increases considerably the total cost of water, which differs between 

different networks. 

References 

Abadía, R., Rocamora, C., & Ruiz, A. (2008a). Protocolo de auditoría energética en 

comunidades de regantes. Instituto para Diversificación y Ahorro de la Energía, IDAE. 

Serie Divulgación Ahorro y Eficiencia Energética en Agricultura. 10. Madrid: Ministerio de 

Industria, Turismo y Comercio. 

Abadía, R., Rocamora, C., Ruiz, A., & Puerto, H. (2008b). Energy efficiency in irrigation 

distribution net-works I: Theory. Biosystems Engineering, 101(1), 21-27. 

Hospido, A., Mila i Canals, L., McLaren, S., Truninger, M., Edwards-Jones, G., & Clift, R. 

(2009). The role of seasonality in lettuce consumption: a case study of environmental and 

social aspects. International Journal of Life Cycle Assessment, 14 (5), 381-391.

Relationship among compaction, moisture and penetration resistance in 

horticultural soil. 

Carlos Gracia 1 , Estela Alemany 1 , Inmaculada Bautista 2 

1 Unidad de Mecanización y Tecnología Agraria, Universidad Politécnica de Valencia. 

2 Unidad de Edafología y Climatología. Grupo REFOREST, Universidad Politécnica de Valencia, 

Camino de vera s/n, 46022 Valencia, Spain. 

cgracia@dmta.upv.es 

ABSTRACT 

Penetration mechanical resistance in agricultural soil is recognized as a limiting parameter on root 

development. This makes it a necessary variable for an adequate management of the soil. However, in field 

measurements by means of a cone penetrometer become hard to achieve. In case of stony soils or soils 

with previous crop residues these measures also turn to be erroneous because of circumstantial 

interpositions into the vertical path of the cone. Therefore, it is useful to relate penetration resistance to 

other variables such as texture, organic matter, bulk density or moisture content which determination is 

more precise. This study sets the relationship among penetration resistance, bulk density and moisture 

content in a sandy clay loam horticultural soil containing a high percentage of small stones, as those found 

in Eastern Spain. However, this stony characteristic does not seem to advise against its use to grow 

vegetables. Penetration resistance was measured periodically by a cone penetrometer from laboratory soil 

samples. Samples got rid of stones, were enclosed in cylindrical containers and led to different levels of 

compaction. Compacted samples were moistened up to field capacity by capillary rise. Measures were 

taken as the soil dries by forced evaporation and up to the wilting point. Finally, the obtained measures led 

to a functional relationship between penetration resistance, moisture content and bulk density. From this, it 

is possible to generate tables for in field application. 

Keywords: compaction, moisture penetration resistance, penetrometer. 


The capacity of plant roots to penetrate the ground is limited with increasing soil resistance (Mason et 

al., 1988). In many species, the growth of roots is prevented completely, from a specific resistance of 2.5 

MPa (Taylor, 1971). The inability of roots to penetrate compacted soil is well documented in the literature 

(Kirkegaardet al., 1992; Venezia et al., 1995; Lakers, 2001). 

According to (Bengough et al., 2001), soil penetration resistance (SR) is, “the force required to push the 

cone into the soil divided by the cross-sectional area of its base.” 

Initially, the SR could be measured by a cone penetrometer (Bengough et al., 2001) considering the 

pressure exerted by the probe over the resistance to friction, and adhesion strength due to soil-metal 

(Farrell and Greacen, 1996). Although this method is widely employed, sometimes the use of a cone 

penetrometer turns out to be tough and defective. This is enhanced in high presence of stones or previous 

crop residues. 

Alternatively, it is proposed indirect measures of resistance to penetration, starting from their 

dependence on certain parameters of the soil. This will take into account, texture, organic matter content, 

bulk density, moisture content, among others. It comes to determining then, the functional relationship of

the soil mechanical resistance to penetration, with these variables applying it to a horticultural soil in the 

Mediterranean area. 

Several laboratory and field studies have been linked empirically, adjusting multiple SR regression 

functions (Busscher, 1990, da Silva et al. 1994 and 1997, Smith et al. 1997) to texture, porosity (Ф), organic 

matter content (Spivey et al., 1986), water content (θ) (Ayers and Perumperal, 1982, Busscher et al, 1997 

and Lehrsch et al, 1982), bulk density (Db) (Taylor and Gardner, 1963, Camp and Lund, 1968; Mirreh and 

Ketcheson, 1972) and matric potential (ψ) and calcium carbonate content (Poch and Verplancke, 1997). 

(Busscher, 1990) used up to ten different adjustments to estimate SR as a dependant variable of matric 

potential and bulk density. Sample soils sieved to 2 mm, with textures ranging from sandy to sandy loam. 

The function that best fit had the following structure: SR = a (ψ b ) • (D b ) c where ψ is the absolute magnitude 

of the matric potential, and a, b, c are constant adjustments. 

Da Silva and Kay (1997) also, obtained a fit function for SR based on the volumetric water content θ (SR 

= c θ d • (D b ) e ) from samples with clay contents between 6% and 37% and organic matter between 9 and 39 

g / kg. Coefficients d and e depend on the content of clay and organic matter in soil sampled. They 

concluded that compaction has a greater impact on SR than it will on bulk density levels. 

The objective of this study is the indirect evaluation of SR as a determinant of root growth and crop 

development (Campbell et al., 1988, Cassel and Nelson, 1979; Grecu et al. 1988; Perumperal, 1987, Sojka 

et al., 1991) and movement of water and air (Rivas et al., 1998). 

2. Materials and methods 

2.1 Soil studied 

The study was carried out from soil samples collected in a horticultural farm in Eastern Spain (Liria, 

Valencia), altitude 190 m. In this farm, a sprinkler with fixed installation is used as an irrigation system and 

cropping intensity allows two annual crops in rotation with conventional tilled practices. There is a high level 

of mechanization in agricultural tasks, in addition to the presence of large harvesters and crop transport 

vehicles which have been stood for the last 20 years. This area has a semiarid Mediterranean climate type 

with dry summers and rainy autumns and winters. The annual rainfall historical average is of 398 mm with a 

evapotranspiration potential of 1091 mm (Montheih Pennman), rain incidence is higher in autumn season. 

The soil is characterized as silty loam Haplic Calcisol (Word Reference Base, FAO 2003) with high 

calcium carbonate content. The organic matter content is low and decreases with depth (Table 1). 

Table 1. Soil properties (mean values of eight samples) 

Particle size distribution: 

Sand (50 -2000 μm), % 53.34 

Silt (2-50 μm), % 24.71 

Clay (< 2 μm), % 21.94 

Chemical properties: 

Organic carbon content, g kg -1 8.13 

CaCO3 , g kg -1 615.8 

pH (water, 1:2.5) 8.4 

Electrical Conductivity ( 1:5) (mmhos cm -1 ) 0.2 

2.2 Samples preparation 

Ten samples (15 kg/each) were taken from random locations in the farm by digging to a depth of 30 cm 

and mixing the extracted material. Samples collected from the field were taken to the laboratory. Coarse 

elements such as stones or crop residues were manually separated from soil. The remaining material was 

sieved with a 4 mm mesh to obtain a fine working soil for laboratory. Soil was dried in an oven at 105°C 

until a moisture value near zero (Figure 1). Subsequently it was wetted up to a 15% of RH. This RH value 

showed in a previous experience that achieves good levels of compaction. Wetting was conducting on dry 

soil by using a spray. In order to get a uniform distribution of moisture, soil was spread in thin layers over 

large trays. To warrant control weights of soil and water inputs a high precision digital scale was used 

(Figure 2). The uniform water distribution process is completed by gentle stirring with a spatula (Figure 3).

Cylindrical containers (191mm diameter, 300mm height) for sampling (Figure 4) were made of polyvinyl 

chloride (PVC). PVC is a resistant material withstands temperatures above 50° without suffering 

deformations 

Figure 1: Dry soil Figure 2: Wetting of the soil sample Figure 3: Distribution of water Figure 4: Sample container 

Containers were filled of three layers of soil, with moisture of 15% RH. Each layer’s thickness was 

approximately of 8 mm, and they were compacted successively with equal loads in order to achieve 

reasonable compaction uniformity throughout the confined volume. A hydraulic press (Figure 5) fed with a 

gear pump was used for the compaction. The press had a flow rate of 18 l/min in an open circuit working 

from 0 to 40 bars and the section of the press piston was of 40 mm 2 . Compaction loads applied ranged 

from 500 N to 5 kN which meant pressures on the soil from 17 to 175 kPa. Eight laboratory samples were 

prepared from different loads of soil compaction, resulting in the following bulk densities: 1.46, 1.40, 1.36, 

1.34, 1.21, 1.15, 1.12 and 1.09 (in g/cm 3 ). 

The samples´ wetting process was carried out by capillary rise until reaching the field capacity 

(saturation level of the soil) levels which means values around 30% of RH. For this purpose, the cylinders 

were immersed in sealed containers of a greater capacity, sheets of water were added as it was absorbed 

by capillary rise through the soil matric potential, until a darker color of the upper layer of soil or even the 

presence of water showed up. The elimination of excess water was accomplished by drain. 

2.3 Test 

Each cylindrical sample was measured (Figure 6) by an Eijkelkamp penetrometer with a one cm 2 cone 

for each of the obtained moistures. To attempt the progressive reduction in the moisture content in between 

SR measurements, the cylinders were successively introduced in a drying oven at 40°C (Figure 7) and 

weighted in a digital scale. SR was measured repeatedly in each cylindrical container (Figure 8) from field 

capacity (about 30%) to wilting point (5-8% RH approx.). 

Figure 5: Hydraulic press for 

compaction 

Figure 6: Measurement of SR by a 

cone penetrometer 

Figure 7: Containers in drying 

oven 

Figure 8: Control of moisture by 

weight difference 

SR values recorded at approximately 25 cm soil depth varied between 0.14 and 4.0 MPa with a standard 

deviation of 0.94 MPa. SR variation was directly proportional to bulk density and it was observed that 

decreasing soil moisture led to increasing the soil strength 

3. Results 

The function defined in (da Silva and Kay, 1997) (equation 1) was particularized to the clay content 

(22%) and soil organic matter (0.8%) sampled, obtaining the three parameter values (lnc, d and e) showed 

in equation 2. 

ln SR = ln c + d ln θ + e ln D b [1] 

ln SR = - 6.23 – 3.04 • ln θ + 5.97 • ln D b [2]

After applying equation 2 to values of soil moisture and bulk density measured, as explained in 

subsection 2.3, it was checked that the expression did not adjust well to the SR values obtained. This 

deviation can be found in certain soil characteristics not taken into account in equation 2. Specifically, it can 

be attributed to the content of calcium carbonate. The presence of calcium carbonate during drying causes 

a greater cohesion of the soil, with the consequent effect on increasing the penetration resistance. Soil 

samples tested had high lime content 615 g/kg. By contrast, Silva and Kay, and others like (Ross et al., 

1991; Rasmussen, 1999; Castro-Filho et al., 2002) Brazil, (Zhang et al., 2007) who have worked on this 

topic, operate in soils ranging from neutral to acidic, carbonates. 

Therefore, a new function for SR was obtained by linear regression according to the expression of 

equation 1. The adjustment was accomplished using software ®Statgraphics Centution XVI, coefficients 

were determined following least squares criteria and the quality of the adjustment is based on the best 

value of the correlation multiple coefficient R 2 . Table 2 shows the new parameters obtained. Equation 3 

depicts the new function for SR. 

Table 2: Multiple regression results for the soil resistance curve model. 

Parameter 

Standard 

Parameter Estímate Error 

ln c -5,11865 0,269829 

d 6,20902 0,492792 

e -2,14001 0,104534 

*F-Ratio = 211.31, Adjusted R 2 =0.865, Standard Error of Est. =0.35, 

**SR=soil resistance (MPa), θ=volumetric water content (cm 3 cm -3 ) D b = bulk density (g cm -3 ). 

ln (SR) = -5,12 - 2,14• ln(θ) + 6,21• ln (Db) [3] 

Table 3 shows values of the variables measured in the tests: Db, Ѳ and SR 0 ; together with the values 

estimated by the functions of equation 2 and equation 3 (SR [2] and SR [3]): 

Table 3. Results and estimates of SR. 

Db 

(g/cm 3 ) 

1.46 

Ѳ 

(cm 3 · 

cm -3 ) 

SR 0 

(Mpa) 

SR [2] 

(Mpa) 

SR [3] 

(Mpa) 

Db 

(g/cm 3 ) 

Ѳ 

(cm 3 · 

cm -3 ) 

SR 0 

(Mpa) 

SR [2] 

(Mpa) 

SR [3] 

(Mpa) 

Db 

(g/cm 3 ) 

Ѳ 

(cm 3 · 

cm -3 ) 

SR 0 

(Mpa) 

SR [2] 

(Mpa) 

0.33 0.25 0.53 0.66 0.35 0.14 0.27 0.35 0.31 0.17 0.13 0.15 

0.31 0.31 0.64 0.76 0.28 0.27 0.53 0.56 0.24 0.25 0.28 0.25 

0.25 1.1 1.25 1.21 0.23 0.61 0.92 0.82 0.18 0.7 0.69 0.47 

0.23 1.44 1.57 1.42 0.22 0.88 1.13 0.95 0.16 0.8 0.96 0.59 

0.21 2 2.01 1.69 0.21 1.13 1.29 1.05 1.12 0.12 1.07 2.67 1.22 

1.34 

0.2 2.77 2.44 1.94 0.2 1.08 1.59 1.21 0.1 1.36 3.73 1.54 

0.18 3.23 3.26 2.38 0.18 1.46 2.14 1.49 0.09 2.14 5 1.89 

0.17 3.88 3.79 2.65 0.16 2.43 2.94 1.86 0.08 2.27 8.58 2.77 

0.15 4 5.81 3.58 0.13 2.59 4.94 2.69 

0.11 3.59 10.27 4.5 

SR [3] 

(Mpa) 

0.07 4 14.74 4.05 

Figures 9, 10 and 11 show the adjustment for three levels of bulk density and compaction, 

representative of the eight samples tested. In general, SR [3] fits well and values obtained are close to those 

measured in the laboratory, especially for soil moistures of 18-20%. It is also observed that on soil with a 

bulk density higher than 1.4 g/cm3, the maximum acceptable resistance to normal root growth (of about 3 

MPa) is achieved for moisture below 15%. While, in loose soils - density of about 1.2 g/cm3-, this 

resistance does not appear until the moisture content falls below 10%. Even, a very loose soil, with 1.1 

g/cm3 density may be in the wilting point -6 to 8% - but never reach high values of resistance to 

penetration.

Figure 9 High compaction. Bulk density, 1.46 

g·cm -3 

Figure 10: Test 4. Medium compaction. Bulk 

density, 1.34 g·cm -3 

Figure 11 Test 8. Low compaction. Bulk density, 

1.12 g·cm -3 

. . 


A good indirect measurement of SR has been obtained from state variables: bulk density and moisture 

content for a representative soil type of Eastern Spain. 

It has been verified that soils rich in limestone, as tested, resulted in higher SR than those expected in 

neutral or acid soils. 

The approximation function proposed here can be used therefore as a reference for calcareous soils, 

which as far as we know, was lacking in the literature. 

References 

Ayers, P.D. and J. V. Perumperal. 1982. Moisture and 

density effect on cone index. Trans ASAE 25: 1169- 

1172. 

Bengough, A.G.,Campbell, D.J., O’Sullivan, M.F., 

2001. Penetrometer techniques in relation to soil 

compaction and root growth, In: Smith, K.A., 

Mullins, C.E (Eds.), Soil and Environmental 

Analysis, 2nd ed. Marcel Dekker, New York, pp. 

377-403. 

Busscher, W.J., 1990. Adjustment of "at-tipped 

penetrometer resistance data to a common water 

content. Trans. ASAE 33, 519–524. 

Busscher, W.J., Sojka, R.E., 1987. Enhancement of 

subsoiling effect on soil strength by conservation 

tillage. Trans. ASAE 30, 888–892. 

Busscher, W.J., Spivey, L.D., Campbell, R.B., 1987. 

Estimation of soil strength properties for critical 

rooting conditions. Soil Till. Res. 9, 377–386. 

Busscher, W.J., Bauer, P.J., Camp, C.R., Sojka, R.E., 

1997. Correction of cone index for soil water 

content differences in a coastal plain soil. Soil Till. 

Res. 43, 205–217. 

Camp, C. R., and Z. F. Lund. 1968. Effect of 

mechanical impedance on cotton root growth. 

Trans ASAE. 11:477-483. 

Campbell, R. B., W. J. Busscher, O. W. Beale, and R. 

E. Sojka. 1988. Soil profile modification and cotton 

production. Proceedings, Beltwide Cotton 

Production Research Conference. Jan. 3 8, 1988, New 

Orleans, LA. 

Cassel, D. K., H. D. Bowen, and L. A. Nelson. 1978. 

An evaluation of mechanical impedance for three 

tillage treatments on Norfolk sandy loam. Soil Sci. 

Soc. Am. J. 42:116-120. 

Castro-Filho, C., Lourenço, A., Guimara˜es, M.F., 

Fonseca, I.C.B., 2002. Aggregate stability under 

different soil 

management systems in a red latosol in the state of 

Parana, Brazil. Soil and Tillage Research 65, 45– 

51. 

Da Silva, A. P., S. Imhoff, and M. Corsi. 2003. 

Evaluation of soil compaction in an irrigated shortduration 

grazing system. Soil Til. Res. 70:83-90. 

Da Silva, A.P. , and B.D. Kay, 1997. Estimating the 

least limiting water range of soils from properties 

and management. Soil Sci. Soc. Am. J., 61 (1997), 

pp. 877–883 

Grecu. S. J., M. B. Kirkham, E. T. Kanemasu, D. W. 

Sweeney, L. R. Stone, and G. A. Milliken. 1988. 

Penetration resistance, root growth, and water 

content in subsoiled claypan. J. Agron. Crop Sci. 

161:195-206.

Farrell, D.A., Greacen, E.L., 1966. Resistance to 

penetration of fine probes in compressible soil. 

Aust. J. Soil Res. 4, 1–17. 

Kirkegaard, J.A., Troedson R.J., H.B. So, B.L. 

Kushwaha.,1992. The effect of compaction on the 

growth of pigeon pea on clay soils. II. Mechanisms 

of crop response and season effects on an oxisol in 

a humid coastal environment Soil Tillage Res., 24 

(1992), pp. 129–147. 

Laker, M.C., 2001. Soil compaction: effects and 

amelioration. Proceedings of the 75th Annual 

Congress of the South African Sugar Technologists’ 

Association, Durban, South Africa, 31 July 3 August 

2001 (2001), pp. 125–128. 

Lehrsch, G. A., J. K. Young, and F. D. Whisler. 1982. 

Penetration resistance of Mississippi soils as 

affected by bulk density and moisture content. In 

Agron. Abs., ASA, Madison, WI, p. 163. 

Mason E.G,. Cullen A.W.J, Rijkse W.C., 1988.Growth 

of two Pinus radiata stock types on ripped and 

ripped/bedded plots at Karioi forest. N. Zeal.J. 

Forestry Sci., 18 (1988), pp.287–296. 

Mirreh, H. F., and J. W. Ketcheson. 1972. Influence 

ofbulk density and matric pressure to soil 

resistance penetration. Can. J. Soil Sci. 52:477- 

483. 

Perumperal, J. V.1987. Cone penetrometer 

application: A review. Trans ASAE 30:939-944. 

Poch, R. M., and H. Verplancke. 1997. Penetration 

resistance of gypsiferous horizons. Eur. J. Soil Sci. 

48:535-543. 

Rasmussen, K.J., 1999. Impact of plough less soil 

tillage on yield and soil quality: a Scandinavian 

review. Soil and Tillage Research 53, 3–14. 

Ross, P.J., J. Williams, and K.L. Bristow. 1991. 

Equations for extending water –retention curves to 

dryness. Soil Sci. 

Soc. Am. J. 55:923-927. 

Smith, C.W., Johnston, M.A., Lorentz, S., 1997. The 

effect of soil compaction and soil physical 

properties on the mechanical resistance of South 

African forestry soils. Geoderma 78, 93–111. 

Sojka, R. E., D. L. Karlen, and W. J. Busscher. 1991. A 

conservation tillage update from the Coastal Plain 

Soil and Water Research Center of South Carolina. 

Soil Tillage Res. 21:361-376. 

Sojka, R.E., Busscher, W.J., Lehrsch, G.A., 2001. In 

situ strength, bulk density and water content 

relationships of a durinodic xeric haplocalcid soil. 

Soil Sci. 166,520–529. 

Spivey, L. D. Jr., W. J. Busscher, and R. B. Campbell. 

1986. The effect of texture on strength in 

southeastern Coastal Plain soils. Soil Tillage Res. 

6: 351-363. 

Taylor, H.M. 1971. Effect of soil strength on seedling 

emergence, root growth and crop yield Compaction 

of Agricultural SoilsAmerican Society of Agricultural 

Engineering (1971) pp. 292-305. 

Taylor, H. M., and H. R. Gardner. 1963. Penetration of 

cotton seedling taproots as influenced by bulk 

density, moisture content, and strength of the soil. 

Soil Sci. 96:153-156. 

Venezia, G., Puglia, S. del, Cascio, B., 1995. Effects of 

different methods of cultivation of an Andisol on soil 

bulk density and on root system development in 

bread wheat (Triticum aestivum L.). Rivista di 

Agronomia 29, 507–513. 

Zhang, G.S., Chan, K.Y., Oates, A., Heenan, D.P., 

Huang, G.B., 2007. Relationship between soil 

structure and 

runoff/soil loss after 24 years of conservation 

tillage. Soil and Tillage Research 92, 122–128.

Simulation of water flow with root water uptake proposed the new 

software SWMRUM 

Abstrat 

Sina Besharat 1 * 

1 Water Engineering Department, University of Urmia, Urmia, Iran 

* s.besharat@urmia.ac.ir 

Soil water simulation models require a description of root water uptake. In this study, water 

flow model including proposed model (SWMRUM) software were compared based on field 

measurement under the same condition in Lysimeter. Tube-time domain reflectometry (TDR) 

was used to measure soil volumetric water content. Root water uptake model includes root 

density distribution function, potential transpiration and soil water stress-modified factor. The 

root water uptake model was developed, and linked into a soil water dynamic model to 

enable simulation of water movement in soil via numerical solution of Richards’s equation. 

The outputs from the model are compared against the measured water content data. 

Simulated and measured water contents were in excellent agreement. Analysis of residual 

errors, differences between measured and simulated values, can be used to evaluate model 

performance. These are root mean square error (RMSE), modeling efficiency (EF), and 

coefficient of residual mass (CRM). Results show that maximum root water uptake was 0.023 

m3m3d-1 at depth 15-25 cm and minimum was 0.003 m3m3d-1 at depth 60 cm. 

Key words: Numerical solution, Richards’ equation, Root distribution, SWMRUM software, 

Water flow. 


Rooting patterns have traditionally been analyzed by means of root weight density or root 

length density. Root length density is often used to characterize the root system. However, it 

is a difficult and time-consuming undertaking to measure and determine root length density 

distributions accurately, especially in the field, because the distributions change with different 

soils, plant species, growing seasons, climate conditions, and others. 

There are some investigations on the root morphology of trees, including the spatial 

distribution of roots under localized water application (Kjelgren et al. 1985; Meyer and Peck 

1985; Roth and Gardner 1985; Sakovich and Post 1986; Clausnitzer and Hopmans 1994). 

Information to date on the spatial and temporal distribution of root water and nutrient uptake 

is limited, especially for partially wetted soils (Clothier 1989; Kramer and Boyer 1995). Root 

water uptake models that can describe spatial and temporal patterns were developed by 

Coelho and Or (1996) and Vrugt et al. (2001). 

Understanding the physical processes in the soil which govern water and chemical entry into 

the root zone, is a necessary step towards developing more efficient and environmentally 

sustainable strategies of root zone management. However, it is also important to understand 

the biological processes that operate in the root zone to govern subsequent uptake of water 

and chemicals by the roots. The movement of soil water, and of any water-borne chemicals, 

is frequently a direct result of the action of plant roots. If we are to understand better, and to 

model effectively, soil and plant processes we need at least a quantitative means of 

describing the process of uptake by the roots (Green and Clothier 1999). 

The objectives of this study are to test SWMRUM model used for root water uptake and to 

develop such as empirically spatial distribution model of an apple tree roots. This model 

established based on the soil properties.


After the surface irrigation practice, soil water content was measured every 2 hours, using a 

TRIME-FM time domain reflectometry (TDR) probe in 12 glass fiber tubes around the apple 

tree. 

Considering the vertical and radial variations of the root distribution, soil samples were taken 

from around the tree, and the position of each sample was recorded including radial distance 

from the trunk and depth to the midpoint of each sample, at the end of the experiment. The 

root-length density (cm cm -3 ) of each sample was determined by dividing the total root length 

by the sample volume. The 2D depth- and radial-wise distribution of roots was determined 

from the average the root-length density of the same sample within the root zone. 

The model (SWMRUM) was obtained based on the observation of root density in field and 

the root density distribution was fitted to deduce the root density function as follow: 

r 

z 

( ( r / rm 

(t )) (z 

/ zm 

(t ))) 

(r,z, t) Cir 

(1 )(1 ) 0e 

(1) 

rm 

(t) z 

m 

(t) 

where â(r, z, t) is the root density function [LL -3 ], C ir is a coefficient used to show growing 

power of root that is evaluated with a penetrometer tool [-], t is the certain time, r is the 

distance in radial direction [L], z is the distance vertical direction [L], r m (t) is the maximum root 

development radius [L] in the radial direction at time t, z m (t) is the maximum root depth [L] in 

the vertical direction at time t, and â 0 , ñ, and are the empirical parameters. Values of the 

coefficient C ir in different soil, evaluated for root distribution ability, have given in Table 1. 

These values were calculated by using a Penetrometer tool (Rimik CP20), which measures 

the resistance against penetration in soil. The instrument consists of a data logger, load cell, 

a cone attached to a shaft and GPS. The data logger records the cone index value of the 

load required for insertion of the cone through the soil as well as time, date, and GPS 

coordinates. The logger plots these cone index values against the depth. 

The root water uptake rate at (r,z) can be calculated by following equation: 

S(r,z,t,h) 

(r,z,h)S 

(r,z,t) 

(2) 

max 

where S(r,z,t,h) is the proposed root water uptake in r-direction and z-direction for spatial soil 

water pressure head (h) at time t, (r,z,h) 

is adjusted water stress function. 

As the potential cumulative root water uptake must equal the potential transpiration rate 

(T pot ), the maximum root water uptake distribution, S max [T -1 ], may be computed from 

(Simunek et al. 2006): 

S 

max 

(r,z, t) 

2 

R 

z m r m 

(r,z, 

t)T 

2 

r 

0 0 

pot 

(r,z, t)drdz 

where S max (r,z,t) denotes the maximum root water uptake rate [T -1 ] and R is the size of the 

flow domain in the r-direction[L]. 

(3) 

3. Results 

The presented two dimensional models of root water uptake were evaluated using measured 

soil water content values, around the apple tree during the irrigation period. For simulating 

water movement in soil, the two-dimensional root water uptake model was developed, which 

was linked to a soil water dynamic model. The spatial two-dimensional maps of simulated 

and measured water content values (m 3 m -3 ) involving the effects of root water uptake after 

irrigation at three different days are shown in Fig 1. During experiment the soil volumetric

water contents were almost greater than 12%. The surface soil water content reached about 

34% (vol. %). The low water contents centered at the depth 10–50 cm and radial distance 0– 

60 cm illustrated that the root water uptakes were intensive in this area. The agreement 

between the simulations and measurements was excellent. 

Radial distance from the trunk (cm) 

0 20 40 60 80 100 120 140 160 

0 


0 20 40 60 80 100 120 140 160 

44 0 

40 

44 

40 

Soil depth (cm) 

20 

40 

60 

80 

Soil water content (vol. %) 

36 

32 

28 

24 

20 

16 

12 

8 


20 

40 

60 

80 


36 

32 

28 

24 

20 

16 

12 

8 

100 

August 26 - Measured 

4 

100 

August 26 - Simulated 

4 


0 20 40 60 80 100 120 140 160 

0 


0 20 40 60 80 100 120 140 160 

44 0 

40 

44 

40 


20 

40 

60 

80 


36 

32 

28 

24 

20 

16 

12 

8 


20 

40 

60 

80 


36 

32 

28 

24 

20 

16 

12 

8 

100 

September 2 - Measured 

4 

100 

September 2 - Simulated 

4 

FIGURE 1: Two-dimensional maps of measured and simulated water content values. 

Consequently, most of the tree root activity, as indicated by temporal and spatial changes in 

soil water, was also concentrated in the surface soil layer. Water content profiles also 

revealed that deeper/younger parts of the root systems did not extract water as efficiently as 

shallower/older roots, suggesting a significant axial resistance could exist in deeper roots 

(Pierret et al. 2006). All these observations converge and indicate that a precise description 

of root water uptake requires the integration of data about soil and root hydraulic properties 

as well as root spatial distribution. In order to study all these aspects of soil–root interplay on 

water uptake, modeling can help, in conjunction with experimental work, to test these 

hypotheses on water transfer in the soil–root system (Garrigues et al. 2006). 

References 

Clothier, B. E., & Green, S. R. (1994). Rootzone processes and the efficient use of irrigation 

water. Agric Water Manag 25:1–12. 

Clothier, B. E. (1989). Research imperatives for irrigation science. J Irrigation Drainage Eng 

115(3):421–448. 

Coelho, E. F., & Or, D. (1999) Root distribution and water uptake patterns of corn under 

surface and subsurface drip irrigation. Plant Soil 206: 123–136. 

Green, S., & Clothier, B. (1999). The root zone dynamics of water uptake by a mature apple 

tree. Plant Soil 206: 61–77. 

Kjelgren, R., Goldhamer, D. A., Uriu, K., & Weinbaum, S. A. (1985). Almond tree response to 

variable nitrogen fertilization rates through low volume sprinklers. In: Proceedings of the 

3rdInternational drip/trickle irrigation congress, Fresno, vol 2.

Kramer, P. J., & Boyer, J. S. (1995). Water relations of plants and soils. Academic Press. 

Meyer, J. L., & Peck, D. (1985). Avocado root distribution with microsprinklers. In: 

Proceedings of the 3rd International drip/trickle irrigation congress, Fresno vol 2, pp 682– 

686. 

Pierret, A., Doussan, C., & Pages, L. (2006). Spatio-temporal variations in axial conductance 

of primary and first-order lateral roots of a maize crop as predicted by a model of the 

hydraulic architecture of root systems. Plant Soil 282: 117–126. 

Roth, R. L., & Gardner, B. R. (1985). Root distribution of mature orange trees irrigated by 

pressurized systems. In: Proceedings of the 3rd International drip/trickle irrigation congress, 

Fresno, vol 2, pp 579–586. 

Sakovich, N. J., & Post SEC (1986). Lemon root distribution in sprinkler. Drip systems 

Citrograph 71(7):143–144. 

Vrugt, J. A., van Wijk, M. T., Hopmans, J. W., & Simunek, J. (2001). One-, two-, and threedimensional 

root water uptake functions for transient modeling. Water Resour Res 37: 2457– 

2470.

Operation and Energy Optimization Model for Gharah-Bagh Water 

Conveyance System 

Mohsen Besharat 1 *, Mohammad T. Aalami 2 , Avin Dadfar, Sina Besharat 

1 Saghez, 66819-73477 Iran, Islamic Azad University, Saghez Branch 

2 Tabriz, 51666-16471 Iran, University of Tabriz 

*Corresponding Author, E-mail: mohsen.besharat@gmail.com 

Abstract 

Optimum and efficient energy consumption has been a considerable issue worldwide. Water 

conveyance systems (WCS) require energy to transfer water to higher elevation by pumping, 

and it causes high electricity costs. As a conclusion, optimization of energy and effective 

consumption lead to lower costs. In this work, an optimization model for Gharah-Bagh WCS in 

Iran has been implemented. The model has two parts. One part manages the operation time of 

pumping system in order to an optimum hourly operation of pump based on electricity tariffs is 

earned. Another part of optimization model refers to idea of producing the electricity in gravity 

branch of system. System has a gravity branch with considerable elevation difference between 

start and end nodes that presents a good opportunity for installation a turbine and producing 

electricity. 

Key words: Energy, Optimization, Turbine, Water Systems 


Water problem is one of the biggest challenges of this century. The problem mandates such a 

situation that requires exact planning and management of water sources to raise the efficiency. 

In Iran 69% of the total amount of water goes to agriculture, 23% goes to industry and 8% goes 

to domestic consumption. Agriculture resources are the main consumers of high quality water. 

Average amount of water taken for irrigation has increased by 60% since 1960 that about 20% 

to 30% of this amount evaporates or goes to waste (NAST, 2000). The amount of water per 

acre, in developing countries due to lack of appropriate instruments is twice of the developed 

countries, while the rate of their crops is one-third. Moreover, in most arid and semi-arid areas, 

due to lack of rainfall climate, 90% of water needed for irrigation is supplied from fresh water, 

while in developed countries this rate is 40% (Aggidis et al. 2010). 

It is not for many years that human being has come to the belief of efficient using of energy. In 

previous times because of world’s few populations and little energy consumption, optimum 

energy consumption was not an apprehension for people. But in recent years by increasing of 

world’s population and its consequences as decreasing in fossil energy sources, increasing in 

fossil energy source costs and most important subject, irretrievable damages of fossil fuels on 

environment and communities, effort for using better forms of energy and decreasing the 

consumption of fossil energy sources has begun (Vieira & Ramos, 2008). 

These problems will be more tangible if the vital role of water in every action on the earth and 

human life be imagined. A huge amount of energy is exhausted in order to supply the required 

water for human being. In all countries big amount of energy is spent for clean water supplying 

for people annually. Therefore in event that decreasing of water supply energy is able, it will be 

mainly useful. Hence many researches have been done in energy efficiency optimization in

water-energy nexus. In the case that many clean and renewable energy sources as solar 

energy, energy of wind, energy of flowing water are there in environment, fossil energy sources 

can be replaced by the clean energy sources for decreasing pollutant energy consumption. This 

idea has been considered and used before and governments had long term plans for that. In 

studies of the European Union the renewables will provide 13.5% of world energy in 2030 

(Arriaga, 2010). 

In this direction, the research follows two goals; 1. Optimization of energy consumption using 

time management and adapting of system component and optimizing operation of pumps by the 

goal of decreasing energy consumption and costs, 2. Using potential opportunities in system for 

energy producing. 

2. Optimization 

Optimization is the relationship between production and consumption of systems. Also, 

Optimization is defined as best usage of all conditions with respect to limitations. 

Generally the objective function can be written as following equation: 

W f x , x , x ,..., x ) 

(1) 

( 

1 2 3 n 

In this equation, W is objective function, that is a mathematical equation between variables of 

x 

1 

, x2, 

x3,..., 

x n 

. Also n is the number of variables of objective function (Fadaee & Besharat, 

2005). 

3. Water-Energy Nexus 

The goal of water supply systems is to produce water for various purposes. Such systems are 

required to spend a lot of energy for water transportation. If the huge amount of water 

consumption on the world is imagined, it can be conceived that a large amount of energy is 

consumed in this systems. Usually in design of systems the effort will be achievement the best 

plan and avoidance of head loss. The path of the pipe and its roughness has direct effect on 

design. Sometimes a lot of energy wastes by means of some devices in order to control the 

flow. For instance, in some cases that high elevation different there is in a pipe line, a high 

speed flow appears. In such cases to prevent the destructive effects of energetic flow, some 

devices such as pressure reduction valves (PRV) are used. PRV not only wastes the useful 

energy of systems, but also are very costly because of some service and maintenance 

requirements. 

In this study, as an innovative idea, it has been tried to stop the energy loss in PRV installed 

points. In this regard, in the location of PRV, water turbine has been installed. The turbine first 

acts as a PRV for controlling the energy of water. In the next step the controlled energy will be 

employed to produce electricity in turbine. The generated electricity can be implemented in the 

system for pumping purpose. But an exact time management operation is required for this goal. 

4. Gharah-Bagh WCS 

The Gharah-Bagh project has been located in north east of Urmia in Iran. The main goal of this 

system is to produce the adequate water for irrigation. Water is gained from Zolla Dam and is 

transported to required place by Gharah-Bagh WCS.

Urmia Salt Lake 

Urmia 

FIGURE 1: Gharah-Bagh WCS Position 

The considered WCS has a pumping station in the level of 1238 meter that drives water to 

higher elevation and then water flows down by in a gravity pipe to lower elevation. Installed 

pipes in this project are Polyethylene pipes that their length and diameter are presented in 

TABLE 1. 

TABLE 1: Pipe Specifications 

Path Number Pipe Material Diameter (mm) Length (m) 

1 Polyethylene 400 481 

2 Polyethylene 315 2750 

Water flows to higher elevation by mentioned pumping station in path number 1 (Line 1) and 

then at the end of line 1 water pours into a reservoir A. At the exit of the reservoir A, water 

enters the path number 2 (Line 2). The elevation of reservoir A is 1292 meter. Dynamic head 

and static head of pump are 54 meter and 48 meter in order. Design discharge of system equals 

to 100 liter per second. Originally, the reservoir A is considered to produce an emergency save 

in case of probable system failure. The volume of reservoir has been calculated in such a way 

that it would be able to present required water for an hour. Base on this approach the volume of 

reservoir is 360 cubic meters. In fact, the water head at the end of line 2 is rather high and 

equals to 100 meters. As a result, a PRV had been installed to reduce the head. In the initial 

design, the pump used to work 24 hours per day completely. Operation of system has been 

modeled in EPANET software area. See FIGURE 2 for system specification in EPANET 

software area.

FIGURE 2: System model in EPANET area before optimization 

Because of continuous working of the pump in initial plan of the system the annual electricity 

cost was very high. The electricity tariffs for cultivation period in project region have been shown 

in FIGURE 3. 

0.009 

0.008 

0.007 

Electricity Tariff ($/Kw) 

0.006 

0.005 

0.004 

0.003 

0.002 

0.001 

0 

0-1 

1-2 

2-3 

3-4 

4-5 

5-6 

6-7 

7-8 

8-9 

9-10 

10-11 

11-12 

12-13 

13-14 

14-15 

15-16 

16-17 

17-18 

18-19 

19-20 

20-21 

21-22 

22-23 

23-24 

Time(hour) 

5. System Optimization 

In the first stage pump operation time adjusted for minimum cost. The second stage was 

replacement of a water turbine instead of PRV. In order to these two stages can be done some

changes have been done in system. First the input discharge rose to 150 liter per second, while 

the output discharge stayed without change (100 liter per second). Also the volume of reservoir 

A increased to 1080 cubic meter and an additional reservoir (reservoir B) added to end of line 2. 

The optimization has been done based on the water level in reservoir A. Then the achieved 

rules from optimization simulated in EPANET software area. In fact, operation schedule of the 

system planed base on following rules: 

a) Pump starts working when the water level in reservoir A reaches to minimum level 

b) Pump stops working when the water level in reservoir A reaches to maximum level 

c) The discharge valve in the end of reservoir A is closed when the water level in reservoir B 

reaches to minimum level 

As a result the operational time of the pump reduced to 18 hours instead of 24 hours. The pump 

works in 3 intervals that each interval longs 6 hours. Therefore the pump will be on rest in 2 

intervals that each long 3 hours. Additional discharge in this case fills the reservoir A during 

operation intervals. At the rest times the required water of system is produced by reservoir A. 

This innovative optimization reduces the operation time of pump to 18 hours. These 18 hours 

working time has been set in a way that is in domain of low cost tariffs. Two considered rest 

intervals causes considerable reduction in electricity costs. 

In addition to electricity costs, since the pump does not work continuously, the pump damping 

and maintenance costs will be very lower. 

The pump is centrifugal pump with power of 132 kilo watt. For purpose of energy production, a 

turbine was installed at the end of line 2. As mentioned, reservoir B has added to end of line 2. 

The role of reservoir B appears in regulation of working of pump that it is a function of water 

level in reservoir A and reservoir B. A Pelton type turbine was selected for system. The pelton 

turbine would be able to generate the electricity of 98 kilo watt per hour with flow rate of 100 

cubic meters per second and the hydraulic head of 100 meters. Turbine supplies the required 

electricity for system during 6 month cultivation period completely. 

FIGURE 3: System model in EPANET area after optimization

6. Conclusion 

An optimization model for working time of pump has presented in this research. Based on this 

optimization model, the working time has been diminished to 18 hours that previously was 24 

hours. Also the operational intervals located in low cost tariffs periods. The electricity costs for 6 

months cultivation period in previous schedule was 2222 $. The mentioned operation time 

optimization has reduced the electricity costs to 1755 $ during same period. Obviously the 

reduction in costs will more considerable in long term prospective, and also for larger pumping 

systems it would be more beneficial. 

At the second stage the PRV replaced by a turbine. The turbine produces the electricity of 98 

kilo watt per hour that causes that pump do not need to get electricity from electricity network. 

7. Reference List 

Aggidis, G.A., Luchinskaya, E., Rothschild, R. (2010). The C osts of Small-Scale Hydro 

Power Production: Impact on the Development of Existing Potential. Journal of Renewable 

Energy, 35, 2632-2638. 

Arriaga, m. (2010). Pump as Turbine – A Pico-Hydro Alternative in Lao People’s Democratic 

Republic. Journal of Renewable Energy, 35, 1109–1115. 

Catalão, J.P.S., Pousinho, H.M.I., Mendes, V.M.F. (2011). Hydro E nergy Systems 

Management in Portugal: Profit-Based Evaluation of a Mixed-Integer Nonlinear Approach. 

Journal of Energy, 36, 500-507. 

Dihrab, Salwan S., Sopian,K. (2010). Electricity generation of hybrid PV/wind systems in Iraq. 

Journal of Renewable Energy, 35, 1303–1307. 

Fadaee, M. J., and Besharat, M. (2005). Design Optimization of Offshore Platforms Using 

Genetic Algorithms and Wave-Net, Eight International Conference on the Application of 

Artificial Intelligence to Civil, Structural and Environmental Engineering, Civil-Comp Press, 

Rome, Italy. 

 

Maurice Pigaht, R.J. (2009). Innovative private micro-hydro power development in Rwanda, 

Journal of Energy Policy, 37, 4753–4760. 

NAST (National Assessment Synthesis Team), (2000). Climate Change Impacts on the 

United States: The Potential Consequences of Climate Variability and Change, Overview 

Report, U. S. Global Change Research Program, Cambridge University Press, Cambridge, 

United Kingdom, 154. 

 

 

Ramos, J.S., Ramos, H.M. (2009). Sustainable application of renewable sources in water 

pumping systems: Optimized energy system configuration. Journal of Energy Policy, 37, 

633–643. 

Vieira, F., Ramos, H.M. (2008). Hybrid solution and pump -storage optimization in water 

supply system efficiency: A case study. Journal of Energy Policy, 36, 4142–4148.

Application of Surface Cover and Soil Amendment for Reduction of 

Soil Erosion from Sloping Field in Korea 

Su-in Lee, Chul-hee Won, Min-hwan Shin, Woon-ji Park, 

Yong-hun Choi, Jae-young Shin, Joongdae Choi* 

Dept. of Regional Infrastructures Eng., Kangwon National Univ., Chuncheon, 200-701, Korea 

*Corresponding author. E-mail: jdchoi@kangwon.ac.kr 

Abstract 

Runoff from sloping fields in Korea has been blamed for the water quality degradation in 

rivers and lakes. No-till is known to be one of the best practices to reduce muddy runoff. 

However, no-till practice does not fit well to intensive vegetation farming and other alternative 

practices are required in Korea. The objective of the paper was to investigate the effect of 

surface mulch materials on the reduction of runoff and sediment from sloping experimental 

plots. The mulch materials were made of straw mat, PAM, rice chaff, sawdust, and gypsum. 

Three surface cover materials were tested and analyzed under 10 and 20% slopes and 30 

mm/h rainfall simulation. Runoff reduced significantly under covered conditions. The average 

reduction of runoff under 10 and 20% slopes was 85.6% and 72.0%, respectively. The 

average reduction of sediment discharge from mulched plots was 99%. It was concluded that 

the cover materials were effective in reducing muddy runoff from sloping fields. 

Key words: Muddy runoff, water quality, sloping field, rice straw mat, sediment. 


Muddy runoff from sloping highland fields during heavy storm events has caused serious 

water quality problems in rivers and dam lakes that are important to domestic water supply in 

Korea. The soil surface of these fields is not well protected either by crop canopy or crop 

residues during the storm events in general because of the timing of vegetable cultivation 

(Won et al., 2011). Muddy runoff are largely influenced by rainfall amount, intensity and 

duration, soil texture, crop, tillage, surface cover, infiltration, slope and slope length, runoff 

amount and velocity (Choi, 1997; Choi et al., 2000; Sharpley and Halvorson, 1994). Effective 

and economic control of these factors could reduce runoff and soil erosion, resulting in the 

reduction of muddy runoff. No-till practice is known to be one of the best BMPs to reduce 

muddy runoff. However, no-till practice does not fit well to intensive vegetable farming and 

other alternatives that could resemble no-till practice are required in Korea. One of the 

alternatives could be rice straw mulch on the soil surface. Shin et al. (2009) tested the effect 

of rice straw mat mulch on runoff, infiltration and sediment discharges under a laboratory 

rainfall simulation condition. Use of anion PAM and gypsum is also an alternative to reduce 

runoff (Flanagan et al., 1997; Choi et al., 2010; Keren and Shainberg, 1981). Use of 

phosphogypsum and PAM mixture could contribute to the reduction of soil erosion (Lee et al., 

2001; Jian et al., 2003; Lee et al., 2010). Won et al. (2011) reported that the treatment of rice 

straw mat, PAM, sawdust and rice chaff mixtures could reduce soil erosion significantly 

compared to control treatment. However, the effect of surface mulch combined with rice 

straw mat, PAM and phosphogypsum has not been reported in Korea. The objectve of this 

research was to experimentally test the effect of surface mulch combined with rice straw mat 

on runoff and soil erosion under laboratory rainfall simulation. 

2. Methods 

The main experimental system of this research composed of eight soil boxes, two Norton 

Ladder-type Rainfall Simulators, and 10% and 20% stands for slope control. The soil boxes

of 1 m × 1 m × 0.65 m (L×W×H) in size were filled with a soil that has the same texture to the 

highland fields. The simulator was developed in the USDA Soil Erosion Laboratory in Purdue 

University, USA. Three soil surface mulch treatmemts were the combination of (1) rice straw 

mat + PAM + phosphogypsum, (2) rice straw mat + sawdust + PAM + phosphogypsum, and 

(3) rice straw mat + rice chaff + PAM + phosphogypsum. The weight of straw mat, PAM, and 

gypsum per ha was 3,300 kg, 10 kg, and 1,000 kg, respectively. The weight of sawdust and 

chaff per ha was about 700 kg, respectively. Slope of the boxes were 10% and 20%, and 

rainfall intensity was 30 mm/h. Three simulations were performed and each simulation lasted 

60 minutes. Runoff and sediment samples were measured and analyzed. The treatments 

were summarized in Table 1. Each treatment was duplicated. The results of these treatments 

were compared with the results of control. 

Surface mulch materials were prepared by gluing straw mat, PAM powder, chaff or sawdust 

together. And gypsum powder was spread evenly over the soil surface. The use of PAM and 

gypsum was much less than the common dose of 20 to 40 kg/ha and 5,000 kg/ha (Choi et al., 

2010; Jian et al., 2003; Lee et al., 2010), respectively, because of environmental concerns. 

PAM (Soilfix G1, Ciba Chemical Co., Germany) and gypsum (Namhae Chemical Co., Korea) 

were purchased at a market. 

Table 1. Summary of the experimental treatments 

Soil box 

No. 

Rain 

(mm/hr) 

Slope 

(%) Code 

Cover materials 

Treatments 

Ⅰ 30 10 Control Bare 

Ⅱ 30 10 SPG Rice straw mat+PAM+Gypsum 

Ⅲ 30 10 SSPG Rice straw mat+sawdust+PAM+Gypsum 

Ⅳ 30 10 SCPG Rice straw mat+chaff+PAM+Gypsum 

Ⅴ 30 20 Control Bare 

Ⅵ 30 20 SPG Rice straw mat+PAM+Gypsum 

Ⅶ 30 20 SSPG Rice straw mat+sawdust+PAM+Gypsum 

Ⅷ 30 20 SCPG Rice straw mat+chaff+PAM+Gypsum 


1.1. Time of initial runoff 

Time of initial runoff from mulched plots was slower than that from control plots. The order of 

initial runoff was Control > SPG > SSPG > SCPG. Under 10% slopes, time of initial runoff 

from SPG, SSPG, and SCPG boxes retarded 81%, 105%, and 193%, respectively, 

compared to that from control boxes. Time of initial runoff from the boxes under 20% 

simulation was faster than that from 10% boxes but the differences among the mulched 

boxes were not significant. It was thought that the chaff and sawdust helped increase the 

surface cover rate, increase infiltration, and retard time of initial runoff. 

1.2. Runoff rate 

Runoff rate varied depending on mulch material, slope, and time of rainfall simulation. The 

compaction condition of soil in the soil box and solubility of PAM seemed to affect the runoff 

rate. It was thought because the runoff rate varied a little wider than expected during 

simulation to simulation (Figure 1). However, runoff rates from mulched boxes were

significantly lower than those from control boxes. Under 10% slope and SCPG treatment, 

runoff rate was lowest and ranged 0.2~2.7%. The average runoff rate was only 1.3% of 

control boxes or the average reduction of runoff was 98.7%. Under 20% and SCPG 

treatment, the similar trend was observed and the average reduction of runoff was 81.7%. 

Average reduction of runoff rate from mulched boxes was 85.6% and 72.0% for 10% and 

20%, respectively. Reduction of runoff rate from mulched boxes decreased as slope 

increased. 

(a) 10% slope 

(b) 20% slope 

Figure 1. Runoff rate with respect to treatment under 30 mm/hr simulation 

1.3. Sediment discharge 

Sediment discharges from mulched boxes were significantly lower than those from control 

ones (Figure 2). However, sediment discharges among mulched boxes were not significantly 

different at the level of 5%. Average sediment discharges from mulched boxes were 1.7% 

and 1.2% of those from control ones. Among the mulch materials, SCPG mulch produced the 

least sediment and the reduction rate was more than 99% (Figure 2), which was much higher 

than 65% reported by Shin et al. (2009). It was thought that the chaff and sawdust helped 

reduce sediment discharge PAM seemed to affect the runoff. However, the reduction rate 

was not much different from the results by Won et al. (2011) who conducted similar 

experiment without adding gypsum. According to previous research, use of PAM and 

gypsum could improve the reduction effect of soil erosion (Jian et al., 2003; Lee et al., 2010) 

but this study did not produce the similar results. It was thought that because of the addition 

of chaff and sawdust and the small scale laboratory simulation, the effect of gypsum on the 

reduction of soil erosion could not be fully discovered and further research was suggested to 

investigate the effect of gypsum on the reduction of soil erosion. 

1.4. Water balance analysis 

Runoff, subsurface runoff, soil retention was measure and analyzed (Table 2). Runoff 

increased was slope increased regardless of treatment. As runoff decreased from mulched 

boxes, subsurface runoff increased significantly. It was shown that subsurface runoff from 

mulched boxes was 60.2~75.4% larger than that from control ones. The mulch material could 

effectively contribute to reduce soil clogging and increase infiltration, resulting the higher 

surface runoff. However, soil retention of mulched boxes were not differed from that of 

control ones. It was thought that the interval of about one week between the simulations 

were not long enough to dry the soil in the soil box to measure the retention differences. 

However, it was thought that the interval was long enough, the soil retention of mulched 

boxes was also higher than that of control ones as McElhiney and Osterli (1996) reported 

that the use of PAM could increase infiltration by 40%.

Figure 2. Average sediment discharge and reduction rate with respect to slope and mulch 

Table 2. Analysis of water balance 

Experimental treatment 

SSPG SCPG SPG Control 

10% 20% 10% 20% 10% 20% 10% 20% 

Precipitation (%) 100 100 100 100 100 100 100 100 

The rate of surface runoff (%) 21.0 31.7 1.1 16.2 16.5 27.6 80.6 82.7 

The rate of groundwater 

discharge (%) 

The rate of retention in soil 

(%) 

66.1 60.2 91.4 75.4 73.2 64.1 8.5 8.1 

12.9 8.1 7.5 8.4 10.3 8.3 10.9 9.2 


Effect of mulch material made of rice straw mat, PAM, sawdust, rice chaff, and 

phosphogypsum on runoff and sediment discharge was experimentally studies under 

laboratory scale with rainfall simulation. Small soil boxes filled with a soil similar to the 

highland fields were set up 10 and 20% slops and rainfall simulation of 30 mm/h were carried 

out. Runoff and sediment discharge were significantly reduced from mulched boxes. 

Reduction of runoff from mulched boxes ranged 72.0~85.6% compared to that of control 

ones. Sediment discharge also significantly reduced by up to 98.3 to 98.8% depending on 

slope. Subsurface runoff from mulched boxes increased between 60.2~75.4% compared to 

control boxes. It was concluded that the mulch materials used in this study could contribute 

to reduce muddy runoff and sediment discharges from highland fields and to improve water 

quality in rivers and dam lakes in Korea. However, it was suggested that field application 

tests need to be performed before the results are used as a best management practices. 

Acknowledgements: This research was supported by the Ecostar Project (Project #. II-7-6) 

of the Ministry of Environment and authors appreciate the generous support. 

References

Choi, J. D., (1997). Effect of Rural Watershed Management on the Discharge of NPS 

Pollutants to Streams. Inst. of Rural Dev., Kangwon Nat’l Univ., 1(1), 91-107. 

Choi, J. D., Jang, S. O., Choi, B. Y., and Lyou, S. H., (2000). Monitoring Study on 

Groundwater Quality of an Alluvial Plane in the North Han River Basin. Journal of the KSWQ, 

16(3), 283-294. 

Choi. Y. B., Choi, B. S., Kim, S. W., Lee, S. S., & Ok, Y. S., (2010). Effects of Polyacrylamide 

and Biopolymer on Soil Erosion and Crop Productivity in Sloping Uplands: A Field 

Experiment. Journal of KSEE, 32(11), 1024-1029. 

Flanagan, D. C., Norton, L. D., & Shainberg, I., (1997). Effect of water chemistry and soil 

amendments on a silt loam soil-Part I. Infiltration and Runoff. Transactions of the ASABE, 40, 

1549-1554. 

Jian Y., Lei, T., Shainberg, I., Mamedov, A. I., & Levy, G. J., (2003). Infiltration and Erosion in 

Soils Treated with Dry PAM and Gypsum. Soil Sci. Soc. Am. J., 67, 630-636. 

Lee, S. S., Gantzer, C. J., Thompson, A. L., & Anderson, S. H., (2010). Polyacrylamide and 

gypsum amendments for erosion and runoff control on two soil series. Journal of Soil and 

Water Conservation, 65(4), 233- 242 

Lee, Y. S., Joung, H. S., and Joung, H. I., (2001). The Engineering and Environmental 

Properties for Utilization of Phosphogypsum as Embankment Materials. Korean Geotechnical 

Society ,17(4), 331-339. 

McElhiney, M., & Osterli, P., (1996). An integrated approach for water quality: The PAM 

connection-West Stanislaus HUA. CA. 27-30. In Sojka, R. E., & Lentz, R. D., (Eds.) Proc.: 

Managing irrigation induced erosion and infiltration with polyacrylamide. College of Southern 

Idaho, Twin Falls, ID. 6-8 May 1996. University of Idaho Misc. Publ. No 101-96. University of 

Idaho, Twin Falls, ID. 

Sharpley, A. N., & Halvorson, A. D., (1994). The Management of Soil Phosphorous 

Availability and its Impact on Surface Water Quality. In Lal, R., & Steward, B. A., (Eds.), Soil 

Processes and Water Quality. Advance in Soil Science. Boca Raton, FL: Lewis Publishers. 

Shin, M. H., Won, C. H., Choi, Y. H., Seo, J. Y., Lee, J. W., Lim, K. J., & Choi, J. D., (2009). 

Simulaion of field soil loss by artificial rainfall simulator-by varing rainfall intensity, surface 

condition and slope. Journal of Korean Society on Water Quality, 25(5), 785-791. 

Won, C. H., Shin, M. H., Choi, Y. H., Shin, J. Y., Park, W. J., & Choi, J. D., (2011). 

Applications of surface cover materials for reduction of soil erosion. Journal of Korean 

Society on Water Quality, 27(6), 848-854.

The experience of using purified wastewater for irrigation in the 

Marina Baixa Coast County (Alicante, Spain). Proposal of future 

hydric design plans. 

Macarena Cavestany 3 , José J. Ferrán 1 , Carlos M. Ferrer 1 , Modesto Pérez 3 , Miguel 

Redón* 1 , Francisco J. Sanchez 1 , Elvira Santamaría 2 , Juan B. Torregrosa 1 , Francisco 

J. Zapata 2 

1 Universidad Politécnica de Valencia, Departamento de Ingeniería Rural y Agroalimentaria. 

Camino de Vera s/n 46022 Valencia. miresan@agf.upv.es 

2 Conselleria de Agricultura, Pesca, Alimentación y Agua. Generalitat Valenciana, Alicante, 

España. 

3 Vaersa, Alicante, España. 

Abstract 

This paper will explore the experimentation and real problematic of using purified wastewater 

for irrigation. A semiarid region located in the east of Spain is chosen as a field study where 

a powerful tourist sector must coexist with the agricultural activity. The mutual relationship 

between them will preserve the landscape achieving the social, economic and environmental 

sustainability of the area. 

Keywords: Irrigation, agriculture uses, purified waste water 


Marina Baixa County presents a historical lack of hydric resources as most of Spanish east 

coast counties; Medio y Bajo Vinalopo, LÁlacantí y Vega Baja (Fig. 1). Besides the scarcity 

of water, it is worthy to mention the marked torrential regime that characterises the 

precipitation events in this area (Twort et al., 2000). 

The historic irrigation surface of the Marina ,Baixa region is about 5.000 ha. Because of that, 

in the 60’s, two reservoirs: Amadorio and Guadalest of 15 hm 3 each one, were built for 

irrigation purposes (Quereda Sala, 1978). However, as new economic activities are being 

developed in the area, agriculture water resources have been forced to seek new water 

sources . 

FIGURE 1: Situation map

1.1. Scope and aim 

The growth of the tourist sector, such as in the city of Benidorm, has supposed a conflict of 

interest between the hotel services and farmers. In the last two decades, this issue has 

generated a noteworthy shortage of water resources being used for agriculture purposes. As 

a consequence of that, in the Marina Baixa area (Fig. 2), water for irrigation uses has been 

got either from urban area surplus volumes or from purified wastewater. 

Nowadays, in the study area, the urban water volumes are guaranteed thanks to the 

construction of desalination plants. Therefore, water surface can be returned to be used for 

agriculture by means of the interconnection of surplus internal basins and the storage of such 

volumes when torrential precipitations occur. 

FIGURE 2: Working area 

In the present paper, it is related the experiments and problematic in the application of the 

wastewater to irrigation in this district as well as the integrated use of surplus water surface. 

2. Analysis of the irrigation scheme 

2.1. Current irrigation situation 

While the current needs of irrigation are estimated around 12 hm 3 , the urban water demand 

is deemed to be greater than 20 hm 3 . 

During rainy seasons, the surface water is stored in the following reservoirs; Amadorio 

(Capacity= 15,8 hm 3 ) and Guadalest (Capacity = 13,0 hm 3 ). Also, the Carrascal-Bernia 

aquifer supplies water. In overall, the present water management can meet entirely the urban 

needs and partially, the irrigation needs. 

On the contrary, in times of drought, water is scarce and there is strong competition for the 

resource. When this situation occurs, urban water supply prevails over irrigation needs and 

therefore, agriculture irrigation areas suffer a strong lack of water. However, even the urban 

volumes are not fully guaranteed during dry seasons. Thereby, additional water from an 

external basin is used; the water conduction called “Fenollar-Amadorio” provides water 

coming from the Tajo River through the Tajo-Segura Transfer. 

The integrated water management has involved looking for new water sources to overcome 

seasons where there is shortage of irrigation supply. In this sense, wastewater from the 

following sewage stations has incorporated into the general irrigation scheme: 

- Wastewater treatment plant of Benidorm: 13.5 hm 3 /year 

- Wastewater treatment plant of Villajoyosa: 3.6 hm 3 /year 

- Wastewater treatment plant of Altea: 3.6 hm 3 /year

In this way, the use of purified water, presents some problems: 

1. Urban water derived to the water treatment plants suffers a quality loss since such 

treated volumes become partially saline in the wastewater treatment plant of 

Villajoyosa and mainly, in the Benidorm facility. 

2. The treated water volumes are uniformly distributed along the year. However, 

agriculture water consumption does not follow such tendency. Mediterranean climate 

conditions set higher demand in summer months. 

3. The treated water volumes have to be carried to the agricultural areas satisfying the 

flow and pressure irrigation conditions. 

2.2. Improvements in the irrigation water management 

The previous issues have involved the search for a set of solutions that may or may not yet 

be implemented. 

As far as the issue of the water quality, the wastewater facility of Benidorm has improved the 

salinization problems with the installation of ultrafiltration equipment (Office of Water 

Programs, 2006). The reverse osmosis system reduces water salinity from 3800 ⁄ to 

1000⁄ . 

The maximum daily treated volume is estimated in 21,000 m 3 when both the water rejection 

and the total capacity of the facility are taken into account. Thereby, the annual usable 

irrigation water can be determined straightforward resulting in a total volume of 7.5 hm 3 /year. 

It can be observed that such volume means around half of the total capacity installed at the 

Benidorm wastewater plant. Globally, the water treated in the three plants achieves a total 

volume of 11 hm 3 /year. If the annual consumption rate of the irrigation crops is 5,000 m 3 /hayear, 

it can be stated that the reuse of water is able to satisfy the irrigation needs of around 

2,200 ha. 

With regard to the non-uniformity of the irrigation water demand, the previous irrigation area 

is estimated in 2,200 ha, but, it is not really true since it can be defined as the potential 

irrigation area. As the supply of treated water does not fit the irrigation demand, the real area 

will be lower. The maximum irrigation needs can be estimated in 35 m 3 /ha-day. Since the 

daily autonomy of the wastewater plants reaches 31,000 m 3 , the real irrigation area results in 

900 ha. 

Then, farmers in the area are facing a critical situation during dry seasons that are very 

common in semi-arid regions. The problem can be solved by means of the design and 

construction of a reservoir, so water can be stored during low irrigation demand seasons. 

Later on, water will be available in times of high consumption. 

In brief, the following works and installations are needed in order to incorporate wastewater 

for irrigation: 

1. Implementation of ultrafiltration and desalination technologies to be applied into the 

present purified wastewater. 

2. Implementation of reservoirs with a storage capacity greater than 1 hectometre. Fig. 3 

shows an overview of the Alfondons reservoir (Capacity = 300,000 m 3 ) storing the 

purified water from the Villajoyosa wastewater treatment plant. 

3. Implementation and construction of water regulation tanks. 

4. Implementation of pipelines driving wastewater from the treatment plants to the 

irrigation agricultural areas. 

Nowadays, public administration is performing the following works. 

1. An ultrafiltration and desalination plant is being built with a daily capacity of 21,000 

m 3 /day, so the annual maximum autonomy reaches 7.7 hm 3 /year. 

2. The main water line conducts treated wastewater through a ductile cast iron pipe of 

900 mm diameter and 25 kilometres length, Fig. 4.

Therefore, the remaining works are 

1. Reservoirs with a storage capacity greater than 1 hectometre. 

2. Water regulation tanks. 

3. Some wastewater pipelines, from the main conduit up to peripheral irrigation areas. 

FIGURE 3: Alfondons Reservoir, Villajososa (Capacity = 300,000 m 3 ) 

FIGURE 4: Main wastewater conduit. a) Aerial passage b) Storage of conduits near 

Benidorm 

a) b) 

Furthermore, the irrigation management of the study area has to sort out an additional issue 

since: 

- Most of the irrigated area has changed from the antique surface irrigation technique 

into pressurized drip irrigation systems. 

- Water irrigation volumes coming from the reuse of urban water resources through the 

purification treatment do not individually resolve the whole problem. The higher 

agricultural water needs requires complementary water works. 

As a result, it is advisable to incorporate surface runoff either in dry season or in wet rainy 

seasons becoming the main water contribution to the irrigation management system. Its 

practical implementation into the pressure irrigation scheme needs some hydraulic works 

since to the present runoff volumes are exclusively used for flood irrigation. 

So, some pumping stations, regulating water tanks and both primary and secondary water 

conduits must be implemented to combine treated wastewater with runoff volumes.

3. Estimated costs of the investments needed 

The adaptation of the present irrigation water infrastructures can be estimated according the 

data exposed in Table 1. 

TABLE 1: Hydraulic work investments 

WATER 

WORKS/INSTALLATIONS 

BUDGET 

(Works / executed 

installations) 

(million €) 

BUDGET 

(Works / installations ) 

In Project stage 

(million €) 

Treated water desalination plant 14 /--/ 

Storage reservoirs 5 10 

Primary wastewater conduits 25 5 

Regulating tanks from the treated plant /--/ 3 

Overall incorporation of the treated 

wastewater into the irrigation system 

Surface runoff regulating tanks and 

complementary installations 

44 18 

/--/ 3 

Primary surface runoff conduits f /--/ 3 

Overall incorporation of surface runoff 

into the irrigation system 

TOTAL (wastewater + surface runoff) 44 24 

TOTAL ALREADY EXECUTED 44 

TOTAL PROJECT 24 

6 

It can be noticed that the water treatment plant means only 23% of the overall estimated 

water treatment investment. Meanwhile, the storage infrastructures together with the 

distribution conduits represent the remaining 77%. 

4. Maintenance costs 

There is not enough data to comprehensively meet the maintenance costs. Although, the 

desalination cost is the key issue of the whole system. In this sense, the observed 

operational tendency is characterised by the exclusive use of the wastewater plant during 

drought seasons. Although, the conservation and maintenance costs have to be assumed. 

Besides, there are a lesser amount costs, derived from the pumping installations used to 

divert water to the water tanks and reservoirs. As it has stated previously, such water 

infrastructure is needed to guarantee the drip irrigation pressure both for wastewater or 

surface runoff volumes. 


The key irrigation issues concerning the hydraulic management of the Marina Baja County 

are: 

1. The incorporation of the treated wastewater will have to solve the following points: 

a. The wastewater quality has to be improved. The high salinity gained during 

the urban water process together with the transfer through the sewage

network makes such volumes unacceptable for the irrigation system. 

Nowadays, the desalination system only is partially implemented in the 

treatment plant of Benidorm. 

b. Wastewater supply must be adjusted to the irrigation demand. The proposed 

solution addresses the issue by designing new storage reservoirs. Water is 

stored in winter and autumn and complements the dairy treated volumes 

during high peak consumption periods. Nowadays, there is little reservoir 

volume. 

c. Full implementation of the water transportation pipelines diverting water from 

the treatment plants to the irrigation areas. 

2. The introduction and use of surface runoff volumes for irrigation purposes needs the 

implementation of additional hydraulic infrastructures; water conduits, pumping 

stations and water regulating tanks. The construction of the previous facilities will able 

to incorporate into the drip irrigation network water of high quality. 

3. As far as possible, urban and irrigation water volumes must share the hydraulic 

infrastructure (reservoirs and main conduits) in order to reduce water costs achieving 

an integrated water management. 

4. The incorporation of wastewater for irrigation represents a significant investment, not 

only due to the required water quality improvement but, the high costs derived from 

the storage and distribution. 

6. References 

Office of Water Programs (2006). Advanced Water Treatment. California Water Environment 

Association. 

Quereda Sala, J.J. (1978). Estudio de Geografia Regional. Comarca de la Marina Baja. 

Diputación Provincial de Alicante. (España). 

Twort A.C., Ratnayaka, D., Brandt M.J. (2000). Water Supply. Arnold – IWA Publishing, 

London.

Indirect Reuse of Reclaimed Wastewater for Agriculture in Korea 

Hanseok Jeong 1 , Taeil Jang 2 *, Choung H. Seong 3 , Seung W. Park 1 

1 Department of Rural Systems Engineering, Seoul National University, 1 Gwanak-ro, 

Gwanak-gu, Seoul 151-742, Republic of Korea 

2 Department of Biological and Agricultural Engineering, University of Georgia, 2360 

Rainwater Road, Tifton GA 31793, USA) 

3 Department of Biological Systems Engineering, Virginia Polytechnic Institute and State 

University, Blacksburg, VA 24061, USA 

*Corresponding author. E-mail: taeiljang@gmail.com 

Abstract 

Reclaimed wastewater has been considered as an alternative water resource due to the 

shortage of established water resources and increasing water demand. Reclaimed 

wastewater having relatively constant volume throughout the year and abundant fertilizer 

ingredients is widely used for agricultural irrigation in Korea. The objective of this study is to 

introduce the project of the development and application of wastewater reclamation systems 

for indirect agricultural reuse. The project could provide cost-effective systems and 

guidelines for indirect reuse of reclaimed wastewater for agriculture. Two reclaimed 

wastewater irrigated monitoring sites, Byeongjeom (BJ) and Osan (OS), and one monitoring 

site of conventional water irrigation, Yongin (YI), were selected and will be monitored and 

analyzed about the crop growth and yield, water quality, and soil characteristics from 2011 to 

2014. We anticipate that the findings from this project could contribute to safe indirect 

wastewater reuse for agriculture in Korea. 

Key words: Indirect wastewater reuse, reclaimed wastewater 


A water shortage problem is an important issue in many countries and world’s 

population increase will be experiencing scarcity of water resources in the future because of 

increasing demand for fresh water (Marecos do Monte et al., 1996). The increasing demand 

of water is caused by population growth, urbanization, and economic development. In 

addition, climate change is accelerating water shortage, i.e., by the 2050s, the area of land 

subject to increasing water stress due to climate change is projected to be more than double 

that with decreasing water stress (Bates et al., 2008). Republic of Korea (Korea) like many 

other countries faces a water shortage problem. Moreover great temporal and spatial 

variations of precipitation and stream flow cause frequent water shortages and floods in 

Korea. These hydrologic characteristics have placed serious constraints on reliable water 

supplies for agriculture (Lee et al., 2010). 

In 2007, a total volume of 15.9 billion m 3 water was used for agriculture in Korea, which 

approximately comprised 48% of the total annual water use in Korea (MOCT, 2012). 

According to Ministry of Environment (MOE) (2009), total wastewater treatment capacity in 

Korea is 6.6 billion m 3 per year, which come to 20% of the total annual water use. A recent 

national survey on the future water demand and supply of Korea reported a predicted 

shortage of over 4.4 billion m 3 of water by 2020 (MLTM, 2006).

Reclaimed wastewater reuse has been considered as an alternative water resource 

due to the shortage of established water resources and increasing water demand. Reclaimed 

wastewater having relatively constant volume throughout the year and abundant fertilizer 

ingredients is widely used for agricultural irrigation in Korea (SNU, 2011). 

Wastewater reuse for agriculture could be categorized as indirect (open) and direct 

(closed) reuse according to the methods. While the direct wastewater reuse means that 

farmers directly take the treated effluents from wastewater treatment plant (WTP) through 

irrigation system, the indirect wastewater reuse can be defined as farmers take the treated 

effluents diluted with fresh water from stream or reservoir after WTP discharges to 

downstream. In case of indirect wastewater reuse, the adequate indirect reuse system is 

required by the level of water quality at a reach of the river (Lee et al., 2010). 

MOE (2011) reported a total volume of 106 million m 3 water will be annually used for 

agriculture from 56 WTPs by 2020. But most of reclaimed wastewater for agriculture has 

been used by means of the indirect reuse. It has been investigated that more than 130 WTPs 

affect irrigation water to farmland including paddy fields in Korea (Kim et al., 2009). In case of 

indirect reuse, irrigated water has not been properly treated for agricultural use and it might 

cause health implications for farmers, consumers and communities. Furthermore, the soil, 

plant, groundwater and other aspects of the local environment should be monitored to protect 

from contaminations by reclaimed wastewater irrigation in particular if compounds 

accumulate in certain phases (Huertas et al., 2008). Therefore, a study on indirect reuse of 

reclaimed wastewater for agriculture should be conducted. The objective of this study is to 

introduce the project of the development and application of wastewater reclamation systems 

for indirect agricultural reuse in Korea. 

2. Indirect wastewater reuse project for agriculture 

2.1. Objectives of the project 

The objectives of this project are 1) to propose proper water quality guideline for 

indirect reuse of reclaimed wastewater for agricultural irrigation based on monitoring or 

modeling in paddy fields, 2) to develop cost-effective wastewater reclamation systems for 

indirect agricultural reuse satisfying the proposed guidelines, 3) to monitor and assess of 

effects of indirect wastewater reuse on paddy rice culture for three years, and 4) to 

implement the developed systems to actual agricultural districts in Korea. 

2.2. Research scopes of the project 

2.2.1. Effect on rice growth and yield of indirect wastewater reuse 

Two monitoring sites, the Byeongjeom (BJ) and Osan (OS), were selected for indirect 

reuse of reclaimed wastewater. They are located near the Suwon and Osan WTPs, 

respectively, in Gyeonggi-do, Korea. Irrigated water of rice paddy fields in the BJ and OS 

monitoring sites is pumped from Whangguji and Osan stream, respectively, which are 

influenced by WTP effluent. The Yongin (YI) monitoring site near the Idong reservoir, which 

satisfies the agricultural water quality criteria in Korea, was selected as control of 

conventional water irrigation (Fig. 1.).

(a) The whole monitoring sites 

(b) Youngin (YI) monitoring site 

(c) Osan (OS) monitoring site 

(d) Byeongjeom (BJ) monitoring site 

FIGURE 1: Study areas: a) entire landscape, b) control site near Idong reservoir, and two 

treatments of c) OS and d) BJ sites with Osan and Suwon WTPs, respectively. 

Paddy rice (Oryza sativa L. ssp. Japonica cv. Chucheongbyeo) widely cultivated in this 

region will be transplanted at all monitoring paddy fields and agricultural activities including 

fertilizing and irrigation will be investigated. The crop height and tiller number will be 

monitored every week at selected five paddy fields in each monitoring site during growing 

season from late May to early October. The rice growth and yield components including clum 

length, panicle number, grain filling rate, thousand grain weight, yields, contents of protein, 

contents of amylase and milled bead rice ratio will be analyzed with more than three sheaves 

of rice from each paddy field according to the standard method. 

FIGURE 2: Comparisons of the rice growth and yield components in 2011.

Fig. 2 shows the monitoring results in 2011 and there are not typical differences in the 

rice growth and yield components among three sites. 

2.2.2. Effect on rice culture and soil characteristics of indirect wastewater reuse 

Ponded water depth in the OS and YI sites will be continuously measured by an 

automatic float type water level recorder. Two paddy fields will be equipped with an 

electronic flow meter with a data logger in the inlet and outlet. Weather data from the Suwon 

National Weather Station near the monitoring sites will be collected. 

The samples of irrigation and ponded water of each paddy field will be weekly taken to 

the laboratory for the growing season and analyzed according to standard methods from 

2011 to 2014. The parameters will be analyzed for water quality are pH, EC (electrical 

conductivity), DO, TOC, BOD, COD, SS, T-N, T-P, NO 3 -N, NH 4 -N, PO 4 -P, CL - , Cu, SO 4 , Ni, 

Ca, Mg, Na, K, Zn, CN, CO 2- 3 , HCO 2- 3 , detergent, total and fecal coliforms and Escherichia 

coli. 

Soil samples will be taken from each paddy field before and after every crop cycle and 

two times during growing season, at depths decreasing from 0 to 0.8 m, every 0.2 m. They 

will be analyzed for pH, CEC (cation exchange capacity), EC, TOC, SiO 2 , T-N, T-P, NO 3 -N, 

NH 4 -N, P 2 O 5 , Cl - , Cd, Pb, Zn, Cu, Ni, As, Ca, Mg, Na, K, Hg, Mn, Cr 6+ and organic matter 

according to the standard method. Fig. 3 shows the analysis results of soil samples for EC 

and Na before the crop cycle. Soil samples of the OS and BJ sites irrigated with reclaimed 

wastewater contain much more sodium than the YI sites. 

FIGURE 3: Soil salinity results of EC and Na at each depth before the crop cycle in 2011 

All the collected data are expected to be used as a basic data for assessing crop safety 

and environmental impact for agricultural wastewater reuse, and establishing comprehensive 

measures for wastewater reclamation and reuse in agriculture. 

2.2.3. Guideline of indirect wastewater reuse for agriculture 

A guideline of indirect wastewater reuse for agriculture that could minimize adverse 

effect on crop safety, agro-ecological environment and human organism will be proposed. In 

order to propose the guideline, internal and external water quality standards for agriculture 

and wastewater reuse will be extensively reviewed. Furthermore, the effects of wastewater 

reuse on the quality of irrigated water will be monitored and simulated through hydrologic and 

water quality models. Each monitoring site of indirect wastewater reuse, the OS and BJ, has 

10 sampling points, at the pumping station, every 0.5 km down the stream from effluent 

outlet to 3.0 km, 4.0 km and 5.0 km. Fig. 4 shows the sampling points for this study.

(a) Osan stream sampling points 

(b) Whanggugi stream sampling points 

FIGURE 4: Sampling points along stream waters for two sites 

The SWAT (soil and water assessment tool), HSPF (hydrological simulation programfortran), 

SWMM (storm water management model) and QUALKO2 will be applied to simulate 

the impact of the amount of stream flow and effluent from WTP on irrigated water quality. 

And both monitored and simulated results could be also used to decide the influenced district 

of indirect wastewater reuse which is preliminary information for the guideline. Open forum 

will be held to establish standards for indirect wastewater reuse at the end of this study. 

2.2.4. Development and application of indirect wastewater reuse systems 

Indirect wastewater reclamation system is defined as the wastewater treatment 

processes and the monitoring system for the rural indirect reuse irrigation districts. This 

system requires the facility and capacity to ensure the environment safety, public health 

protection, appropriate wastewater treatment system, and water management. For the 

agricultural use, it should be the low-cost-high-efficient reuse system because of the 

numerous amount of water demand compared with the domestic or industrial uses. 

Several types of wastewater treatment system according to the agricultural facilities like 

a pumping station, weir, and reservoir for indirect reuse will be designed through this project 

and Fig. 5 shows the schematic of wastewater treatment system for a pumping station. One 

or two types of wastewater treatment system will be invented in the first year of this project 

and the developed system will be established on the test-bed in the second year. In the last 

year of this project, the developed systems will be implemented to several districts of actual 

agricultural lands in Korea. 

FIGURE 5: Schematic diagram of wastewater treatment system


Reclaimed wastewater reuse has great potential to solve agricultural water shortage 

problems in Korea. The project could provide cost-effective systems and guidelines for 

indirect reuse of reclaimed wastewater for agriculture. Two reclaimed wastewater irrigated 

monitoring sites and one conventional water irrigated monitoring site as control were 

selected. They will be monitored and analyzed about the crop growth, crop yield, water 

quality, and soil characteristics from 2011 to 2014. Wastewater reclamation systems for 

indirect agricultural reuse and the guidelines will be developed and suggested based on 

results of this project. It is also anticipated that the findings from this project could contribute 

to safe indirect reuse of reclaimed wastewater for agriculture in Korea. 


This project is sponsored by Korea Institute of Planning and Evaluation for Technology 

in Food, Agriculture, Forestry and Fisheries. 

References 

Bates, B.C., Z.W. Kundzewicz, S. Wu and J.P. Palutikof, Eds., 2008. Climate Change and 

Water. Technical Paper of the Intergovernmental Panel on Climate Change, IPCC 

Secretariat, Geneva, 210 pp. 

Huertas, E., M. Salgot, J.Hollender, S. Weber, W. Dott, S. Khan, A. Schafer, R. Messalem, B. 

Bis, A. Aharoni, H. Chikurel. (2008). Key objectives for water reuse concepts. Desalination. 

218:120-131. 

Kim, Haedo, Kwangya Lee, and Youngjik Lee (2009). Application of wastewater reuse 

system for agriculture: status and prospects, Water for Futrue, 42(9), 36-43 (in Korean). 

Lee, E. J., S. W. Park, C. H. Seong, H. K. Kim, and K. W. Jeong (2010). Wastewater 

reclamation and reuse practices for agriculture in Korea, XVII th World Congress of the 

International Commission of Agricultural Engineering (CIGR). 

Marecos do Monte, M.H.F, A.N. Angelakis, and T. Asano. 1996. Necessity and basis for 

establishment of European guidelines for reclaimed wastewater in the Mediterranean region. 

Water Sci. Technol. 33(10-11):303-316. 

MOCT (2012). National water resource plan. Ministry of Construction and Transportation, 

Republic of Korea (in Korean). 

MOE (2009). Wastewater reuse guide book, Ministry of Environment, Republic of Korea (in 

Korean). 

MOE (2011). Water reuse plan, Ministry of Environment, Republic of Korea (in Korean). 

MLTM (2006). Water Vision 2020 (2006 National Water Resources Plan Update). Ministry of 

Land, Transportation and Maritime Affaris (MLTM). Republic of Korea (in Korean). 

SNU (2011). Application of integrated technologies for wastewater reclamation and reuse 

system for agriculture (code#4-5-3). Seoul National University, Seoul, Korea (in Korean).

Comparison between Curve Number empirical values and Curve 

Number obtained by handbook tables at basin scale in Sicily, Italy 

Francesco D’Asaro 1 *, Giovanni Grillone 1 , Giorgio Baiamonte 1 

1 

Department of Agro-Environmental Systems, University of Palermo, viale delle 

Scienze 13, Edificio 4, Ingresso E, 90128, Palermo, Italy 

*Corresponding author. Email: francesco.dasaro@unipa.it 

Abstract 

The National Resources Conservation Service Curve Number (NRCS-CN) method is a 

simple lumped method for estimating surface runoff depth from rainstorms and based on the 

main parameter CN, which represents the lumped expression of basin response. 

CN estimation, based on handbook CN tables in ungaged watersheds, is the weak link of the 

NRCS-CN method when it is applied in regions where the validity of the above mentioned 

tables was not verified. 

Towards the aim of investigating the applicability of handbook CN tables in Sicily (mid- 

Mediterranean area), the curve numbers estimated using hydrologic soil-cover complexes, 

as suggested by the SCS-NRCS tables, are compared with CN evaluated at basin scale from 

rainfall-runoff multi-daily events in 36 Sicilian basins, CN emp . 

Finally, in order to estimate CN in ungaged watersheds, a relationship between CN and 

watershed morpho-climatic and hydrologic characteristics is investigated in Sicily. 

Keywords: Curve Number, Mediterranean area 


The Curve Number method, originally intended for small ungaged agricultural watersheds 

and later used for nonagricultural watersheds (Ponce & Hawkins 1996), such as urban and 

even mining areas (Ritter et al. 1991), is a widely used procedure for estimating the volume 

of direct runoff Q resulting from a given rainfall event P by means of a single lumped 

parameter, CN, introduced as a measure of watershed hydrologic response based on soil 

type, land cover and land use. 

In application CN is obtained by the well-known handbook tables developed in the 1950s by 

the SCS (Soil Conservation Service), today NRCS (National Resources Conservation 

Service) and updated many times over the years, according to the hydrologic soil-cover 

complexes (USDA NRCS 2004, 2009) that include Hydrologic Soil Group (HSG), land use, 

surface condition and Antecedent Runoff Condition (ARC). This derivation of CN is valid for a 

basin with a uniform hydrologic soil cover complex, while, in the presence of variable 

conditions (soil type, land cover and land use) within the basin, an area-weighted-average 

CN w is usually used. 

The targets of this study are (1) to compare CN w with CN evaluated at basin scale from 

rainfall-runoff multi-daily events in 36 Sicilian basins, CN emp , (2) to find a simple relationship 

between CN and Sicilian watersheds’ morpho-climatic and hydrologic characteristics, which 

allows the use of the CN method in ungaged watersheds. 


2.1 Methods 

The general runoff equation introduced by the SCS-NRCS (1964, 1972, 1985, 2004) is:

Q 

 

 

P 

Ia 

 

2 

P 

Ia 

S 

 

for P≥Ia 

Q 

0 

for P

In this approach, called asymptotic fitting method (AFM), the CN of the watershed is defined 

in standard and violent cases as the constant CN value at higher rainfalls (CN ∞ ). If a clear 

CN ∞ is not identified, an asymptotic equation suggested by Hawkins et al. 2009 allows to 

determinate CN ∞ . 

AFM uses all events, but of course the results are mostly influenced by the largest event, 

which is in keeping with the usual intended applications of the method. For this reason this 

procedure is now suggested in literature for the determination of watershed CN from rainfallrunoff 

data, CN emp (Van Mullem et al. 2002; Hawkins et al. 2009). 

As already mentioned, in ungaged sites, watershed CN is obtained by the handbook tables 

developed by SCS-NRCS according to the hydrologic soil-cover complexes (USDA NRCS 

2004, 2009), as area-weighted-average CN w . 

2.2 Study area 

The mountain ranges of Sicily (Fig. 1), the largest island of Italy and of the Mediterranean 

Sea with its 25,700 km 2 , split up the island into three versants: the first one in the north, the 

second one in the south and the last one in the oriental part. 

Sicilian territory is 62% hilly, principally in the inland areas of the island, 24% mountainous, 

mainly in the north and 14% plains in the coastal areas. 

The 1,636,690 ha of agricultural land is mainly made up of: sown land (50%), olive groves 

(15%), orchards (10%, with prevalence of citrus orchards), vineyards (10%). 

The mean annual rainfall P m varies in the mountain ranges from 600 mm to 1,600 mm, while 

in the rest of island P m varies from 300 mm to 800 mm. 

The mean annual temperature T m is about 14-15 °C, with lower T m in the mountain ranges 

(8-13 °C) and higher T m in the costal areas (18-19 °C). 

Using P e T data from about 150 stations located all over the island, the Sicilian Agrometeorological 

Informative Service (SIAS) obtained the De Martonne’s aridity index (2002), 

which indicates a major presence of semi-arid and semi-humid areas rather than humid 

zones. 

According to the well-known Köppen climate classification, many authors (McKnight & Hess 

2000; SIAS 2002; Peel et al. 2007) report that Sicily has a typical Mediterranean climate 

(Group C -Temperate/mesothermal climates), with hot and dry summers. 

1 

2 

3 

FIGURE 1: Location of 61 Sicilian watersheds studied and three Sicilian versants. 

2.3 Data and previous studies 

D’Asaro & Grillone (2010, 2012) collected daily total runoff data Qt (mm), measured in 61 

Sicilian streamflow gauging stations (Fig. 1, Table1), and the correspondent daily rainfall

data P (mm), gauged in 130 pluviographs placed inside the 61 watersheds published by 

Dipartimento dell’Acqua e dei Rifiuti of Sicilian Region in the observation period 1940-1997 

(mean record length equal to 20 years). 

The authors evaluated the daily rainfall event P for each watershed using the Thiessen 

Polygon method, while the correspondent direct runoff event Q i (mm) at day i was calculated 

as 

Q i = Qt i – Qb i (5) 

where Qt i is total runoff at day i (mm, obtained dividing volumetric runoff by catchment area), 

Qb i is daily baseflow at the day i (mm), evaluated by means of a single-parameter digital 

filter: 

Qbi 1 Qbi 

1min Qt i;Qti4 

(6) 

where Qb i-1 is the baseflow at day i-1, Qt i-4 is the total runoff at day i-4 and (1-) is the 

recession constant equal to 0.93 for South Italy (Manfreda et al. 1993). 

Digital filter expressed by (6) is different from the original filter proposed by Chapman and 

Maxwell (1996) because of the use of min(Qt i ;Qt i-4 ) instead of Q i . The latter assumption 

allows to avoid the unrealistic sharp peak of baseflow right under the measured hydrograph 

peak found in the Chapman digital filter (Tan et al. 2009). 

Once obtained rainfall-runoff P i ,Q i data as mentioned above, D’Asaro & Grillone (2010, 2012) 

evaluated CN emp at basin scale from rainfall-runoff multi-daily events (Mockus 1964), 

computing about 35,000 events, using AFM and NEH4M (Table 2). 

Results indicated that the NEH4M detects improbably high median CN values in a narrow 

range for each watershed (Table 2), caused by the process of computing CN for small events 

that biases the CN toward high values (Hawkins et al. 2009). 

This evidence shows how the NEH4M leads to an overall unlikely rainfall-runoff response of 

the Sicilian watersheds: most of P is transformed into Q, as if all basins were almost totally 

composed of impervious areas. This unrealistic result underlines that the NEH4M is not able 

to give a correct CN emp for Sicilian watersheds. 

The results obtained for the AFM indicated that 43 out of 61 basins (about 75%) of the 

studied watersheds have a standard behavior and 3 out of 61 (5%) have a violent response 

(Table 2). Thus, the runoff curve number method can be correctly used and CN emp can be 

defined in 80% of the Sicilian watersheds studied. 

Using tabulated CNs, Viola et al. (2011) estimated CN w in 36 out of 46 watersheds classified 

by D’Asaro & Grillone (2012) as basins where the curve number method can be correctly 

used, basing on land cover and hydrologic soil properties Sicilian maps. 

3. Results 

The comparison between CN emp estimated using NEH4M (D’Asaro & Grillone, 2012) and 

CN w (estimated by handbook CN tables, Viola et al. 2011) shows that CN emp are in a narrow 

range (about 90) and there is no link with CN w (Fig. 2). 

On the contrary, comparison between CN emp estimated using AFM (D’Asaro & Grillone, 

2012) with CN w shows (Fig. 2) that CN w values are generally higher than corresponding 

CN emp and their range is narrower than CN emp range. 

Thus, it is clear that CN w does not match CN emp in a semi-arid climate, such as 

Mediterranean area and in particular in Sicily, tending to overestimate watershed CN and 

thus runoff Q. 

Thus, in order to estimate the right CN L (lumped CN) in ungaged watersheds, it is preferable: 

1. to estimate CN w using the tabulated CN 

2. to “adjust” the CN w estimation using the following simple linear relationship: 

CNL 

0.8064CNw 

7.95 

(7) 

obtained in this study for Sicilian watersheds (Fig.2). In this way the CN w is brought to a more 

reliable value, close to the CN emp estimated by means of AFM, nowadays considered the 

best way to evaluate the watershed CN (Woodward et al. 2010, D’Asaro & Grillone 2012).

ID 

Station 

TABLE 1: Streamflow gauging stations and watershed main characteristics 

Station 

Watershed 

Area 

[Km 2 ] 

River 

length 

[Km] 

Versant 

Station 

altitude 

[m] 

Max 

basin 

altitude 

[m] 

Mean 

basin 

altitude 

[m] 

Mean 

annual 

rainfall P m 

[mm] 

Mean 

annual 

runoff Q m 

[mm] 

Mean 

annual 

temperature 

T m [°C] 

1 Falcone Elicona 54 22.2 1 30 1344 705 987 400 15.17 

2 Aculeia Pollina 52 15.4 1 330 1979 1040 923 246 13.30 

3 Ponte Vecchio Castelbuono 99 24.8 1 200 1979 929 831 227 13.89 

4 Bivio Cerda Torto 414 60.8 1 25 1326 505 588 85 16.04 

5 Monumentale S. Leonardo 522 56.0 1 2 1613 580 676 192 15.62 

6 Lupo Eleuterio 10 5.4 1 524 1613 776 791 289 14.86 

7 Rossella Eleuterio 10 4.5 1 484 1029 647 1103 405 15.38 

8 Serena Valle dell'Acqua 22 9.0 1 285 1029 652 893 216 15.33 

9 Risalaimi Eleuterio 53 10.5 1 198 1029 624 715 209 15.46 

10 Parco Oreto 76 13.0 1 113 1333 632 1007 432 15.41 

11 Zucco Nocella 57 13.8 1 80 1194 552 990 177 15.88 

12 Fellamonica Iato 49 15.0 1 210 1333 594 802 337 15.58 

13 Taurro Iato 164 33.5 1 124 1333 408 656 244 16.54 

14 Alcamo Scalo Fiumefreddo 273 37.0 1 60 825 242 544 115 17.33 

15 Lentina Forgia 46 14.0 1 88 1008 307 587 115 17.01 

16 La Chinea Fastaia 23 8.0 1 210 751 341 544 121 16.98 

17 Chinisia Birgi 293 43.5 1 4 751 178 504 85 17.72 

18 Pozzillo Delia 139 21.4 2 93 713 273 728 150 17.20 

19 Sparacia Belice destro 116 32.5 2 251 1233 437 800 233 16.32 

20 Casebalate Belice sinistro 342 42.5 2 179 1613 568 626 211 15.72 

21 Finocchiara Senore 77 26.5 2 126 1180 411 609 145 16.57 

22 Ponte Belice Belice 807 94.2 2 58 1613 452 650 159 16.30 

23 Bruciato Belici 131 23.0 2 363 1081 618 564 105 15.42 

24 Passofonduto Platani 1186 76.1 2 136 1580 519 621 109 15.96 

25 Mandorleto S. Biagio 74 20.0 2 92 607 356 506 81 16.79 

26 Petralia Imera Merid. 28 8.5 2 760 1912 1237 805 602 12.50 

27 Cinquearchi Imera Merid. 545 45.0 2 340 1912 730 681 151 14.95 

28 Capodarso Imera Merid. 631 62.0 2 270 1912 691 632 122 15.19 

29 Donna Paola Gibbesi 63 15.6 2 260 652 437 503 82 16.36 

30 Drasi Imera Merid. 1782 125.0 2 56 1912 529 534 106 15.95 

31 Castello Castello 26 7.7 2 460 1007 647 542 50 15.37 

32 Castelluccio Tellaro 102 22.5 3 160 770 444 611 59 16.32 

33 Biscari Simeto 696 60.5 3 211 3274 1075 681 267 13.19 

34 Ponte Gagliano Salso 499 46.7 3 375 1558 790 661 156 14.61 

35 Giarretta Simeto 1832 120.0 3 17 3274 811 633 300 14.52 

36 Casecelso Girgia 25 10.7 3 340 920 507 733 205 16.18 

37 Bozzetta Dittaino 79 15.2 3 330 1192 551 808 233 15.84 

38 Case Carella Crisà 47 15.6 3 331 1025 611 643 180 15.59 

39 Chiusitta Saraceno 19 6.1 3 1170 1754 1480 1117 828 11.20 

40 Moio Alcantara 342 34.0 3 510 3274 1153 822 228 12.74 

41 Alcantara Alcantara 570 58.0 3 20 3274 949 937 408 13.78 

42 S. Giacomo Alcantara 25 7.0 3 1100 1611 1228 1005 679 12.38 

43 Ponte Grande Isnello 33 10.7 1 566 1979 1220 841 267 12.40 

44 Scillato Imera Settent. 105 15.7 1 236 1869 841 733 235 14.38 

45 Roccapal. Scalo Torto 173 31.7 1 335 999 572 514 78 15.73 

46 Vicari S. Leonardo 253 27.0 1 250 1615 675 654 179 15.20 

47 Milicia Milicia 112 22.7 1 130 1257 496 658 137 16.13 

48 Sapone Baiata 29 9.8 1 44 330 112 478 66 18.20 

49 Rinazzo Chitarra 37 17.8 1 50 368 166 460 68 17.74 

50 Re Giovanni Gangi 61 11.8 2 540 1333 866 648 171 14.28 

51 Besero Imera Merid. 995 74.0 2 230 1912 636 616 123 15.42 

52 Monzanaro Salso 184 24.9 2 389 1660 787 608 123 14.64 

53 Raffo Salso 21 8.6 2 685 1660 1038 706 378 13.41 

54 S. Pietro Ficuzza 128 27.0 2 130 692 395 544 41 16.65 

55 Noto Asinaro 55 14.5 3 70 590 362 621 180 16.68 

56 S. Nicola Anapo 82 20.8 3 356 986 627 675 275 15.45 

57 Rappis Trigona 72 23.4 3 88 747 466 599 169 16.16 

58 Serravalle Troina di Sopra 157 32.0 3 545 1566 965 671 212 13.75 

59 Torricchia Sciaguana 67 19.6 3 200 824 426 437 45 16.38 

60 Petrosino Martello 43 11.0 3 800 1800 1319 866 562 11.93 

61 Zarbata Flascio 31 10.4 3 970 1611 1292 926 637 12.09

TABLE 2: CN emp values obtained for 46 Sicilian watersheds using NEH4 method and 

asymptotic fitting method by D’Asaro & Grillone (2012) and CN w derived using handbook 

tabulated CN for 36 out of 46 Sicilian basins by Viola et al. (2011). 

ID 

Station 

Station 

Watershed 

Number of 

events 

NEH4 METHOD 

(natural data, 

=0.20, median 

CNs=CN emp ) 

ASYMPTOTIC FITTING 

METHOD (ordered data, 

=0.20, CN ∞ =CN emp ) 

CN w from 

handbook 

tables 

CN ∞ behavior 

1 Falcone Elicona 657 88 54 standard 70 

2 Aculeia Pollina 319 87 56 standard 

3 Ponte Vecchio Castelbuono 592 88 68 standard 74 

4 Bivio Cerda Torto 469 89 76 standard 80 

5 Monumentale S. Leonardo 1072 91 79 standard 79 

6 Lupo Eleuterio 972 91 77 standard 73 

7 Rossella Eleuterio 230 88 63 standard 

8 Serena Valle dell'Acqua 1095 86 70 standard 74 

9 Risalaimi Eleuterio 806 90 71 standard 76 

10 Parco Oreto 1633 88 61 standard 74 

11 Zucco Nocella 1204 84 57 standard 74 

12 Fellamonica Iato 472 90 79 standard 79 

13 Taurro Iato 374 91 83 standard 

14 Alcamo Scalo Fiumefreddo 236 88 70 standard 81 

15 Lentina Forgia 503 89 66 standard 

18 Pozzillo Delia 659 88 80 violent 

20 Casebalate Belice sinistro 835 91 81 standard 

21 Finocchiara Senore 376 89 72 standard 79 

22 Ponte Belice Belice 921 90 77 standard 79 

24 Passofonduto Platani 1019 89 65 standard 80 

28 Capodarso Imera Merid. 839 90 71 standard 80 

29 Donna Paola Gibbesi 353 89 60 standard 

30 Drasi Imera Merid. 1055 90 65 standard 79 

31 Castello Castello 416 88 50 standard 76 

36 Casecelso Girgia 439 90 72 standard 

37 Bozzetta Dittaino 431 89 67 standard 

38 Case Carella Crisà 812 91 80 violent 

39 Chiusitta Saraceno 478 89 76 standard 66 

41 Alcantara Alcantara 893 90 54 standard 70 

42 S. Giacomo Alcantara 468 87 68 standard 69 

43 Ponte Grande Isnello 450 88 66 standard 70 

44 Scillato Imera Settent. 697 90 73 standard 77 

Roccapal. 

Scalo Torto 454 90 78 standard 81 

45 

46 Vicari S. Leonardo 451 91 78 standard 80 

47 Milicia Milicia 602 90 74 standard 81 

48 Sapone Baiata 535 87 70 standard 85 

49 Rinazzo Chitarra 263 89 88 violent 80 

50 Re Giovanni Gangi 521 90 68 standard 81 

51 Besero Imera Merid. 269 91 71 standard 79 

53 Raffo Salso 480 92 82 standard 80 

54 S. Pietro Ficuzza 456 88 59 standard 77 

55 Noto Asinaro 328 88 58 standard 76 

56 S. Nicola Anapo 809 91 62 standard 69 

57 Rappis Trigona 258 89 78 standard 56 

58 Serravalle Troina di Sopra 590 90 70 standard 80 

59 Torricchia Sciaguana 406 90 68 standard 78 

Mean 613 89 70 76 

Statistics 

Median 492 89 70 79 

Stand. Dev. 302 1.60 8.77 5.58 

max 1633 92 88 85 

min 230 84 50 56

100 

90 

AFM 

NEH4M 

80 

CNemp 

70 

60 

50 

CNemp = 0.8064 CNw + 7.95 

40 

40 50 60 70 CNw 80 90 100 

FIGURE 2: Pairs (CN w ,CN emp ) with CN emp estimated using AFM and NEH4M and CN w 

derived from CN tables (watersheds n. 31 and 57 are not represented because outliers). 

Finally, in order to estimate CN in ungaged watersheds without using handbook CN tables, a 

relationship between CN emp and watershed morpho-climatic and hydrologic characteristics 

was investigated in Sicilian basins. 

Using the following continuous variables: drainage area, river length, mean slope, mean 

annual rainfall, mean annual temperature, average normalized difference vegetation index 

(NDVI), mean basin altitude, gauging station altitude and the three versants of Sicily as a 

categorical variable, a unique regression relationship was sought for the 46 watersheds with 

standard and violent responses (Table 2). The following linear equations for watershed CN 

estimation are obtained by stepwise regression: 

CN = 96,52 - 0.034 P m (9a) for the north side of Sicily (versant 1 in Fig.1) 

CN = - 2,33 + 0.117 P m (9b) for the south side of Sicily (versant 2 in Fig.1) 

CN = 70,34 - 0.0025 P m (9c) for the oriental side of Sicily (versant 3 in Fig.1) 

where P m is the mean annual rainfall in mm and the value of the regression coefficient R, 

equal to 0.68, shows that equations (9) do not allow a good CN estimation. It is noteworthy 

that only P m climatic variable resulted significant, mostly affecting CN estimation for versant 

2. Thus, further investigations are necessary to explain watershed CN estimation in Sicily by 

means of other variables. 


The validity of handbook CN tables was investigated in Sicily (mid-Mediterranean area) 

comparing the watershed CN w obtained using the hydrologic soil-cover complexes as 

suggested by the SCS-NRCS tables, with curve numbers evaluated at basin scale from 

rainfall-runoff multi-daily events in 36 Sicilian basins, CN emp , using the asymptotic fitting 

method (AFM) and the NEH4M (NEH4 method as introduced by the SCS-NRCS). 

The comparison between CN emp estimated using NEH4M (D’Asaro & Grillone, 2012) and 

CN w (estimated by the handbook CN tables, Viola et al. 2011) shows that CN emp values are in 

a narrow range (about 90) and there is no link with CN w , while the comparison between 

CN emp estimated using AFM (D’Asaro & Grillone, 2012) and CN w shows that CN tab values are 

generally higher than corresponding CN emp . 

Finally, as far as the determination of an empirical relationship between CN L and some 

morpho-climatic basin variables, only a link between CN L and the climatic variable mean 

annual rainfall P m was found.

References 

Chapman, T. G. & Maxwell , A. I. (1996). Baseflow separation-comparison of numerical 

methods with tracer experiments. Proceedings of Hydrological and water Resources 

Symposium, Institution of Engineers Australia, Hobart, Australia, 539-545. 

D’Asaro, F. & Grillone G. (2010). Runoff Curve Number method in Sicily: CN determination 

and analysis of the Initial abstraction ratio. Proceedings of the 4th Federal Interagency 

Hydrologic Modeling Conference, Las Vegas, Nevada (USA), 06/27/2010-07/01/2010. 

D’Asaro F. & Grillone G. (2012). Empirical investigation of Curve Number method 

parameters in the Mediterranean area. Accepted for publication in Journal of Hydrologic 

Engineering the 04/01/2012. In Press. 

Hawkins R.H. (1973). Improved Prediction of Storm Runoff in Mountain Watersheds. Journal 

of the Irrigation and Drainage Division, 99(4), 519-523. 

Hawkins, R.H. (1990). Asymptotic determination of curve numbers from rainfall-runoff data. 

Symposium Proceedings, Watershed Planning and Analysis in action, Durango CO, 

ASCE, New York, 67-76. 

Hawkins, R.H., Ward, T. J., Woodward, D.E. & Van Mullem, J.A. (2009). Curve Number 

Hydrology: state of practice. American Society of Civil Engineers, Reston, Virginia 

(USA), 106 pp. . 

Hjelmfelt, A.T. (1980). Empirical Investigation of Curve-Number Technique. Journal of the 

Hydraulics Division, 106(9), 1471-1476. 

Manfreda, S., Giordano C. & Iacobellis, V. (2003). Stima dei deflussi di base mediante un 

filtro fisicamente basato. Proceedings of Giornata di Studio: Metodi Statistici e 

Matematici per l'Analisi delle Serie Idrologiche, Rome, Italy, 247-258. 

McKnight, T. L. & Hess, D. (2000). Physical Geography: A Landscape Appreciation. New 

Jersey: Prentice Hall (624 pp.). 

Mockus, V. (1964). Personal communication, Letter to Orinn Ferris dated March 5, 1964, 5 

pp., USDA, NRCS, Washington DC (USA). 

Peel, M. C., Finlayson, B. L. & McMahon T. A. (2007). Updated world map of the Koppen- 

Geiger climate classification. Hydrology and Earth System of Sciences, 11, 1633-1644. 

Ponce, V.M., Hawkins R.H. (1996). Runoff Curve Number: Has it reached maturity? . Journal 

of Hydrologic Engineering, 1(1), 11-19. 

Rallison, R E. (1980). Origin and Evolution of the SCS Runoff Equation. Proceeding of the 

Symposium on Watershed Management ’80, Boise, ID (USA), American Society of Civil 

Engineering, New York, NY, 912-924. 

Ritter, J.B. and Gardner T.W. (1991). Runoff Curve Numbers for reclaimed surface mines in 

Pennsylvania. Journal of Irrigation and Drainage Engineering, 117, 657-666. 

SIAS -Sicilian Informative Agro-meteorological Service- (2002). Sicilian Climatologic Atlas. 

Italy: Department of Agriculture of Sicilian Autonomous Region. 

Tan, S.B.K., Lo, E.Y., Shuy, E.B., Chua, L.H.C. & Lim, W.H. (2009). Hydrograph separation 

and development of empirical relationships using single parameter digital filters. Journal 

of Hydrologic Engineering, ASCE, 14(3), 271-279. 

USDA, SCS (1964, 1972, 1985). National Engineering Handbook, Sec. 4 Hydrology. 

Washington D.C. (USA). 

USDA, NRCS (2004, 2007, 2009). National Engineering Handbook, Part 630 Hydrology. 

Washington D.C. (USA). 

Van Mullem, J.A., Woodward, D.E., Hawkins, R.H., Hjelmfelt, A.T. & Quan, Q.D. (2002). 

Runoff Curve Number Method: Beyond the Handbook. Proceedings of Second Federal 

Interagency Hydrologic Modeling Conference, Las Vegas, Nevada (USA). 

F. Viola, L. V. Noto, M. Cannarozzo, & G. La Loggia (2011). Regional flow duration curves 

for ungauged sites in Sicily. Hydrology and Earth System Science, 15, 323-331. 

Woodward, D.E., Van Mullem, J.A., Hawkins, R.H. & Plummer A. (2010). Curve Number 

Completion Study”. Consultant’s report to USDA, NRCS, Beltsville MD, 38pp.

Empirical methods to determine average annual 

runoff coefficient in Sicilian basins 

Giorgio Baiamonte 1 , Francesco D’Asaro 1 *, Giovanni Grillone 1 

1 Department of Agro-Environmental Systems, Università di Palermo, 

viale delle Scienze 13, Edificio 4, Ingresso E, 90128, Palermo, Italy 

*Corresponding author. Email: francesco.dasaro@unipa.it 

Abstract 

Runoff estimation in ungauged basin is a challenge for the hydrological engineers and 

planners. For any hydrological study on an ungauged basin, a methodology has to be 

appropriately selected for the determination of runoff at its outlet. Several methods have 

been used to estimate the basin runoff production. In this work the empirical Kennessey 

method to determine average annual runoff coefficient, RC, is tested on 61 Sicilian basins 

characterized by different climate conditions, surface permeability, mean slope and 

vegetation cover. A comparison between observed and calculated RC showed that a 

calibration of the Kennessey model could be necessary. The slight and not satisfying 

improvement of the calibrated model suggested that the main factors accounted for the 

Kennessey method could not be enough to describe mean runoff production. So the analysis 

has been focused on researching empirical relations between RC and other variables which 

could play a significant role on RC estimation. Finally, the best result on RC estimate was 

obtained by a simple linear regression for two Sicilian sub-zones, by considering only two 

main climatic parameters, average annual rainfall depth and average annual temperature. 

Keywords: ungauged watershed, runoff coefficient, empirical models 


One of the central problem in hydrology deals with the estimation of average annual runoff 

production at basin scale. Runoff estimation in ungauged basin is a challenge for the 

hydrological engineers and planners. The problem becomes much more essential in arid and 

semiarid regions as population increases and land use have continues to change, 

furthermore, in all those regions, such as Sicily, where the problem of water scarcity is 

particularly nearby so to be arduous water resources planning. 

Several methods are available for estimation of runoff (USDA SCS 1964, 1972, 1985). Most 

of them are based on the estimate of the average annual runoff coefficient, RC. RC can be 

defined as the fraction of the average annual precipitation that does not infiltrate into the soil 

and is not transferred back to the atmosphere through evapotranspiration. Thus, runoff 

coefficient represents the fraction of the precipitation, in excess of the deep percolation and 

evapotranspiration, which becomes surface flow and ends up in either perennial or 

intermittent surface water bodies. 

Because of difficulties on modeling spatial variability of topography, geology, soil type and 

vegetation, as well in climate fluxes such as rainfall, infiltration and evapotranspiration, 

simple empirical approaches to determine average annual runoff coefficient (RC) have been 

widely applied (Barazzuoli et al. 1988, Santos and Hawkins, 2011). Between the simple 

empirical models the Kennessey method (Kennessey 1930) provides RC values by 

accounting for the main factors wherefrom RC is influenced: climate characteristic, surface 

permeability, mean slope and vegetation cover. After computing a climatic aridity index 

which, the method involves calculating RC as simple addition of three partial runoff 

coefficients related to the same components, according to empirical tabled values proposed 

by Kennessey.

This work, after applying Kennessey model for 61 Sicilian basins, and after a not satisfying 

attempt to calibrate it on the base of rainfall and runoff data, aims to provide an empirical and 

reliable tool to determine average annual runoff coefficient in Sicily. 

2. Materials and Method 

The study has been carried out for 61 Sicilian gauged basins, quite uniformly distributed all 

over the region (Fig. 1). Table 1 reports main characteristics of the considered basins. Firstly, 

each basin has been characterized in terms of climate, morphology, land use; same 

indications of soil permeability were also available from previous study (Fierotti et al., 1988). 

1 

2 

FIGURE 1 – Sicily Region and location of the 61 considered basins. North and south subzones, 

1 and 2, finally used for the RC linear regression are also indicated. 

2.1 Observed average annual runoff coefficient 

For the 61 considered basins, daily measurements rainfall data and discharge data about in 

the period 1940 -1997 are available. Spatial variability of rainfall into the basins has also 

considered for evaluating annual rainfall depth, by using data collected in 130 pluviometric 

stations. Observed average runoff coefficient, RC obs , were computed as the ratio between 

average annual runoff volume, Q, and average annual rainfall depth, P (Table 1). 

2.2 Kennessey method 

The Kennessey method let to estimate the average runoff coefficient as a function of three 

main basin components: slope component, Ca, Permeability component, Cp and vegetation 

component, Cv. For each of the three components, partial runoff coefficients have to be 

evaluated, according to their description reported in Table 2. Partial runoff coefficient is 

assigned to the basin, once the basin De Martonne aridity index, Ia, is evaluated. 

According to the physical meaning of each component, partial runoff coefficient increases 

with increasing of slope, with decreasing of soil permeability, and by passing from forest land 

use to bare rock. Furthermore, partial runoff coefficient increases with increasing Ia, i.e by 

passing from dry to wet climate basin conditions. 

Once the partial runoff coefficients are identified, the basin RC is evaluated by their simple 

addition, after weighting with the basin homogeneous area fractions, where homogeneity has 

to be intended for each of the 39 classes of Table 2 (13 x 3).

TABLE 1 – Main characteristics of the considered basins 

ID 

Station 

Station 

Watershed 

Area 

[Km 2 ] 

River 

length 

[Km] 

Sicily subzone 

Station 

altitude 

[m] 

Max basin 

altitude 

[m] 

Mean basin 

altitude 

[m] 

Mean 

annual 

rainfall P 

[mm] 

Mean 

annual 

runoff Q 

[mm] 

Mean annual 

temperature 

[°C] 

1 Falcone Elicona 54 22.2 1 30 1344 705 987 400 15.17 

2 Aculeia Pollina 52 15.4 1 330 1979 1040 923 246 13.30 

3 Ponte Vecchio Castelbuono 99 24.8 1 200 1979 929 831 227 13.89 

4 Bivio Cerda Torto 414 60.8 1 25 1326 505 588 85 16.04 

5 Monumentale S. Leonardo 522 56.0 1 2 1613 580 676 192 15.62 

6 Lupo Eleuterio 10 5.4 1 524 1613 776 791 289 14.86 

7 Rossella Eleuterio 10 4.5 1 484 1029 647 1103 405 15.38 

8 Serena Valle dell'Acqua 22 9.0 1 285 1029 652 893 216 15.33 

9 Risalaimi Eleuterio 53 10.5 1 198 1029 624 715 209 15.46 

10 Parco Oreto 76 13.0 1 113 1333 632 1007 432 15.41 

11 Zucco Nocella 57 13.8 1 80 1194 552 990 177 15.88 

12 Fellamonica Iato 49 15.0 1 210 1333 594 802 337 15.58 

13 Taurro Iato 164 33.5 1 124 1333 408 656 244 16.54 

14 Alcamo Scalo Fiumefreddo 273 37.0 1 60 825 242 544 115 17.33 

15 Lentina Forgia 46 14.0 1 88 1008 307 587 115 17.01 

16 La Chinea Fastaia 23 8.0 1 210 751 341 544 121 16.98 

17 Chinisia Birgi 293 43.5 1 4 751 178 504 85 17.72 

18 Pozzillo Delia 139 21.4 2 93 713 273 728 150 17.20 

19 Sparacia Belice destro 116 32.5 2 251 1233 437 800 233 16.32 

20 Casebalate Belice sinistro 342 42.5 2 179 1613 568 626 211 15.72 

21 Finocchiara Senore 77 26.5 2 126 1180 411 609 145 16.57 

22 Ponte Belice Belice 807 94.2 2 58 1613 452 650 159 16.30 

23 Bruciato Belici 131 23.0 2 363 1081 618 564 105 15.42 

24 Passofonduto Platani 1186 76.1 2 136 1580 519 621 109 15.96 

25 Mandorleto S. Biagio 74 20.0 2 92 607 356 506 81 16.79 

26 Petralia Imera Merid. 28 8.5 2 760 1912 1237 805 602 12.50 

27 Cinquearchi Imera Merid. 545 45.0 2 340 1912 730 681 151 14.95 

28 Capodarso Imera Merid. 631 62.0 2 270 1912 691 632 122 15.19 

29 Donna Paola Gibbesi 63 15.6 2 260 652 437 503 82 16.36 

30 Drasi Imera Merid. 1782 125.0 2 56 1912 529 534 106 15.95 

31 Castello Castello 26 7.7 2 460 1007 647 542 50 15.37 

32 Castelluccio Tellaro 102 22.5 2 160 770 444 611 59 16.32 

33 Biscari Simeto 696 60.5 2 211 3274 1075 681 267 13.19 

34 Ponte Gagliano Salso 499 46.7 2 375 1558 790 661 156 14.61 

35 Giarretta Simeto 1832 120.0 2 17 3274 811 633 300 14.52 

36 Casecelso Girgia 25 10.7 2 340 920 507 733 205 16.18 

37 Bozzetta Dittaino 79 15.2 2 330 1192 551 808 233 15.84 

38 Case Carella Crisà 47 15.6 2 331 1025 611 643 180 15.59 

39 Chiusitta Saraceno 19 6.1 2 1170 1754 1480 1117 828 11.20 

40 Moio Alcantara 342 34.0 2 510 3274 1153 822 228 12.74 

41 Alcantara Alcantara 570 58.0 2 20 3274 949 937 408 13.78 

42 S. Giacomo Alcantara 25 7.0 2 1100 1611 1228 1005 679 12.38 

43 Ponte Grande Isnello 33 10.7 1 566 1979 1220 841 267 12.40 

44 Scillato Imera Settent. 105 15.7 1 236 1869 841 733 235 14.38 

45 Roccapal. Scalo Torto 173 31.7 1 335 999 572 514 78 15.73 

46 Vicari S. Leonardo 253 27.0 1 250 1615 675 654 179 15.20 

47 Milicia Milicia 112 22.7 1 130 1257 496 658 137 16.13 

48 Sapone Baiata 29 9.8 1 44 330 112 478 66 18.20 

49 Rinazzo Chitarra 37 17.8 1 50 368 166 460 68 17.74 

50 Re Giovanni Gangi 61 11.8 2 540 1333 866 648 171 14.28 

51 Besero Imera Merid. 995 74.0 2 230 1912 636 616 123 15.42 

52 Monzanaro Salso 184 24.9 2 389 1660 787 608 123 14.64 

53 Raffo Salso 21 8.6 2 685 1660 1038 706 378 13.41 

54 S. Pietro Ficuzza 128 27.0 2 130 692 395 544 41 16.65 

55 Noto Asinaro 55 14.5 2 70 590 362 621 180 16.68 

56 S. Nicola Anapo 82 20.8 2 356 986 627 675 275 15.45 

57 Rappis Trigona 72 23.4 2 88 747 466 599 169 16.16 

58 Serravalle Troina di Sopra 157 32.0 2 545 1566 965 671 212 13.75 

59 Torricchia Sciaguana 67 19.6 2 200 824 426 437 45 16.38 

60 Petrosino Martello 43 11.0 2 800 1800 1319 866 562 11.93 

61 Zarbata Flascio 31 10.4 2 970 1611 1292 926 637 12.09 

To determine the De Martonne aridity index, Ia, for the 61 considered Sicilian basins, Ia map 

of the Sicilian Region has been extracted from the “Atlante Climatologico della Sicilia” (SIAS, 

2002). Ia map has been developed on rainfall data and temperature data from 1965 to 1994, 

collected for 55 thermo-pluviometric stations e 124 pluviometric stations distributed all over 

the region.

TABLE 2 - Partial runoff coefficients of each basin component accounted for the Kennessey method 

Slope component Ca 

Permeability component Cp 

Vegetation component Cv 

Ia < 25 25 < Ia < 40 Ia > 40 

> 35% 0.22 0.26 0.3 

_10 - 35 % 0.12 0.16 0.2 

_3.5 - 10 % 0.01 0.03 0.05 

< 3.5 % 0 0.01 0.03 

very poor 0.21 0.26 0.3 

poor 0.17 0.21 0.25 

moderate 0.12 0.16 0.2 

good 0.06 0.08 0.1 

very good 0.03 0.04 0.05 

bare rock 0.26 0.28 0.3 

grass land 0.17 0.21 0.25 

farm land 0.07 0.11 0.15 

forest land 0.03 0.04 0.05 

To determine basins area fractions, for slope component, and particularly for the 

corresponding area fractions associated to the four slope classes of Table 2, 100 m 

resolution digital elevation model (DEM) of Sicily has been used. 

With reference to the permeability component, it has to be observed that soils of Sicily are 

characterized by a large variety, going from less to more developed pedologic types (Fierotti 

et al., 1988). This is due to the different geolithological formations, sedimentary to volcanic to 

metamorphic, which characterizes the Sicilian Region, as a consequence soil permeability 

can be considered the most arduous component to determine. For the purpose of this study, 

in view of the very small spatial scale of this investigation, soil permeability has been roughly 

estimated by the pedological map mentioned above, by considering a mixed of the qualitative 

indications there reported (soil depth, soil structure and texture). 

Differences in land cover were accounted by the average normalized difference vegetation 

index (NDVI) obtained in a previous study for the Sicily, by using NOAA satellite images, for 

the period 1988-2005 (Bono et al., 2007). Thus, in this study seasonal variability of the 

vegetation component was not taken into account for the estimation of the average runoff 

coefficient. Figure 2 reports the four classes of NDVI considered in this study and associated 

to the vegetation components of the Kennessey method. 

NDVI 

FIGURE 2 – Classes of NDVI associated to the four vegetation components of the Kennessey method 

The determination of the average runoff coefficient of each basin, according to Kennessey 

method, RC K , is therefore obtained by adding the partial runoff components of Table 2, 

weighted with the homogeneous area fractions derived by intersecting the four different 

thematic maps: acclivity (Ca), permeability (Cp), vegetation (Cv) and climate condition (Ia). 

2.3 Calibration of the Kennessey method 

Partial runoff coefficients of the Kennessey method (Table 2) were also calibrated by 

minimizing the root mean square error (RMSE) between observed, RC obs , and calculated

RC K , setting up the above discussed expected trend of partial RC by varying with the classes 

of each component. Table 3, analogously to Table 2, reports the partial runoff coefficients 

obtained by calibrating the Kennessey method based on the observed RC values. Firstly, 

table 3 shows that partial RC is completely unaffected by vegetation component and it is 

generally weakly influenced by the other components. Particularly, slope and permeability 

components result weakly influenced in the down-left side of the table (low Ia and slope 

values and low Ia and high permeability values), while RC is completely unaffected in the upright 

side of the table (high Ia and slope values and high Ia and low permeability values). 

Calibration results highlights that at basin scale, for Sicily, a spatial averaging effect could 

probably obscures the important roles of the considered Kennessey components. 

TABLE 3 - Calibrated runoff coefficients of each component accounted for Kennessey method 

Ia < 25 25 < Ia < 40 Ia > 40 

> 35% 0.20 0.20 0.20 

Slope component Ca 

_10 - 35 % 0.11 0.20 0.20 

_3.5 - 10 % 0.03 0.03 0.20 

< 3.5 % 0.03 0.03 0.20 

very poor 0.08 0.46 0.46 

poor 0.08 0.46 0.46 

Permeability component Cp moderate 0.08 0.13 0.38 

good 0.04 0.04 0.04 

very good 0.04 0.04 0.04 

bare rock 0.05 0.05 0.05 

Vegetation component Cv 

grass land 0.05 0.05 0.05 

farm land 0.05 0.05 0.05 

forest land 0.05 0.05 0.05 

3. Results 

Results of the comparison between observed runoff coefficients RC obs and estimated ones by 

the Kennessey method are presented in Figure 3. The pairs (RC obs , RC K ) are almost 

dispersed around the line of perfect agreement, indicating a clear overestimating/ 

underestimating of the Kennessey method for the Sicilian environment for small/high RC 

values. 

0.8 

0.6 

RCk 

RCk,c 

RC(P,T) 

1:1 

RC calc 

0.4 

0.2 

0 

RC K RC K,c RC(P,T) 

R 0.263 0.788 0.846 

RMSE 0.175 0.100 0.086 

0 0.2 0.4 0.6 0.8 

RC obs 

FIGURE 3 – Comparison between observed RC, RC obs , and RC calculated by Kennessey method, 

RC K , by calibrated Kennessey method, RC k,c , and by using simple linear regression as a function of P 

and T, RC(P,T), for the considered 61 Sicilian basins. Figure also report the corresponding correlation 

coefficient, R, and the root mean square error, RMSE

Figure 3 also reports a comparison between observed RC, RC obs , and calculated RC with the 

calibrated Kennessey method, RC K,c , obtained by using partial runoff coefficients of Table 3. 

As expected, calibration strongly improves RC estimation (see R e RMSE in Fig. 3), but 

showed that results are still slights and not at all satisfactory, so to suggest that the 

components accounted for the RC in the Kennessey method could not be enough to 

describe mean runoff production. Thus, the analysis has been focused on researching 

empirical relationships between RC obs and other variables which could play a significant role 

on RC estimation. In particular, average annual rainfall, average annual temperature, 

average annual evapotranspiration, vegetation indexes, surface basin, main aspect and 

distance from coast line, mean altitude and height, distance from basin outlet to cost, as 

regression variables were also considered. Finally, the best result on RC estimate was 

carried out by a stepwise regression. In the final relationship, that follows, RC is a function of 

only the two main climate parameters, average annual rainfall depth, P (mm), and average 

annual temperature, T (°C): 

RC - 0.06 0.000411P 0.0012 T for the north sub-zone 1 of Sicily (Fig. 1) 

RC 1.09 0.000411P - 0.0707T for the south sub-zone 2 of Sicily (Fig. 1) 

The relationship shows a good fitting of the data with a multiple regression coefficient equal 

to 0.846 and RMSE = 0.086 (Figure 3). Application of the proposed equations to distributed P 

and T data yet available (SIAS, 2002), could provide an RC map for Sicily Region. 


After applying Kennessey method to 61 Sicilian basins, a comparison between observed and 

calculated RC showed that a calibration of the model was necessary. The slight and not 

satisfying improvement of the calibrated model suggested that the components accounted for 

the RC estimation could not well explain mean runoff production. So the analysis has been 

focused on researching empirical relationships between RC obs and other variables which 

could play a significant role on RC estimation. In particular, mean annual precipitation, mean 

altitude and height, mean potential evapotranspiration, surface, main aspect and distance 

from coast line, were also considered. Finally, a regional relationship to estimate mean 

annual runoff production, involving only the two main climate parameters, the average annual 

rainfall depth and the average annual temperature, is proposed for Sicily Region. Application 

of the proposed equations could provide an RC map for Sicily Region. 

References 

Barazzuoli P., Izzo S., Menicori P., Micheluccini M. & M. Salleolini (1988). A new practical aid 

to regional hydrogeologic planning: the runoff coefficient map, Environmental 

Management, 13(5), 613-622. 

E. Bono, F.Capodici, G. Ciraolo, G. La Loggia, A. Maltese & L. V. Noto (2007). Study of 

vegetation evolution in Sicily using time series analysis of remote sensing and climatic 

data. Remote Sensing for Environmental Monitoring and Change Detection 

(Proceedings of Symposium HS3007 at IUGG2007, Perugia, 07/2007). IAHS Publ. 17(4) 

Fierotti G., Dazzi C. & S. Raimondi (1988). Carta dei suoli della Sicilia. Italy: Regione 

Siciliana. 

Kennessey, B. Lefoljasy tènyezok ès renenciok. Vizugy, Koziemènyek, Hungary,1930. 

Santos F. L. & R.H. Hawkins (2011). Generalized Mediterranean Annual Water Yield Model: 

Grunsky’s Equ. and Long-Term Average Temperature, J. of hydr. Eng. ASCE, 16(874). 

SIAS - Sicilian Informative Agro-meteorological Service - (2002). Sicilian Climatologic Atlas. 

Italy: Department of Agriculture of Sicilian Autonomous Region. 

USDA, SCS (1964, 1972, 1985). National Engineering Handbook, Sec. 4 Hydrology. 

Washington D.C. (USA).

Accumulation of the chloride and sodium in precocious dwarf 

cashew irrigated with saline water during the fruiting stage 

Arlington R. R. de Oliveira 1 *, Ronaldo Nascimento 2 , Maiene de F. C. Queiroga 3 , 

Hugo O. C. Guerra 4 

1 Arlington Ricardo Ribeiro de Oliveira, Av. Aprígio Veloso, 882 - Bodocongó 

Campus I - UFCG - Bloco CM - 1º. Andar - CEP 58429-140 - Campina Grande, PB – Brasil 

2 Ronaldo Nascimento, Av. Aprígio Veloso, 882 - Bodocongó 


3 Maiene de Fátima Cordeiro Queiroga, Av. Aprígio Veloso, 882 - Bodocongó 


Hugo Orlando Carvallo Guerra, Av. Aprígio Veloso, 882 - Bodocongó 


* Autor para correspondência. E-mail: ricardo75jp@hotmail.com 

ABSTRACT - The cultivation of cashew tree (Anacardium occidentale L.) is an activity of 

great economic and social importance for the Brazilian Northeast region, because it offers 

income for low resources families. The use of irrigation with low water quality has caused 

salinization problems in semi-arid areas, especially in the Brazilian Northeast. The aim of 

this study was to evaluate the effects of irrigation water salinity on the sodium and chloride 

concentrations in the dwarf cashew plant CCP76 clone during the fructification phase. 

Key words: Salinity, irrigation, agriculture, fruit production. 


The cashew tree plant, botanically classified as Anacardium occidentale L., belongs to the 

Anacardiaceae family, belong to this family about 60 to 70 genera and 400-600 species and 

genetic types of the most popular stand the cashew tree and dwarf cashew tree(Lima, 1988). 

The cultivation of cashew tree is an activity of greater economic and social importance for 

the Brazilian Northeast. The exploration of the cashew fruit became even greater after 

obtaining genetic materials and improved use of irrigation, however, the inappropriate use of 

irrigation in semi-arid areas, which predominate in northeastern Brazil, has been a factor 

causing the salinization of soils (Audry & Suassuna, 1995). Salt stress, as Izzo et al. (1991), 

represents one of the most serious limiting factor of growth and production cultures induced 

morphological changes, metabolic structural and higher plants. Maas and Hoffmann (1977) 

and Maas (1986), however, report the existence of a great variability of behavior across 

cultures in relation to salinity tolerance limits, and within the same species, there may be 

variations between genotypes and also for the same genotype, the tolerance level may vary 

between stages of development. Despite knowledge of the harmful effects of salinity on fruit 

and socioeconomic relevance of the cashew crop for the Northeast, few research works 

were carried out with cashew (Meireles, 1999, Ferreira et al., 2000; Viégas et al., 2001, 

Carneiro et al., 2002, Carneiro et al., 2004), all investigating the effects of salinity on the 

formation of rootstocks, only two studies were found (Meireles, 1999; Bezerra et al., 2002) 

covering the phase of the grafting cashew, but restricted to the formation of grafted 

seedlings. Thus, this study aimed to evaluate the effects of saline irrigation water on the 

content of sodium chloride in the plant parts of the dwarf cashew tree CCP76 clone of during 

the fruiting phase.


The experiment was conducted in a protected environment of the Unidade Acadêmica de 

engenharia Agrícola (UAEAg), Centro de Tecnologia e Recursos Naturais (CTRN), 

Universidade Federal de Campina Grande (UFCG), Campus I, in Campina Grande, PB (7 ° 

15 '18 'S, 35 ° 52'28 "W, 550 m) in plastic pots with 150L capacity, drilled in the base to allow 

leaching. The pots were filled with a sandy loam soil material, no salt and no sodium. 

Treatments consisted on five levels of salinity, called S1, S2, S3, S4 and S5, corresponding 

respectively to the electrical conductivity of irrigation water (electrical conductivity) of 0.8, 

1.6, 2.4, 3.2 and 4.0 dS m -1 at 25 o C, designed in randomized blocks with five treatments and 

six replications. The irrigation water were prepared by adding NaCl (without iodine) to the 

water supply system location, multiplying the desired value of the electrical conductivity (dS 

m -1 ) 640, as Richards (1954). Irrigation, drip, were taken every three days early in the 

morning, based on water consumption in the previous irrigation of the plants, dividing the 

estimated volume by a factor of 0.8, reestablishing thus the moisture soil to field capacity 

and using a leaching fraction (FL) of 0.2. Plants subjected to salt stress during fruiting were 

irrigated with water of lower salinity (0.8 dS m -1 ) during periods of vegetative growth and 

flowering. At the end of the first production cycle, we evaluated the content of chloride and 

sodium in the roots, rootstocks, grafting and branch and leaves. The sodium was determined 

by Flame Photometer according to the methodology suggested by Silva (1999) and chloride 

by titration with AgNO 3 . For Na in the roots, rootstocks, grafts and branches, the values were 

transformed into .. Data were analyzed using analysis of variance test with 'F' 

(SISVAR, 2003). We conducted polynomial regression analysis, being a factor of salinity 

quantitative. 


It is noted in Table 1 that the effect of saline irrigation water on the chloride content was 

highly significant (p

Folhas ( mg kg -1 ) 

Porta-enxerto (mg kg -1 ) 

Enxerto ( mg kg -1 ) 

S 4 (3,2 dS m -1 ) 0,74 0,63 0,62 0,94 0,64 

S 5 (4,0 dS m -1 ) 0,87 0,98 0,79 0,67 0,57 

In the leaves there was a 26.64% decreasing of the nutrient content per unit increased. 

Plants irrigated with water salinity of 0.8 dS m -1 had an average weight of 0.85 mg kg -1 while 

the plants irrigated with 4.0 dS m -1 obtained 0.57 mg kg -1 as a middle weight. The greatest 

increasing in chloride content in the grafts was observed where the content of this medium 

were 0.37 and 0.79 mg kg -1 , respectively, to the plants were irrigated with ECw of 0.8 dS m -1 

and 4,0 dS m -1 , which afforded an increase of 53.16%. The roots and branches obtained an 

increase of 33% and 6, respectively. Regression analysis of the variation of chloride content 

in the different parts of the plant by increasing the salinity of the water irrigation and their 

equations are shown in Figure 1. Changes in the levels of chloride with salinity of irrigation 

water in the rootstocks, grafts and fitted sheets in a highly significant (p

TABLE 2: Summary of variance analysis and averages for levels of sodium in the roots, 

rootstock, graft, branches and leaves of the dwarf cashew tree CCP76 clone irrigated with 

different salt concentrations water, after 90 days of salt stress. 

Branche 

s 

Sources of 

Roots Rootstock Graft 

Leaves 

GL 

Variation 

Mean Square 

Salinity 4 1,29** 0,934** 0,51** 0,59** 0,3725 ns 

Linear 

1 1,18** 3,679** 1,40** 1,56** 0,0003 ns 

Regression 

Quadratic 

1 3,66** 0,051 n s 0,07 ns 0,61* 1,1389 ns 

regression 

Desviation 2 0,15 ns 0,004 ns 0,28** 0,09 ns 0,1753 ns 

Block 5 0,03 ns 0,051 ns 0,10 ns 0,19 ns 0,0511 ns 

Residue 20 0,10 0,157 0,05 0,11 0,1361 

CV (%) 12,65 14,46 8,74 11,86 8,40 

Averages of the sodium content 

(dS m -1 ) mg kg -1 

S 1 (0,8) 2,58 3,81 3,68 4,49 15,66 

S 2 (1,6) 5,00 5,36 4,47 6,85 21,18 

S 3 (2,4) 8,67 7,00 5,50 8,83 19,37 

S 4 (3,2) 7,33 8,14 4,61 7,91 19,22 

S 5 (4,0) 4,73 9,41 7,53 8,60 16,71 

As the same case of chloride, with the increasing of the sodium salinity of the water is mainly 

due to the fact that the water were prepared with sodium chloride, and well as increased the 

amount of sodium in the irrigation water, the increased amount of sodium added to the soil 

and consequently the plant. In the case of cashew tree leaves allegedly directed sodium to 

the old leaves (with low metabolic activity) as reported by Shannon et al. (1994) for some 

species tolerant to salinity. According to Marschner (1995) would be a restriction on imports 

of sodium and chloride to the young leaves, which is a characteristic of salinity tolerant 

species. 

The regression analysis of the variation of sodium content in different parts of the plant by 

increasing the salinity of the water irrigation and their equations are shown in Figure 1. For 

the content of Na in roots and branches, there was a statistically significant quadratic effect 

(p

Enxerto ( mg kg -1 ) 

Ramos ( mg kg-1) 

Raízes ( mg kg -1 ) 

Porta- enxerto (m g kg -1 ) 

4 

4 

3 

3 

2 

2 

1 

Y = 0,6411 + 1,7408**X - 0,3261**X2 

R² = 0,9401 

0 

0,8 1,6 2,4 3,2 4,0 

1 

Y = 1,9970 + 0,3095**X 

R² = 0,9844 

0 

0,8 1,6 2,4 3,2 4,0 

CEa ( dS m -1 ) 

CEa ( dS m -1 ) 

C 

4 

D 

4 

3 

3 

2 

2 

1 

Y = 2,0005 + 0,1989**X 

R² = 0,6890 

0 

0,8 1,6 2,4 3,2 4,0 

CEa ( dS m -1 ) 

1 

Y = 1,7740 + 0,8406**X - 0,1331nsX 2 

R² = 0,9218 

0 

0,8 1,6 2,4 3,2 4,0 

CEa ( dS m -1 ) 

Figure 2: Sodium contents of the roots (A), rootstocks (B) grafts (C) and branches (D) in 

precocious dwarf cashew tree CCP76 clone in function of electrical conductivity (ECw) used 

in irrigation after 90 days of salt stress in fruiting phase. 

In plant parts where the salinity had a significant effect on the levels of sodium, except for 

roots, we observed an increasing sodium concentration with salinity which could be 

consistent with that reported by Silva et al. (1997), cited by Fernandes (2000) who say that 

sodium may act by stimulating plant growth, therefore, is considered a useful complement to 

many cultures for physiological effects themselves or by replacing part of K + required by the 

plant. The degree of substitution will depend on the potential for absorption and translocation 

of Na + to the shoot of the plant and the efficiency of plant using K + , which is possibly 

accepted in view of the plant is at the stage of fruit, a phase responsible for a period of very 

large demand for potassium, with a view to the formation of the fruits. For example, in the 

presence of high external concentration of sodium, potassium and calcium absorption can 

be inhibited, causing deficiencies of these nutrients and increase the sodium content in plant 

cells (Fernandes, 2000). 


The sodium and chloride contents, in general, were affected by the accumulation of salts in 

the root zone caused by irrigation water. 

For both rootstocks and grafts, there was an increase in chloride content with salinity of 

irrigation water. But in the leaves it was observed a decreasing. With the exception of roots, 

other plant parts of dwarf cashew tree had an increasing in the sodium content by the salinity 

of irrigation water. 

5. References 

AUDRY, P.; SUASSUNA, J. A salinidade das águas disponíveis para a pequena irrigação 

no sertão do Nordeste: caracterização, variação sazonal, limitação de uso. Recife: CNPq, 

1995. 128 p.

BEZERRA, I. L.; GHEYI, H. R.; FERNANDES, P. D.; GURGEL, M. T.; NOBRE, R. G. 

Germinação, formação de porta-enxertos e enxertia de cajueiro anão-precoce, sob estresse 

salino. Revista Brasileira de Engenharia Agrícola e Ambiental, v. 6, n. 3, p. 420-424. 2002. 

CARNEIRO, P. T.; FERNANDES, P. D.; GHEYI, H. R.; SOARES, F. A. L. Germinação e 

crescimento inicial de genótipos de cajueiro anão-precoce em condições de salinidade. 

Revista Brasileira de Engenharia Agrícola e Ambiental, PB, v. 6, n. 2, p. 199-206, 2002. 

CARNEIRO, P. T.; FERNANDES, P. D.; GHEYI, H. R.; SOARES, F. A. L.; VIANA, S. B. A. 

Salt tolerance of precocious dwarf cashew rootstocks - physiological and growth indexes. 

Scientia Agricola, v. 61, n. 1, p. 9-16, 2004. 

FERREIRA, O. S.; MATOS, N. N.; MENESES JÚNIOR, J.; BARROS, L. DE M.; LIMA 

JÚNIOR, A.; SILVEIRA, J. A. G. da. Avaliação inicial da tolerância ao estresse salino em 

materiais de cajueiro (Anacardium occidentale L.) através de índices de crescimento. In: 

Congresso Brasileiro de Fruticultura, 16, 2000, Fortaleza, Anais... Fortaleza: SBF, 2000. 

CD-Rom. 

INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA. Anuário Estatístico do Brasil. 

Rio de Janeiro: IBGE, 2006. 

IZZO, R. NAVARI-IZZO, F.; QUARTACCI, F. Growth and mineral absorption in maize 

seedlings as affected by increasing NaCl concentrations. Journal of Plant Nutrition, New 

York, v.14, p.687-699, 1991. Lima, V. de P.M.S. A cultura do cajueiro no Nordeste do Brasil. 

Fortaleza: Banco do Nordeste do Brasil (BNB),1988. 454p. 

LIMA, V. de P. M. S. A cultura do cajueiro no Nordeste do Brasil. Fortaleza: Banco do 

Nordeste do Brasil (BNB), 1988. 454 p. 

MAAS, E. V. Salt tolerance of plants. Applied Agric. Research, v. 1, p. 12-26, 1986. 

MAAS, E. V., HOFFMAN, G. J. Crop salt tolerance - current assessment. In: ASCE (ed.). 

Journal of Irrigation and Drainage Division: American Society of Civil Engineers, v. 103, n. 

IR2, p. 115-134. 1977. 

MARSCHNER, H. Mineral nutrition of higher plants. . 2a ed. Londres, Academic Press, 

1995, 889p. 

MEIRELES, A. C. M. Salinidade da água de irrigação e desenvolvimento de mudas de 

cajueiro anão-precoce (Anacardium occidentale L.). Fortaleza: UFC, 1999. 60p. 

(Dissertação de Mestrado). 

RICHARDS, L. A. (ed.). Diagnoses and improvement of saline and alkali soils. Washington: 

United States Salinity Laboratory, 1954. 160 p. (USDA. Agriculture Handbook, 60). 

SILVA, F. C. Manual de análises químicas de solos, plantas e fertilizantes. Brasília: 

Embrapa, 1999. 370p. 

SISVAR. Sistema de Analise de Variância para dados Balanceados: versão 4.3. Software 

para análises estatísticas por meio do Windows. Lavras: UFLA, 2003 

VIÉGAS, R. A.; SILVEIRA, J. A. G. da; LIMA JR., A. R. de; QUEIROZ, J. E.; FAUSTO, M. J. 

M. Effects of NaCl-salinity on growth and inorganic solute accumulation in Young cashew 

plants. Revista Brasileira de Engenharia Agrícola e Ambiental, v. 5, p. 216-222, 2001. 

YAHYA, A. Salinity effects on growth and on uptake and distribution of sodium and some 

essential mineral nutrients in sesame. Journal of Plant Nutrition, v.21, n.7, p. 1439-1451, 

1998.

Enhancements of using RTD instead of thermocouples for 

estimating evapotranspiration by means of energy balance method 

D. Escarabajal 1 *, J.M. Molina 1 , D.G. Fernández-Pacheco 1 , 

A. Ruiz-Canales 2 , R. López-Urrea 3 

1 

Universidad Politécnica de Cartagena, Paseo Alfonso XIII 48, 30203 Cartagena, Spain 

2 Universidad Miguel Hernández, Ctra. de Beniel Km 3.2, 03312 Orihuela, Spain 

3 Instituto Tecnológico Agronómico Provincial, Avda. Gregorio Arcos s/n, 02080 Albacete, Spain 

* Corresponding author. E-mail: david.escarabajal@gmail.com 

Abstract 

At present, commercial equipment based on the BREB method that measures the 

required temperature gradients by using thermocouples (e.g. chrome-constantan) can be 

found in the market. In addition, these devices are endowed with another high precision 

instrumentation for measuring the water vapour pressure gradients, such as a high precision 

hygrometer. The existence of combined temperature and humidity sensors in the actual 

market, which consist of a resistance temperature detector (RTD) and a capacitive humidity 

sensor, allows obtaining the required gradients to calculate the Bowen ratio with a simplified 

and economical device that provides high precision and better linearity and stability. In this 

paper an evaluation of both systems (thermocouples and RTDs) for determining the 

temperature gradients and its incidence in the evapotranspiration values estimated by the 

BREB method by means of a comparison with the values measured in a weight lysimeter 

and the values calculated by the FAO-56 Penman-Monteith equation, is accomplished. 

Keywords: Bowen ratio, lysimeter, energy balance, RTD, thermocouples. 


Estimation of evapotranspiration (ET) by means of the Bowen Ratio-Energy Balance 

method (BREB) is commonly used for getting crop coefficients and for evaluating models 

developed for the calculation of ET (Kjelgaard et al., 1994; Farahani and Bausch, 1995; 

Ortega-Farias et al., 1996; Ibáñez and Castellví, 2000; Casa et al., 2000). The Bowen ratio 

(β=γ . ΔT/Δe) (Bowen, 1926) and the Energy Balance equation are the basis of the BREB 

method for determining the ET, being considered as a simple, economic and precise method. 

This fact has led to the development and implementation of new equipment, and justifies the 

efforts dedicated to its optimization. 

It is common to find in the market commercial equipment based on the BREB method 

that measures the required temperature gradients by using thermocouples (e.g. chromeconstantan) 

and a high precision hygrometer. However, the existence of combined 

temperature and humidity sensors in the actual market, which consist of a resistance 

temperature detector (RTD) and a capacitive humidity sensor, allows obtaining the required 

gradients to calculate the Bowen ratio with a simplified and economical device. Moreover, 

these kind of combined sensors demand a minor maintenance and provide high precision 

and better linearity and stability. 

In this paper an evaluation of the performance of both systems, thermocouples and 

RTD, for determining the temperature gradients that will be used to calculate the Bowen 

ratio, and its impact on the evapotranspiration values estimated by the BREB method, 

compared with other methods such as lysimeter and Penman-Monteith FAO-56 version, is 

accomplished.


The study was performed at the Las Tiesas experimental farmland of the Agronomic 

Technical Institute of the Province of Albacete, over a reference crop (Festuca arundinacea 

Schreb) grown over a surface area of 1 hectares, and during a comparative period of forty 

days, from September 10th to October 19th of 2011. 

Concerning the calculation of the ET, two different methods were used: 

a) A weight lysimeter of 2.3x2.7x1.7m installed at the centre of the parcel (see 

figure 1), which is endowed with the required equipment to perform a complete 

water balance and to evaluate with precision both water deliveries (rain and 

irrigation) and losses (evapotranspiration and deep drainage). 

b) The FAO-56 Penman-Monteith equation (Allen et al., 1998) by using the 

meteorological data acquired by a weather station placed at the reference 

crop. 

Figure 1. Lysimeter at the Las Tiesas experimental farmland of the Agronomic Technical 

Institute of the Province of Albacete 

In order to carry out the comparative study between thermocouples and RTDs for 

estimating the ET, a fully equipped Bowen station was installed (see figure 2). This station 

was endowed with a NR-LITE net radiometer (Campbell Sci. Inst., USA), placed at 2m above 

ground level, an A100 cup anemometer (Campbell Sci. Inst., USA), a RAIN-O-MATIC 

pluviometer (Campbell Sci. Inst., USA), two HFP01 soil heat flow plates (Hukseflux, Holanda) 

and a CS616 water content reflectometer (Campbell Sci. Inst., USA).

Figure 2. Fully equipped Bowen station 

Both compared sensors were installed at a height of 0.55m and 1.19m. Concretely 

two E-type fine-wire thermocouples (chrome-constantan) with a diameter of 76 μm and two 

CS215 temperature and relative humidity sensors (Campbell Sci. Inst., USA) constituted by a 

thermometric probe for measuring air temperature (which integrates a platinum resistance of 

1000 Ω) and a capacitive relative humidity sensor, were used. The ET values were 

determined in duplicate: on the one hand, by using the ΔT values acquired from 

thermocouples in the calculation of the Bowen ratio, and on the other hand, by using the 

values obtained from RTDs. Collected data were analysed and filtered, and a regression 

analysis of the calculated ET values was performed, discarding those values in which the β 

value entered into the exclusion interval (Pérez et al., 1999). 

3. Results 

The water balance analysis gives evidence of the existence of sensible heat advection, 

which was registered almost daily, except for some days. Several days, this phenomenon 

was especially severe, reaching this sensible heat advection to contribute up to 64% of the 

energy consumed in the evapotranspiration process. 

The ET values measured by the lysimeter during all the days of the study, and mainly 

in those in which the advection phenomenon was more severe, were underestimated by the 

values provided by the BREB method (see figure 3). These results coincide with the ones 

obtained by Dunin et al. (1991) and Prueger et al. (1997), who found that Bowen method 

tends to underestimate the lysimetric values of ET in advection conditions.

Figure 3. Hourly values of ET estimated by: lysimetry (ET lys ), Penman-Monteith (ET p-m ), BREB 

with thermocouples (ET tmc ), BREB with RTD (ET rtd ) 

The regression analysis performed to the hourly values of ET obtained by the Penman- 

Monteith equation and the ones calculated by using the BREB method (thermocouples and 

RTDs) indicates that both systems underestimated ET, being higher for values around 0.2 – 

0.5 mm . h -1 . Nevertheless, the use of RTD shows better results when estimating ET with the 

BREB method (see figure 4), since precision and stability of these devices is almost ten 

times higher. 

Figure 4. Comparison between the Penman-Monteith equation (ET p-m ) and the BREB method 

with: a) RTD (ET rtd ), b) thermocouples (ET tmc )


When comparing the evapotranspiration values estimated by means of the Bowen 

Ratio-Energy Balance method (BREB) with the values measured in the lysimeter, in any of 

the modalities studied in this paper, it was followed that Bowen method underestimated the 

evapotranspiration flux, allowing to detect a process of sensible heat advection, which can be 

considered as an important energy source that increases the crop evapotranspiration. 

Nevertheless, no greater attention to this phenomenon was paid, since it was out of the 

scope of this study. The heat flux advection and its influence when measuring and estimating 

evapotranspiration was analysed by Gavilán (2002), who considers that it can contribute up 

to 40% of the total energy used in the evapotranspiration process. 

A comparison of the hourly values of ET calculated by applying the FAO-56 Penman- 

Monteith equation (Allen et al. 1998) with the ones estimated by the BREB method, using 

both thermocouples and RTDs for measuring the temperature gradients, proved that both 

systems underestimated the evapotranspiration, existing significant differences between both 

systems. Even though, the ET values estimated with the BREB method by using RTDs 

showed a better adjustment, precision and stability, highlighting a better suitability for 

calculating the Bowen ratio. 


This work has been partially supported by the PPII10-0319-8732 (Ministry of Education 

and Science from the Government of Castilla la Mancha) and 08729/PI/08 (Seneca 

Foundation) projects. 

References 

Allen, R.G., Pereira, L.S., Raes, D., & Smith, M. (1998). Crop evapotranspiration: guidelines 

for computing crop water requirements. Paper number 56. Rome: FAO Irrigation and 

drainage. 

Bowen, J.S. (1926). The ratio of heat losses by conduction and by evaporation from any 

water surface. Physical Review, 27, 779-787. 

Casa, R., Russell, G., & Lo Casciom, B. (2000). Estimation of evapotranspiration from a field 

of linseed in central Italy. Agricultural and Forest Meteorology, 104(4), 289-301. 

Dunin, F.X., Barrs, H.D., Meyer, W.S., & Trevitt, A.C.F. (1991). Foliage temperature and 

latent flux of irrigated wheat. Agricultural and Forest Meteorology, 55, 133-147. 

Farahani, H.J., & Bausch, W.C. (1995). Performance of Evapotranspiration models for maize 

–bare soil to closed canopy. Transactions of the ASAE, 38(4), 1049-1059. 

Gavilán, P.D. (2002). La advección de calor sensible en el Valle Medio del Guadalquivir y su 

influencia en la medida y estimación de la evapotranspiración. Doctoral Thesis. Córdoba: 

Universidad de Córdoba. 

Ibañez, M., & Castellví, F. (2000). Simplifying daily evapotranspiration estimates over short 

full-canopy crops. Agronomy Journal, 92, 628-632. 

Kjelgaard, J.F., Stockle, C.O., Villar Mir, J.M., Evans, R.G., & Campbell, G.S. (1994). 

Evaluating methods to estimated corn evapotranspiration from short-time interval weather 

data. Transactions of the ASAE, 37(6), 1825-1833.

Ortega-Farias, S.O., Cuenca, R.H., & Ek, M. (1996). Daytime variation of sensible heat flux 

estimated by the bulk aerodynamic method over a grass canopy. Agricultural and Forest 

Meteorology, 81, 131-143. 

Pérez, P.J., Castellví, F., Ibáñez, M., & Rossell, J.l. (1999). Assessment of reliability of 

Bowen ratio method for partitioning fluxes. Agricultural and Forest Meteorology, 97, 141- 

150. 

Prueger, J. H., Hatfield, J.L., Aase, J.K., & Pikul Jr., J.L. (1997). Bowen-ratio comparisons 

with lysimeter evapotranspiration. Agronomy Journal 89, 730-736.

Irrigation of Brachiaria brizantha pasture with wastewater of 

cassava industry 

Altair Bertonha 1 *, Daiane de C. Mariano 2 , Paulo S. L. de Freitas 1 

1 

Professor, University of Maringá, Av. Colombo 5790, Maringá, PR, 870200.900, Brasil 

2 University of Maringá, Av. Colombo 5790, Maringá, PR, 870200.900, Brasil 

*abertonha@uem.br 

Abstrat 

The water reuse from food industries of vegetable origin, as source of water, nutritious and 

organic matter for the soil and plants is a practice traditionally used in the agriculture and 

may be treated as the fertirration is. At this research, it was evaluated the cassava waste 

water application effects in Brachiaria brizantha cv. MG-5, being employed a hydraulic 

sprinkler, having as treatments all the waste water depth accumulated during the crop cycle, 

which are 0, 100, 275, 290, 328 and 366, applied during 10 weeks, for 4 continuous hours of 

irrigation a week, totaling 40 hours of irrigation that occurred from November 20, 2008 to 

January 30, 2009, when the pasture was cut. Soil and tissue plant were analyzed before and 

at the end of the experiment. Biomass and dry matter were analyzed at the end of the 

experiment. It was conclude that there is no restriction in the use of cassava waste water in 

the fertigation of the evaluated grass for these waste water depths; that the plant’s height 

isn’t a good reference to estimate the dry matter productivity of this grass when irrigated with 

waste water; that the waste water application caused an organic matter level increasing at 

the layer from 20 to 40 cm of depth, and an Al level increasing at the layer from 0 to 20 cm of 

depth; and that, in function of waste water depth (L), the absorbing efficiency of N and P 

related to the witness was adjusted by a quadratic function, and for the K, it was adjusted 

linearly. 

Key words: waste water, irrigation, dry mass 


In the process of industrialization of cassava starch, each ton of processed roots can 

produce up to 2.5 m 3 of wastewater (Cereda 2001) composed of formation water from the 

roots, washing and process. 

The application of this waste, according to Saraiva et al (2007) increases the levels of 

organic matter, nitrogen, phosphorus and potassium in the soil. On the other hand its 

indiscriminate use can change the balance of cations and pollute the soil and groundwater, 

presenting itself as a residue favourable for fertilization and unfavourable to pollution of soil 

and water, depending on the management practices used in your application. 

The quantity of nitrogen (N) and potassium (K) of this wastewater can meet crop demand 

(Anami et al., 2008 and Pelissari et al., 2009), but their applications must be monitored 

because the mobility of these ions on the ground in various stages of plant growth 

(Santos et al., 2009) and soil management (Pearson and Ison, 1997). 

In addition to nutrients this residue is an important source of water for irrigation in the border 

of the cassava industry, reaching estimated values of 10.000.000m 3 a year in the 

northwest of Paraná State. 

The acclimation of Brachiaria brizantha Stapf in the northeaster state of Paraná, this 

allows grass to produce up to 18 Mg DM ha -1 yr -1 (Souza 2002), often pastured 30-35 days 

(Correa 1999), presenting in its nutritional composition, 11 to 18, 0,6 to 1.2; 11 to18, 2 to 

4 and 1.2 to 2.3 gKg -1 respectively of N, P, K, Ca and Mg. 

The objective of this study was to take the wastewater from the cassava industry as a source 

of water and nutrients applied on Brachiaria brizantha cv. MG-5.

2 Material end methods 

The wastewater (WW) was derived from the first environment of a system for wastewater 

treatment industry cassava and applied with a hydraulic gun with a fixed, maintaining a range 

of application of 30 meters for 10 weeks, 4 hours per week, totalling 40 hours of irrigation in 

the period from 20 November 2008 to January 23, 2009. 

It was used a point source with 6 treatments, 0, 100, 275, 296, 328 and 366 mm of WW 

applied during the production cycle, respectively L1, L2, L3, L4, L5 and L6, spaced bands at 

35, 5, 10, 15, 20, 25 and 30m away from the hydraulic gun. The samples analyzed for 

nutritional grass and soil fertility, were performed in the same rays according to Oliveira 

et al. (1991) and Embrapa (1997). 

The experimental area was set equal to a cut grading on November 20, 2008. Quantifying 

the production of dray matter (DM) was performed on /1/30/2009, using samples of the grass 

cut 1.0 cm from the soil in an area of 0.16 m 2 . 

The soil was characterized as Udult soil (Embrapa 1999) and during experiment were 

recorded by station City Gaucha, Paraná, Brazil, 431,8 mm of rainfall and the temperature 

were 30.0 and 21.0 o C respectively maximum and minimum . 

The fertility of the soil was measured by the difference between the control and each 

treatment of the bases sum (Sb) and the organic matter (OM) layers of soil from 0.20 and 

0.40 m .depth. 

To evaluate the extraction of soil nutrients by the grass was calculated efficiency of 

absorption of nutrients which is the percentage of increase of nutrients in relation fo control 

according to equation 1. 

Ni Nt 

Ear .100 (1) 

Nt 

Were: 

Era: relative efficiency of nutrient absorption by the crops, %; 

Ni: content in the leaves of grass, after harvest, gKg -1 ; 

I, treatment, mm and 

Nt: content in the leaves of the grass after harvest the control treatment, gKg -1 

3 Results and discussion 

The chemical composition of major plant nutrients was found in RA used in this study 

collected the hydraulic gum at the time of application is presented in Table 1 which differs 

from those shown by Fioretto (2003) and Silva (2005) demonstrating the diversity 

of composition of this waste. 

Table 1 Analysis of WW collected the nozzle of the hydraulic gun 

N P K + Ca 2+ Mg 2+ C pH 

mgL -1 

168 13.3 91.8 21.35 13.23 3500 5.61 

In the Figure 1 is observed that the height of the grass (H) presents a quadratic 

relationship with the blades of WW, reaching a maximum height of 154 cm to 262 mm L, 

using a regression equation of the second order to fit the data. However the production of dry 

matter (DM) grass has been continued increasing in the range of L studied, 6.7 

to 26.0 Mg ha -1 . Both the linear and quadratic equation and its terms are significant at 

p≤ 0.01.

As the DM production was increased in the range of slides were evaluated, it is understood 

that not worked with the blade that maximizes the productivity of the grass, but the values 

are higher than those quoted by Mitidiere (1983) and Correa (1999), demonstrating that there 

is no restriction on the use of wastewater for irrigation and fertilization of grass. He also 

noted that there is a direct relationship between height and DM yield of grass. 

Figure 1 - Relationship between plant height (H), dry matter yield (DM) and the blades 

mean of WW applied in the area (L). 

Evaluating the results shown in Figure 2 it is observed that in the 0 to 0.20 m estimates of Sb 

according to AR applied blades reach a maximum of increase of 0.212 cmol c dm- 3 to the 

blade of 200 mm and the layer 0.20 to 0.40 m depth Sb maximum, .802 cmol c dm -3 was 

estimated with the blade of 270 mm. 

It is also observed that the addition of Sb was higher in the layer of 0.20 to 0.40 m in depth 

and that the reduction of Sb in the descending part of both curves results in leaching of the 

bases for the deeper regions of the soil. 

Figure 2 - Alteration in the sum of bases 0-20 and 20-40 cm soil depth

Queiroz et al. (2004) and (Fonseca et al. 2005) also obtained an increase in the sum of 

bases respectively applying swine wastewater and treated sewage effluent thus 

demonstrating that the bases are applied through the wastewater can supplement water 

demand of culture. However the balance of calcium magnesium and potassium may be 

compromised. 

The concentration of organic matter in soil extracts studied, differ from that of Malavolta 

et al. (2002) who observed a tendency of concentration of organic matter in swine 

wastewater decreases with the depth of the soil. This is due grained organic matter present 

in the AR is lower than that of swine wastewater. It should also be the efficiency of the 

system of treatment of these wastewaters. 

Figure 3 - Alteration in organic matter content in soil layers 0-20 and 20-40 cm depth 

In Figures 4.5 and 6 shows that the Ear were higher than the control which demonstrates 

the importance of WW for the purpose of fertirrigation of Brachiaria brizantha cv. MG-5. The 

values of the Ear nitrogen show that the presence of WW did not affect the transformation 

process of the nitrogen molecules in the soil a fact pointed out by Reis et. al. (2005). 

However, these do not coincides with the addition of MS accumulated by the plant during the 

experiment, which was linear and growing as shown in Figure 1, but correlated with the 

production factor H, maximized with 215 mm while the Ear nitrogen was maximized with the 

depth of 213 mm 

The Ear potassium, adjusted with a linear regression equation due to the applied layer of 

WW, showing that the potassium level of RA were not sufficient to limit the Ear this nutrient 

by the crops.. 

The Ear phosphorus showed lower values compared to the N and K, that fits as a second 

order equation with minimum point when it receives the estimated treatment of 238.3 mm 

and has Ear 9.3%.

Figure 4 - Efficiency of utilization of nitrogen on the grass 

Figure 5 - Efficiency of utilization of phosphorus on the grass 

Figure 6 - Efficiency of utilization of potassium on the grass


CEREDA, M.P. (2001) Characterization of the byproducts of industrialization of cassava In: 

Management, use and processing of cassava by-products of industrialization.São Paulo: 

fundação Cargill, v.4, cap.1,( Series cultures starchy tubers Latin American), 31-35 p. 

CORRÊA, L. A. (1999) Production of beef cattle on pastures fertilized In: SYMPOSIUM ON 

PRODUCTION OF BEEF CATTLE , 1., Goiânia. Anais... Goiânia: CBNA, 81-94 p. 

EMBRAPA National Research Center for Soil (1997), Manual of methods of soil analysis 

2.ed. Rio de Janeiro, 212p. 

EMBRAPA Centro Nacional de Pesquisa de Solo (1999). Brazilian System of Soil 

Classification Rio de Janeiro, 412p. 

FIORETTO, R. A. (2003) Direct use of effluent cassava industry in fertirrigation. 

Series: Cultures of Latin American starchy tubers. Volume 4 - Management, use 

andprocessing of cassava by-products of industrialization. SP, Fundação Cargill. 

Fonseca, A. F. ; Herpin, U; Paula, A. M.; Victoria, R. L.; Melfi, A. J. (2007) Agricultural use of 

treated sewage effluents: Agronomic and environmental implications and perspectives for 

Brazil. Scientia Agricola, v. 64, n.2, p.194-209. 

MALAVOLTA, E.; PIMENTEL G. F.; ALCARDE, J.C. (2002) Fertilizers and fertilization. São 

Paulo: Nobel, 199p. 

MITIDIERI, J., (1983) Manual of Grasses and Legumes for Tropical Pastures. São Paulo, 

Nobel, Ed. Of University of São Paulo, 75 a 76 p. 

OLIVEIRA, A J.; GARRIDO, W. S.; ARAÚJO, J. D. & LOURENÇO (1991). Research 

Methods in Soil Fertility. Brasília, EMBRAPA-SEA, 24 p. 

PEARSON, C.J.; ISON, R.L. (1997) Agronomy of grassland systems. Cambridge, 

Cambridge University Press, 222 p. 

QUEIROZ, F. M.; MATOS, A. T.; PEREIRA, O. G.; OLIVEIRA, R. A. (2004) Chemical 

characteristics of soil subjected to treatment with liquid swine manure and cultivated with 

grasses. Ciência Rural, v.34, n.05, p.1487-1492. 

REIS N. DE S.; SOARES, A. A.; SOARES, P. C.; CORNÉLIO, V. M. DE O. (2005) 

Absorption of N, P, K, Ca, Mg and S by rice influenced by nitrogen fertilization. Ciência 

Agrotécnica, Lavras, v.29, p. 707-713. 

SARAIVA, F. Z.; SAMPAIO, S. C.; SILVESTRE, M. G.; QUEIROZ, M. M. F. de; NÓBREGA, 

L. H. P.; GOMES, B. M. (2007) Using the effluent cassava industry in the development 

vegetative growth of corn in a greenhouse. In: Rev. bras. eng. agríc. ambient, v. 11, n. 1, 

30-36 p. 

SILVA, F. F.; FREITAS, P. S. L.; BERTONHA, A.; MUNIZ, A. S.; REZENDE, R.2004) Impact 

of application of effluent matured cassava starch by soil and sorghum. Acta Scientiarum. 

Agronomy, v. 26, n. 4, p. 421-42.

Evaluating the Impact of Climate Change on Irrigation Vulnerability 

in South Korea 

Min-Won Jang 1 *, Soo-Jin Kim 2 , Dae-Sik Kim 3 , Sang-Min Kim 1 

1 Gyeongsang Nat’l University & Institute of Agriculture and Life Sciences, Jinju-daero 501, 

Jinju, 660-701 Republic of Korea 

2 Gyeongsang Nat’l University, Jinju-daero 501, Jinju, 660-701 Republic of Korea 

3 Chungnam Nat’l University, Daehak-ro 99, Daejeon, 305-764 Republic of Korea 

*Corresponding author. E-mail: mwjang@gnu.ac.kr 

Abstract 

This study aims to assess climate change impacts on irrigation vulnerability in South Korea. 

Irrigation vulnerability is determined by a quantitative balance between crop water 

consumption and water resource availability in a specific area. South Korea was divided into 

5 km x 5 km zones, and a simple water balance model was applied to the grid units. Two 

types of data, climatic and hydrologic, was prepared and pre-processed to produce the 

attribute information associated with each zone. The irrigation vulnerability of each grid was 

evaluated based on the simulated water balance data for all four decades since 1971. 

Different vulnerability indices such as CWSR (Crop Water Satisfaction Ratio), AWBR 

(Accumulated Water Balance Ratio), and REIC (Rainfall Effectiveness Index for Crops) are 

suggested to represent the potential risk of water stress for cropland. This proposed 

methodology is expected to be adopted for global-scale assessment of vulnerability to 

agricultural water stress. 

Keywords: climate change, irrigation, paddy fields, vulnerability 


The IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report (2007) 

defined vulnerability as “the degree to which a system is susceptible to, and unable to cope 

with, adverse effects of climate change, including climate variability and extremes.” Fűssel 

(2010) defined vulnerability as a function of the character, magnitude, and rate of climate 

change, as well as the variation to which a system is exposed, its sensitivity, and its adaptive 

capacity. The concept of vulnerability has been adopted in a wide range of disciplines and 

has been used in studies on the assessments, indicators, and adaptations that have been 

occurring in various parts of the world (Jun et al., 2011; Perveen & James, 2011; Antwi-Agyei 

et al., 2012). Especially in terms of agricultural water management, measuring irrigation 

vulnerability would provide critical information for identification and prioritization of adaptation 

opportunities against climate change in a region. Design standards and management rules 

for irrigation facilities might need to be adjusted according to the vulnerability assessment. 

In South Korea, irrigation is a very sensitive issue for paddy rice cultivation. Discrepancies 

between water supply (precipitation) and demand (irrigation requirement) in time and location 

has motivated policies establishing strong water use systems, and resulted in more than 

17,500 irrigation reservoirs, 18,000 weirs, and 23,400 tube wells (MFAFF & KRCC, 2011). 

However, the unsteady and unpredictable climate variation induced by global warming is 

threatening traditional water management practices in Korea, and it may increase 

vulnerability to water scarcity in agriculture. Therefore, this study was done in order to 

determine a method to assess irrigation vulnerability to drought in paddy fields, and to 

analyze vulnerability in the past and future with regard to climate variability.

2. Data and Methods 

2.1. Methods 

Irrigation vulnerability is determined by a quantitative balance between crop water 

consumption and water resource availability. A vulnerability assessment model was 

developed using two modules: simulation of water requirements in paddy fields and 

calculation of hydrologically effective runoff. All processes were designed to be conducted 

over a grid in order to make the process extendable to global scale-application, as 

vulnerability does not need to be assessed only at country or regional levels such as 

administrative or watershed boundaries (Naudé et al., 2011). 

2.1.1. Simple water balance model 

A simple water balance equation was formulated to simulate daily water balance at a location 

(Eq. 1). The daily water requirement and ponding depth was simulated successively using 

daily climate data and recommended water management practices. 

PD(t) = PD(t-1) + PR(t) – AET(t) – DP (1) 

where PD is ponding depth (mm) with an upper limit of 80 mm and the negative values of PD 

trigger water deficit (WD), PR is the precipitation (mm/day) just in case of more than 5.0 

mm/day, AET is actual crop evapotranspiration (mm/day) calculated by multiplying the 

Penman-Monteith reference evapotranspiration by the 10-day crop coefficient (Table 1), DP 

is a deep percolation of 4.0 mm/day (Lee, 1988), and t is time. 

Irrigation requirements (IR) cannot be greater than the desired ponding depth by growth 

stages (Table 2). Effective rainfall (ER) is the amount of rainfall below the upper limit of 

ponding depth. 

TABLE 1: Crop coefficients for use with the Penman-Monteith equation (Yoo et al., 2008) 

Days after 

transplanting 

10 20 30 40 50 60 70 80 90 100 110 120 

Crop coefficients 0.78 0.97 1.07 1.16 1.28 1.45 1.50 1.58 1.46 1.45 1.25 1.01 

TABLE 2: Desired ponding depth by growth stages in paddy fields (Jang et al., 2004) 

Days since transplanting 10 40 60 90 130 

Growth stage On transplanting Tillering Elongation Heading Ripening 

Ponding depth 0.78 0.97 1.07 1.16 1.28 

2.1.2. Cell-based simple runoff model 

Input parameters for the model were limited by a lack of quality data. Therefore, this study 

examined a simplified runoff model using a curve number (CN) method at a cell unit. 

2.1.3. Vulnerability indices 

Vulnerability is a broad measure which is open to interpretation, and there are several 

approaches to its measurement (Jun et al., 2011). Expression of vulnerability is complicated 

by everything from the quality of the available data, to the selection and creation of indicators,

to the assumptions used in the weighting of variables and the mathematics of aggregation 

(Eakin & Luers, 2006; Fűssel, 2010; Luers et al., 2003). 

This study proposes three different vulnerability indices: CWSR (Crop Water Satisfaction 

Ratio), AWBR (Accumulated Water Balance Ratio), and REIC (Rainfall Effectiveness Index 

for Crop). 

(2) 

(3) 

where SRO is the sum of surface runoff (mm/yr), CWC is the sum of consumptive use by 

crops (AET + DP), and SRO surp is the sum of the surplus as the accumulated surface runoff 

is over the accumulated crop consumptive use (mm/yr). CWC surp is the sum of the surplus 

part as the accumulated crop consumptive use is over the accumulated surface runoff 

(mm/yr). 

(4) 

2.2. Data collection and pre-processing 

National daily climate data such as temperature, relative humidity, wind speed, sunshine 

hours, and precipitation from 1971 to 2010 were collected and pre-processed. The results of 

water balance simulation by weather stations, derived in daily time-steps, were summed over 

the growing period from late May to late September, and interpolated to 5 x 5 km grids. The 

ME (Ministry of Environment, Korea) Land Cover Map (1:25,000) and soil maps were 

prepared, and the former was used to determine the irrigated paddy field shares of each cell 

(Fig. 1). In terms of future climate change scenarios, the A1B scenario of the 

Special Report on Emissions (SRES), distributed by Hong et al. (2009), was tested first. The 

IPCC’s newly published climate change scenario, RCP (Representative Concentration 

Pathway) will be investigated in the future. Transplanting days and irrigation periods were 

assumed to be in late May and from May 21 to September 30, respectively. 

FIGURE 1: Fraction of paddy fields at each 5 x 5 km cell in South Korea. Most of the 

paddy fields are concentrated in the western plain area.

3. Results 

The water balance model was developed based on daily water balance on the 5 x 5 km grid, 

and then aggregated into administrative (provincial) units. 

3.1. Change in water balance from 1971 to 2010 

Annual mean rainfall increased over the analyzed period, while annual mean crop 

evapotranspiration decreased, as shown in Figs. 2 and 3. As a result, irrigation requirements 

decreased. The average amount of irrigation required in the 2000s, 511.8 mm/yr, was 

reduced by about 7.5% from that of the previous decade (Fig. 4). 

a) 1971-1980 (b) 1981-1990 (c) 1991-2000 (d) 2001-2010 

Figure 2: Annual mean precipitation (PR) by decade from 1971 to 2010. 

( 

a) 1971-1980 (b) 1981-1990 (c) 1991-2000 (d) 2001-2010 

Figure 3: Annual mean actual crop evapotranspiration (AET) by decade from 1971 to 2010. 

( 

a) 1971-1980 (b) 1981-1990 (c) 1991-2000 (d) 2001-2010 

Figure 4: Annual mean irrigation requirement (IR) by decade from 1971 to 2010. 

(

The data in Fig. 5 shows that the REIC was better in 2000s than in 1970s as a result of more 

effective rainfall and less crop evapotranspiration. 

a) 1971-1980 (b) 1981-1990 (c) 1991-2000 (d) 2001-2010 

Figure 5: REIC by decade from 1971 to 2010. 

( 

3.2. Changes in water balance in the future 

By the predictions of the SRES A1B scenario, annual mean rainfall will decrease in the 

2040s compared with the 2000s, while a significant rise in annual mean temperature might 

result in an increase in crop evapotranspiration. Fig. 6 shows increases of about 16.6% and 

7.2% in AET and IR, respectively. As for the predicted REIC, the improved trend over the 

past 40 years would reverse. 

a) Rainfall (b) AET (c) IR (d) REIC 

Figure 6: Water balance and REIC during the period from 2041 to 2050 under a climate 

change scenario, A1B. 

( 

4. Summary and Discussion 

This study proposes a cell-based simple water balance model for evaluating the irrigation 

vulnerability of paddy fields. Several vulnerability indices such as CWSR, AWBR, and REIC 

were designed to express changes in time and location. Simulation and statistics using 

observed climate data showed that water balance in South Korea has improved over the last 

four decades. Climate variation predicted by the SRES A1B scenario was also examined. 

This study is on-going, and further work will be carried out as follows: a) the construction of a 

cell-based runoff model, b) vulnerability assessment using RPC scenarios, c) the verification 

of irrigation vulnerability indices, and d) modification for global-scale application.

Acknowledgments 

This work was carried out with the support of the “Cooperative Research Program for 

Agriculture Science & Technology Development (Project No. PJ0083352012)” of the Rural 

Development Administration, Republic of Korea. 

References 

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Mapping the vulnerability of crop production to drought in Ghana using rainfall, yield and 

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Brown, C. & Hansen, J. W. (2008). Agricultural Water Management and Climate Risk. Report 

to the Bill and Melinda Gates Foundation. IRI Tech. Rep. No. 08-01 (pp. 19). New York: 

International Research Institute for Climate and Society, Palisades. 

Eakin, H., and Luers, A. L. (2006). Assessing the vulnerability of social-environmental 

systems. Annual Review of Environment and Resources, 31, 365-394. 

Luers, A. L., Lobell, D. B., Sklar, L. S., Addams, C. L., & Matson, A. P. (2003). A method for 

quantifying vulnerability, applied to the agricultural system of the Yaqui Valley, Mexico. 

Global Environmental Change, 13, 255-267. 

Fűssel, H. M. (2010). How inequitable is the global distribution of responsibility, capability, 

and vulnerability to climate change: A comprehensive indicator-based assessment. Global 

Environmental Change, 20, 597-611. 

Hong, E. M., Choi, J. Y., Lee, S. H., Yoo, S. H., & Kang, M. S. (2009). Estimation of paddy 

rice evapotranspiration considering climate change using LARS-WG. Journal of the Korean 

Society of Agricultural Engineers, 51(3), 25–35 (in Korean). 

IPCC (2007). Climate Change 2007: Climate Change Impacts, Adaptation, and Vulnerability. 

Cambridge University Press, Cambridge. 

Jang, M. W., Chung, H. W., & Choi, J. Y. (2004). Development a single reservoir agricultural 

drought evaluation model for paddy. Journal of the Korean Society of Agricultural Engineers, 

46(3), 17-30 (in Korean). 

Jun, K. S., Chung, E. S., Sung, J. Y., & Lee, K. S. (2011). Development of spatial water 

resources vulnerability index considering climate change impacts. Science of the Total 

Environment, 409, 5228-5242. 

Lee, N. H. (1988). Simulating daily operation of water management system of irrigation 

districts. Ph.D. thesis. Seoul National University, Seoul, Republic of Korea (in Korean). 

MFAFF (Ministry of Food, Agriculture, Forestry and Fisheries) & KRCC (Korean Rural 

Community Corporation) (2011). Statistical yearbook of land and water development for 

agriculture. Uiwang: Korean Rural Community Corporation. 

Perveen, S., & James, L. A. (2011). Scale invariance of water stress and scarcity indicators: 

Facilitating cross-scale comparisons of water resources vulnerability. Applied Geography, 31, 

321-328. 

Yoo, S. H., Choi, J. Y., & Jang, M. W. (2008). Estimation of design water requirement using 

FAO Penman-Monteith and optimal probability distribution function in South Korea. 

Agricultural Water Management, 95, 845–853. 

.

Manuscript Preparation Guidelines for CIGR-Ageng2012 

International Conference of Agricultural Engineering 

Response of sugar cane crop to irrigation sprouting and use of 

organic mulch in soil cover in the cerrado region, Brazil 

Patrick F. Campos 1 , José Alves Jr. 1* , Rogério A. B. Soares 2 , Udo Rosenfeld 2 , P. H. 

P. Ribeiro 3 , A. W. P. Evangelista 1 , Derblai Casaroli 1 

1 Federal University of Goiás, College of Agronomy and Food Eng., Campus II Samambaia, 

74001-970. Goiânia-GO, Brazil. 

2 Jales Machado S.A., Sugar Mill, Goianésia-GO, Brazil. 76380-000. 

*Corresponding author. E-mail: jose.junior@pesquisador.cnpq.br 

Abstrat 

An experiment was conducted in a sugarcane mechanical harvest field in Jalles Machado 

S.A. Sugar Mill in Pirinópolis-GO, Brazil. The soil was a Yellow Red Latossol, and the 

sugarcane crop (3 th harvest) was grown from July 1998 to May 1999. It was evaluated the 

effect of soil cover with organic mulch on yield and quality sugarcane using the SP79-1011 

cultivar with different levels of dry season irrigation (sprouting irrigation of 0, 20, 40, 60 and 

80 mm). The design was randomized block with a bifactorial (5 x 2) and 3 blocks. The 

improvement of irrigation level resulted in a significant yield, sugar increase, stem height. 

The soil cover with straw from mechanical harvest also showed a significant effect in yield, 

sugar increase, stem diameter. 

Key words: Saccharum officinarum, sprinkler system, sprouting irrigation, salvation, 

mechanical harvest 

. 


Brazil is the biggest producer and exporter sugar (34%) in the world, and is the 

second biggest producer and consumer of ethanol (35%), (Kohlhepp, 2010). All this, due to 

the significant increase in area planted with sugarcane in the Brazil, and increased 

productivity, both of cane per hectare (average 75 t / ha), and increased productivity of 

ethanol per ton of cane (Bertrand et al ., 2007). 

Driven by increasing domestic demand for ethanol and depending on the success of 

its export, it is estimated that at least in 10 years, Brazil will have to double the amount of 

sugar cane harvested to offer to internal market. The big challenge is to achieve to 1 billion 

tons of sugarcane harvested, without doubling the area cultivated. For conflicts of interest 

with the production of foodstuffs can be avoided by increasing productivity (Kohlhepp, 2010). 

Current one of the major problems to productivity increase is water deficit in the new 

agricultural frontiers of the country (Cerrado Region). 

In Goiás, the rainfall is characterized by irregularity in the distribution of rainfall, with a 

rainy summer (October to April) and a dry winter (May to September). The need therefore of 

supplemental irrigation of sugar cane in Goiás is obvious and essential, to ensure the growth 

of these stumps of cut cane mainly in the months July, August and September. 

Another way to reduce water deficit is the use of organic mulchs in soil cover. The 

effects of organic mulch on the productivity of cane sugar are cited by Thompson & Wood 

(1967), in studies in South Africa. In Brazil, there are not information about that. With the 

increase in the areas of mechanical harvesting of sugarcane due to environmental pressures 

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and the need to reduce costs, it becomes necessary to increase knowledge about the effects 

of organic mulch on the productivity of cane sugar. 

This study aimed evaluate the response of cane sugar crop to 

different irrigation levels and the use of organic mulch, in Vale do São Patrício in Goiás. 


An experiment was conducted in a sugarcane mechanical harvest field in Jalles 

Machado S.A. Sugar Mill in Pirinópolis-GO, Brazil. The soil was a Yellow Red Latossol 

(Prado, 2003), and the sugarcane crop (3 th harvest) was grown from July 1998 to May 1999. 

It was evaluated the effect of soil cover with straw on yield and quality sugarcane using the 

SP79-1011 cultivar with different levels of dry season irrigation (sprouting irrigation of 0, 20, 

40, 60 and 80 mm. The design was randomized block with a bifactorial (5 x 2) and 3 blocks. 

The climate is classified according to the climatic classification of Köppen (2011), as 

tropical savannah with dry winter and rainy summer (Aw), with an annual average rainfall of 

1540 mm, with a water deficit period well defined, between May and October. 

The experiment was conducted between Jully 24 and 30th,1998. Starting at ten days 

after harvest of second crop, with the application of irrigation at one time, and the harvest of 

the experimental area was on May 28th, 1999. 

The experiment was installed in a complete randomized block with 3 blocks in a 

factorial design 5 x 2, quantitatively and qualitatively, respectively. Five types of irrigation 

level (0, 20, 40, 60 and 80 mm) and two cropping systems (with and without organic mulch), 

totaling 10 treatments. The plots consisted of 18 lines of 15 m in-row spacing of 1.30 m. The 

six central rows were considered useful area of the plot to carry out evaluations. 

Was performed weekly, collecting soil samples for determination of water content at 

depths of 0.0-0.05 m, 0.05-0.10 m, 0.10-0.20 m, and 0.20 to 0.40 m, using the gravimetric 

method, following the methodology proposed by Embrapa (1997). The weed control was 

done as recommended by Procopius (2003) and was performed topdressing in order to 

provide the elements nitrogen, potassium, zinc and boron as recommended by Korndörfer 

(1994). 

At harvest (May 28th, 1999) were counted the total number of stems of the usable 

area of the plot. It was also determined the average weight per stem, collecting and weighing 

six samples of 10 canes per plot. A bundle sampled (per plot) was used for weighing 

technology for analysis. The productivity of the parcel was determined following the 

methodology proposed by Gheller et al. (1999). 

Took advantage of the beams aimed at weighing to quantify the average diameter, 

number of internodes and the average height of stalks. To measure the diameter used a 

caliper, measuring 60 stems per plot. The measurement time was defined as the stem height 

divided by three measured from the base of the stem. To determine when the component 

was measured with a ruler, the average length of the beam. 

The computer program ASSISTAT Beta version 7.6 of Silva (2011) was used for the 

analysis of variance (ANOVA), followed by comparison of means by Tukey method at 5% 

probability levels for qualitative (cropping systems), and regression analysis to the qualitative 

levels (irrigation water). 

Lay-out of area 

75 m 

Block 

75 m 

Treatment 

1.3 m 

Block 2 

Block 1 

140 

m 

23.4 

m 

T 

T 

T 

T 

T 

T 

T 

T 

T 

T1 

23.4 m 

Lines 

avaliable 

Block 3 

15 m 

15 m 



Figure 1. Lay out of the experimental area, especially the treatments distributed within each 

block and available lines of sugar cane within treatments. 


Table 4 presents the data analysis of variance (ANOVA) for each variable. It was 

observed that there were significant differences for weight of stems, yield of cane and sugar 

yield, stems height and diameter of stems when subjected to increasing irrigation level. 

These results are illustrated by the regression curves presented in Table 6. It was also 

observed (Table 1), there was a significant effect on the weight of the straw stems yield of 

cane and sugar yield, moisture, Pol, and stem diameter. In Table 1, it was observed that 

there was no interaction between irrigation and soil cover for the variables evaluated. 

The results of productivity and yield of sugar cane are shown in Table 2 and Table 6. The 

yield of cane sugar was less than 70 t/ha due to irregularity in the distribution of rainfall 

during the period in which the experiment was conducted. 

TABLE 1. Results of analysis of variance (ANOVA) for number and weight of stems, agricultural 

productivity and industrial cane sugar by area. 

SQUARE AVERAGE 

Variation cause 

Fredow 

Weigth of 

Yield of sugar 

Stems / m 

Yield of cane 

degree 

stems 

Irrigation levels 4 0.62558 -- 0.04317 -- 402.93995 -- 10.21767 -- 

Organic mulch 1 0.01531 ns 0.04307** 312.14273 * 2.88116 ns 

Irrig. x Org. mulch 4 0.68954 ns 0.00391 ns 35.49160 ns 0.54313 ns 

Treatment 9 0.58620 ns 0.02571 ** 229.54099 ** 5.10271 ** 

Blocs 2 3.56127 ns 0.00437 ns 236.56535 * 2.39692 ns 

Error 18 0.39432 0.00317 45.22659 1.21203 

Total 29 

SQUARE AVERAGE 

Variation cause Moisture Fiber Pol Diameter Heigth 

Irrigation levels 1.22113 -- 0.78266 -- 0.86944-- 0.02205 -- 1374.05222 -- 

Organic mulch 22.22241 ** 1.61472 ns 1.54587* 0.14100 ** 146.67111 ns 

Irrig. x org. mulch 0.12184 ns 0.10119 ns 0.05418 ns 0.00306 ns 57.79978 ns 

Treatment 3.06603 ** 0.57224 ns 0.58226 ns 0.02683 ** 652.67546 ** 

Blocs 7.37347 ** 0.60817 ns 3.10657 ** 0.00602 ns 671.29255 ** 

Error 0.65223 0.36986 0.26247 0.00614 72.04587 

Total 

* significant at 5% probability ** significant at 1% of probability. 

TABLE 2. Average agricultural productivity of sugar cane and sugar per area 

(3rd harvest) in relation to irrigation water rescue applied in areas with and 

without straw covering soil, Pirinopolis-GO, Brazil. 

Yield cane (t/ha) 

Yield sugar cane (t/ha) 

Treatment With organic 

mulch 

Without organic 

mulch 

With organic 

mulch 


mulch 

No irrigated 51.30 46.90 6.80 6.30 

20 mm 59.00 56.50 8.10 7.90 



40 mm 65.30 59.00 8.70 8.10 

60 mm 67.60 63.40 9.40 9.20 

80 mm 78.10 63.30 10.70 9.10 

Average 64.28 a 57.83 b 8.74 a 8.12 a 

DMS 5,16 0,84 

CV% 11,02 13,06 

* Means followed by same letter are not statistically different from each other. We used the Tukey test at 5% 

probability 

These results are in agreement with the results found by Inman-Bamber (2004). This 

author explains that the water deficit negatively affects the growth of shoots of sugarcane, 

especially leaf production, accelerating senescence and plant as a whole, and may also lead 

to a reduction in radiation interception, the efficiency of use of water and photosynthesis, as 

well as increased radiation transmitted to the soil surface. 

Despite the statistical analysis show that there was no interaction between the effects 

of mulch and irrigation water used (Table 1), the results in Table 5 show the highest yield of 

cane and sugar when the variety SP79-1011 was cultivated under mulch. 

In Table 3 are the data on the number of stems per meter and stem height. No differences 

were seen between the number of stems per meter when subjected to the effect of mulch. 

Furthermore, results shows that significant effects of plant height when the plants were 

subjected to increasing irrigation levels. Showing that water deficit influences significantly the 

height of the stems and consequently productivity. According to some authors, such as 

Inman-Bamber (2004) and Silva et al. (2008), the variation in plant height is an indicator of 

tolerance or susceptibility of cane sugar to water deficit. For this case, the increase in 

irrigation promoted an increase in stem height. The results also agree with Dantas Neto 

(2006), who reported that irrigation water influence of linear and quadratic growth parameters 

and production of sugar cane in the variety SP79-1011. 

TABLE 3. Mean number of stems per meter and stem height (m) for irrigation applied. 

Nº of Stems /m Heigth (m) 

Treatment With organic 

mulch 


mulch 

With organic 

mulch 

Without 

organic mulch 

No irrigated 11.30 10.40 124.78 122.00 

20 mm 11.10 11.20 134.56 146.44 

40 mm 10.80 11.20 151.67 153.56 

60 mm 10.50 11.30 152.89 162.78 

80 mm 12.00 11.40 159.33 160.56 

Average 11.16 a 11.11 a 144.64 a 149.07 a 

STD 0.48 6.51 

CV% 5.64 5.78 


probability. 

. 

The data relating to the stem diameter and weight of stems are in Table 4. Increased 

irrigation did not cause an increase in stem diameter. There was a decrease the stem 

diameter with increasing water depth. Moreover, the results showed a significant difference 

in the diameter of stem. The stem diameters of plants evaluated were higher in the mulch. 

This increase in diameter of stems in the presence of mulch match those obtained by 

Thompson & Wood (1967). The weight of the stems was greater with the increase in the 

irrigation water (Table 6) and in the presence of the mulch (Table 4). 

TABLE 4. Stem diameter of cane sugar (cm) and weight of stems (kg / stem) as a function of 

irrigation levels applied, in areas with and without mulch in Pirinopolis-GO, Brazil. 



DIAMETER (cm) 

WEIGHT (kg/stem) 

Treatment With mulch Without mulch With mulch Without mulch 

No irrigated 2.23 2.03 0.59 0.58 

20 mm 2.15 2.06 0.69 0.65 

40 mm 2.13 2.03 0.78 0.68 

60 mm 2.13 2.03 0.83 0.73 

80 mm 2.09 1.92 0.85 0.72 

Average 2.14 a 2.01 b 0.75 a 0.67 b 

STD 0.06 0.043 

CV% 3.77 7.93 


probability. 

Table 5 shows the data relating to the cane Pol (%), fiber (%) and humidity (%). The 

Pol cane (%) was higher in the treatments without mulch. The opposite was observed by 

moisture (%), which was higher in the treatments with mulch. While the straw did not 

influence the percentage of fiber. These results are consistent with Stupiell (1987), which 

states that water availability, the type of crop, variety, among others, interfere with the 

chemical composition of cane sugar, in its industrial quality. Since the irrigation, had no effect 

on Pol (%) in Fiber (%) and moisture of the cane (%). 

TABLE 5. Chemical and technological characteristics of the stalks of cane sugar, in relation to 

saving irrigation water applied in areas with and without straw in the soil cover in Pirinopolis-GO. 

Treatment 

POL % CANE FIBER (%) MOISTURE (%) 

Without With Without With 

organic organic organic organic 

mulch mulch mulch mulch 

With organic 

mulch 

Without 

organic 

mulch 

No irrigated 13.20 13.47 13.00 13.70 73.10 71.20 

20 mm 13.70 13.95 13.90 14.00 72.20 70.50 

40 mm 13.26 13.72 13.00 13.60 73.00 71.40 

60 mm 13.94 14.56 13.80 14.40 71.80 70.50 

80 mm 13.73 14.39 13.50 13.80 72.80 70.70 

Average 13.56 b 14.02 a 13.44 a 13.90 a 72.58 a 70.86 b 

STD 0.39 0.47 0.62 

CV% 3.71 4.45 1.13 

TABLE 6. Average yield of cane sugar (t / ha), sugar yield, stalk weight, stalk diameter and 

height, in an study using different irrigation levels in areas of cane sugar with and without 

organic mulch (3rd haverst), Pirenópolis-GO, Brazil. 

Yield Cane Y = 0.2552*X+50.845 (R2 = 0,9695**) 

Yield sugar Y = 0.0405*X + 6.806 (R2 = 0.9635 **) 

Weigth stems Y = 0.0026*X + 0.6077 (R2 = 0.9206 **) 

Heigth stems Y = 0.4522*X + 128.77 (R2 = 0.893 **) 

Diameter stems Y = -0.0017*X + 2.1462 (R2 = 0.8202 **) 

CONCLUSIONS 

Under conditions in which the study was conducted, was observed positive response of soil 

covering with organic mulch from mechanized harvesting of SP79-1011 variety of cane sugar 

(third haverst), stem weight, cane yield, productivity sugar, moisture and stem diameter. And 

negative response in Pol (%). Also, was observed a positive response when subjected to 

irrigation levels by sprinkler irrigation in Pirinopolis-GO, Brazil, in yield of cane, sugar yield, 

weight of stems and plant height. And negative response in stem diameter. 



REFERENCES 

BERTRAND, J. P. et al. Le contexte agricole des biocarburants au Brésil. Rumbos, 

Université Toulouse-le-Mirail, 8.9. 2007. Disponível em:

MODELING OF WATER QUALITY PARAMETERS OF 

DISSOLVED OXYGEN AND BIOCHEMICAL OXYGEN DEMAND 

IN THE SUB-BASIN OF POXIM RIVER, BRAZIL 

Anderson. N. do Vasco* 1 , Marinoé G. da Silva 1 , Antenor. de O. Aguiar Netto 1 , 

Neylor A. Calasans Rego 1 , Aderson Soares de Andrade júnior 2 

1 Department of Agronomy, University Federal of Sergipe, São Cristovão - Sergipe, Postal code: 

49100-000, Brazil. 

2 Embrapa Mid-North, PO Box 01, Teresina, PI, postal code 64006-220. 

*Corresponding author. E-mail: anderovasco@yahoo.com.br 

Abstract 

The major cause of scarcity of the water resources, especially in large urban centers, is 

caused by the degradation of water quality; this is because of the inadequate release of 

industrial effluents and domestic sewage. The application of models that consider 

aspects of quantity and water quality are extremely important in case to understand 

and try to solve this problem. Thus, this paper aims are to show how computational 

modeling can be used to assess pollution by sewage water resources in the sub-basin 

of Rio Poxim, contributing in this way to solve environmental problems. To conduct the 

study, we employ the data monitored DO and BOD during the period from July 2009 to 

June 2010, which were inserted in the AcquaNet for calibration and validation. The 

simulations were performed for the current situation, (calibrated) with two scenarios 

increase of 10 thousand and 20 thousand inhabitants in the area of influence. The 

results of parameter calibration and validation of OD showed a good correlation 

between the observed and calculated data, the same can not be observed for the 

parameter BOD. The results show that the parameters DO and BOD present critical 

situations at Station E4 mainly for the month of May where they were observed DO and 

BOD concentrations of 0.0 mg L-1 and 16.52 mg .L-1 with respective population 

increases. Computer modelings allows monitoring of water quality parameters in rivers 

and seek some solutions for that serious problems related to the quality of life and 

environmental health in areas where the risk of contamination by sewage is higher. 

For those reasons it is recommended to study what are the best treatment solutions or 

launch strategy and develop specific levels of monitoring for future situations. 

Key words: Environmental simulation, calibration and validation, AcquaNet program. 


All activity developed by man, bring on directed or undirected ways impacts in 

watershed. Nowadays, the intense population growing and the technological 

development have been causing an intense degradation in the natural resources, 

mainly the water. For those reasons, water resources management has been 

emphasizing as a manner for planning and administrates in a sustainable way the 

multiple uses of the water. Giving assistance to this management, the protection and 

the control of the water resources is also important the use of some tools that make 

possible to analyze the physical, chemical and biological processes that happen in a 

watershed, in a way we can anticipate a scenario and prognosis about the uses of the 

water resources. The math models about water quality can be used as useful tools for 

watershed management, and also as a support for choosing the best method to be 

used. Those tools are used for simulating self - purification processes of the river and 

in consequence, helps to take decisions about the intervention and management 

measures in the watershed.

The mathematical modeling in the water quality emerge in this context as a tool 

of extremely importance in the watershed management process, once this can help 

choosing of management alternatives, with a view to answering of the model to a 

different kinds of residual discharges (RODRIGUES, 2005). 

Originally developed to help in the solution of problems, besides been used to 

minimize the pollution problems, the simulation problems enable a better understand of 

the environment and visualize in an integrated way, whereas the math models 

associate the physical, chemical and biological information. In spite of the city’s growth 

in the last decade has been responsible for the increasing of the pressure in the 

anthropic activities related with natural resources like, the pollution caused by the 

introduction of organic matter (NAGALLI; NEMES, 2009). 

With the launching of human effluent in the water resources, in spite of the 

unpleasant visual aspect, the exhalation of putrescence gas and also the possibility of 

contamination, for its use or contact. There is a reduction in the concentration of the 

oxygen solved in the phase, put at risk the survival of the aquatic organisms 

(SARDINHA et al., 2008). 

The evaluation of the water pollution effects providing of the launching of sewage 

can be done through the monitoring of some chemical parameters related with the 

water quality for example (Dissolved Oxygen) (DO), Biochemical Oxygen Demand 

(BOD). To this end the water quality computational models which contemplates source/ 

sink in these parameters, the transportation all through the water resource and its 

reaction with other substances, are important tools for the environment monitoring, 

which has as a main way of pollution the domestic sewage(BachBACH et al., 1995 ). 

The present article has the objective of analyzing the water quality in the Poxin 

River drainage sub basin using the (DO) and (BOD) parameters relating them with the 

domestic effluents generated for both simulated scenarios, the main reason for it is 

contribute with useful information for management of the resources in this drainage sub 

basin. 


The Poxin River drainage sub basin is located between the geographical 

coordinates 11°01’ and 10°47’ of south latitude, and 37°01’ and 37°24’ of longitude 

west and it is inserting in the metropolitan region of the capital Aracaju. Nowadays 

about 20% of the water is consumed by people in the city is from that drainage sub 

basin, emphasizing the importance of this study in the region. 

The data for this study were provided through 12 sample swabs in 4 monitoring 

places, during the period of July in 2009 to same month in 2010, totalizing one year of 

data. The water samples were collected in the superficial phase, respecting the swab 

and storing procedures, following the hygiene standard and the sample control 

described by AGUDO (1987) and MACÊDO (2003). The analysis respected the 

methodology obeys the Standard Methods for the Examination of Water and 

Wastewater (APHA, 2005). 

2.1 Modelling using the AcquaNet program 

The version 3.16.00 of the AcquaNet program used in this work is divided in 6 

modules. Two of them were applied for calibration and simulation in the Poxim River 

drainage sub basin and in the Poxim-Mirim, Poxim-Açu and Poxim River: The 

allocation module (AlocaLS) and the quality module (QualityLS). The mentioned 

modules will be described in the nest topic. 

2.2 Characteristics of the Quantity and Quality modules.

The quality module (QualityLS) integrated with the AcquaNet program, used to 

simulate the water quality in the rivers, is a unidimentional and considered a permanent 

flux system. It is possible to be considered the punctual launching (the entrance of 

industrial and domestic effluents), simulating the concentrations of DO and BOD total 

coliform bacteria, total phosphorus, algae, organic nitrogen, ammonia, nitrite and 

nitrate (PORTO et al., 2004; TEIXEIRA et al., 2005). 

The rivers or artificial canals which compound the studied water system are 

segmented in some of their parts, those ones are considered by the model as a 

computational element where the transportation mechanisms cargo and also where the 

concentration of components responsible for the quality water are mixed. The hydraulic 

parameters (area section, speed, outflow and the medium height of the waterline) 

should be constants in each part. Each segment represents a controlled volume about 

what the equations that coordinates the mass balance will be applied. 

2.3 The entrance of the quantitative and qualitative data 

The aquanet model requires as entrance the data of outflow and the parameters 

of the water quality. In this present study the simulated parameters were DO and BOD. 

The data used were obtained through the collecting of water samples and the outflow 

measurement in the sub basin Poxim River, made between July 2009 to July 2010. 

The first step for the utilization of AcquaNet software was to build a flux network in 

which we could represent the system of the water resource formed by “nós” and 

“arcos”. The “nós” represent the elements of location in the system like (reservoir, 

demand and confluences) while the “arcos” symbolize the connections among the 

“nós” (the stretch of the river, water supply network, natural or artificial canals and other 

similar elements). After building the network, the quantitative data was inserted for the 

monitoring stretch. 

After that, the entrance of a suitable quantitative data, the next step was the 

entrance of the hydraulic data of each stretch of the rivers, indicated at Table 1. The 

needed data were obtained in the “Atlas de Recursos Hídricos de Sergipe” (SERGIPE, 

2011). 

TABLE 1: Entrance data in the AcquaNet software about the hydraulic conditions in different 

stretch of Poxim-Mirim, Poxim-Açu and Poxim Rivers. 

Hydraulic characteristics adopted 

Attribute Trecho 1 Trecho 2 Trecho 3 Trecho 4 

Stretch Length (km) 4 3 4 4 

smaller base (m) 3 6 15 15 

Canal declivty (m.m -1 ) 0,0002 0,0003 0,0001 0,0001 

Number of Manning 0,03 0,03 0,03 0,03 

River Classification Classe 2 Classe 2 Classe 2 Classe 2 

Altitude da bacia(m) 11 11 10 10 


3.1 Calibration parameters 

It was adopted K1, K2, K3 and K4 variables which better adjusted the relation 

between the DO and BOD observed and calculated by the model. The Table 2 

presents the variable concentration used in the calibration of the drainage sub basin of 

the Poxim River in different studied stretch.

OD (mg L -1 ) 

OD obs (mg L -1 ) 

TABLE 2: Calibrated values for the different parameters used for simulation of DO and BOD in 

AcquaNet software. 

Trechos K1(day -1 ) K2 (day -1 ) K3 (Manual) K4 (g O 2 .m 2 day -1 ) 

1 1,2 0,12 10 0,50 

2 1,2 0,15 10 0,50 

3 1,2 0,12 11 0,50 

4 2,9 0,70 6 0,25 

(a) Parameter BOD decay rate, (b) Parameter BOD sedimentation, (c) Parameter reaeration DO and (d) 

Sediment Oxygen Demand 

3.2 The validation for calibration 

The validation was verified according to the correlation between the variable of 

the DO and BOD coefficients observed and calculated by the model, according to 

Santos’ (2007) classification. The Figure 1 presents the analyzed data. In the months 

of September 2009 to April 2010 wasn’t observed the DO data and these variables 

were not taken in consideration. In the months of July and September in 2009 were not 

observed BOD data and like the previous variable were not taken in consideration too. 

In figure 1 is presenting the correlations between the OD variables observed 

and calculated by the model. The linear correlation coefficients were classified as 

moderate according to Santos (2007). 

In figure 2 is presenting the correlations between the BOD variables observed 

and calculated by the model. The linear correlation coefficients were classified as low 

according to Santos (2007). This parameter presents a big distortion between the 

observed and calculated data. In the months of December 2009 and January 2010 

was founded the biggest differences. The difficulty of BOD calibration is the uncertainty 

associated with the launching of organic cargo in the point 3 from the network. The 

estimative of cargo in the organic effluent cannot be representative. The lapse used for 

each simulation was one month. This lapse undoubtedly turns the calibration process 

for this parameter more difficulty and also reduced the correlation coefficients. A few 

part of the population used in the correlation also contributed for increasing random 

mistakes, according what it was commented DO results. From the statistical point of 

view one cannot consider the calibrated model for BOD, however, even in the 

face of random errors exist, you can use the model for planning given that in 

December the model underestimates the calculation of the concentration on the 

order of 7.2 mg L -1 and overestimates the concentration in the month of January 

in the order of 4.45 mg L -1 . 

Correlação entre dados observados e dados calculados 

8 

7 

6 

5 

4 

3 

2 

1 

0 

jul ago set 

out nov dez jan fev mar abr mai jun 

8 

7 

6 

5 

4 

3 

2 

1 

0 

y = 0,8716x + 0,1744 

R² = 0,763 

R = 0,87 

0 1 2 3 4 5 6 7 

Dados observados 

Dados calculados 

OD cal (mg L -1 ) 

Figure 1 - Correlation between the observed and calculated parameters for the OD, the 

station E4 in the river basin Poxim.

DBO (mg L -1 ) 

DBO obs (mg L -1 ) 

18 

16 

14 

12 

10 

8 

6 

4 

2 

0 

jul ago set out nov dez jan fev mar abr mai jun 

Figure 2 - Correlation between observed and calculated data for the parameter BOD at 

station E4, the sub-basin of the Rio Poxim. 

3. 3 Simulation scenarios for effluent discharge 

4 

y = 0,4649x + 4,2389 

2 

R² = 0,42 

R= 0, 648 

0 

0 2 4 6 8 10 12 14 

Once calibrated model, the water quality can simulate the AcquaNet specific 

conditions of launch of the effluents from the point loads. Simulations were made by 

assigning values of effluents (untreated sewage) launched by Elze Neighborhoods 

Rosa (City of São Cristovão) and Parque dos Faróis,Tijuquinha and Pai André (City of 

Nossa Senhora do Socorro) together, for two different scenarios where were taken 

loads "per capita", taking into account an increase in the overall population of 10 000 

and 20 000 inhabitants in all neighborhoods. The values for volume of effluent released 

were determined using data in the literature (VON SPELING 2006), in that the volume 

of organic effluent (drain) of the population can be estimated by the product of the per 

capita consumption of water (q) and coefficient return drain (c), as shown in Table 3 

TABLE 3: Typical values of consumption "per person" for people endowed with 

household connections according to population size. 

Faixa da população Consumo per capita- q Coeficiente de retorno de 

Porte da comunidade 

(hab.) 

(l/hab.dia) 

esgoto (c)** 

Povoado rural < 5.000 90-140 0,80 

Vila 5.000 -10.000 100-160 0,80 

Pequena localidade 10.000 - 50.000* 110-180 0,80 

Cidade média 50.000 - 250.000 120-220 0,80 

Cidade Grande >250.000 150-300 0,80 

* Value adopted for the region; ** Value recommended by the NBR 9649 (ABNT, 1986) when 

there are no data from local research. Source: Von Sperling (2006). 

The volumes of effluent organic "calculated" for scenarios 1 and 2, whereas 

increases of 10 and 20 thousand inhabitants (0.014 and 0.028 m3 s-1, respectively) 

were inserted every month throughout the evaluation period the program AcquaNet. 

Thus we could analyze the behavior of the concentrations of DO and BOD during the 

year, the control point (station S4). Simulations of the concentrations of DO and BOD, 

as parameters to evaluate the environmental pollution at station S4 show the impacts 

on water quality considering the population growth and its implications for pollutant 

loads. A summary of RE and BOD concentrations simulated can be seen in Figure 3 

16 

14 

12 

10 

8 

6 

Correlação entre dados observados e dados calculados 

Dados observados Dados calculados DBO cal (mg L -1 )

OD (mg L -1 ) 

DBO (mg L -1 ) 

8,00 

7,00 

6,00 

5,00 

4,00 

3,00 

2,00 

1,00 

0,00 

Período 

Chuvoso 

Período 

Seco 

Período 

Chuvoso 


17,50 

15,00 

12,50 

10,00 

7,50 

5,00 

2,50 

0,00 

Período 

Chuvoso 

Período 

Seco 

Período 

Chuvoso 


População atual (Calibrado) 

Aumento da População 10000 hab 

População atual (Calibrado) 


Limite CONAMA 357/05 


Limite CONAMA 357/05 


Figure 3: Concentration of the parameter OD simulated for two scenarios for release of organic 

effluent in the river basin Poxim. 

Through the figure 3 we can infer that the current condition of water resources 

at the station S4 was crucial for the parameters DO and BOD, more specifically 

between the months of November 2009 to June 2010 where concentrations were 

below the minimum value for OD and above the maximum value for BOD, as defined in 

the Resolution CONAMA 357/2005, reflecting a major problem in maintaining water 

quality in Class 2 frame. The presence of organic sewage water triggers processes 

organic matter decomposition, and proliferation of microorganisms and oxygen 

depletion (BRANCO, 1993; Pelczar JR. et al., 1996; VON SPERLING, 2005). 

According to the CONAMA Resolution 357/2005 laying down the limits of parameters 

or indicators for water intended for domestic supply and primary contact recreation, the 

DO concentrations should not be less than 5 mg L -1 O2 and should not be more than 5 

mg L -1 BOD. From these limits can be set by the responses obtained by the model, 

which months are more problem with the water quality and also check the influence of 

the increased release of effluent (untreated), associated with increased population, 

water quality. It was observed that the end of the dry season, specifically in the month 

of March, had the lowest DO concentrations (0.0 mg L -1 to March) and higher 

concentrations of BOD (16.39 and 16.62 mg L -1 for scenarios 1 and 2, respectively). 

The influence of sewage discharge commits more steeply (greater amplitude 

between the different scenarios) the water quality in the dry season, this can be 

explained, as understood in this period is the lowest flow rates causing a higher 

concentration of these parameters in place. The model indicates that the increase in 

population further compromises the quality of water. Knowing the magnitude of the 

impact caused by the increased organic load effluent is essential to the planning of 

collection systems and treatment of domestic sewage since this population should be 

achieved in a short time interval. The amount of investment and time of development of 

infrastructure to be made in the basin may be indicated by the simulation model of 

water quality. 


The model of analysis of water quality program AcquaNet was adequate as a 

tool to aid decision making for management and planning of water resources. Despite 

the short series of data obtained, it was considered that the model was successfully 

calibrated for the parameters DO and BOD in the drained basin of Poxim River. 

The simulations indicated that degradation of water quality in the basin was 

influenced by the organic loading point releases. The DO and BOD concentrations 

were higher in the dry season probably due to less dilution effect. 

The simulation results showed that there is a decrease in water quality with 

population increases, the month of March being the most critical parameters for DO 

and BOD at station S4. 

The simulated values show that the parameters DO and BOD did not meet the 

standards of CONAMA 357/2005, 2009 to June 2010.

From the results obtained with the simulation of water quality of the basin Poxim 

River, one can say that immediate investment is needed in collecting and treating 

sewage in order to be improved sanitary conditions in the watershed. 

5. Bibliographical references 

AGUDO, E. G. Companhia de Tecnologia de Saneamento Ambiental. Guia de coleta e 

preservação de amostras de água. 1º ed. São Paulo. 1987. 150p. 

ALVES, J. P. H., GARCIA, C. A. B. Qualidade da água. In: Diagnóstico e avaliação ambiental 

de sub-bacia hidrográfica do Rio Poxim. Relatório Interno UFS/FAPESE, Aracaju, 

2006. 

APHA. AMERICAN PUBLIC HEALTH ASSOCIATION. Standard Methods for Examination of 

Water and Wastewater. 20th Edition, 2005. SMEWW 9222 A, B, C, D, E. 

ARAÚJO, S. C. S. Modelos de simulação baseados em raciocínio qualitativo para 

avaliação da qualidade da água em bacias hidrográficas. 2005. 218 f. Tese 

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Sanitária e Ambiental. 452 p. 2005.

Effect of Rice Straw Mulch on Runoff and NPS Pollution Discharges 

from a Vegetable Field 

Joongdae Choi 1* , Min-hwan Shin 1 , Ji-seong Yoon 1 , Jeong-ryeol Jang 2 

1 Dept. of Regional Infrastructures Eng., Kangwon Nat’l Univ., Chuncheon, 200-701, Korea 

2 Rural Research Institute, Korea Rural Corporation, Ansan, 426-908, Korea 

*Corresponding author. E-mail: jdchoi@kangwon.ac.kr 

Abstract 

Six runoff plots of 5x22 m in size were prepared to investigate the effect of rice straw mat 

mulch on runoff and agricultural non-point source (NPS) pollution discharges from mild 

sloped vegetable fields in 2011. Radish and Chinese cabbage were cultivated in spring and 

fall, respectively. Experimental treatments were control, rice straw and rice straw mat cover. 

The cover rate of the straw and straw mat after the treatment was 64.7% and 73.7%, 

respectively. Each treatment was duplicated. Sixteen rainfall events were monitored and the 

effect of the straw mulch was analyzed. Annual runoff reduction of straw and straw mat was 

26.9% and 55.1%, respectively. And annual NPS pollution reduction by straw and straw mat 

mulch was 38.6% and 67.2%, respectively. It was concluded that straw and straw mat mulch 

could reduce both runoff and NPS pollution loads from vetable fields. And it was also 

recommended that government incentives for farmers to adopt the residue mulch be 

encouraged. 

Key words: Rice straw mat, runoff plot, water quality, NPS pollution, vegetable field. 


Agricultural NPS pollution has been acknowledged as one of the major pollution sources in 

Korea. Various best management practices (BMPs) to control and reduce the pollution has 

been applied to upland fields, specially in the highland sloping fields. The sloping fields 

composed mostly of sandy and sandy loam soils and rainfall intensity is quite high, and thus, 

heavy muddy runoff and NPS pollution occurs during moonson season. Most of these BMPs 

are not to target to reduce runoff and NPS pollution at fields (source) but to treat runoff 

discharged from fields or stabilize the peripheral areas of the fields. Cement concrete 

drainage channels, small sediment traps and basins, gabion walls and levy slope 

stabilization are typical examples of the BMPs. These structural BMPs are not effective in 

terms of reduction of runoff and NPS pollution. Vegetated filter strips, vegetated waterways 

and riparian buffer strips also have tried. However, these practices are not well adopted by 

farmers because the size of individual land is generally small not to accomodate such 

practices. No-till practice is known as one of effective BMPs that could reduce runoff at the 

source but it does not fit well to vegetable farming that generally requires conventional 

plowing and growth bed preperation. It is necessary to develop effective practices that could 

reduce runoff, soil erosion and NPS pollution load from the sloping fields. One of the 

methods that could reduce runoff at the fields is surface mulch with crop residues. Because 

vegetables do not leave stable residues that could be used as residue cover, other residue 

cover materials need to be introduced and tested for the reduction of runoff and NPS 

pollution. The authors and colleagues have been tested the effect of rice straw and rice straw 

mat on the reduction of runoff, soil erosion and NPS pollution discharge from sloping fields 

(Choi et al., 2009; Shin et al., 2009; Shin et al., 2010; Won et al., 2011). However, these 

studies were carried out in a laboratory scale and could not measure runoff and NPS 

pollution load under field scale experiments. The objective of this research was to evaluate

the effect of rice straw mulch and rice straw mat mulch on the reduction of runoff and NPS 

pollution discharges from field scale runoff plots under natural rainfall conditions. 

2. Methods 

Six runoff plots of 5x22 m in size were prepared in an existing sandy loam field of about 3% 

slope. A flume, water level meter and water sampler was installed at the lower bottom of 

each plot to measure runoff and collect water samples during rainfall-runoff events. Three 

treatments of control, rice straw mulch and rice straw mat mulch were applied right after 

plowing and growth bed preparation. Each treatment was duplicated. The size of rice straw 

and rice straw mat that was applied to the runoff plot was 3,409 kg/ha and 3,136 kg/ha, 

respectively. And the resulting residue cover rate of the soil surface was 64.7% and 74.7%, 

respectively. Spring radish and fall Chinese cabbage were cultivated and runoff and selected 

NPS pollution was measured under sixteen natural rainfall-runoff condition in 2011 growing 

season. Sixteen rainfall events were monitored with respect to runoff and concentration of 

selected NPS pollutants. Collected water samples were analyzed with respect to SS, TN and 

TP concentration by the relevant standards. And the effect of the sresidue mulch on the 

reduction of runoff and NPS pollution load was analyzed. 


3.1. Rainfall characteristics 

Thirty year (1981~2010) average annual rainfall of the study area was 1,298.7 mm which 

was a little smaller than the national average of 1,307.7 mm. Frequency of heavy rainfall of 

100 mm/day or higher was 1.5 times per year. Total rainfall amount of the heavy rainfall took 

about 17% of the total rainfall. Annual rainfall of the study area in 2010 and 2011 was 

1,476.4 mm and 2,029.1 mm, respectively, which was greater than average. In 2011, rainfall 

frequency of 50 mm/day and 100 mm/day or higher occurred 10 and 3 times, respectively. 

Rainfall in 2011 was exceptionally higher than other years. It might mean that runoff and 

NPS pollution discharge could be larger in 2011 than other years because of the large 

annual rainfall. 

3.2. Runoff rate 

The size of rainfall events during the study ranged from 12.8 mm to 538.2 mm. Runoff during 

the events was 0.02-39.6 m 3 from control, 0-37.4 m 3 from straw mulch, and 0-26.6 m 3 from 

straw mat mulch plots. Runoff rate of the 16 runoff events ranged between 0.01-0.67 

(control), 0-0.63 (straw mulch), and 0-0.45 (straw mat mulch). Annual average runoff rate 

from control, straw mulch and straw mat mulch was 0.409, 0.299, and 0.184, respectively. 

These results were smaller than the results of Shin et al. (2011) who performed similar 

experiment with straw mat and wood shavings. It was thought that the large rainfall in 2011 

increased the runoff rate in general. Reduction of runoff by straw and straw mat mulch 

ranged 5.4-99.7% (annual average 26.9%) and 32.9-100% (annual average 55.1%), 

respectively, compared to that of control plots. The annual average reduction of runoff was 

somewhat less than expected because of large and heavy rainfall in 2011. However, it was 

thought that the straw mulch effectively covered the soil surface, prevented the soil from 

clogging, and helped keep infiltration high, compared to control plots. Residue cover rate of 

straw mulch was lower than that of straw mat because the straws at the top of the ridge 

moved down to furrow during the growing season. Because of this, runoff reduction was 

larger in the straw mat mulch plots than in the straw mulch plots. The same trend also 

observed in NPS pollution reduction. 

3.3. NPS pollution 

Average EMC (event mean concentration) of SS, TN and TP from control plots was 490.7 

mg/L, 16.2 mg/L, and 1.4 mg/L, respectively. Average EMC from straw mulch was 289.9

mg/L, 14.6 mg/L, and 1.2 mg/L, respectively. And the EMC from straw mat mulch was 140.0 

mg/L, 12.1 mg/L, and 1.2 mg/L, respectively. Average EMCs from mulched plots seemed 

lower than those from control plots. However, the EMCs were not significantly different at the 

level of 5%. NPS pollution load was computed by multiplying the EMC and runoff volume. 

Annual SS, TN and TP loads from control plots were 1,463.3 kg/ha, 75.1 kg/ha, and 10.4 

kg/ha, respectively. Annual SS, TN and TP loads from straw mulch plots were 702.5 kg/ha, 

53.7 kg/ha, and 6.7 kg/ha, respectively. And annual SS, TN and TP loads from straw mat 

mulch plots were 295.3 kg/ha, 23.8 kg/ha, and 4.8 kg/ha, respectively. Reduction of SS, TN 

and TP loads from straw mulch plots was 52.0%, 28.5%, and 35.2%, respectively, compared 

to those of control plots. And reduction of SS, TN and TP loads from straw mat mulch plots 

was 79.8%, 68.3%, and 53.3%, respectively. It was concluded that the effect of straw mulch 

and straw mat mulch could help reduce muddy runoff and improve water quality of receiving 

waters downstream even under a heavy rainfall condition in 2011. It was thought that if the 

rainfall in 2011 was similar to the average annual rainfall, the NPS load reduction would be 

much higher than those in 2011. 

3.4. Productivity 

Leaf length, number and weight, and root stock and weight were measured at radish harvest 

and yield was measured. Radish yield from control, straw mulch, and straw mat mulch plots 

was 2,227 kg/10a, 3,050 kg/10a, and 3,126 kg/10a, respectively. It means that straw mulch 

and straw mat mulch increased the radish productivity 37% and 40%, respectively. For fall 

cabbage cultivation, cabbage yield from control, straw mulch, and straw mat mulch plots was 

12,123 kg/10a, 12,927 kg/10a, 13,849 kg/10a, respectively. Productivity increase of cabbage 

by straw and straw mulch was 6.6% and 14.2%, respectively. The weather condition of the 

study site was not favourable for vegetable cultivation because of large rainfall and resulting 

lack of sunshine duration. And the radish and cabbage yield were less than the national 

average. However, it could be concluded that straw and straw mat mulch could increase 

yield even under unfavourable weather condition and reduce NPS pollution discharges 

significantly. 

One of very important issues in Koran rural communities is aging. Farming practices are 

mostly carried out by aged farmers and farm machineries. For those aged farmers, small 

productivity increase by the residue mulch might not be the cause to adopt the practice. 

Adoption and practice of crop residue mulch should be approached from the standpoint of 

environmental protection. And it is seriously considered that government incentives as a 

subsidy to improve water quality might be endowed farmers who adopt the practice. 


The effect of straw mulch and straw mat mulch was investigated under natural rainfall 

condition in 2011. Sixteen rainfall-runoff events ranging from 12.8 mm to 538.2 mm were 

monitored. Rainfall in 2011 was 2,029.1 mm that was much larger than the average and the 

weather was not favourable to vegetable cultivation. Annual reduction of runoff by straw and 

straw mat mulch was 26.9% and 55.1%, respectively. Average EMCs from mulched plots 

seemed lower than those from control plots but they were not significantly different at the 

level of 5%. Reduction of SS, TN and TP from straw mulch plots was 52.0%, 28.5%, and 

35.2%, respectively. And reduction of SS, TN and TP from straw mat mulch plots was 79.8%, 

68.3%, and 53.3%, respectively, compared to those of control plots. Yield of radish and 

cabbage increased with the straw mulch. Radish yield from straw mulch and straw mat mulch 

increased 37% and 40%, respectively. Increase of cabbage yield was 6.6% and 14.2%, 

respectively. It was concluded that straw and straw mat mulch could increase vegetable yield 

and reduce NPS pollution discharges significantly. It was also recommended that 

government incentives for farmers to adopt straw mulch practices be seriously considered.

Acknowledgements: The research was partly supported by the Korea AgBMP program 

administered by the Rural Research Institute and Kangwon National University. The authors 

appreciate their generous support. 

References 

Choi, Y. H., Won, C. H., Seo, J. Y., Shin, M. H., Yang, H. J., Lim, K. J., & Choi, J. D. (2009). 

Analysis and comparison about NPS of plane field and alpine field. Journal of Korean Society 

on Water Quality, 25(5), 682-688. (in Korean) 

Shin, M. H., Won, C. H., Choi, Y. H., Seo, J. Y., Lee, J. W., Lim, K. J., & Choi, J. D. (2009). 

Simulation of field soil loss by artificial rainfall simulator -by varying rainfall intensity, surface 

condition and slope-. Journal of Korean Society on Water Quality, 25(5), 785-791. (in 

Korean) 

Shin, M. H., Won, C. H., Choi, Y. H., Seo, J. Y., & Choi, J. D. (2010). Simulation of generable 

nutritive salts by artificial rainfall simulator in field -by varying amount of fertilization and 

slope-. Journal of the Korean Society of Agricultural Engineers, 52(3), 31-38. (in Korean) 

Shin, M. H., Won, C. H., Park, W. J., Choi, Y. H., Jang, J. R., Lim, K. J., & Choi, J. D. (2011). 

Analysis of the reduction effect on NPS pollution loads by surface cover application. Journal 

of the Korean Society of Agricultural Engineers, 53(4), 29-37. (in Korean) 

Won, C. H., Shin, M. H., Choi, Y. H., Shin, J. Y., Park, W. J., & Choi, J. D. (2011). 

Applications of surface cover materials for reduction of soil erosion. Journal of Korean 

Society on Water Quality, 27(6), 848-854. (in Korean)

1 

PAPAYA SEEDLINGS PRODUCTION FROM SOIL GROUP AND FORMOSA 

GENOTIPS UNDER WATER LEVELS IN SOIL 

Evandro Franklin de Mesquita 1 Lúcia Helena Garófalo Chaves 2 Flaviana de Andrade Vieira 1 . 

1 Universidade Estadual da Paraíba, Departamento de Agrárias e Exatas, Campus IV, Catolé do Rocha-PB; 

2 Universidade Federal de Campina Grande, Campus I, Campina Grande-PB. 

ABSTRACT: The term economy of water in the agriculture doesn't mean obligatorily they be 

supplied to the plants smaller volumes than demanded they mean them more properly than the 

applied amount is efficiently used by the culture. In this direction, an experiment was carried out in 

order to evaluate the effects of water levels in soil on seedlings formation papaya tree from group 

Soil and Formosa. The treatments were distributed in delineation completely randomized using the 

factorial design 5x2 referring to values of soil content at levels of 60, 70, 80,90 and 100% field 

capacity of the soil and the papaya tree from Soil and Formosa group. The plants irrigation was 

made by weighing process supplying daily each experimental unit with water volume transpired by 

plants in each studied treatment. The substratum was constituted of a mixture of 2 kg of soil 

material + earthworm humus in the proportion of 1:1 v/v, conditioned in black polyethylene bags 

with 15 cm of diameter and 30 cm of height. The sowing consisted of four seeds for experimental 

unit and to 25 days after the emergency of normal seedlings took place the rough-hewing, just 

staying the most vigorous seedling. The analyzed variables were: Height, stem diameter, number of 

leaves, dry matter of the aerial part, of roots and total of the plants and relationship between dry 

matter date of root and aerial part. From results the highest values of height, diameter of stem 

and leaves emitted were obtained from the substrate with humidity between 85 and 100% of field 

capacity in both genotypes.The values of dry biomass of shoots, roots and dry biomass ratio of root 

/ shoot increased with moisture in the substrate, with supremacy of the Solo on the Formosa papaya. 

Papaya Formosa develops more shoot and yields root dry matter less than the genotypes Solo. 

Key words: Carica papaya. growth of seedlings. water in the soil. 

INTRODUCTION 

Papaya (Carica papaya L.) occupies a prominent place in the national fruit and the states of 

Bahia, Espírito Santo and Rio Grande do Norte were the largest producers and exporters in the 

country. The cultivars most commonly planted in Brazil belong to Solo and Formosa groups. 

Productivity and quality of papayas depend on the cultivation of plants exempted from 

obtaining seed to seedling production. Among the factors that may affect the production of 

seedlings of good quality, are the control or irrigation, seed quality, fertilizer and substrate used, 

since they contribute to better development and health of plants (Yamanishi, 2004). 

The nutrient supply is directly associated with the water supplied need for irrigation since 

excess promote rinsing of the substrate and consequent leaching of nutrients. On the other hand,

2 

insufficient irrigation influence seedling growth due to the nutritional imbalances and may also 

increase the salinity of the substrate by increasing the concentration of the fertilizer (Santos, et al., 

2010a) 

Irrigation is an essential technique in the greenhouse, however, inadequate management of the 

water supply can impair the production of seedlings. Thus, the production of quality seedlings in the 

state of Paraiba, depends on the application of an appropriate volume to genotype Solo and Formosa 

during the initial growth for the sustainable production of seedlings. The adoption of irrigation 

water suitable for irrigation can maximize the profits of papaya fruit (Lyra et al., 2010). 

This work aimed to evaluate the effect of different levels of soil water in the production 

of papaya seedlings of Solo and Formosa groups. 

MATERIALS AND METHODS 

The survey was carried out under greenhouse conditions on the State University of Paraiba, 

Catole do Rocha, State of Paraíba, Brazil (6°2’38”S; 37°44’48”W; 275 a.s.l.) from March 19 to May 12, 

2010. The experiment was conducted in a completely randomized design in factorial 

arrangement 5x2, corresponding to five water levels (60, 70, 80, 90 and 100% of substrate field 

capacity) and two genotypes of papaya Solo and Formosa group, with three replicates. Irrigation 

was made based on the weighing process, providing the daily amount of water corresponding to 

each treatment. 

The substratum was constituted of a mixture of 2 kg of soil material + earthworm humus in 

the proportion of 1:1 v/v, conditioned in black polyethylene bags with 15 cm of diameter and 30 cm 

of height. The chemical attributes are shown in Table 1. 

Table 1. Resultados da análise química do solo e húmus de minhoca utilizados no substrato para obtenção de 

mudas de mamoeiro. 

pH P K Ca Mg Al H Na BS CEC OM 

H 2 O ..mg dm 3 .. ............................cmol c dm 3 .............................. g/kg 

Soil 7,15 5,5 109 3,85 2,01 0,0 0,0 0,30 6,44 6,44 8,1 

Humus 7,38 55 551 35,40 19,31 0,0 0,0 57,95 57,9 57,9 - 

BS= base sum (Ca 2+ + Mg 2+ + K + + Na + ); CEC = cation exchange capacity; OM= organic matter 

At 55 days after sowing, maintaining only one seedling per experimental unit were 

evaluated the number of leaves, height of seedlings from the cervix to the apical bud, and stem 

diameter. Then the shoot (stem + leaves) of each seedling was separated from the roots and put

3 

into an oven with circulating air at a temperature of 65 o C until constant weight to obtain dry 

biomass of shoots and roots. 

The results were subjected to analysis of variance and polynomial regression using the 

software System for Analysis of Variance – SISVAR. 

RESULTS AND DISCUSSION 

Water levels and the interaction of soil water levels and genotypes (Table 2) hadsignificant 

effects on all variables. This situation shows different behaviors among the genotypes as water 

requirements during the initial growth. 

Table 2. Summary of variance analysis of height (H), stem diameter (SD), leaf number (LN), shoot 

dry matter (SDM), root dry matter (RDM), total dry matter (TDM) and root/shoot ratio (R/S) in 

papaya seedlings from the Solo and Formosa group, 55 days after emergence. 

Sources of 

Mean Square 

variation DF H SD LN SDM RDM TDM R/S 

Water level 

(WL) 

4 161,99** 10,31** 4,96** 0,29** 14,48** 16,92** 2,45** 

Genotype (G) 1 3,24ns 1,31ns 2,70* 0,11 ns 12,63** 15,15** 2,12** 

WL x G 4 23,90* 5,12** 1,03** 0,44** 3,55** 3,98** 0,86** 

Residue 18 6,58 0,35 0,43 0,03 0,71 0,85 0,13 

CV 21,45 6,06 9,54 8,11 18,93 13,93 17,92 

*, **, ns, Significant at 5 and 1% (F test) and no significant, respectively 

The increased level of water in the soil stimulated the growth in height of the genotypes; 55 DAS 

seedlings of Solo and Formosa reached the greatest heights of 32.48 and 31.82 cm in soil with 93% and 

100% moisture of field capacity, respectively (Figure 1), corroborating Posse et al. (2009). However, at 

55 DAS, the seedlings irrigated with 60% of field capacity, had already reached the 

recommended ideal height to transplant in situ, ie, 15 cm as Soares (1998). 

Even accepting the small difference between the heights of seedlings (32.48 cm 

and 31.82 cm), corresponding to only 2.1% at the heights, the economy of water was 7% 

compared seedling Formosa with Solo. However, the heights of seedlings with 100% of field 

capacity, in this study were lower than the height of 43.83 cm, corresponding to changes 

of Baixinho de Santa Amália, grown under optimal soil moisture up to 34 DAS (MAHOUACHI et 

al., 2006).

4 

Height of seedlings (cm) 

35 

30 

25 

20 

15 

10 

5 

y = -0,0042x 2 + 0,9003x - 16,201 

R 2 = 0,9622 

y = -0,0147x 2 + 2,728x - 94,055 

R 2 = 0,8967 

Solo 

Formosa 

0 

60 70 80 90 100 

Available water in soil (%vol) 

Figure 1. Height of seedling of papaya Solo and Formosa group as a function of available water in soil 

The increase in soil moisture stimulated the development of stem diameter of seedlings of 

both genotypes (Figure 2). Genotype in Solo, the stem diameter increased linearly to the level of 

0.1364 mm by increasing unitary of soil moisture in relation to field capacity reaching the highest 

value of 12.8 mm in the soil with moisture kept equal to 100% field capacity. This treatment 

exceeded by 74.8, 47.1, 20.8 and 11.9% regarding irrigation to maintain soil moisture levels of 60, 

70, 80 and 90% field capacity, respectively. The stem diameter of genotype Formosa increased as a 

function of moisture reaching the maximum value of 10.47 mm with treatment maintained the 

moisture de100% of field capacity, however, the deficit and excess water affected the number of 

seedlings of both genotypes. These higher results observed in the genotypes Formosa and Solo 

were above 7.6, 7.4, 7.9 and 9.0 mm obtained by Cavalcante et al. (2010), Negreiros et al. (2005), 

Medeiros et al. (2008) and Araújo et al. (2010). However were lower than 12 mm and 16.4 

mm recorded by Souza et al. (2007) and Melo et al. (2007) with cultivars Formosa and Baixinho 

Santa Amalia, respectively. The stem diameter of seedlings Solo and Formosa was greater than 9.79 

cm observed by Mahouachi et al. (2006) with seedlings of the cultivar Baixinha Santa Amalia, 

subjected to water stress.

5 

14 

12 

Stem diameter (mm) 

10 

8 

6 

4 

2 

y = 0,1364x - 0,844 

R 2 = 0,9785 

y = -0,0006x 2 + 0,137x + 2,7719 

R 2 = 0,9315 

Solo 

Formosa 

0 

60 70 80 90 100 


Figure 2. Stem diameter of seedling of papaya Solo and Formosa group as a function of available water in 

soil 

The issue of seedling leaves of both genotypes increased as a function of soil 

moisture (Figure 3). However, according to the results, the genotype Formosa, during 

the formation of seedlings, was less water demanding than the Solo issuing eight leaves on the 

ground with moisture content of 85.2% compared to 7 sheets of Solo, with 89.1% in the 

soil moisture level of the field capacity. Moisture levels in the substrate above the values 

listed inhibit leaf emergence in plants of both genotypes. This situation indicates that the water 

excessive causes loss of breath with negative consequences on the absorption and nutrients, and 

indeed, in the production of treated organic (Taiz & Zeiger, 2008), resulting in inhibition of growth 

and the quality loss of the seedlings. 

The number of leaves of the seedlings in this study were similar to 7-8 leaves and 8-9 leaves 

found on seedlings belonging to the Formosa group, which reached at the time, 25 DAS (Garcia et 

al., 2007) and time of 60 DAS (Mendonça et al., 2004), respectively. 

Number of leaves of the seedlings issued by Solo was similar and Formosa, more to 7 

sheets per seedlings obtained by Medeiros et al. (2008), testing level nitrogen and sources 

in Hawaii papaya seedlings.

6 

Number of leaves 

9 

8 

7 

6 

5 

4 

3 

2 

1 

0 

y = -0,0024x 2 + 0,4276x - 11,895 

R 2 = 0,9286 

y = -0,0043x 2 + 0,7324x - 23,105 

R 2 = 0,9894 

60 70 80 90 100 

Solo 

Formosa 


Figure 3. Number of leaves of papaya Solo and Formosa group as a function of available water in soil 

The dry matter accumulation by shoots of seedlings increased as a function of soil moisture, 

up to an estimated level of 83.2% with 2.3 g per seedling in genotype Solo and 2.6 g per seedling in 

the soil with 100% field capacity by a Formosa of papaya seedlings (Figure 4). In general, the 

accumulated water deficit caused the temporary wilting at times of higher temperature of some 

plants, affecting their physiology and consequent decrease in biomass production. 

3,0 

Shoot dry matter (g plant -1 ) 

2,5 

2,0 

1,5 

1,0 

0,5 

y = -0,0005x 2 + 0,1035x - 2,9739 

R 2 = 0,93 

y = -0,001x 2 + 0,1667x - 4,3574 

R 2 = 0,8585 

Solo 

Formosa 

0,0 

60 70 80 90 100 

Available water in soil (% vol) 

Figure 4. Shoot dry matter of seedling of papaya Solo and Formosa group as a function of available water in 

soil 

Except for treatment with humidity at 100% of field capacity, where the values are similar 

between the two genotypes, the Solo papaya plants produced more dry mass of roots with 

increasing soil moisture in relation to Formosa (Figure 5). Comparing the values shown in Figures 4 

and 5 showed that both genotypes produce more dry roots (2.6 and 2.3 g seedlings -1 ) that shoot 

(6.1 and 6.2 g seedlings -1 ).

7 

Root dry matter (g plant -1 ) 

8 

7 

6 

5 

4 

y = 0,0025x 2 3 

- 0,2981x + 10,931 

R 2 = 0,915 

2 

y = -0,0017x 2 + 0,3454x - 11,336 

1 

R 2 = 0,8495 

0 

60 70 80 90 100 


Solo 

Formosa 

Figure 5. Root dry matter of seedling of papaya Solo and Formosa group as a function of available water in 

soil 

The data of total dry matter of papaya Solo group until the level of soil moisture of 96% of 

field capacity were significantly higher than the data of Formosa group (Figure 6). The behavior of 

these data was similar to those observed by roots of plants. In both genotypes, the highest values 9.2 

and 8.3 g plant -1 obtained in the treatment of 100% and 96% soil moisture were higher than 2.28, 

2.16, 1.63, 0,53 and 2.18 g plant -1 obtained by Costa et al. (2005), Negreiros et al. (2005), Melo et 

al. (2007), Kusdra et al. (2008) and Hafle et al. (2009) in papaya Solo and Famosa group in 

different substrates and volumes. 

Total dry matter (g plant -1 ) 

10 

9 

8 

7 

6 

5 

y = 0,0019x 2 - 0,1679x + 7,0262 

4 

R 2 = 0,9725 

3 

2 

1 

y = -0,0026x 2 + 0,4992x - 15,658 

R 2 = 0,9271 

0 

60 70 80 90 100 


Solo 

Formosa 

Figure 6. Total dry matter of seedling of papaya Solo and Formosa group as a function of available water in 

soil

8 

The relationship between the values of dry matter of roots with the shoots of seedlings 

increased with the humidity of the substrate, with the highest ratio in seedlings of treatments with 

humidity of 100% of field capacity, with the highest values of 3.35 and 3.41 g g -1 for the genotypes 

Formosa and Solo (Figure7), respectively. These values express the inadequate proportion between 

the development of roots and shoots of seedlings. According to Daniel et al. (1997) appropriate 

values of the relative mass of roots/ shoots mass must be situated around 0.50 or 50%. Values in 

this range are indicative of chemical and physical conditions of substrates appropriate to plant 

growth. 

3,5 

Relation root/ shoot (g g-1) 

3,0 

2,5 

2,0 

1,5 

1,0 

y = 0,0004x 2 - 0,0219x + 0,9173 

R 2 = 0,9531 

Solo 

0,5 

y = -0,0009x 2 + 0,1967x - 7,2949 

R 2 = 0,9179 

Formosa 

0,0 

60 70 80 90 100 


Figure 7. Relation root/shoot of seedling of papaya Solo and Formosa group as a function of available water 

in soil 

CONCLUSION 

The highest values of height, diameter of stem and leaves emitted were obtained from 

the substrate with humidity between 85 and 100% of field capacity in both genotypes. 

The values of dry biomass of shoots, roots and dry biomass ratio of root / shoot increased with 

moisture in the substrate, with supremacy of the Solo on the Formosa papaya. 

Papaya Formosa develops more shoot and yields root dry matter less than the genotypes Solo. 

REFERÊNCIAS BIBLIOGRÁFICAS 

ARAÚJO, W. B. M.; ALENCAR, R. D.; MENDONÇA, V.; MEDEIROS, E. V.; ANDRADE, R. 

C.; ARAÚJO, R. R. Esterco caprino na composição de substratos para formação de mudas de 

mamoeiro. Ciência e Agrotecnologia, Lavras, v. 34, n. 1, p- 68-73, 2010.

CAVALCANTE, L. F.; CORDEIRO, J. C.; NASCIMENTO, J. A. M.; CAVALCANTE, I. H. L.; 

DIAS, T. J. Fontes e níveis da salinidade da água na formação de mudas de mamoeiro cv. Sunrise 

Solo. Semina: Ciências Agrárias, Londrina, v. 31, suplemento 1, p. 1281-1290, 2010. 

COSTA, M. C.; ALBUQUERQUE, M. C. F.; ALBREHT, J. M.; COELHO, M. F. B. Substratos 

para produção de mudas de jenipapo (Genipa americana L.). Pesquisa Agropecuária Tropical, 

Goiânia, v.35, n.1, p.19-24, 2005. 

DANIEL, O.; VITORINO, A. C. T.; ALOVISI, A. A.; MAZZOCHIN, L.; TOKURA, A. M.; 

PINHEIRO, E. R.; SOUZA, E. F. Aplicação de fósforo em mudas de Acácia mangium Willd. 

Revista Árvore, Viçosa, v. 21, p. 163-168, 1997. 

GARCIA, F. C. H.; BEZERRA, F. M. L.; FREITAS, C. A. S. Níveis de irrigação no 

comportamento produtivo do mamoeiro Formosa na Chapada do Apodi, CE. Revista Ciência 

Agronômica, Fortaleza, v.38, n.2, p.136-141, 2007 

HAFLE, O. M.; SANTOS, V. A.; RAMOS, J. D.; CRUZ, M. C. M.; MELO, P. C. Produção de 

mudas de mamoeiro utilizando Bokashi e lithothamnium. Revista Brasileira de Fruticultura, 

Jaboticabal, v. 31, n. 1, p-245-251, 2009. 

KUSDRA, J. F.; MOREIRA, D. F.; SILVA, S. S.; ARAÚJO NETO, S. E.; SILVA, R. G. Uso de 

coprólitos de minhoca na produção de mudas de mamoeiro. Revista Brasileira de Fruticultura, 

Jaboticabal, v.30, n.2, p.492-497, 2008. 

LYRA, G. B.; PONCIANO, N. J.; SOUZA, P. M.; SOUZA, E. F.; LYRA, G. B. Viabilidade 

econômica e risco do cultivo de mamão em função da lâmina de irrigação e doses de sulfato de 

amônio. Acta Scientiarum. Agronomy, Maringá, v. 32, n. 3, p. 547-554, 2010 

MAHOUACHI, J.; SOCORRO, A. R.; TALON, M. Responses of papaya seedlings (Carica papaya 

L.) to water stress and re-hydration: growth, photosynthesis and mineral nutrient imbalance. Plant 

and Soil, Dordrecht, v. 281, p. 137-146, 2006. 

MEDEIROS, P. V. Q.; LEITE, G. A.; MENDONÇA, V.; PEREIRA, R. G.; TOSTA, M. S. 

Crescimento de mudas de mamoeiro ‘Hawai’ influenciado por fontes e doses de nitrogênio. 

Agropecuária Científica no Semiárido, Patos, v. 4, n. 1, p- 42-47, 2008. 

MELO, A. S.; COSTA, C. X.; BRITO, M. E. B.; VIEGAS, P. R. A.; SILVA JUNIOR, C. D. 

Produção de mudas de mamoeiro em diferentes substratos e doses de fósforo. Revista Brasileira de 

Ciências Agrárias, Recife, v. 2, n. 4, p. 257-261, 2007. 

MENDONÇA, V.; RAMOS, J. D.; DANTAS, D. J.; MARTINS, P. C.C.; GONTIJO, T. C. A.; PIO, 

R. Efeito de doses de Osmocote e dois tipos de substrato no crescimento de mudas do mamoeiro 

‘Formosa’. Revista Ceres, Viçosa, v.51, n. 296, p. 467-476, 2004. 

NEGREIROS, J. R.; BRAGA, L. R.; ÁLVARES, V. S.; BRUCKNER, C. H. Diferentes substratos 

na formação de mudas de mamoeiro do grupo solo. Revista Brasileira de Agrociência, Pelotas, 

v.11, n.1, p.101-103, 2005. 

SANTOS, R. V.; CAVALCANTE, L. F.; VITAL, A. F. M. Interações salinidade-fertilidade do 

solo. In: GHEYI, H. R.; DIAS, N. S.; LACERDA, C. F (eds). Manejo da salinidade na agricultura: 

Estudos básicos e aplicados. Fortaleza: INCTSal, p. 221-250, 2010. 

9

SOARES, N.B. Mamão Carica papaya L. In: FAHL, J. I.; CAMARGO, M. B. P.; PIZZINATTO, 

M. A.; BETTI, J. A.; MELO, A. M. T.; DEMARIA, I. C.; FURLANI, A. M. C. (eds). Instruções 

agrícolas para as principais culturas econômicas. Campinas: IAC, 1998. p.137-0 (Boletim, 200). 

SOUZA, T. V.; PAZ, V. P. S.; COELHO, E. F.; PEREIRA, F. A. C.; LEDO, C. A. S. Crescimento 

e produtividade do mamoeiro fertirrigado com diferentes combinações de fontes nitrogenadas. 

Irriga, Botucatu, v. 12, n.4, p. 563-574, 2007. 

TAIZ, L.; ZEIGER, E. Fisiologia vegetal. Porto Alegre: Artmed Editora, 2008. 820 p. 

YAMANISHI, O.K. ; FAGUNDES, G. R. ; MACHADO FILHO, J. A. ; VALONE, G. V. Different 

growth medium and fertilizer effects on papaya seedlings growth. Revista Brasileira Fruticultura, 

Jaboticabal, v.26, n.2, p. 276-279, 2004. 

10

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DESORPTIONS, EXTRACTABLES AND BOUND RESIDUES OF 

ALACHLOR IN SOIL WITH THE ADDITION OF ORGANIC MATTER 

FROM SWINE WASTEWATER 

Tatiane C. Dal Bosco 1* , Silvio C. Sampaio 2 , Silvia R.M. Coelho 2 , Natássia J. 

Cosmann 2 , Marcos H. Kunita 3 , Morgana S.Gonçalves 4 

1 Universidade Tecnológica Federal do Paraná (Technological University of Paraná), 

Câmpus Londrina, Avenida dos Pioneiros, 3131, Londrina-PR, 86036-370, Brazil. 

2 Universidade Estadual do Oeste do Paraná (State University of West Paraná), Câmpus 

Cascavel, Rua Universitária, 2069, Cascavel –PR, 86819-110, Brazil. 

3 Universidade Estadual de Maringá (State University of Maringá), Avenida Colombo, 5970, 

Maringá –PR, 87020-900, Brazil. 

4 Universidade Tecnológica Federal do Paraná (Technological University of Paraná), 

Câmpus Francisco Beltrão, Linha Santa Bárbara, sem número, Francisco Beltrão-PR, 

85601-970, Brazil. 

Corresponding author. E-mail: tatianebosco@utfpr.edu.br 

Abstract 

Swine wastewater application into soil to reuse water on cropping provides the addition of 

total and dissolved organic matter to soil, which interferes in the dynamics of pesticides in 

soil. This study aims at evaluating the effects of total and dissolved organic matter 

application from two systems of swine wastewater, biodigestor and lagoon treatments, in 

alachlor formation of bound residues into soil. Extraction and quantification of desorption, 

extractable and bound residues were carried out after the evaluation of miscible 

displacement of alachlor performed by disturbed soil columns. The dissolved organic matter 

did not show desorption residues, only extractable ones. From a soil contamination 

perspective, biodigester swine wastewater in dissolved form would be the treatment that 

would less contribute to this process. Whereas from a toxicological perspective, biodigester 

swine wastewater in dissolved form would result in less damage to soil biota, since it showed 

greater bound residue formation and dissipation of alachlor. 

Keywords: biodigestor wastewater, lagoon treatment wastewater, pesticides. 


In soil, pesticides may be sorbed to soil particles, degraded into other chemical forms 

by physical and / or microbiological chemical processes, leached downward to groundwater 

or transferred from surface water to groundwater, causing impacts on public health (Cheng et 

al., 2010; Bouchonnet et al., 2011). These processes occur simultaneously and are subject 

to complex interactions. Considering that the majority of pesticides is found in middle-depth 

soil, pesticide residues are the main source of contamination of groundwater and of 

agricultural crops (Majumdar & Singh, 2007). 

According to Andréa (1992), during the dissipation process, pesticides can react with 

soil organic matter and in several manners, many of such reactions lead to the formation of 

residues. These residues may be from the pesticide itself and / or from metabolites which 

may be removable or, alternatively, residues that are not extractable, also called bound 

residues. Muller et al. (2007) reported that irrigation with effluents can promote remobilization 

of bound residues in the degradation of organic matter mediated by microorganisms. 

Moreover, the introduction of organic and inorganic chemical compounds from irrigation with 

effluents can increase the amount of dissolved organic matter, favoring the formation of 

bound residues. According Lerch et al. (2009), the first consequence of the formation of nonextractable 

bound residues is associated to decreased availability of pesticide residues with 

the consequent increase in persistence in soil. The possibility of reversal among the forms of

extractable and non-extractable bound residues plays an important role in the destination of 

pesticides in the soil in the long term. 

Accordingly, this study aims at quantifying desorption, extractable and bound residues 

of alachlor in swine wastewater (SWW) treated soil, in dissolved and total forms, from two 

effluent treatment systems and subjected to tests of miscible displacement. Moreover, this 

work also aimed at determining the percentage of extractable residues of alachlor according 

to solvents used for extraction. 


Tested treatments included: Control: no addition of SWW, MOD-B: dissolved organic 

matter from SWW treated in biodigester, MOT-B: total organic matter from SWW treated in 

biodigester; MOD-E: dissolved organic matter from SWW treated in lagoon treatments, and, 

MOT-E: total organic matter from SWW treated in lagoon treatments. 

The SWWs were collected from two farms that have piglet production system. One of 

the properties has integrated biosystem for the treatment of pig manure, and the collection 

was conducted at the point where the effluent leaves the biodigester, because most of the 

properties that work with pig manure in biodigesters do not perform the other treatment steps 

provided in the integrated biosystem. The SWW from lagoon treatments was collected in 

another farm that treats swine waste in a sequence of three lagoon treatments. The 

collection was conducted at the output of the third lagoon effluent. 

The MOT consisted of SWW just as it was collected, and the MOD was extracted from 

SWW according to an adaptation of the methodology described by Zhaohai et al. (2008). In 

the extraction of MOD, centrifugation and filtration methods were used. Initially, centrifugation 

at 3200 rpm (2474 g) was performed for 15 minutes, and then the supernatant was filtered 

through a membrane of cellulose acetate of 0.45 mm in porosity. After filtration, the material 

was frozen. The main physical and chemical characteristics of SWW treated in biodigester 

and lagoon treatments in dissolved and total form, can be found in Table 1. 

TABLE 1: Swine wastewater characterization 

Parameters Unit MOT-B MOD-B MOT-E MOD-E 

pH (CaCl2) - 7.15 8.27 7.20 8.07 

Electric conductivity µS cm -1 6,810.00 5,820.00 6990.00 6270.00 

Oxigen chemical demand 

4,830.00 1,539.00 2154.00 1405.00 

Total nitrogen 

mg L -1 1,190.00 905.30 967.90 863.30 

Total solids 3,860.00 2510.00 3193.00 2104.00 

Total organic carbon (TOC) 967.00 355.60 547.30 255.40 

Fixed solids 2,106.00 1674.00 2129.00 1457.00 

Volatile solids 1,755.00 837.00 1064.00 647.00 

Protocol of APHA, AWWA and WEF (1998). Total organic carbon (TOC) was determined by TOC analyzer. 

The soil (Oxisol, according to EMBRAPA, 2006) was collected in forest area, in order to 

ensure no soil contamination by alachlor and other pesticides. Collection depth was 30-60 

cm to eliminate the effect of organic matter resulting from litter. This soil consists of 10.87% 

sand, 12.32% silt and 76.81% clay. The pH is 4.25, the organic matter content is 17 g dm -3 , 

CEC is 151 mmol c dm -3 and the concentration of total nitrogen is 467 mg dm -3 . 

It was used the alachlor (2-chloro-2,6-diethyl-N-(methoxymethyl acetamide)), an 

herbicide from the chloroacetamide group, analytical grade (Pestanal ® ), with water solubility 

of 172 mg L -1 . 

Quantification was performed using the high-performance liquid chromatography 

(HPLC) technique in Shimadzu ® , Prominence chromatograph. The samples were filtered 

through a membrane of 0.45 mm pore size, and injected into the chromatograph at the 

following conditions: C-18 column (150 x 4.6 mm), mobile phase acetonitrile: water (60:40, v 

/ v) Detector UV - 220 nm, continuous flow of 1 mL min -1 , oven temperature of 35 °C, and 

injection volume of 20 µL (Silva & Vieira 2009; Sopeña et al., 2009).

The soil used for the determination of desorption, extractable and bound residues was 

acquired by a test of alachlor leaching, in accordance with the treatments. Figure 1 shows 

the steps carried out in the leaching test. 

Steps 

5th 

4th 

3rd 

Stages 

Passage of 12 V p ultra pure water 

Contact period 

Application of alachlor on top of columns: 5 times the concentration of 3360 g of active 

ingredient per hectare (NORTOX, 2011). 

2nd Control 1 V p of MOT-B 1 V p of MOD-B 1 V p of MOT-E 1 V p of MOD-B 

 

1st 

 

Saturation with CaCl 2 (0.01 M) 

FIGURE 1: Scheme of the stages performed during the leaching test. 

After the leaching test, column soil was air dried, pounded to break up clods and sifted 

in 2 mm mesh, and this material was stored in glass vials for subsequent extraction and 

quantification of desorption, extractable and bound residues. 

Adapting the methodology described by Lavorenti et al. (1998), in triplicate, 10 grams 

of each column soil were weighed, and placed in 50mL polyethylene centrifuge tubes. 

Moisture content was determined for the soil of each treatment to make the correction in the 

soil mass to be used in the extraction. To these tubes, 20 mL CaCl 2 solution (0.01 M) was 

added, and stirring was carried out on horizontal shaker at 200 rpm for 24 hours. After this 

period, samples were centrifuged for 56 minutes at 6000 rpm (4757 g). Alachlor 

concentration present in the supernatant of centrifuged samples was analyzed and 

characterized as desorption residue. The same extraction procedures were carried out in 

triplicate for a control sample contaminated with 50 mg L -1 of alachlor, to determine the 

percentage of recuperation of method. 

After this desorption, soil samples received organic solvents, chosen according to 

polarity grade, with solvent / sample ratio of 2:1 (volume / weight). Four extractions were 

performed: the first with a mixture of acetonitrile / water (1:1), the second and the third with 

acetonitrile, and the fourth with ethyl acetate. At each addition of organic solvent to the 

sample, horizontally mechanical stirring for 1 hour at 200 rpm was performed. Subsequently, 

the sample was centrifuged for 56 minutes at 6000 rpm (4757 g) at 20 ° C. After each 

centrifugation, the supernatant was reserved in glass vials properly identified according to 

treatment and solvent used for extraction. In this material, which represents the fraction of 

extracted residues, concentration of alachlor was determined and results were expressed in 

mg in the soil column, based on the relationship between the concentration in the 

supernatant and the volume of extracted solution, and the relationship between soil mass 

used in the extraction and soil mass used in the column. According Lavorenti et al. (1997), 

the molecules remaining in the soil after these procedures are considered to be bound 

residues. 


It was observed in the balance of alachlor in the soil column (Table 2) that the leaching 

was stronger MOD than in MOT, representing 88.50% and 90.98% of the total applied in

MOD-E and MOD-B, and 65.99% and 80.68% in MOT-B and MOT-E, respectively. Such 

results are consistent with the GUS index, which classifies alachlor as a leaching pesticide 

(Gustafson, 1989). According to Inoue et al. (2003) alachlor is classified as a leaching 

pesticide not only by the GUS index, but also by the index adopted by the California 

Department of Food and Agriculture (CDFA) and by the Cohen index. This class of 

herbicides show distribution coefficient normalized by the soil organic carbon content (K OC ) 

values less than 512 L kg -1 and 300 L kg -1 and half-life exceeding 11 and 21 days, 

respectively. 

Treatment 

TABLE 2: Alachlor mass balance in soil colunm 

Applied 

(mg) 

Leached 

(mg) 

Desorption 

residue 

(mg) 

Extractable 

residue 1 

(mg) 

Bound and 

dissipated 

residue 

(mg) 

Control 29.40 33.53 0.26 1.04 * 

MOT-B 29.40 19.40 0.22 0.66 9.12 

MOD-B 29.40 26.75 0.00 1.98 0.67 

MOT-E 29.40 23.72 2.98 0.65 2.05 

MOD-E 29.40 26.02 0.00 0.54 2.84 

1 

Sum of results of four solvents used for extraction of extractable residues. * It was not possible to complete the 

balance for Control, possibly due to the adjustment of the integration method in the graph area. Note: percentage 

of recuperation of method: 95.90%. 

The alachlor that remained in the soil after the leaching test in the treatments with MOD 

was not removed by desorption, but only by extraction with organic solvents. This indicates 

that the interaction of MOD and alachlor promotes its leaching. It was observed the 

desorption of alachlor in treatments with MOT, confirming the hypothesis that the fraction of 

non-dissolved organic matter aggregates with the soil particles, blocking macropores 

conductivity, and thus reducing the leaching of the fraction of alachlor that could be desorbed 

(Oliveira et al., 2000, Cox et al., 2001, Stoddard et al., 2005; Fenoll et al., 2011). 

The extractable residues were observed in all treatments (Table 3), especially in MOD- 

B. Even though alachlor has high polarity (Costa et al., 2008), the found result indicates that 

the fraction of alachlor in the soil binded to the organic matter, possibly creating a more 

complex nonpolar. 

Treatment 

TABLE 3: Extractable residues according to solvent used 

Extractable Acetonitrile: 

Acetonitrile 1 Acetonitrile 2 

residue Water 

(%) (%) 

(mg) (%) 

Ethyl acetate 

(%) 

Control 1.04 65.38 27.69 6.93 0.00 

MOT-B 0.66 91.22 8.78 0.00 0.00 

MOD-B 1.98 49.77 0.00 50.23 0.00 

MOT-E 0.65 62.24 28.29 9.47 0.00 

MOD-E 0.54 75.51 11.44 0.00 13.05 

In general, the extractable residues were identified in higher levels when extracted 

using acetonitrile: water and only the treatment with MOD-E showed extractable residues 

using ethyl acetate, indicating higher apolarity of the alachlor-soil organic matter complex of 

this treatment (Table 3). 

The bound residues and dissipated alachlor (Table 2) were higher for treatments MOT- 

B (31.02%), MOD-E (9.66%), MOT-E (6.97%) and MOD-B (2.28%). Soils that received the 

addition of waste have been identified as responsible for the formation of bound residues and 

/ or dissipation of pesticides (Doyle et al., 1978; Printz et al. 1995, Houot et al. 1998). 

According to Barriuso et al. (2008), the increase of soil organic matter can result in an 

increase of bound residues, as it occurred in MOT-B, that was the treatment with highest

addition of TOC to soil (Table 1). Fenlon et al. (2011) pointed out that the organic matter or 

clay induces the formation of bound residues, providing less mobility of the pesticide. 

According to Muller et al. (2007) and Fenoll et al. (2011), the formation of bound 

residues or dissipation of pesticides occurs due to microbial activity enhanced by the 

application of organic waste. Furthermore, one can not rule out the possibility of 

remobilization of bound residues to the form of extractable or desorption residues, because 

irrigation with effluent introduces many organic and inorganic compounds into the soil, which 

change the chemical characteristics and increase organic matter content, inducing the 

release of bound residues (Muller et al., 2007). 

4. Conclusion 

Dissolved organic matter did not show desorption residues, only extractable residues, 

predominantly in acetonitrile:water, which was the solvent that most extracted residues from 

treatments with total organic matter and Control. MOD-B is the treatment that least 

contributed to the process of soil contamination, however, it has lower efficiency from an 

agricultural perspective, due to high leaching. Moreover, from a toxicological point of view, 

MOT-B causes less damage to soil biota, due to its higher bound residue formation and 

dissipation of alachlor. 

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APPLICATION OF TREATED DOMESTIC SEWAGE IN THE SOIL 

FOR DESIGN THE SUBSURFACE DRIP IRRIGATION 

Marcelo L. C. Elaiuy 1* , Leonardo N. S. dos Santos 1 , Allan C. M. de Sousa 1 , Edson E. 

Matsura 1 

1 University of Campinas / College of Agricultural and Engineering, Campinas-SP, 13083- 

875, Brazil *Corresponding author: trangokauk@gmail.com 

ABSTRACT: The use of treated sewage effluent (TSE) combined with the subsurface drip 

irrigation (SDI) method in agriculture can decrease the costs in agricultural production, in 

attempts to fertigate crops more efficiently. In this paper we compare the dimensions of the 

wet bulb formed by the application of TSE and municipal water supply (MWS) in a dusk red 

latosol. We have evaluated the effect of water quality and discharge between drippers used 

in sugar cane crop. Comparing the results from different wetted soil profiles we observed 

that dimensions vertical and horizontal of the wet bulb are similar for the MWS and TSE, 

being peculiars according to the discharges used and volume applied. In addition, the results 

suggest that the TSE presents a greater solute concentration near the emitter, decreasing 

progressively towards the wetting front. 

KEYWORDS: Fertigation; Wastewater; TDR; Water Content; Electrical Conductivity. 

INTRODUCTION 

Although profitable, irrigated agriculture is the human activity responsible for increases 

water demand in worldwide generating conflicts in relation for other water uses. 

Growing competition over dwindling water resources in many agricultural areas in 

Brazil increases the use of marginal quality water with drip irrigation which requires sound 

fertigation practices that reconcile environmental concerns with viable crop production 

objectives. In this context, the subsurface drip irrigation system are becoming increasingly 

popular as a means for supplying water more efficiently contributing to increase agricultural 

productivity (CAMP, 1998; SINGH et al., 2006). In São Paulo/Brazil the use of irrigation 

system such as the subsurface is also a technical viability to increase the productivity levels 

of sugar cane, due to the high cost of production areas (BARROS et al., 2009). 

Nowadays there is a worldwide trend that aims to use treated sewage 

effluent (TSE) for crop irrigation. In addition, the use of TSE in agriculture delivery a required 

amount of water and nutrients (ferigation) to the plant and it´s a practice of water reuse and 

preservation of water resources. The combined use of TSE with subsurface drip irrigation 

aimed at sustainable use of this resource and implements the concept of modern agriculture 

that seeks not only to increase the tillage production, but also press for the preservation of 

the environment. In this case the soil is used as a debugger and decreases the 

contamination risk of the environment allowing its use for the TSE application. 

In the midst of various drip irrigation systems used, the subsurface applies water 

directly to the root zone forming the wet bulb. In this region, the soil water content keeps 

close to the field capacity and evaporative losses are minimized. Nevertheless, it is 

necessary to known the support capacity of each soil-plant system in order to establish the 

most appropriate application rate by preserving the integrity of natural resources. The main 

problems related to the effluent application in the soil are salinization and deep water 

contamination caused by leaching process. 

The wet bulb sizing assists in proper estimate of the number of driplines per plant and 

its location relative to the plants or plants rows, directly influences the project costs of 

irrigation and crop yields. Unfortunately, these sizing are often overlooked and current 

practices in Brazil and elsewhere in the world are too often based on empirical information or 

on data gleaned indiscriminately from professional literature. Alternatively, according to 

SOUZA et al. (2009) the shape of a wetted soil volume can be measured and controlled 

using water content sensing equipment such as time domain reflectometry (TDR), which

measures water content and electrical conductivity using a single probe within the same soil 

volume. Although several studies that investigate the wet bulbs sizing in subsurface drip 

irrigation are available in the literature, none use the TSE with the TDR technique to monitor 

the dynamic of the water and solute in the soil. 

In this paper we shape and compare the dimensions of wet bulbs from the subsurface 

drip irrigation with MWS and TSE. Our findings contributes to underpin the design and 

management of sugar cane fertigation, increasing this crop productivity and reducing costs 

with fertilizers and water consumption, evaluating concomitantly possible impacts of the TSE 

application in the environment. 

MATERIAL AND METHODS 

The field experiment was performed during 2011 at the College of Agricultural 

Engineering (University of Campinas), with geographic coordinates 22º81’ 89’’ South latitude 

and 47º06’22’’ West longitude. The soil of the study area is classified as dusk red latosol, 

medium to clayey texture, according to criteria set by (EMBRAPA, 1999). 

The experiment was based according to flow rate 1.0 Lh -1 and 1.6 Lh -1 , and the water 

quality classified as municipal water supply (MWS) and treated sewage effluent (TSE). The 

effluent used comes from the college which is composed by sanitary and domestic wastes. It 

is treated in an up-flow ascendent sludge blanket (UASB) and subsequently forwarded to the 

“wetlands” for a secondary treatment. The physical and chemical carachteristics of the TSE 

and the MWS were analyzed based on the “Standard Methods for the Examination of Water 

and Wastewater”, before being applied in soil. 

Three trenches were opened and 21 three-rod TDR probes were installed. The TDR 

probes were placed at 0.15, 0.25, 0.35, 0.45, 0.55 and 0.65 m – in depth, and 0.05, 

0.15, 0.25 and 0.35 m – distance from the dripper, totaling 21 probes in mesh per trench. 

This layout was described in detail by BARROS et al. (2009). Can be observed that in two 

opposite walls of each trench this procedure was replicated using a pressure-compensating 

dripper (Netafim - DripNet PC TM AS 16150) buried at 0.30 m for each constant discharge of 

1.0 L h -1 and 1.6 L h -1 . According to PIRES et al. (2008) this depth value is ideal for sugar 

cane irrigation. The three rod probes TDR used in the experiment were built in the laboratory 

of hydraulic and irrigation and the constructive details are described in SOUZA et al. (2006). 

Due to differences in soil physical properties caused during its movement and 

consequently the distribution of the MWS and the TSE, the readings were only taken after 

the restructuring period of soil that was in approximately two months. 

Firstly we applied 1L of MWS at each hour for a total of 10 applications. The monitoring 

of water distribution was performed before and after each application. This methodology was 

developed based on the work of COELHO & OR (1999). For the MWS evaporation, we 

waited a period of 15 days to start the applications with TSE. 

Using the Reflectometer TDR 100 equipped with RS 232 interface and data collector 

CR 1000, we monitored the water content and electrical conductivity analyzing the 

electromagnetic signal. 

We based the schedule of the readings on application of MWS and TSE at a dripper at 

a time, with the 21 readings being carried out in real time, with the aid of multiplexers SDMX 

50. The TDR requires a calibration equation to convert measured bulk dielectric permittivity 

(Ka) to soil water content (Ѳ). In this study we used the equation based on the work of 

ROQUE (2007) as follows: 

RESULTS AND DISCUSSION 

The treatments used in this field experiment were encoded to facilitate the discussion 

of the results as: Municipal water supply flow rate 1.0 Lh -1 (W1), Treated sewage effluent flow 

rate 1.0 Lh -1 (E1), Municipal water supply flow rate 1.6 Lh -1 (W1.6) and Treated sewage 

effluent flow rate 1.6 Lh -1 (E1.6). Due to the large number of figures, the wet bulbs chosen to 

represent the profiles were the 1,3,5,7,10 L to 1.0 Lh -1 and 1,3,5,8,10 L to 1.6 Lh -1 .

The Figures 1 and 2 show the water content profiles for each application (from 1 to10 

L) of MWS and TSE using a flow rate of 1.0 Lh -1 . Each contour line represents an increase of 

0.01 m 3 m -3 . The results show that the drippers discharge and physical properties of the soil 

perform different effects on the shape of the wet bulb. In accordance with the water content 

values obtained with the TDR can be noted that the bulbs have submitted forms features. 

The volumes of water applied formed bulbs similar to those which are described by ZUR 

(1996), rounded shapes and elliptical. 

The vertical dimensions of the bulb are represented by the axes (+z) and (-z) from the 

emitter point shown by semicircle. The axis (r) represents the largest radial distance 

achieved by the wetting front during the applications. 

Can be noted an accentuated downward water movement relative to lateral spreading. 

The downward dimension (-z) reached by the wetting front is in accordance with KOFFLER 

(1986), since is ideal for providing water at the effective root system of sugar cane, to water 

stress does not occur. 

The spacing between emitters proposed by the manufacturer of the drippers that we 

use in this experiment is 0.55m for the flow rate of 1.0 Lh -1 . Evaluating the radial dimension 

from the wetting front after the last application can be seen that, in both treatments a 

singularity between this dimension and the spacing suggested by the manufacturer. This 

horizontal radius value for treatments W1 and E1 is approximately 0.20m, and represents 

nearly half the distance between the emitters, assuming the formation of a continuous 

horizontal band of water content along the irrigation line. 

FIGURE 1. Soil water profiles (m 3 m -3 ) at the end of the infiltration process of each 

application of MWS at a flow rate of 1.0 L h -1 . 

FIGURE 2. Soil water profiles (m 3 m -3 ) at the end of the infiltration process of each 

application of TSE at a flow rate of 1.0 L h -1 . 

The wet bulbs for treatments W1.6 and E1.6 are presented in Figures 3 and 4. It is 

noted in these treatments that the bulbs have submitted features forms, rounded and 

elliptical, as described by ZUR (1996). The results also confirm the observations made by 

KANDELOUS et al. (2011) when comparing experimental and analytical results obtained 

from bulbs of subsurface dripping irrigation on clay soil at 0.30 m.

As observed, increasing the discharge of the dripper to 1.6 Lh -1 increases the 

horizontal radius. However, decreasing the discharge to 1.0 Lh -1 increases the vertical radius 

of the wet bulb. It happens due to the change of the infiltration area according to the 

treatments. It was also described in works by SCHWARTZMAN & ZUR (1986) and SOUZA & 

MATSURA (2004), thus confirming the findings presented here. In addition, the spacing 

between emitters proposed by the manufacturer of the drippers is 0.65m for the flow rate of 

1.6 Lh -1 , which as the same explanation given for the horizontal dimension of discharge of 

1.0 Lh -1 . Therefore, we also propose an occurrence of a continuous horizontal band of water 

content along the irrigation line. 

FIGURE 3. Soil water content profiles (m 3 m -3 ) at the end of the infiltration process of each 

application of MWS at a flow rate of 1.6 L h -1 . 

FIGURE 4. Soil water content profiles (m 3 m -3 ) at the end of the infiltration process of each 

application of TSE at a flow rate of 1.6 L h -1 . 

The electrical conductivity of TSE as a function of water content is estimated by TDR 

and the profiles are presented in Figures 5 and 6. The bulbs shaped by interpolating the 

values of EC showed similar formats when compared to the water content bulbs. However, 

we note a reduction in the dimensions of axes (+z), (-z) and (r). LOPES et al. (2010) 

observed the same occurrence and suggested that the ions come forward in advance of 

water, and it moves slightly ahead of solutes toward to the extreme of the bulb. 

Taking as a reference the dripping point and comparing the dimension (-z) for both flow 

rates 1.0 Lh -1 and 1.6 Lh -1 the ions in TSE tends to reach greater depths in the lowest flow. 

From the fertigation use with TSE it may be suggested a loss of nutrients by leaching and a 

potential environmental contamination of deepwater, as observed by CHARLESWORTH & 

MURIRHEAD (2003). Besides, the nitrates are very soluble, have high mobility in soils and 

are easily transported in depth affecting the quality of groundwater (ABAIDOO et al., 2009). 

Another observation is based in the interactions between the different soil water 

content and solute concentration distribution, which shows spatial gradient with greater 

storage of solutes near the dripper and gradual decrease towards the wetting front.

FIGURE 5. Distribution of electrical conductivity in the soil, 1.0 Lh -1 

FIGURE 6. Distribution of electrical conductivity in the soil, 1.6 Lh -1 

CONLUSION 

The following conclusions may drawn from the results: (1) There were no significant 

differences between the dimensions of the wet bulb formed from the application of MWS and 

TSE to the flow rate of 1.0 Lh -1 in a dusk red latosol at 0.30 m of depth, as well as to the flow 

rate of 1.6 Lh -1 ; (2) The interactions between the different profiles (water content versus 

electrical conductivity) revealed a gradient distribution of the solute in the soil near the 

emitter, decreasing progressively towards the wetting front; (3) Increasing the flow rate from 

1.0 Lh -1 to 1.6 Lh -1 raised the horizontal radius of the wet bulb suggesting a wider spacing 

between drippers, such as recommended by the manufacturer of the dripper. 

AKNOWLEDGMENTS 

Fapesp – São Paulo Research Foundation / CNPq - National Council for Scientific and 

Technology Development 

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Jaboticabal, v.30, n.5, p.932-947, 2010. 

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(Doutorado em Engenharia Agrícola) – Universidade Estadual de Campinas, Faculdade de 

Engenharia Agrícola. 

SCHWARTZMAN, M.; ZUR, B. Emitter spacing and geometry of wetted soil volume. Journal 

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SINGH, D. K.; T. B. S. RAJPUT; D. K. SiNGH; H. S. SIKARWAR, R. N. SAHOO; T. AHMAD. 

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EFFECT OF MACHINE TRAFFIC ON SOIL COMPACTION DURING 

THE SEMI-MECHANIZED PLANTING PROCESS OF SUGAR CANE 

Adriano C. Bastos 1,2* , Henrique L. Silveira 1 , Francelino R. Junior 1 , Marcelo J. Silva 1 , 

Paulo S. G. Magalhães 1,2 . 

1 College of Agricultural Engineering (FEAGRI / UNICAMP), Candido Rondon Avenue 501 

Campinas-SP, Brazil 

2 Brazilian Bioethanol Science and Technology Laboratory, Giuseppe Máximo Scolfaro Street 

10000 Campinas-SP, Brazil 

*Corresponding author. E-mail: adriano.bastos@bioetanol.org.br 

Abstract 

In past few years significant changes in sugar cane semi-mechanized planting system had 

occurred in Brazil with significant increase machinery traffic, due mainly by law restrictions in 

order to improve workers safety. This planting system, characterized by traffic-intensive, 

cause soil compaction with negative consequences on its structure and sustainability, 

reducing the porosity, gas exchange, infiltration and retention of water. These factors directly 

reflect the crop, reducing yield and field longevity, increasing the production cost and 

subsequent increasing the expenditure of land renovation operations. In this method of 

planting after preparing the whole area by subsoiling and harrowing, the field is divided in two 

zones, one called "planting zone" (PZ) consist of six rows each (9 m wide) where the 

mechanized operation of furrowing/fertilization, manual distribution of “seedcanes” and 

mechanized operation of closing of the furrow are done with only two pass of the tractor in 

alternated rows. The second zone called "Truck path for seedcane distribution" (TPSD) 

consist of four rows (6 m wide) used prior to planting for truck and machinery traffic which 

supply fertilizers and “seedcane” to the area. After finishing planting the TPSD zones are 

prepared in the same way as PZ zone. The objective of this study was to verify the influence 

of machinery traffic, in semi-mechanized planting process of sugar cane, on soil compaction, 

using data of soil resistance to penetration at different depths in a commercial field. Data 

were collected from mechanical soil penetrometer with electric power and control speed for 

constant penetration rate. The penetration resistance values were measured up to a depth of 

600mm. Two treatments were performed: after planting in the PZ zone and TPSD zone. The 

results showed that the additional traffic in and out of control in the TPSD zone reflected 

directly in the soil compaction, unlike PZ zone, where the traffic of tractors with implements 

were on parallel lines, especially in the operation of furrow opening, performed by the 

autopilot system. In the depths of 110-200 and 210-300 mm values penetration resistance 

TPSD zone were significantly higher than in PZ zones. It can be concluded that the semimechanized 

planting of sugar cane in the model currently used in Brazil causes soil 

compaction, especially in the TPSD zone which there is an intense and uncontrolled traffic of 

machines and agricultural implements in the cultivation area, which may reflect directly on 

the productivity and longevity of sugar plantation. 

Key words: soil compaction, sugar cane planting, cone index 


One of the current problems that affect directly the agriculture productivity is the soil 

compaction, that occurs because of the soil particles rearrangement when it receive external 

pressures over the support capacity, making the soil denser and with less porosity. Many 

studies show that the mainly reason of that compaction is the machines traffic in the 

agricultural field, in addiction of the mechanical vibration effects of the equipment during the

field operations (STRECK et al., 2004; ELAOUD & CHEHAIBI, 2011). This condition results 

in many problems connected with the developed of the crop during the growing stages. 

Tests made under control field conditions by PATEL & MANI (2011) with the goal of 

determinate the level of compaction in the soil profile caused by the traffic of tractors in three 

different loads and four distinct pass, showed that both density and penetration resistance 

raised gradually with the number of pass, showing the cumulative effect of the first two pass 

traffic mainly, resulting in significant reduction on the other pass. 

ARANTES et al. (2010) analyzed the effect of the traffic control in the soil compaction in 

cultivated areas with sugar cane, in mechanized harvest for two years. The results showed 

that the traffic of machines raise the resistance of penetration in the soil and reduce the 

macro porosity in the track line in relation of the plantation line. 

In the last years we observed substantial alterations in the sugar cane sector with the 

significant raise of mechanization and modernization of the process of the plantation, cutloading 

and transportation of sugar cane. This mechanization brought immediate benefits to 

the system, but some studies show that the intensive use of machines cause damage to the 

soil too, compromising the sustainability. MAGALHÃES & BRAUNBECK (2010) showed how 

the current sugar cane mechanization model, characterized by intensive traffic of machines 

and equipment, result in the soil compaction with negative consequences in its structure. It 

reduces the porosity, the gas changes and hampers the water infiltration and retention. 

These factors, combined with the wrong soil managed, went far to the decline of production 

along the years, making necessary heavy tillage operations to recuperate the cultivation 

area. 

The sugar cane planting may be made by two systems: semi-mechanized and mechanized. 

Despite the mechanical planting process is in expansion in Brazil, the semi-mechanized 

system is still used in cultivation areas because of the technology restrictions, the operational 

quality or the topography of region. But this system has suffered alterations in recent years 

because of the significant increase of machines traffic and equipment on the cultivate areas 

replacement of manual labor. This was due to restrictions in labor laws which prohibit the 

transportation of workers in agricultural equipment under hazardous conditions. 

In the system of semi-mechanized planting, after the preparation of the field with tillage 

operations of subsoiling and harrowing, the area is divided in two zones: one called “Planting 

zone” (PZ zone) that consists of six lines each (9 m wide), where occur mechanized 

operations of opening furrow and fertilization, manual distribution of “seedcanes” and the 

mechanized operations of closing of the furrow, using only two pass of tractor in alternate 

rows. The second zone called “Truck seedcane path for distribution” (TPSD zone) consists of 

four rows (6 m wide) used before planting to traffic of machines and trucks that distribute 

“seedcane” in the area. After the distribution of “seedcane” TPSD zone are prepared by the 

same way of PZ zone. 

This paper wants to verify the influence of machine traffic on soil compaction during the 

sugar cane semi mechanized planting process, for penetration resistance data on different 

depths in a commercial planting area. 


The tests were conducted in an experimental area of 9.56 ha Fazenda TOCA, located in the 

Serra Azul / SP (21º16’40” S, 47º32’24” W and 595 m), belonging to Pedra Agroindustrial 

S.A., from December/2010 to July/2011. The soil is classified as Dystrophic Yellow Red 

Latosoil, and the climate is classified as mesothermal humid with a little water stress (IBGE, 

2011). 

The tillage operation was composed of subsoiling, harrowing and leveling the ground, with at 

least 3 pass of the tractor. Planting, which includes two additional pass of the tractor, was

composed of 3 other operations: furrow opening with fertilizer distribution, manual seedling, 

and closing of the furrow wit micronutrients supply. This resulted in general in 5 pass of the 

tractor in the PZ zone. It is important to observe that the planting operation was conducted 

using autopilot system, and rows were spaced 1.5m. In TPSD zone the traffic of 2 tractors, 2 

trucks and a hydraulic winch for distribution of “seedcane” were added, and there was no 

traffic logistical control of the machines and equipment at this stage. 

Data were collected using an automatic penetrometer equipped with electric motor and 

speed control for constant penetration rate, with data acquisition system (PLG5200- 

SoloTrack, Falker ©, Porto Alegre-RS). Using a cone type 2 with 129 mm 2 circular based 

according to ASABE Standard S313.3 (ASAE, 2009) and the values of penetration 

resistance were collected up to of 600mm depth. 30 points with 3 repetitions were allocated 

in regular intervals of 50 m (grid 50 x 50 m), 90 observations at all. The location of sampling 

points was made with the support of the receptor GPS GeoExplorer 3 (Trimble© 

Navigation). 

Data of penetration resistance were collected in two different occasions, before soil tillage 

(90 observations) in December 2010 and two treatments were evaluated after the planting in 

semi-mechanized TPSD zones (45 observations) and the PZ zones (45 observations) in May 

2011. The operation of furrow opening and demarcation of the two treatments was made by 

a two lines plow-fertilizer attached to an agricultural tractor (BH205I, Valtra Corporation, São 

Paulo), equipped with an autopilot system (System 150, Topcon© Positioning Systems). 

Figure 1 shows the lines of TPSD zones and PZ zones and identifies the points of data 

collection. 

The depth tracks are divided into 6 soil layers with 100 mm each. Where in each layer was 

determined the maximum value of resistance to penetration. An analysis of variance and 

mean comparison between treatments, and ranges in depth using the Duncan test (p

3. Results and discussions 

Table 1 shows the water content in soil and number of observations of resistance to 

penetration and location where they were taken. 

The wet soil due to rainy season favored the collection of data and 90 observations have 

records of resistance to penetration to a depth of 600 mm. However, data collection after 

planting at some points did not reach a depth of 600 mm and was considered incomplete 

observations. It can be seen in Table 1 that after planting soil water content in was on 

average 34% lower than in the data collected before soil tillage operations. This reduction in 

soil water increased resistance to penetration, without necessarily increasing the 

compaction, but resulting in more than 45% of the number of incomplete data, and in some 

cases the penetration depth of the equipment could not exceed 100 mm because the high 

resistance to penetration of the soil. 

TABLE 1. Values of soil water content and data used collected from the penetration 

resistance 

Period Treatments N SWC (%) CV(%) TO IO Data used (%) 

Before tillage ------------ 30 22,55 a 9,95 90 0 100,0 

After planting 

TPSD zone 15 14,95 b 20,65 45 25 44,4 

PZ zone 15 14,71 b 15,54 45 19 57,7 

Means followed by lower case in the same column do not differ statistically among themselves (Duncan, p

Soil Depth (mm) 

Soil Depth (mm) 

in the region 100-300 mm, below this area there is a reduction indicating that the compacting 

vehicle traffic causes damage primarily in the layers between 100 and 300 mm. 

It is noted in Table 3 that the PZ zone had the highest coefficient of variation between 25.9 to 

65.2%, indicating that less intensive traffic promoted an uneven structure on the ground. In 

TPSD zone was observed lower coefficients of variation. This may indicate a negative factor 

that traffic more intensive machinery promoted greater uniformity in the soil structure, 

reflected by higher compaction. 

TABLE 3: Average cone index (CI), standard deviation (SD), coefficient of variation (CV) and 

medium comparison test (MCT) for treatments and depths analyzed after planting. 

Treatment 

N 

TPSD zone 20 

PZ zone 26 

CI (kPa) 

SD (kPa) 

CV (%) 

MCT 

IC (kPa) 

SD (kPa) 

CV (%) 

MCT 

Depths (mm) 

0-100 110-200 210-300 310-400 410-510 510-600 

4414 5481 4810 4304 4043 3612 

2048 1277 1115 1093 804 700 

46,4 23,3 23,2 25,2 19,9 19,4 

A / bc A / a A / ab A / bc A / bc A / c 

3293 

2147 

65,2 

A / a 

4004 

2274 

56,8 

B / a 

3633 

1947 

53,6 

B / a 

3525 

1825 

51,8 

A / a 

4184 

1502 

35,9 

A / a 

3576 

926 

25,9 

A / a 

Means followed by upper case in the same column do not differ statistically among themselves (Duncan, p


It can be concluded that the semi-mechanized planting of sugar cane in the system currently 

used in Brazil causes soil compaction, especially in the “Truck seedcane path for distribution 

zones” (TPSD zone) which there is an intense and uncontrolled traffic of machines and 

agricultural implements in the cultivation area, which may reflect directly on the productivity 

and longevity of sugar cane plantation. 

5. Acknowledgements / References 

ARANTES, A. ROQUE, D. O. SOUZA, Z. M. D.; BARBOSA, R. S. Agricultural traffic control 

and soil physical attributes in sugarcane areas. Brazilian Journal of Agricultural Research, 

v.45, n. 7, p. 744-750, 2010. 

ASAE, E. F. Procedures for Using and Reporting Data Obtained with the Soil Cone 

Penetrometer Test. v. 1999, p.4, 2009. 

CTBE. Brazilian Bioethanol Science and Technology Laboratory. Low Impact 

Mechanization. Available: http://www.bioetanol.org.br/interna/index.php?pg=ODk= Accessed: 

05/05/2012. 

ELAOUD, A.; CHEHAIBI, S. Soil Compaction Due to Tractor Traffic. Journal of Failure 

Analysis and Prevention, 2011. 

FARONI, C.E.; TRIVELIN, P.C.O. Quantification of sugarcane active metabolism roots. 

Brazilian Journal of Agricultural Research, v.41, n.6, p.1007-1013, 2006. 

IBGE – INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA. Interactive Maps. 

Available: mapas.ibge.gov.br. Accessed: 10/07/2011. 

MAGALHÃES,P.S.G.; BRAUNBECK,O.A. Technological Roadmapping for ethanol– 

Agriculture Component. In: CORTEZ, L.A.B. São Paulo: Blucher, p.897-907, 2010. 

PATEL, S. K.; MANI, I. Effect of multiple passes of tractor with varying normal load on 

subsoil compaction. Journal of Terramechanics, v. 48, n. 4, p. 277-284, 2011. ISTVS. 

STRECK, C. A. REINERT, D. J. REICHERT, J. M.; KAISER, D. R. Soil physical alterations 

with soil compaction induced by traffic of a tractor in no-tillage system. Ciência Rural, v. 34, 

n. 3, p. 755-760, 2004. 

VAZ, C. M. P. MANIERI, J. M. MARIA, I. C. DE; TULLER, M. Modeling and correction of soil 

penetration resistance for varying soil water content. Geoderma, 2011.

Rural Stream Monitoring for the Investigation of Stream Depletion in 

Rural Areas 

Sung M. Kim 1* ․Sung J. Kim 1 ․Sang M. Kim 2 

1 Graduate School, Gyeongsang National Univ., Jinju 660-701, Korea 

2 Dept. of Agricultural Engineering (Inst. of Agric. & Life Sci.), Gyeongsang National Univ., 

Jinju 660-701, Korea 

*Corresponding author. E-mail: kin8945@naver.com 

ABSTRACT 

The purpose of this study was to monitor the stream flow of rural streams for investigating the status of 

stream depletion located downstream from irrigation reservoirs. The Bonghyun and Hai reservoirs, located in Haimyeon, 

which is in the city of Gosung in the Gyeongnam Province, were selected for stream and watershed study. 

The stream flow monitoring was conducted seven times from March to September, 2011. The stream flow was 

measured in eight stations downstream from the two reservoirs. Stream depletion was found in most of the 

reservoirs downstream for the non-irrigation periods, and even in the irrigation periods when there were a lot of 

antecedent precipitation. The correlation analysis for water quality data indicated that the correlation between 

BOD and T-N was highest for the reservoirs. The correlation among BOD, T-N, and turbidity was high for both the 

Hai and Bonghyeon reservoirs. Continuous monitoring of rural streams located downstream from reservoirs are 

required to quantify the status of stream flow depletion, as well as to determine the amount of environmental flow. 

Key words - Environmental flows, Stream flow monitoring, Irrigation reservoir, Water supply 

Ⅰ. Introduction 

Due to massive urbanization and industrial restructuring of Korea during its rapid economic 

growth period after 1970, Korea's waterside environment has been severely destroyed. In 

particular, the mass production and consumption from human activities released pollutants in 

excess of the self-purification systems in streams; consequently, the streams have lost their 

original functions (Yang, 2004). In recent years, interests about the environmental functions 

of streams as a buffer zone have increased as citizens' income levels and their quality of life 

improve. Also, a reassessment is being made actively about the ecological and 

environmental features in the cities of Korea. (Lim, 2001). Therefore, a need for the 

introduction of water used for environmental maintenance has been raised. The maintenance 

of stream flow is defined as the drought flow of streams in need to maintain the normal 

functioning of the streams (Kim, 2011). However, the natural and social conditions, while 

considering the possibility of using the supply capabilities of water for the maintenance of 

streams were calculated by considering the eight categories of water quality maintenance 

(KRCC, 2010). Currently, the many streams in Korea have lost their function as water 

sources. The drying out of medium-sized and small streams due to the lack of water in them 

will cause problems in irrigation, along with agricultural land shortages, with an increase in 

water pollution and a loss of function of the environment. As a result, the loss of economic 

aspects worsens every year. Hwang & Lee (2005) suggest that there is an urgent need to 

seek causes and implement preventive measures. 

Most advanced nations have accumulated environmental technology and know-how about 

water management. By contrast, Korea has not yet achieved sustainable environmental 

water management, and knowledge about the hydraulic characteristics of streams and 

ecosystems has been very limited. Environmental water management with its unique 

environment of watersheds, having a constant flow like drought flow, was also thought to be 

limited. In the past, most studies were based on the habitat evaluative methods of fish for the 

environment with their optimal flows (KICT, 1995). The introduction of automated equipment 

is difficult and requires the participation of skilled ecology professionals. A few overseas 

examples are the IWMI (International Water Management Institute), the IBRD (International 

Bank for Reconstruction and Development), and the CRC (Co-operative Research Centre). 

They operate on-site monitoring systems adapted for specific purposes in environmental 

1

water maintenance. At the same time, thess systems are equipped with estimation 

procedures to determine appropriate environmental water levels according to the levels of 

the observed performance data. In other words, the previous case shows that on-site 

monitoring is extremely important (KRCC, 2010). It shows the importance of systematic onsite 

monitoring. Therefore, the purpose of this study was to monitor the stream flow of rural 

streams in order to investigate the status of stream depletion located downstream from 

irrigation reservoirs. 

Ⅱ. Materials and Methods 

2.1 Watershed Study 

The Bonghyun and Hai reservoirs, located in Hai-myeon, which is in the city of Gosung in 

the Gyeongnam Province, Korea were selected for watershed and stream study. The Seokji 

stream has a length of approximately 2,600 m from the Hai reservoir spillway. The Seokji and 

Bonghyeon streams meet downstream. The flow goes into the southern sea. The Bonghyeon 

reservoir has a watershed area of 2.80 km 2 and the irrigation area is 0.38 km 2 . The Hai 

reservoir has a watershed area of 13.42 km 2 , and the irrigation area is 1.67 km 2 . The scale of 

the land use data by the Ministry of Environment is 1:25,000 which indicates that paddies 

cover 62.3% of the total area or 4.40 km 2 . Cropland has an area of 0.71 km 2 and the 

residential area is 0.75 km 2 . The remaining area covers 17% of the total area. Stream water 

is released regularly from the reservoirs to use as irrigation water because most of the area 

is covered with paddies. 

2.2 Meteorological data 

It is important to have a steady water supply to prevent stream depletion. The outflow 

discharge, the amount of evapotranspiration, and reservoir flood routing should be 

considered in order to maintain stream environment. The weather data was collected from 

the Jinju weather station from 1970 through 2011. The rainfall data is divided into irrigation 

periods and non-irrigation periods (FIGURE 1). The city of Jinju's annual average 

precipitation was 1,503 mm, higher than Korea's annual average precipitation. In 1989, 

Jinju's annual average precipitation reached a record high. It reached a low 784.9 mm in 

1994. According to the weather data, the mean wind velocity in Jinju was the fastest at 2.9 

m/s. The lowest was when the relative humidity was 45.2% in February, 2000. The mean 

wind velocity was lowest at 0.8 m/s in 1977, 2006, 2007, and 2008. 284 hours of recorded 

sunshine were the most recorded in July, 1994 and the lowest of 32.2 hours were recorded 

in July, 1984. 

FIGURE 1 Compared rainfall of irrigation periods (May-Oct.) and non-irrigation periods (Nov.-Apr.) 

2.3 Reservoir Storage Capacity Assessment and Investigation 

A selection of watersheds was made for the study after considering their accessibility, their 

storage amount, stream lengths, and the usages of riverbeds from the reservoirs. The Hai 

reservoir (Standard code, 4882010042), located in Hai-myeon, which is in the city of Gosung 

in the Gyeongnam Province, Korea was completed in 1971. Now it is managed and operated 

by the Goseong and Geoje offices of the Korean Rural Corporation. The Hai reservoir is a fill 

dam. It has 1,000 m 3 in volume, is more than 23.2 m tall and has a length that just reaches 

2

394 m. The Hai reservoir can store 2,594×10 3 tons of water. The design frequency of 

droughts is 10 years, and the flood frequency is 200 years. The Bonghyun reservoir 

(Standard code, 4882010045) is also located in Hai-myeon but was completed in 1998. It is 

also managed and operated by the Goseong and Geoje offices of the Korean Rural 

Corporation. This reservoir is also a fill dam, as the Hai reservoir. The Bonghyun reservoir is 

90,823 m 3 in volume, is more than 28.4 m tall and has a length that just reaches 246 m. The 

Bonghyun reservoir can store 910×10 3 tons of water, its design frequency of drought is 10 

years, and its flood frequency is 200 years. 

2.4 River Survey 

The standard stations and periods were determined after considering the conditions that 

affected the changes in flow. Five stations were downstream: 750 m, 1,260 m, 1,730 m, 

4,190 m, and 5,500 m from the Bonghyeon reservoir. Three stations were downstream: 30 m, 

2,000 m, and 2,810 m from the Hai reservoir. A total of eight stations were selected to 

measure time-flow. The period under study was selected to compare with the irrigation 

periods and the non-irrigation periods from March through September, 2011. Stream 

monitoring was conducted regularly at the end of every month. 

2.5 Statistical Analysis Method of River Water Quality Data 

In this study, the water quality data at each station were statistically analyzed using the 

partial correlation coefficients. The control variable was the flow. The water quality factor was 

the independent variable. The commonly used Pearson's correlation coefficient r was the 

correlation coefficient of the two variables X and Y. The values for each case (x 1 , y 1 ), (x 2 , 

y 2 ), ..., (x n , y n ) when the following equation (1) was calculated was: 

: − = ∑( − ̅)( − ) 

, 

− 1 

∶ h = ∑( − ̅) 

, 

− 1 

∶ h = ∑( − ) 

r = 

× 

(1) 

− 1 

Ⅲ. Results and Discussion 

3.1 Analysis of the Reservoir and River 

From March to September, 2011 a total of seven field surveys were conducted to measure 

the water levels of the observed stream stations. The flow was calculated by measuring the 

flow speed of a cross-sectional area of stream. The changes in stream flow were analyzed 

according to five days of antecedent precipitation. According to TABLE 1, the low outflows of 

reservoir and rainfall were dry at all times from March to May. On June 29th, a large amount 

of antecedent precipitation was expected to create a large river flow. However, a stream flow 

did not occur downstream of the Hai reservoir. Also, the majority of the stations at 

Bonghyeon stream had little stagnant or no amount of water. It was presumed that the 

ground surface was dry before the start of rainfall. Relatively, the many outflows from the 

reservoir and rainfall had a flow of a fixed quantity from July to September. In TABLE 2, the 

average flow of each station from May to September during the irrigation periods is relatively 

larger than the average flow of each station from March to April during the non-irrigation 

periods. The flows of each station are shown to have a small difference, but the irrigation 

periods and the non-irrigation periods are shown to have large differences in flow. 

3

TABLE 1 Stream discharge for each monitoring section with 5 days antecedent precipitation and reservoir storage (2011) 

Date 

Antecedent 

precipitation 

(mm) 

Storage in 

Hai 

reservoir 

(%) 

Seokji Stream 

530 m 

stream discharge 

(m 3 /s) 

2,000 

m 

2,810 

m 

Storage in 

Bonghyeon 

reservoir 

(%) 

750 m 

Bonghyeon Stream 

1,260 

m 

stream discharge 

(m 3 /s) 

03/26 0.3 90 0.00 0.00 0.00 92 0.00 0.00 0.00 0.00 0.00 

04/29 8.5 98 0.00 0.00 0.00 100 0.00 0.00 0.00 0.00 0.00 

05/28 25.5 93 0.00 0.00 0.00 100 0.00 0.00 0.00 0.00 0.00 

06/29 150.5 85 0.21 0.00 0.00 100 0.14 0.00 0.30 0.00 0.36 

07/28 45.5 99 1.11 0.80 3.47 94 0.05 0.26 0.71 0.29 1.03 

08/29 14.1 89 0.00 0.00 0.00 94 0.00 0.14 0.24 0.00 0.07 

09/26 0.0 58 0.13 0.00 0.00 63 0.00 0.10 0.05 0.00 0.08 

1,730 

m 

4,190 

m 

5,500 m 

TABLE 2 Stream discharge for irrigation and non-irrigation periods (2011) 

Period 

Discharge of Seokji stream (m 3 /s) Discharge of Bonghyeon stream (m 3 /s) Average discharge 

(m 3 /s) 

530 m 2,000 m 2,810 m 750 m 1,260 m 1,730 m 4,190 m 5,500 m 

Non-irrigation 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Irrigation 0.29 0.16 0.69 0.04 0.10 0.26 0.06 0.31 0.24 

During the actual field survey, some sections appeared to have a flow reduction due to the 

impact around the station from kiwi-fruit orchards, mills, and barns. At the Seokji stream, 

despite the rainy season in July, the flow appeared to have a significant decrease at the point 

of 2,000 m. This phenomenon was estimated to be from the result of the impact of plentiful 

grass, as well as the presence of beams and kiwi-fruit orchards located from the reservoir 

downstream. At the Bonghyeon stream, the flow appeared to have a significant decrease at 

the point of 4,000 m. This was estimated to be due to the pumping of water from the kiwi-fruit 

orchards to be used as irrigation water. The flow increases at several junctions of the stream 

was determined to be affected from the effluent coming from the inlets and drainage areas of 

Seokji stream. 

3.2 Analysis of the Reservoir and River Water Quality 

Using a portable water quality measuring device, the pH of the agricultural reservoirs and 

the rivers was measured a total of seven times to investigate the changes in water quality. 

The National Instrumentation Center for Environmental Management (NICEM) at Seoul 

National University was asked to analyze the following seven items of water quality: BOD, 

COD, TOC, SS, Turbidity, T-P, and T-N. The results in TALBE 3 show the analyses of each 

water quality item according to the survey period of watershed study. July was the only 

month in which the water samples were able to be collected. In all the other months, it was 

difficult to measure the water quality and flow due to the streams being dry. 

TABLE 3 Water quality analysis of Seokji stream and Hai reservoir 

03/26 

04/29 

05/28 

Hai pH BOD (mg/L) COD (mg/L) TOC (mg/L) SS (mg/L) Turbidity (NTU) T-P (mg/L) T-N (mg/L) 

Reservoir 7.54 0.27 2.80 1.74 0.0 0.42 0.003 0.412 

530 m 7.80 0.99 1.36 1.84 0.0 0.41 0.007 0.247 

Reservoir 7.22 1.25 1.46 2.74 2.0 1.68 0.020 0.659 

530 m 7.19 0.52 1.84 1.90 2.0 0.79 0.009 0.576 

Reservoir 7.06 0.24 1.16 2.12 16.0 0.32 0.022 0.000 

530 m 6.79 0.78 2.78 3.48 12.0 1.11 0.193 0.000 

06/29 Reservoir 7.06 1.73 2.82 2.34 11.0 1.63 0.055 0.817 

Reservoir 7.02 1.77 2.02 2.06 8.0 0.98 0.021 0.577 

07/28 

530 m 7.12 1.17 1.60 1.75 8.0 0.25 0.080 0.796 

2,000 m 7.10 1.45 1.46 1.53 4.0 0.55 0.017 0.851 

2,810 m 7.08 0.85 1.60 1.36 3.0 0.33 0.028 1.510 

08/29 

Reservoir 6.72 0.66 2.18 1.90 3.0 0.96 0.020 0.577 

530 m 7.05 0.81 1.26 1.28 4.0 0.46 0.010 0.412 

09/26 

Reservoir 7.13 1.13 1.26 1.730 6.0 1.30 0.031 1.098 

530 m 7.35 0.23 0.72 1.070 0.0 0.32 0.029 0.000 

4

FIGURE 2 shows the SS and Turbidity variations of Seokji stream. The variations were 

divided into irrigation and non-irrigation periods to analyze the changes in water quality to the 

differences in the flow. The pollutant concentrations regarding COD, TOC, and Turbidity of 

the non-irrigation periods were slightly higher than the pollutant concentrations of the 

irrigation periods in the Hai reservoir. The pollutant concentrations of the regarding SS, COD, 

COD, TOC, Turbidity, T-N, and T-P of the non-irrigation periods were higher than the 

pollutant concentrations of the irrigation periods in the Seokji stream. The contaminant 

concentrations decreased nearer downstream. However, at the last station, there was a 

showing of an increase in concentration. This phenomenon was judged to be from the effects 

of ambient pollutants, like incinerated waste. The concentrations of SS were almost 

immeasurable during the non-irrigation periods. However, the concentrations of SS were 

judged to be high due to the inflow of ambient pollutants during the irrigation periods. 

FIGURE 2 SS and Turbidity variations for irrigation and non-irrigation periods of Seokji stream 

3.3 Correlation Analysis between Water Quality Parameters 

The correlation of water quality items from the reservoir and stream studies were analyzed 

using the water quality data obtained in July. Water quality was the independent variable and 

the control variable was the flow. In the case of the station located 530 m of Seokji stream, 

the correlation coefficients between SS and T-P, and TOC and Turbidity were shown to be 

0.925 and 0.960, respectively at a 0.01 level of significance. The correlation coefficients 

between COD and TOC, SS and TOC, SS and Turbidity, and TOC and T-P were shown to 

be 0.865, 0.854, 0.856, and 0.836, respectively at a 0.05 level of significance (TABLE 4). In 

the case of the station located 750 m of Bonghyeon stream, the correlation coefficient 

between COD and TOC was shown to be 0.887 at a 0.05 level of significance. At the station 

located 1,260 m of Bonghyeon stream, the correlation coefficients between the pH and COD, 

the pH and TOC, BOD and T-N, and COD and TOC were shown to be 0.920, 0.930, 0.938, 

and 0.932, respectively at a 0.01 level of significance. The correlation coefficients between 

the pH and T-P, BOD and COD, BOD and T-P, COD and T-P, TOC and T-P were shown to 

be 0.813, 0.814, 0.822, 0.866, and 0.818, respectively at a 0.05 level of significance (TABLE 

5). 

TABLE 4 Correlation analysis of water quality data at Seokji stream (530 m) 

pH BOD COD SS TOC Turbidity T-P T-N 

pH 1.000 0.649 0.672 0.294 0.631 0.578 0.229 0.535 

BOD 1.000 0.594 0.777 0.743 0.777 0.534 0.467 

COD 1.000 0.571 0.865 * 0.744 0.530 0.449 

SS 1.000 0.854 * 0.856 * 0.925 ** -0.069 

TOC 1.000 0.960 ** 0.836 * 0.188 

Turbidity 1.000 0.800 0.238 

T-P 1.000 -0.343 

T-N 1.000 

* p

TABLE 5 Correlation analysis of water quality data at Bonghyeon stream 

750 m 

1,260 m 

pH BOD COD SS TOC Turbidity T-P T-N 

pH 1.000 0.335 0.652 -0.408 0.791 0.041 -0.185 -0.429 

BOD 1.000 0.756 0.104 0.710 -0.586 -0.144 0.004 

COD 1.000 -0.064 0.887 * 0.033 -0.591 0.055 

SS 1.000 -0.366 -0.126 0.362 -0.350 

TOC 1.000 -0.057 -0.413 0.040 

Turbidity 1.000 -0.554 0.315 

T-P 1.000 -0.642 

T-N 1.000 

pH 1.000 0.660 0.920 ** 0.158 0.930 ** 0.655 0.813 * 0.503 

BOD 1.000 0.814 * -0.156 0.768 -0.070 0.822 * 0.938 ** 

COD 1.000 -0.209 0.932 ** 0.452 0.866 * 0.759 

SS 1.000 0.002 0.229 -0.044 -0.450 

TOC 1.000 0.429 0.818 * 0.700 

Turbidity 1.000 0.417 -0.200 

T-P 1.000 0.727 

T-N 1.000 

* p

Wind-Induced Flow in a Closed Water Body with Floating Culture 

System 

Abstrat 

Kunihiko Hamagami 1 *, Masayuki Fujihara 2 , Ken Mori 3 , Hidekazu Yoshioka 4 

1 Faculty of Agriculture, Iwate University, 3-18-8 Ueda Morioka, 020-8550 JAPAN 

2 Faculty of Agriculture, Ehime University, Matsuyama city, Ehime, JAPAN 

3 Former Professor of Kyushu University, Fukuoka city, Fukuoka, JAPAN 

4 Faculty of Agriculture, Kyoto University, Sakyo-ku, Kyoto, JAPAN 

*Corresponding author. E-mail: ham@iwate-u.ac.jp 

Hydraulic experiment by using a test tank and the construction of water flow prediction model 

were conducted to take into account the effect of the floating culture system on wind-induce 

flow. As the result of hydraulic experiment, it was revealed that a surface wave development 

was significantly inhibited due to the coverage. When the coverage is set up transversally at 

water surface, two wind-driven circulations are formed at the up- and down-wind portions of 

the coverage. The water flow prediction model employing CIP-CUP (CIP-Combined Unified 

Procedure) method and introducing air-water interaction of two-phase flow model well 

reproduce the development of surface wave and the pattern of internal circulation obtained 

by the hydraulic experiment. 

Key words: wind wave, internal circulation, C-CUP method 


Water quality degradation due to eutrophication is a serious problem in stratified closed 

water bodies in Japan. When there is no disturbance in closed water bodies with little inflow 

and outflow, they are easily stratified according to their density, and then vertical mixing 

becomes weak. The stratification also causes oxygen depletion in waters. Therefore, 

biological purification, which largely depends on the oxygen concentration, is scarce in 

closed waters compared to natural rivers. So, the water in closed waters is easily 

eutrophicated or polluted. Recently, due to the increasing environmental concerns, the 

heavily eutrophicated closed waters have been studied in various fields of research. 

In recent studies, water purification by plant nutrient absorption attracts great attention as a 

solution to the water quality problem. The floating culture system, which was originally 

developed to produce crops on the water surface of lakes and rivers in China (Song et al. 

1991), seems a possible option. In Japan, this has been introduced as the method for water 

purification in closed waters by taking out nutrients using plants grown in a floating board 

without soil (Miyazaki et al. 2000; Agata et al. 2000). Nutrients are removed from the water 

while the plants grow; hence, the water is purified. Although previous studies discussed the 

nutrient absorption ability of plants and considered the aspects of actual operation and 

management, those had hardly considered the physical dimension of the system, i.e. the 

relationship between the existence of coverage and the flow in the water. 

The main driving forces of water movement in closed waters with little inflow are the wind on 

the water surface and the water density distribution. The flow generally depends on the 

characteristics of the water body, like its shape or depth; hence, it is necessary to estimate 

the effect of the floating culture system on the flow at each water body. In the closed waters 

with the floating culture system, the floats shorten the fetch, and then weaken the 

entrainment at the density interface. Ozaki et al., (2003) reported that when floats are set on 

the water surface of a closed water body, the entrainment velocity decreases as the area of 

coverage increases. This is because the existence of the floats decreases the amount of

turbulent flow energy produced by wind and then reduces the capability of the vertical 

mixture. 

The premises above indicates that, to evaluate the ability of water quality purification by the 

floating culture system, it is necessary to examine the adequate covering rate of floats for the 

water purification considering their effects on the circulation flow in the closed waters. To 

take into account the effect of the floating culture system on wind-induce flow, this study 

therefore conducted hydraulic experiment by using a test tank with wind tunnel and 

constructed a water flow prediction model in the closed water body with the floating culture 

system. 

2. Hydraulic Experiment 

2.1 Material and Methods, 

Hydraulic experiment was conducted in a test tank (6m long x 0.3m wide x 0.4m deep) with a 

wind tunnel to investigate the effect of floating objects on the structure of wind-induced flow 

in closed waters (cf. Fig.1). In the experiment, three layout patterns of coverages (0.3m x 

0.6m) made of polystyrene foam were examined: Type A (the boards are set at the center of 

the tank and uniformly in the transverse direction of the tank), Type B (the boards are set at 

the same position as Type A, but set at the central part in the transverse direction) and Type 

C (the boards are set at the same position as Type B, but set at the side part in the 

transverse direction). 

Firstly, the characteristics of the water surface wave were examined to evaluate the influence 

of the layout patters on the wind-induced flow. The wind velocity was measured with a hotwire 

velocimeter at the center of the test tank, and the wind wave was measured with a wave 

meter of resistance line type. Moreover, the vertical distribution of flow velocity in the waters 

was measured by the flow visualization experiment using nylon particles and a laser light 

sheet. The images taken with a video camera were analyzed by PIV system. Each 

measurement position is shown in Fig.1. 

2.2 Results of the hydraulic experiment 

FIGURE 1: Experimental equipment 

Figure 2 shows the power spectrum obtained from the time-dependant wind wave in each 

covering type when rate of covering is 10%. The symbol F in the figure shows the 

measurement point in the test tank, and the solid line shows the spectrum characteristics of a 

well-developed wind wave derived by Phillips(1958) as follows, 

2 5 

ps( 

f ) g f 

(1) 

where, ps is the power spectrum of wind wave, f the frequency, g is the acceleration of 

gravity, and is the constant (=9.51 10 -6 ) following Burling(1967). From this figure, it is 

understood that the power spectra conform well to Eq.1 in any point when there is no

ps (cm·s) 

Water depth (m) 




coverage. On the other hand, the power spectra shift greatly from Eq.1 in the case of Type A. 

This indicates that the development of water surface wave is significantly inhibited by the 

existence of the coverage in Type A. Moreover, the power spectra in the case of Type B and 

Type C demonstrate the wind is developed enough compared with Type A. This means that 

the development of the wind wave was not greatly intercepted because the progressive wave 

passed through the area where the coverage did not exist. These experimental results also 

indicate that the layout of floating object with respect to the wind direction significantly affects 

on the hydraulic structure in the waters. 

1.E-02 

1.E-02 

1.E-02 

1.E-02 

1.E-03 

1.E-03 

1.E-03 

1.E-03 

1.E-04 

1.E-04 

1.E-04 

1.E-04 

1.E-05 

1.E-05 

1.E-05 

1.E-05 

1.E-06 

1.E-06 

1.E-06 

1.E-06 

1.E-07 

1.E-07 

1.E-07 

1.E-07 

1.E-08 

1.E-08 

1.E-08 

1.E-08 

1 10 100 1 10 100 1 10 100 1 10 100 

f (Hz) 

f (Hz) 

f (Hz) 

f (Hz) 

(a) No coverage (b) Type A (c) Type B (d) Type C 

FIGURE 2: Experimental equipment 

To investigate the effect of floating object existence in detail, the characteristics of the flow 

velocity and the turbulent energy in the cases of Type A and no coverage are compared in 

Fig. 3. In the case of no coverage, the flow velocity decreases from the water surface to 

about 1/3 of depth (wind-induced current), and the flow reverses in deeper layer (return 

current). That is, it turns out that the vertical circulation flow arises in the test tank. The 

turbulent energy is largest near the water surface. On the other hand, in the case of Type A, 

the flow velocity under the coverage is very small and two wind-induced circulations are 

formed at both the upwind and downwind portions of the coverage. The distribution of the 

turbulent energy is also small in the downwind portion of coverage. 

3. Numerical simulation 

3.1 Material and Methods 

8cm/s 

0 

10 

20 

30 

40 0 100 200 300 400 500 600 

(a) Flow velocity (No coverage) 

0.5cm 2 /s 2 

0 

10 

20 

30 

40 0 100 200 300 400 500 600 

(b) Turbulent energy (No coverage) 

8cm/s 

0 

10 

20 

30 

40 0 100 200 300 400 500 600 

(c) Flow velocity (Type A) 

0.5cm 2 /s 2 

0 

10 

20 

30 

40 0 100 200 300 400 500 600 

(d) Turbulent energy (Type A) 

FIGURE 3: Experimental equipment

The numerical model was validated and applied to the wind-wave flow in the closed water 

body with floating culture system. The numerical model can provide detailed information 

about pressure and velocity distributions for the whole calculated area. There are several 

methods to solve the free surface flows: Volume of Fluid (VOF) methd (Hirt and Nichols; 

1981), Level-Set method (Sussman et al.; 1994) and the Cubic-Interpolated Pseudo-particle 

Combined Unified Procedure (CIP-CUP) method (Yabe and Wand; 1991). In this study, a 

numerical model was developed based on CIP-CUP method equipped with a Large Eddy 

Simulation (LES) model. 

The governing equations of three-dimensional continuity, momentum and pressure equations 

are modified into the filtered equations for the LES modelling: 

 

 

ui 

u j 

(2) 

t 

x 

x 

ui 

u j 

t 

j 

u 

x 

i 

j 

1 P 

 

 

x 

x 

i 

i 

u 

i 

(2( 

) D 

e 

ij 

) g 

P P 

i 

ui 

C 

2 

s 

(4) 

t 

xi 

xi 

Where, is the density, t is the time, Superscript means the Grid Scale (GS) value of 

the each component. u i is the GS value of the velocity component u i . Subscript i , j (=1, 2, 

3) correspond to the coordinates x , z and y respectively, is the kinematic viscosity, e is 

the sub grid scale eddy viscosity, g is the gravitational acceleration constant, i2 

is the 

Kronecker delta, C s is the local sound velocity. The GS value of the strain-rate tensor D ij is 

as follows, 

1 

 

u 

u 

i j 

D 

(5) 

ij 

2 

 

x 

j xi 

 

P is defined as, 

1 

P p ii 

(6) 

3 

Where p is the the GS value of the pressure, ij uiu 

j uiu 

j is the residual stress. The SGS 

eddy viscosity coefficient e 

( ) D 

(7) 

2 

e C smg 

Where C smg is the Smagorinsky constant, is the filter width. D means the absolute value 

of the strain-rate tensor. In this study, CIP-CUP method was applied as the numerical model. 

CIP-CUP method is coupled with the unified procedure for the flow field calculation of the two 

or more phases. The method introduces a time dependent Poisson equation for pressure. 

Moreover, the density function was applied as the function of physical conditions. 

The calculation area have a surface dimension of 168 cm x 20 cm and depth of 25.6 cm. The 

number of grid point are 220, 25 and 32, respectively.The each grid size is 0.8cm. The 

velocity of the inlet air flow is uniformly 1m/s at the wind tunnel set up on the windward. The 

leeward wind tunnel is a slope with a constant gradient for wave-dissipating. In the following 

calculation results, only the region of water tank is displayed. 

3.2 Result of numerical simulation 

Fig. 4 shows the interface shape of wind wave and the the power spectrum obtained from 

the time-dependant wind wave at the 10 seconds, respectively. The wind-wave has been 

formed uniformly in a span ( y ) direction of the tank by the action of wind soon after the 

begging of blowing. The significant wave height and wave length increases with an increase 

in fetch. Moreover, a wind-induced circulation is formed with a wind-driven surface water 

flows downward to the lower layer at the end of tank. The power spectrum of wind wave has 

a remarkable peak as well as the experiment result. The distribution of spectrum is similar to 

i2 

(3)

the experimental results and close to the Eq. 6 with an increase in fetch except the upstream 

part of tank. This indicates that the prediction model well reproduced the development of 

wind-wave obtained by the hydraulic experiment. 

20cm 

8cm 

Flow 

17.6cm 

Air phase 

160cm 

Water phase 

(a) The shape of interface 

(b) The power spectrum 

FIGURE 4: The interface shape and the the power spectrum of wind wave 

Since this numerical model deals with air and water phases, the characteristics of vertical 

transport of vortex through the water surface can be considered. Fig. 5 shows the isosurface 

of the second invariant of velocity gradient tensor Q in the air and liquid phases at the 10 

seconds. Q represents the local balance between the shear strain rate and vorticity 

magnitude. The region of positive implies the the rotation tensor dominates over the rate of 

strain tensor. In addition, the color distributuion at the water surface represents the turbulent 

intensity of the velocity in the flow direction. This figure illustrates that two-dimensional vortex 

structure is formed along the lines with the wind wave which develops in parallel to the span 

direction at the air and liquid phases, respectively. This indicates the wind induced flow has a 

vortex structure with a strong three-dimensional feature. 

z 

y 

x 

(a) Air phase 

(b) Water phase 

FIGURE 5: The isosurface of the second invariant of velocity gradient tensor 

Finally, we discuss the effect of the coverage on the development of wind wave and the 

characteristics of circulation flow. Fig. 6 shows the shape of water surface and the velocity 

distribution near the coverage in case of Type A. The shape of water surface indicates that 

the development of water surface wave is inhibited by the existence of the coverage. Then, 

the wave height decrease significantly behind the coverage. Moreover, the velocity is large in 

the vicinity of the water surface in front of the coverage, and it seems to be transported 

downstream under the board. The velocity around the back edge of coverage is very small, 

but in the vicinity of the water surface it starts to grow again. In this way, two wind-induced 

circulations are formed. 

y 

z 

x

4. Conclusion 

FIGURE 6: The shape of water surface and the velocity distribution 

Main results from the hydraulic experiment are as follows. 1) Surface wave development was 

significantly inhibited due to the coverage which transversally covers water surface from one 

side of the tank to another. 2) The region below the coverage became stagnant; hence two 

wind-driven circulations were formed at the up- and down-wind portions of the coverage. 3) 

When the coverage was set at the center or along both sides of the tank, surface wave was 

developed through the clearance around the coverage so that its spectral distribution was 

similar to that of well-developed wave. The water flow prediction model employing CIP-CUP 

(CIP-Combined Unified Procedure) method and introducing air-water interaction of twophase 

flow model well reproduced the development of surface wave and the pattern of 

internal circulation obtained by the hydraulic experiment. 


Agata, W., Takeuchi, Y., Aoki, N., Yamaji, H., Kawanabe, Y., & Miyazaki, A. (2000). 

Botanical character and cultural method of umbrella plant (Cyperus alternifolius L.). Bull. 

Nishinihon Green Res. Inst., 2, 27-36. (in Japanese with English summary) 

Burling, R. W., & Stewart, R. W. (1967). Ocean-Atmosphere Interaction (microprocesses), 

Encyclopedia of Oceanography, R. Fairbridge, Ed., Rheinholdt, 571-576. 

Hirt, C. W., & Nichols, B. D., (1981). Volume of Fluid (VOF) Method for the Dynamics of Free 

Boundaries. Journal of Computational Physics, 39, 201-225. 

Miyazaki, A., Kubota, F., Agata, W., Yamamoto, Y., & Song, X. (2000). Plant production and 

water purification efficient by rice and umbrella plants grown in a floating culture system 

under various water environmental conditions J. Fac. Agric., Kyushu Univ., 45, 29-38. 

Ozaki, A., Muramatst, R., Mori, K., Inoue, E. & Haraguchi, T. (2002). Effect of Wind Induced 

Flow in a Closed Density Stratified Water Area Partially Covered with Floating Water Plants. 

Journal of the Faculty of Agriculture, Kyushu University, 47, 139-147. 

Philips, O. M. (1958). The Equilibrium Range in the Spectrum of Wind-generated Waves, 

Journal of Fluid Mechanics, 4, 426-434. 

Song, X., Ying, H., Zhu, M., & Wu, W. (1991). A study on growing rice with floating method 

on the waters. Sci. Agric. Sin, 24, 8-14. (in Chinese with English abstract) 

Sussman, M., Smereka, P., & Osher, S., (1994). A Level Set Approach for Computing 

Solutions to Incompressible Two-Phase Flow. Journal of Computational Physics, 114, 146- 

159. 

Yabe, T. andWang, P.Y. (1991) United Numerical Procedure for Compressible and 

Incompressible Fluid. Journal of the Physical Society of Japan, 60(7), 2105-2108.

Development of a Conceptual Model for Drought Analysis 

(Case Study: Zayandeh-Rud Basin) 

Hamidbabaei*, Shahab Araghinejad 

University of Tehran, Deparetment of water respurce manegement, karaj, 31587-77871, Iran 

*Corresponding author. E-mail: hamidbabaei1@gmail.com 

Abstrat 

The study was intended at devising a suitable technique for assessment of vulnerability to 

drought. The Analytic Hierarchy Process (AHP) develops a framework to evaluate the relative 

priorities of assessment drought based on a set of preferences, criteria and indicators for the 

areas. The objective of this study was to apply of AHP with Geographic Information System 

(GIS) techniques using the drought indices and hydrological factors for assessment of regional 

drought in the Zayande-Rud basin, Iran. Therefore, the used indicators include the Palmer 

Drought Severity Index (PDSI), Surface Water Supply Index (SWSI), Standardized Precipitation 

Index (SPI), water demand of watershed and groundwater balance. The results showed that this 

method provides a comprehensive idea of drought vulnerability by conducting comparative 

analysis among drought indices and hydrological factors in the spatial and temporal domains. 

Key words: The Analytic Hierarchy Process, Geographic Information System, SPI, PDSI, SWSI 


Drought is one of the most important natural disasters that show its influences slowly by time. 

Drought commonly develops with no clear warning and without identifiable borders, and leads to 

agriculture losses of billions of dollars annually (Kagon, 2000). Various methods and indices 

have been developed by many scientists (Palmer 1965, Gibbs & Maher 1967, Shafer & Dezman 

1982, McKee et al., 1993) for drought analysis using different drought-causative and drought 

responsive parameters such as rainfall, soil moisture, potential evapotranspiration, groundwater 

and surface water levels. These drought indices often have little correlation among themselves. 

Therefore, it is quite common that when one drought index identifies drought at a particular 

place, another drought index indicates a normal condition at the same place and time. In this 

study combination of bivariate drought indices (SPI, PDSI and SWSI) and other factors 

(Groundwater Balance, Water Demand) for presented a Conceptual Model for drought 

assessment of regional drought in the Zayande-Rud basin, Iran. 

2. Material and Methods

2.1 Case study 

The Zayandeh-Rud basin is located in central part of Iran with the area of 41,500 km2 (Fig. 1). 

The dominant climate in this basin is arid or semiarid climate. The averages of precipitation are 

about 1500 mm per year, most precipitation occurs as snowfall during December to April. Large 

economical and social damages accrue annually because of the widespread droughts in this 

region. Thus, the lack of current water causes limit of available amount of water for using 

economical options. In this paper, drought trends in the basin have been investigated from 1668 

to 2007 years. 

FIGURE 1 Zayandeh-Rud basin, Iran 

2.2 The AHP method 

The analytic hierarchy process (AHP) first developed by Saaty (1980) and used in different a 

multi-criteria decision problem. The process makes it possible to incorporate judgments on 

qualitative and quantitative aspects criteria. The AHP method is based on three principles: first, 

structure and dominance of the hierarchy; second, comparative judgment of the alternatives and 

the criteria, sub-criteria, sub sub-criteria and so forth; third, synthesis of the priorities for 

estimating the consistency ratio. In the literature, AHP, has been widely used in solving many 

complicated decision-making (Banai, 1993). 

2.3 Conceptual framework 

The six parcels in the Zayandeh-Rud basin are represented in a raster GIS. The parcels are 

determined to evaluate drought assessment with regard to four criteria (meteorological, 

agricultural, hydrological and socioeconomic drought) and five sub-criteria. The decision 

problem includes ranking the alternative parcels based on drought vulnerability. The AHP 

method was used to weight the factors. Developing a hierarchal structure for the decision

problem is the first step in the AHP process. To determine the drought vulnerability, a four-level 

hierarchal model is devised. The goal at the top level is to determine drought sensitivity. At the 

second level, this goal is divided into four main criteria: meteorological, agricultural, hydrological 

and socioeconomic drought factors. The third level of hierarchy contains five sub-criteria. 

Finally, the fourth level contains six decision alternatives (parcels) of that the decision makers 

required to compare the evaluation of drought vulnerability (Fig. 2). 

FIGURE 1 Conceptual model for drought assessment 

3. Results and Conclusion 

The mentioned approach was introduced to integrated management of watersheds and make 

decision in drought conditions in considering the drought importance and all conditions 

influencing on its occurrence. This approach is based on combined AHP and GIS it is the 

difference between mentioned approach and other ones. To utilize in decision making process, 

presented issue was arranged in a hierarchical structure. This hierarchical structure can state 

expert’s knowledge from different viewpoints and involves the opinions of individuals who have 

experienced the drought. Using AHP methods, it is possible to enter all influencing and affected 

variables on the drought in the model. Both natural and artificial factors can affect on the 

drought while applying drought indices involve the natural factors solely. Determination of the 

most vulnerable region in terms of drought is conducted without respect to data uncertainty, 

input data and expert’s knowledge. The input data are complex, continues and uncertain maps 

and based on them, the priority of regions to drought was conducted. 

This study points out opportunities for future research: for more comprehensive evaluation of 

drought vulnerability and further validation, it is necessary to insert other relevant social and

economic factors. In this is a very useful application AHP analysis applied to a number of 

drought measures in order to balance them to arrive at a single score of drought 

severity. 

References: 

Gibbs, W. J., & Maher, J. V. (1967). Rainfall Deciles as Drought Indicators. Bureau of 

Meteorology Bulletin No. 48. Commonwealth of Australia, Melbourne. 

Kagon, F. N. (2000). Global drought detection and impact assessment form space, in drought. A 

Global Assessment, 1, 196-210. 

McKee, T .B., Doesken, N. J., & Kleist, J. (1995). Drought monitoring with multiple time scales. 

In: Proceedings of the Ninth Conference on Applied Climatology, Am. Meteorol. Soc. Boston, 

pp. 233–236. 

Palmer, W. C. (1965). Meteorological Drought, Research Paper No. 45. U.S. Department of 

Commerce Weather Bureau, Washington, DC. 

Shafer, B .A., & Dezman, L.E. (1982). Development of a Surface Water Supply Index (SWSI) to 

assess the severity of drought conditions in snowpack runoff areas. In: Proceedings of the 

Western Snow Conference, Fort Collins, CO, pp. 164–175. 

Saaty, T. (1980). The analytical hierarchy process. McGraw-Hill, Suffolk. 

Banai, R. (1993). Fuzziness in geographical information systems: contributions from the analytic 

hierarchy process, International Journal of Geographical Information Systems, 7, 315-329.

Variability of water quality in a lake receiving drainage water 

from the Hetao irrigation system in the Yellow River basin, 

China 

Biao Sun 1 , Changyou Li 1 , Claudia M d S Cordovil 2 , Keli Jia 1 , Sheng Zhang 1 , 

Zhongyi Qu, Amarilis de Varennes 2 , and Luis S Pereira 2 

1 College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural 

University, Hohhot, 010018, PR China 

2 CEER - Biosystems Engineering, Institute of Agronomy, Technical University of Lisbon, 

Tapada da Ajuda, 1349-017 Lisbon, Portugal 

* Email: lspereira@isa.utl.pt 

Abstract 

The Wuliangsuhai Lake is very important for the irrigation and drainage system of the 

Hetao Area in China. Between 2005 and 2010,water quality of the lake was monitored 

using physical, chemical and biological parameters. Chemical changes over time were 

not significant while COD was affected by the building of a new tomato plant as well as 

by a new Sewage Treatment Plant. To this day large amounts of organic industrial 

wastewaters are discharged into the lake without any treatment affecting water quality. 

Freezing of the lake during the cold season and flow direction affected several of the 

parameters monitored. 

Keywords: water quality dynamics, Irrigation, Wuliangsuhai Lake 


Awareness of an impending water crisis began in the 1970’s but it was only in the 

1990’s that water eutrophication became a serious problem in China (Jingan and 

Hongqing, 2002) affecting all economical activities dependent on freshwater quality. The 

Northwest of China is an arid or semi-arid region, depending on water for local 

economic development, namely water derived from the lakes. The Hetao Region is one 

of the three largest agricultural regions in China (Yang and Liu, 2002), with an irrigated 

area of about 5640 km 2 . Irrigation water comes mainly from the Yellow River (5 billion 

m 3 ) and is discharged into the Wuliangsuhai Lake (WL) (Fig. 1). In Hetao, pesticides 

and fertilizers were first used by the 1960’s. Rapid economic development led to an 

increase of urban wastewater discharge (0.5 billion m 3 ) and agricultural runoff into the 

WL from the upper channels (Wan, 2009). Currently, 1500 to 2000 tons of pesticides 

and 600000 tons of fertilizers are used per year (Liu, 2004), impacting the quality of thw 

WL water and compromising natural ecosystems. Groundwater quality of WL has been 

studied before (Liu et al., 2010) but little is known about surface water quality in the 

Hetao irrigation area. It is therefore urgent to identify polluting sources as well as the 

available practices to mitigate euthrophication of the lakes.

FIGURE 1. Location of the Wuliangsuhai Lake in Hetao 

2 Materials and methods 


The WL is the largest in the Yellow River Basin in China, located between 108°43' 

and 108°57' E, and 40°36′ and 41°03′ N (0). It is about 35 to 40 km long, and 5 to 10 km 

wide, with a total area of 306 km 2 . A area of 177 km 2 is covered with reed and 129 km 2 

is open water (Sun et al. 2011). The WL is very important for the irrigation and drainage 

system of Hetao area. The losses and discharges of wastewater from municipal and 

animal production sources, as well as losses from agricultural fields located around the 

lake, drain mainly into the Main Drainage Channel (90%). A net of irrigation channels 

connects the Main channel and WL (Fig. 1). The WL is frozen for about five months per 

year, usually from mid November to mid April. The WL capacity is about 0.33 billion m 3 

and depth ranges from 0.5 to 3.0 m. Annual average air temperature is 7.3 ºC, with an 

average of 3185 hours of sunshine, 224 mm of annual rainfall, 1502 mm of evaporation 

per year and a 3.5 km h -1 wind speed. 

volume of irrigation water(10 9 m 3 ) 

2,0 

1,8 

1,6 

1,4 

1,2 

1,0 

0,8 

0,6 

0,4 

0,2 

diverted for irrigation water 

discharged + surface drainage water 

0,0 

0,08 

0,07 

0,06 

0,05 

0,04 

0,03 

0,02 

0,01 

Jan. 

Apr. 

volume of discharge water(10 9 m 3 ) 

July 

Oct. 

0,00 

FIGURE 2. Average annual use of irrigation water in Hetao and discharge into WL.

About 5.2 billion m3 water is diverted each year from the Yellow River to irrigate this 

area (Qu et al., 2003) During the last 10 years, the average water use in the Hetao 

area was greatest from April to November (Fig. 2). Although from January to April no 

irrigation was carried out, there was still some wastewater discharge into the lake (Fig. 

2). A study on impacts of various irrigation scenarios on the groundwater dynamics was 

carried out by Xu et al., (2010). 

2.2. Sampling, analytical and statistical methods 

From 2005 to 2010 (Table 1), twenty-one geo referenced sites with a grid of 

about 2×2 km 2 and covering about 85% of the open water, were marked in the 

lake. Sites were chosen according to the distribution of pollution sources and 

hydrodynamic characteristics of the lake. Water samples were collected at a 

depth of 20 cm with polyethylene or glass bottles according to different water 

quality indicators, then stored at controlled temperature and analyzed for 

chemical, physical and biological parameters, within 24 h. 

Table 1 . Sampling times in the WL from 2005 to 2010 

Sampling time 2005 2006 2007 2008 2009 2010 

January (frozen lake) 8th 7th 14th 

May 10th 16th 12th 18th 

June 28th 13th 19th 7th 5th 23th 

July 20th 19th 16th 8th 27th 

August 27th 12th 22th 13th 10th 24th 

September 15th & 30th 12th 19th 12th 16th 26th 

October 19th 12th 23th 23th 14th 23th 

Data was analyzed with excel 2003 and with the Kriging Geostatistical technique of 

Geostatistical Analyst Arc GIS 9.3. Maps of concentration for different water quality 

indicators were created to show spatial distribution. 

3. Result and discussion 

3.1. Temporal variability of parameters 

Some parameters showed a clear seasonal variability which was repeated over the 

years (Fig. 3), while others, namely total nitrogen (N), chlorophyll a and electrical 

conductivity, appeared to decrease with time. In contrast, suspended solids, COD and 

dissolved organic increased with the years, showing a probable increase in urban 

wastewater discharge into the lake. The marked season variability shown in figure 3 

suggests a great influence of irrigation on water quality of the lake. In fact, values of total 

N (TN) and total phosphorus (TP) were significantly higher in the winter compared with 

other seasons. The greater organic load in winter was reflected on a higher 

concentration of suspended solids as well as COD. Together, these parameters may 

increase the risk for eutrophication of the lake.

WT( o C) 

(a) 

30 

25 

20 

15 

10 

5 

0 

-5 

WT 

TN(mg/L) 

(b) 

TP(mg/L) 

COD(mg/L) 

(c) 

(d) 

Chl.a(mg/m 3 ) 

(e) 

SS(mg/L) 

(f) 

EC(ms/cm) 

(g) 

12.0 

10.0 

8.0 

6.0 

4.0 

2.0 

0.0 

0.7 

0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

0.0 

160 

120 

80 

40 

0 

90 

75 

60 

45 

30 

15 

90 

75 

60 

45 

30 

15 

0 

5.0 

4.0 

3.0 

2.0 

1.0 

0.0 

10.0 

9.0 

0 

TN 

TP 

COD 

Chl.a 

2005 2006 2007 2008 2009 2010 

SS 

EC 

pH 

pH 

(h) 

8.0 

7.0 

6.0 

DO(mg/L) 

(i) 

18.0 

15.0 

12.0 

9.0 

6.0 

3.0 

0.0 

2005 2006 2007 2008 2009 2010 

FIGURE 3. (a) water temperature WT, (b) total Nitrogen TN, (c) total phosphorus TP, (d) 

chemical organic demand COD, (e) chlorophyll a Chl.a, (f) suspended solids SS, (g) 

electrical conductivity EC, (h) pH and (i) dissolved organics DO. 

DO

3.2. Variability of parameters 

The spatial distribution of the overall means of measured parameters is shown in Fig. 

4. The greatest values for temperature, electrical conductivity, pH and dissolved 

organics was measured in the south of the lake in agreement with the direction of the 

water flow, from northeast to southwest. Totals of N and P were higher near the 

entrance of the channels which discharge into the WL (Fig 4.). COD and Chl.a are very 

consistent in this spatial distribution, thus revealing the discharge of wastewater into the 

WL. Nitrogen and P consumption by reed which covers about 15% of the lake might 

explain the decrease in the concentrations along the flow. 


The main factors influencing temporal variations in water quality seem to be 

agricultural losses of nutrients as well as wastewater discharge into the channels which 

lead into the WL. Winter seems to be the season where the water has a greater load of 

nutrients and evaporation during summer may influence parameters concentration. The 

direction of water flow and the position of channels in and out of the WL also influenced 

the concentration of parameters concentration in the water. 


We would like to thank the lake research team in Inner Mongolia Agricultural 

University for their persistent efforts in collecting/measuring the data in this study. The 

study is supported by the Sino-Portuguese cooperative research project, MOST, China, 

and FCT, Portugal . 


Ma, J. & Li, H. (2002). Preliminary discussion on eutrophication status of lakes, 

reservoirs and rivers in China and overseas. Resources and Environment in the 

Yangtze Basin 6, 575-578 (in Chinese). 

Yang, L. & Liu, Y. (2002). Discussion on water resources utilization in Hetao Irrigation 

District in Inner Mongolia Autonomous Region. Proceedings of agricultural engineering 

science and technology, 128-130. 

Liu, Z. (2004). Research about estimation the input to the lake Wuliangsuhai from farmland 

surface pollution. Inner Mongolia university Master Degree Thesis, 14-33 (in Chinese). 

Wan, F. (2009). Study on Ecological Water Supplement of Wu Liang Su Lake. Xi'an 

University of Technology Master Degree Thesis, 10-41 (in Chinese). 

Liu, W., Gao, C., Liu B. & Chen, Y. (2010). Hydro-chemical constituents and correlation 

analysis of shallow groundwater in the Hetao Plain. Geology in China 37, 816-823 (in 

Chinese). 

Qu, Z.Y., Chen, Y.X., Shi, H.B., Wei, Z.M., Li, Y.L. & Zhang, Y.Q. (2003). Regional 

groundwater depth forecast by BP model of post-water-saving reconstruction in the 

Hetao Irrigation District of Inner Mongolia. Trans. CSAE 19 (1), 59–62 (in Chinese). 

Xu X, Huang GH, Qu ZY & Pereira LS (2010) Assessing the groundwater dynamics 

and predicting impacts of water saving in the Hetao Irrigation District, Yellow River basin. 

Agric. Water Manage 98, 301-313

(a) (b) (c) 

(d) (e) (f) 

(g) (h) (i) 

FIGURE 4. Spatial distribution of water quality for (a) WT, (b) TN, (c) TP, (d) COD, (e) 

Chl.a, (f) SS, (g) EC, (h) pH and (i) DO (for key to parameters see fig. 3 legend)

Surface Energy Balance to Estimate Evapotranspiration of Irrigated 

Orange Orchards under Mediterranean Semi-arid Conditions 

Simona Consoli 1 , Rita Papa 1 * 

1 Dept di Gestione dei Sistemi Agroalimentari e Ambientali, University of Catania, Via S. Sofia 

n.100, Catania, 95123, Italy 

*Corresponding author. E-mail: rita.papa@gmail.com 

Abstract 

Eddy covariance (EC) is the generally preferred technique today for measuring energy and 

mass fluxes of vegetated surface, with many experimental sites established in the global 

Fluxnet network. A fundamental problem with EC, violating the principle of energy 

conservation, is that energy balances determined are generally “unclosed”, with combined 

sensible and latent heat fluxes commonly underestimating available energy by 20% or more. 

In this paper, based on the analysis of a long-term energy balance monitoring program, a 

Bowen ratio-based method (BR) was proposed to resolve the lack of closure of the EC 

technique to obtain reliable ET values. ET values determined from BR method were 

compared with up-scaled transpiration data determined by the sap flow method. In addition a 

model of crop ET using a Penman-Monteith-type model was applied and used to determine 

crop coefficient values. 

Key words: Closure of energy balance, Evapotranspiration, Irrigation, Orange groves. 


Since the mid-1990s the establishment of the Fluxnet network allowed a long-term high 

quality observation of heat and mass exchanges between land surface and the atmosphere, 

for a wide range of ecosystems. Eddy covariance (EC) is the most widely used technique at 

currently operational flux-tower sites worldwide. However, an analysis by Wilson et al. (2002) 

of surface flux measurements at 27 EC sites distributed across North America and Western 

Europe, showed that energy budget closure was lacking at all the investigated sites. Aubinet 

et al. (2000) reported a similar finding based on analyses of EC data collected at European 

sites. Typically, the lack in annual energy closure ranges between 5% and 30%. 

Consequently, the sensible heat and latent heat associated with turbulent movement are 

systematically underestimated. The current inability of EC to close the energy budget is a 

well-known issue, which has led several authors to emphasize the necessity to find a way to 

handle it. In order to improve the usefulness of eddy covariance measurement, Twine et al. 

(2000) suggested adjusting sensible and latent heat to force the energy balance. However, 

some researchers have pointed out the difficulty to apply and evaluate ecosystem models 

using flux measurements that exhibit a lack of energy closure and the imperative need for 

resolving observed energy budget imbalances in measured data prior to their use to test 

models. The objective of the paper is to investigate and discuss the effects of using corrected 

energy budget measurements of sensible and latent heat fluxes on the estimation of crop 

evapotranspiration (ET) and crop coefficient for orange orchards. Therefore, the key points of 

the paper can be outlined as follows: 

• The evaluation of the Bowen Ratio (BR) correction method to solve the unclosed 

surface energy balance at the study site; 

• The evaluation of the performance of the sap flow method for the measurement of 

actual evapotranspiration through comparison with micrometeorological method; 

• The development of a model of the orange orchard evapotranspiration following a 

Penman-Monteith approach, using standard meteorological variables as input to 

determine canopy resistance;

• The effectiveness of the crop coefficient method to determine water requirements of 

the orange orchard and to verify the suitability of the K c value proposed for a generic 

citrus crop. 

2. Materials and methods 

2.1. Site information and field measurements 

The trial was carried out during the monitoring period 2010-2011 within an orange orchard 

located in Sicily, Southern Italy (Lentini, lat. 37°16’N, long. 14°53’E). This area has a 

Mediterranean semi-arid climate (annual mean air temperature 17°C and rainfall less than 

600 mm). The experimental field was planted with 15-25 year old orange trees, grown in an 

orchard of about 120 ha. The mean canopy height was 3.75 m. Leaf area index (LAI, m 2 m -2 ) 

was found to be in the range 4.0-4.7. For the dominant wind direction (the main were W and 

NW), the fetch was larger than 550 m. The crop was maintained in a well-watered conditions 

by irrigation supplied every day during hot months (May-October). Water was supplied by 

drip irrigation, with on-line labyrinth drippers, in a number of four per plant, spaced at 0.80 m, 

with discharge rate of 4 l/h at a pressure of 100 kPa. 

Continuous energy balance measurements were made from January 2010 until December 

2011. Net radiation (R n , W m -2 ) was measured with two CNR 1 Kippen&Zonen net radiometer 

at height of 8 meter. Soil heat flux density (G, W m -2 ) was measured with three soil heat flux 

plates, which were placed horizontally 0.05 meter below soil surface. The air temperature 

and the three wind speed components were measured at two heights, 4 and 8 meter, using 

fine wire thermocouples (76 µm diameter) and sonic anemometers (CSAT, Campbell Sci.). A 

gas analyzer (CSAT, Campbell Sci.) operating at 10 Hz was deployed at 8 meter. The raw 

data were recorded at a frequency of 10 Hz using two synchronized data loggers. 

Low frequency measurements were taken for air temperature and humidity, wind speed and 

direction, and atmospheric pressure at 4 and 8 meter. Rainfall was measured nearby. 

2.2. Energy closure at the orange orchard and correction of measured sensible and latent 

heat fluxes 

Neglecting the amount of available energy at the land surface that is used for photosynthesis 

(typically less then 1% of net radiation), the surface energy balance can be expressed at 

hourly or longer time scale as: 

R n = H + λE 

+ G 

(1) 

R n -G is commonly termed available energy and the surface heat storage (G) at daily or 

longer time scales is negligible. 

The EC method, applied at the site selected for this study, allows for estimates of H and λE 

from direct measurements of fluctuations in the vertical wind velocity and the scalar 

concentration. The lack of closure in the energy budget is commonly quantified by the 

relative difference between (R n -G) and (H+λE), expressed as a percentage: 100×[((R n - 

G)/(H+λE))-1]. Figure 1 shows the hourly data on (H+λE) plotted against (R n -G). Assuming 

that R n and G measurements are rather accurate, Fig. 1 shows that during both the 

monitored years (H+λE) is underestimated at the site. This may arise from an 

underestimation of H or λE, or both. The mean annual energy imbalance is 29.3% during 

2010 and 31.1% in 2011, showing peaks during winter and a variation of about 30%. 

The BR approach assumes that the EC technique provides correct estimates of the Bowen 

ratio (β=H/λE) even though it underestimates H and λE, as some studies tend to confirm (El 

Maayar et al., 2008). Thus rearrangement of eq. 1 yields: 

Rn − G 

λE 

= 

(2) 

1+ β

3.0 

y = 0.8935x 

R 2 = 0.917 

3.0 

y = 0.8628x 

R 2 = 0.8979 

2.0 

2.0 

H+λE (MJ m -2 h -1 ) 

1.0 

0.0 

H+λE (MJ m -2 h -1 ) 

1.0 

0.0 

-1.0 

-1.0 

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 

a) monitoring year 2010 Rn-G (MJ m -2 h -1 ) 

b) monitoring year 2011 Rn-G (MJ m -2 h -1 ) 

FIGURE 1: Hourly lack of energy closure in measured data at the selected site in 2010 (a) 

and 2011 (b). The solid line indicates the 1:1 line. 

Then corrected estimates of λE are assumed to be given by eq. 2, after which H can also be 

inferred from: 

H = Rn − λE 

− G 

(3) 

Equations (2) and (3) effectively redistributed the imbalance to H and λE according to their 

measured relative proportions. In the follow, corrected latent and sensible heat fluxes refer to 

λE corr and H corr as calculated from measured data using equations (2) and (3). The crop 

evapotranspiration (ET c,corr ) was calculated transforming the λE corr into millimetres of water. 

The calculation of ET c,corr at a daily time scale was obtained by summation of all 1 hour 

values for 24h periods. 

2.3. Sap flow measurements 

Measurements of water consumption at tree level were done in by using HPV (Heat Pulse 

Velocity) technique. For HPV measurements, two 4-cm sap flow probes with 4 

thermocouples embedded were inserted in the trunks of three trees. The probes were 

positioned at North and South sides of the trunk at 50 cm from the ground and wired to a 

data-logger for heat-pulse control and measurement; sampling interval was 30 min. Data of 

the two probes were processed according to Green et al. (2003) to integrate sap flow velocity 

over sapwood area and calculate transpiration. To this purpose, fraction of water in the 

sapwood was determined both on sample trees, during the experiment, and directly on the 

trees where sap flow probes were installed, at the end of the observation period. Woundeffect 

correction (Green et al., 2003) was done on a per-tree basis. The scaling up of the sap 

flow from the single tree to the field scale was carried out by the analysis of the spatial 

variability of plant leaf area. Thus, scaling was done only on the basis of the ratio between 

orchard LAI and tree leaf area. 

2.4. Modelling of crop evapotranspiration 

The analysis of orange orchard crop evapotranspiration (ET c,mod ) was made on the basis of 

the Penman-Monteith model. At hourly time scale ET c,mod was calculated using: 

∆A 

+ ( ρCpD /ra 

) 

λ E = 

(4) 

∆ + γ 

( 1+ 

r /r ) 

c 

a 

where A=R n -G (W m -2 ), ρ is the air density in kg m -3 , ∆ is the slope of the saturation pressure 

deficit versus temperature function in kPa °C -1 , γ is the psychrometric constant in kPa C -1 , C p 

is the specific heat of moist air in J kg -1 C -1 , D is the vapour pressure deficit of the air in kPa, 

r c is the bulk canopy resistance in s m -1 and r a is the aerodynamic resistance in s m -1 .

As evidenced by Rana et al. (2005), for irrigated crops r c is not a constant, but it varied 

depending on the available energy and the vapour pressure deficit. Katerji and Perrier (1983) 

proposed to calculate r c as: 

* 

rc 

r 

= a + b 

(5) 

* ∆ + γ ρCpD 

r = ⋅ 

(6) 

ra 

ra 

∆γ A 

where a and b are empirical calibration coefficients which require experimental 

determination; r* (s m -1 ) is given as (Monteith, 1965). 

In our study, the canopy resistance was calculated from eq. 4, by introducing the λE corr 

values calculated by eq. 2, together with the measured values of D and A, and the estimated 

values of r a : 

ln(z − d) /(hc 

− d) 

ra 

= (7) 

* 

ku 

where z is the reference point above the canopy (8 meter), d (m), the zero plane 

displacement is estimated as a portion of the canopy height where an intermediate scaling is 

d=0.75 h c , h c is the mean height of the orchard (3.75 m), k=0.4 is the von Karman constant 

and u* is the friction velocity (m s -1 ) measured by the EC method. The obtained values of r c 

were combined with eq. 5 to estimate the parameter a and b. 

The model was calibrated using 3 months of data (June-August) during the irrigation season 

2010. A linear curve fit resulted in a=0.364 and b=0.0422 (coefficient of determination 

R 2 =0.6287). 

The final expression of the model at hourly time scale is: 

∆A 

+ ( ρCp 

D ra 

) 

λ Emod 

= 

(8) 

∆ + γ( 1.0422 + 0.364(r * / ra 

)) 

The calculation of the orange orchard ET c,mod at daily time scale was obtained by summation 

of the hourly values of λE mod (from eq. 8), after dividing by λ. 

2.5. Determination of the crop coefficient Kc 

Crop coefficients are determined by calculating the ratio K c = ET c,mod /ET o , where ET c,mod is the 

evapotranspiration of a well-watered crop and ET 0 is the reference evapotranspiration 

calculated by the Penman-Montetih method (Allen et al., 1998). The variables used for ET 0 

determination were measured in an agrometeorlogical station of the Sicilian 

Agrometerological Service (SIAS) located 3.0 km away from the experimental field. The 

station was equipped with instruments for measuring the standard meteorological variables 

(solar radiation, wind speed and direction, air temperature, relative humidity). 


3.1. BR-correction of measured sensible and latent heat fluxes 

The energy balance ratio, i.e. the ratio of turbulent energy fluxes to available energy was 

0.89 in 2010 and 0.86 in 2011. The RMSE (root mean square error) for 1 h values turbulent 

fluxes was 1.27 and 1.29 MJ m -2 h -1 , during 2010 and 2011 respectively, evidencing the good 

quality of the dataset. The latent heat flux (λE) was always in excess of the sensible heat flux 

(H) during daylight hours. The H was higher than the soil heat flux (G). At the night the 

results from Eddy Covariance showed H and LE approaching to zero. Unstable atmospheric 

conditions predominated above the orchard, with the sensible heat flux (H) accounting for 

about 30% of R n during both the monitoring periods. The significant leaf area index (LAI) of 

orange crop within the study site (LAI of about 4-4.7 m 2 m -2 ) caused solar radiation to hardly 

penetrate through the canopy. As a consequence, the soil heat flux (G) at daily scale was 

small and negative, with daily average value less than 1% of R n . The largest part of R n was 

used as latent heat flux (λE), that represents on average 67% of R n during the year 2010 and 

57% of R n during 2011. The corresponding evaporative fractions (E F =λE/(R n -G)) were 0.70 

and 0.60. Monthly data show that, after forcing (through the BR approach) the measured 

energy balance data to close, the discrepancy between the measured available energy (R n - 

G) and the turbulent fluxes (H corr +λE corr ) tend to be neglected. In particular, H corr increased of

8.6% and 10%, respectively, in 2010 and 2011 with respect to EC measurements of H; λE 

tends to increase of 2% and 3.7% in 2010 and 2011, respectively. 

3.2. Comparison between BR-corrected Eddy Covariance and Sap Flow measurements of 

evapotranspiration 

A fairly good linearity was observed both in morning and afternoon values, whereas midday 

values showed a weak relationship, with a small slope value, denoting lower xylem flux (SF 

values) in comparison to canopy transpiration as estimated by BR-correct EC. Large part of 

the differences in water use dynamics observed in this study could be interpreted by tree 

capacitance. The unbalance between canopy transpiration and tree water uptake observed is 

revealed by a large hysteresis occurred (data not showed), with higher afternoon SF values. 

It is interesting to note that the hysteresis loop appears specularly reflected, with a larger 

hysteresis in the morning-midday hours. The difference between cumulated values of T SF 

and ET c,corr during 2010 and 2011 was of 10%; this difference can possible be attributed to 

the soil evaporation, which is not taken into account by the sap flow method. 

3.3. Crop evapotranspiration by a Penman-Monteith-type model 

The relationships of daily values of T SF and ET c,mod were shown in Figure 2. The values of 

ET c,mod followed the atmospheric demand in both growing seasons, being higher during May- 

October (from flowering to fruit maturation), with a peak of 6.7 mm d -1 and 6.0 mm d -1 during 

2010 and 2011, respectively. The minimum values were around 1.2 mm d -1 . The cumulated 

value of the entire experimental periods are 913 mm and 883 mm for the sap flow 

measurements of transpiration during 2010 and 2011, respectively, and 1008 mm and 984 

mm for the modelled ET c during the two years, with small differences not higher than 3%. 

The average daily values of ET c,mod and T SF are of 3.9 mm d -1 and 3.4 mm d -1 , respectively, 

during May-October 2010 and of 3.7 mm d -1 and 3.2 mm d -1 in 2011. 

3.4. Analysis of crop coefficient values 

Figure 3 compares the crop coefficient calculated at a daily time scale with K c value given by 

Allen et al. (1998) for a generic citrus crop. In the study, K c varies between 0.20 and 1.10, 

with mean values of 0.68. The values of ET c,mod largely followed the ET 0 . During the rainy 

periods, mainly at the start of the year, ET c,mod rates exceeded ET 0 , resulting in daily K c 

values exceeding 1. The higher values of K c in the period January-June could be due to the 

following reasons: (i) the period coincides with phenological stages “flowering” and “swelling 

of buds” of active growth, when stomatal conductance in usually high; (ii) the period 

corresponds to days with high wind speed and vapour pressure deficit, than can cause high 

value of ET rates from the trees, much greater than ET 0 . 

8.0 

6.0 

y = 0.7069x + 0.5301 

R 2 = 0.7825 

a) 

8.0 

6.0 

y = 0.8007x + 0.2268 

R 2 = 0.8736 

b) 

TSF (mm d -1 ) 

4.0 

TSF (mm d -1 ) 

4.0 

2.0 

2.0 

0.0 

0.0 2.0 4.0 6.0 8.0 

0.0 

0.0 2.0 4.0 6.0 8.0 

ΕΤc,mod (mm d -1 ) 

ET c,mod (mm d -1 ) 

FIGURE 2: Relationship between daily values of T SF and ET c, mod during 2010 (a) and 2011 

(b).

1.20 

1.20 

2010 2011 

0.90 

0.90 

K c 

0.60 

Kc 

0.60 

0.30 

0.30 

0.00 

January February March April May June July August September October NovemberDecember 

0.00 

January February March April May June July August September October NovemberDecember 

FIGURE 3: Comparison between the calculated daily crop coefficient (Kc) and the value 

(constant) given by FAO 56 for the whole experimental period. 


In our study, the use of the Bowen ration method to correct the Eddy Covariance 

measurements of sensible and latent heat fluxes for energy closure was performed, resulting 

appropriate for orange orchards. The crop evapotranspiration rates (ET c,mod ) were analysed 

and modelled, starting from a simple formulation based on the Penman-Monteith model, 

where the canopy resistance has been determined as function of standard microclimatic 

variables. The calibration coefficients of the proposed model depend only on the crop and 

they have validity with respect to the site under study. Modelled ET c permitted to calculate 

the crop coefficient (K c ) of orange orchards during the growing seasons; this was compared 

with the FAO 56 approach based on a K c considered constant during the different growth 

stages. Modelled ET c were compared with daily transpiration (T SF ) data measured by the sap 

flow method, with fairly good results. Simultaneous use of ET c,mod and T SF measurements 

provides an interesting experimental approach to obtain an insight of biophysical behaviour 

of tree crops. 


Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop evapotranspiration, guidelines 

for computing crop water requirements. Paper No. 56, Rome, Italy, 300 pp. 

Aubinet, M., Grelle, A., Ibrom, A., Rannik, U., Moncrieff, J., Foken, T., Kowalski, A. S., 

Martin, P. H., Berbigier, P., Bernhofer, C., Clement, R., Elbers, J., Granier, A., Grunwald, T., 

Morgenstern, K., Pilegaard, K., Rebmann, C., Snijders, W., Valentini, R., & Vesala, T. (2000). 

Estimates of the annual net carbon and water exchange of European forests: the 

EUROFLUX methodology. Advances in Ecological Research, 30, 114-175. 

El Maayar, M., Chen, J. M., & Price, D. T. (2008). On the use of field measurements of 

energy fluxes to evaluate land surface models. Ecological Modelling, 214, 293-304. 

Green, S., Clothier, B., & Jardine, B. (2003). Theory and practical application of heat pulse to 

measure sap flow. Agronomy Journal, 95, 1371-1379. 

Katerji, N., & Perrier, A. (1983). Modélisation de l’évapotranspiration réelle ETR d’une 

parcelle de luzerne: rŏle d’un coefficient cultural. Agronomie, 3 (6), 513-521. 

Monteith, J. L. (1965). Evaporation and environment. In G. E. Fogg (Ed.) The State and 

Movement of Water in Living Organism. Proceedings of the XIX Symposium on Society for 

Experimental Biology (pp. 205-234). New York: Academic Press. 

Rana, G., Katerji, N., & de Lorenzi, F. (2005). Measurements and modelling of 

evapotranspiration of irrigated citrus orchard under Mediterranean conditions. Agricultural 

and Forest Meteorology, 128, 199-209. 

Twine, T. E., Kustas, W. P., Norman, J. M., et al. (2000). Correcting eddy-covariance flux 

underestimates over a grass land. Agricultural and Forest Meteorology, 103, 279-300. 

Wilson, K., Goldstein, A., Falge, E., et al. (2002). Energy balance closure at fluxnet sites. 

Agricultural and Forest Meteorology, 113, 223-243.

Finding Location for Nitrate Sources along Kitakami River, Japan 

Using the Natural Abundance of Nitrogen Isotope 

Abstract 

Kosuke Noborio 1* , Chitoshi Mizota 2 , Koji Harashina 2 , Mitsuomi Orisaka 3 

1 School of Agriculture, Meiji University, Kawasaki, 214-8571 Japan 

2 Faculty of Agriculture, Iwate University, Morioka, 020-8550 Japan 

3 Iwate Agricultural Research Center, Kitakami, 024-0003 Japan 

*Corresponding author. E-mail: noboriok@isc.meiji.ac.jp 

It is well known that natural abundance of nitrogen isotope, δ 15 N, in nitrate varies depending 

on the sources of nitrate. Nitrate concentration with δ 15 N was determined by sampling water 

bimonthly at ten locations along the Kitakami River in Japan. We examined if a various land 

use such as forest, rice paddy fields, and upland fields in a watershed affect river water quality, 

such as nitrate concentration, and the feasibility of locating a source of nitrate. A mixing 

model successfully estimated NO 3 concentration or δ 15 N values of the main stream based on 

those values obtained at tributaries only when there was no major denitrification. 

Key words: nitrate, δ 15 N, watershed, animal manure, chemical fertilizer 


River water quality not only affects people’s lives living alongside the river but sometimes also 

attributes to hypoxia, damaging fishing industries, in a bay where river water runs in. A 

proper management of a watershed may need to consider living and industrial environments 

involving land-use in an entire watershed. Changes in water quality in river may somehow 

be detectable using nitrate concentrations monitored at monitoring stations. It is, however, 

quite difficult to find contaminant sources in a watershed using concentration data only 

because nitrate is easily diluted water. 

Coastal eutrophication, often resulting in hypoxia, is a major environmental problem 

worldwide. Relationships between hypoxia and river inputs, and between hypoxia and 

increased nitrate-nitrogen, NO 3 , loadings in particular were known before 1990, and additional 

research in the early 1990s accumulated compelling evidence of these relationships 

(Rabalais et al., 2002). Mitsch et al. (2005) proposed using their modelling results that 

creating 22,000 km 2 wetland, which was 65 times larger area than the net gain of wetlands in 

the entire US, in the Mississippi River Basin would remove 40% of NO 3 discharged into the 

Gulf of Mexico from the river basin. Their proposal, however, seems to be apparently 

unrealistic. 

Rice paddy fields in the monsoon Asia may act like the wetland in the Mississippi River Basin. 

Using a 1,500 m 2 rice paddy field, Takamura et al. (1977) found that surface runoff from the 

rice paddy field mainly contained ammonium-nitrogen, NH 4 , but little NO 3 . Tabuchi et al. 

(2005) reported, indeed, that NO 3 concentration decreased by half during water run for about 

25 m in an experimental rice paddy field in Japan. Although research on NO 3 behavior in a 

small scale of rice paddy fields has been conducted, research on a relationship between NO 3 

in river water and land use, specifically for rice paddy fields, in a watershed scale has been 

taken little attention. 

For upland fields in Hokkaido, northernmost Japan, Tabuchi et al. (1995) and Hatano (2005) 

reported that there was a linear relationship between NO 3 concentration in river water and 

grassland percentage in a watershed. Although the slope of the linear relationship varied 

one watershed to another, the linear relationship remained for all the watersheds that they 

examined. However, they have not conducted research on seasonal variation of these linear

elationships. 

There is forest area, where little anthropogenic nitrogen except atmospheric deposition has 

been applied, in a watershed. Therefore, runoff water from forest is expected to contain a 

small amount of NO 3 . Kuroda et al. (1991) revealed that river water in a watershed with 

mostly100 % of forest contained low concentration of NO 3 tending to increase a little bit during 

summer time when runoff water also increased. They concluded that the forest was a sink 

for NO 3 . 

It is well known that natural abundance of nitrogen isotope, δ 15 N, in nitrate varies depending 

on the sources of nitrate, e.g., δ 15 N=-2 ‰ for chemical fertilizer, and δ 15 N=+15 ‰ for cattle 

manure compost (Choi et al., 2003). With a preliminary experiment, we found that δ 15 N

Land use in each sub-watershed was characterized using GIS as rice paddy fields, forest, and 

upland fields with a ratio of each land use area to the total area of each sub-watershed. 

Concentration of nitrate dissolved in sample waters was quantitatively determined by an ion 

chromatography using Dionix IC 20. Two litters of the sample waters were passed through a 

Millipore filter with the pore size of 0.2 µm, and concentrated down to about 40 ml on an 

electric hot plate, reducing the volume in a stainless steel vat. Special care was paid for 

prompt contamination during the concentration procedure. Nitrate in the concentrates 

containing nitrogen less than 300 µg was reduced by addition of Devarda’s alloy under the 

gas-tight container (Kjeldahl steam distillation apparatus) into ammonia. The evolved 

ammonia was quantitatively fixed as an ammonium sulfate in an excess of sulfuric acid 

medium. Ammonium in the solution was eventually converted into ammonium salt of 

tetraphenyl-borate that was hardly soluble in acidic water. The precipitate was recovered 

and air-dried. The 15 N/ 14 N ratios of the dry precipitate were determined by a continuous-flow 

mass spectrometer (Finnigan DELTA plus). Nitrogen isotopic ratios were expressed by 

common δ 15 N notation, per mil variation relative to atmospheric dinitrogen (δ 15 N = 0 ‰). The 

overall precision during the protocol established in the present study is better than ±0.2 ‰. 

quantitative recovery of reagent-grade nitrate in range from 300 to 1,000 µg-nitrogen during 

the reduction and precipitation, together with the nitrogen isotopic measurement were 

repeatedly tested, confirming analytical accuracy. 

2.1. Relationship between δ 15 N and NO 3 concentration 

As NO 3 in the main stream was mixed with NO 3 in tributaries, the following relationship for the 

main stream might be described with a mixing model (Mariottiet al., 1988): 

δ m 

Q m 

= ∑ δ i 

Q i 

[1] 

i 

Q = A× 

H × C 

[2] 

where δ was nitrogen isotopic ratio (‰), Q was the mass of nitrate (kg), A was the area of a 

watershed (km 2 ), H was precipitation (mm), and C was NO 3 concentration of river water 

(mg/L). Subscripts m and I indicated the main stream and a tributary, respectively. If we 

assumed that precipitation in all sub-watersheds was identical, Eqs. 1 and 2 were reduced to: 

δ C 

2.2. Estimation of NO 3 origin 

m 

m 

= 

∑ 

i 

δ A C 

i 

i 

i 

A 

m 

. [3] 

The amount of N supplied to river water might be estimated based on differences in land use 

and different δ 15 N values for the various origins of N, i.e. chemical fertilizer, animal manure 

compost, and rain water. There were following relationships of NO 3 concentration and δ 15 N 

for those origins (Morita, 2002): 

A=B+C+D [4] 

aA=bB+cC+dD [5] 

where A, B, C, and D indicated the NO 3 concentrations (mg/L) of river water, chemical 

fertilizer origin, animal manure origin, and rainwater origin, respectively, and a, b, c, and d 

indicated δ 15 N values (‰) of NO 3 for river water, chemical fertilizer origin, animal manure 

origin, and rainwater origin, respectively. 

The NO 3 concentration of the chemical fertilizer origin, B (mg/L), might be estimated by 

substituting measured values of A and a for Eqs. 4 and 5, respectively, as:

B = 

( c − a) A − ( c − d) 

c − b 

and that of the animal manure origin, C (mg/L) as: 

C = 

( b − a) A − ( b − d) 

b − c 

D 

D 

, [6] 

where it was assumed that the δ 15 N values (‰) of NO 3 for chemical fertilizer origin, animal 

manure origin, and rainwater origin are b=-2 ‰, c=+15 ‰, d=-8 ‰, respectively, and that NO 3 

concentration of rainwater was D=0.1 mg/L. 

[7] 


For a period between September and January, estimated NO 3 concentration held a 1:1 

relationship with measured values (Fig. 2A). For this period, estimated δ 15 N values agreed 

well with measured ones as well (Fig. 2B). During this period, there was negligible 

denitrification of river water during running down in the main stream and little N load from 

tributaries. Relatively high δ 15 N values implied that N of the animal manure origin merged 

the main stream. 

For the period of paddling and transplanting in rice paddy fields, between May and June, 

measured δ 15 N values became smaller than estimated values because of chemical fertilizer 

applied to rice paddy fields during this period (Fig. 2B). Over estimates of δ 15 N resulted in 

under estimates of NO 3 concentration according to Eq. 3 as shown in Fig. 2A. Small values 

of δ 15 N implied that N of chemical fertilizer origin was dominant in river water. 

Because of restively large δ 15 N values between March and August, N of the animal manure 

origin might merge the main stream. The model provided smaller estimates of both NO3 

concentration and δ 15 N values than measured. Other sub-watersheds of tributaries that 

were not considered in this study might be responsible for this event. 

NO 3 -N concentration estimated (mg/L) 

1.2 

1 

0.8 

0.6 

0.4 

0.2 

(A) 

 

 

 

 

0 

0 0.2 0.4 0.6 0.8 1 1.2 

NO 3 -N concentration measured (mg/L) 

 

 

-4 

-4 -2 0 2 4 6 

FIGURE 2: Relationships between measured and estimated values of river water using 

Eq. 3 at no. 9: (A) NO 3 concentrations assuming δ 15 N was known, and (B) δ 15 N values 

assuming NO 3 concentration was known 

δ 15 N estimated (‰) 

6 

4 

2 

0 

-2 

(B) 

 

 

 

δ 15 N measured (‰) 

 

 

 

Concentration of NO 3 tended to be higher during winter and lower during summer for either 

the animal manure or the chemical fertilizer origin. This might be resulted from less NO 3 loss

y denitrification because of lower air temperature during winter. The NO 3 concentration of 

the animal manure origin tended to be always higher in the upper stream, no. 2, than in the 

mid stream, no. 9 (Fig. 3A). During flow from the upper stream to the mid stream, 

denitrification and/or dilution might attribute to lower NO 3 concentration at no. 9 than that at no. 

2. 

At no. 9, the NO 3 concentration of the chemical fertilizer origin tended to higher than that of 

the animal manure origin whereas at no. 2 that of either origin was similar. During summer, 

the NO 3 concentration of the chemical fertilizer origin tended to be similar at no. 2 and 9. 

This might be reflected by the fact that a large amount of chemical fertilizer was used from the 

upper stream to the mid stream. 

NO 3 -N concentration (mg/L) 

0.9 

0.8 

0.7 

0.6 

0.5 

0.4 

0.3 

0.2 

(A) 

Animal manure origin 

No 2 

No 9 

NO 3 -N concentration (mg/L) 

0.9 

0.8 

0.7 

0.6 

0.5 

0.4 

0.3 

0.2 

(B) 

Chemical fertilizer origin 

No 2 

No 9 

0.1 

0.1 

0 

Dec-03 Jun-04 Dec-04 Jun-05 Dec-05 Jun-06 Dec-06 

Measuring date 

0 

Dec-03 Jun-04 Dec-04 Jun-05 Dec-05 Jun-06 Dec-06 

Measuring date 

FIGURE 3: Temporal changes in estimated NO 3 concentrations at no. 2 and 9: (A) for 

the animal manure origin with Eq. 7, and (B) for the chemical fertilizer origin with Eq. 6 


The mixing model described by Eqs. 1-3 successfully estimated NO 3 concentration or δ 15 N 

values of the main stream based on those values obtained at tributaries only when there was 

no major denitrification. Discrepancies between modeled and measured values implied that 

N of either the chemical fertilizer or the animal manure origin merged the main stream. We 

examined to distinguish the origin of N using the mixing model. Because of large temporal 

variations in NO 3 concentrations and δ 15 N values, it was quite difficult to specify the NO 3 of the 

animal manure origin along the river. 

To monitor NO 3 concentration originated by animal manure or chemical fertilizer, more 

monitoring sites and more frequent sampling periods will be needed. It would be possible to 

improve the accuracy of the mixing model with the information on the quantities of flow in 

each sub-watershed. 


This research was partly supported by the River Environment Management Foundation 

(project #1211). We are grateful to Ms. A. Nakano, and Mr. M. Yoshida of Iwate Agricultural 

Research Center for their technical assistance.

References 

Choi, W.-J., Lee, S.-M., & Ro, H.-M. (2003). Evaluation of contamination sources of 

groundwater NO 3 - using nitrogen isotope data. A review. Geosci. J., 7, 81-87. 

Hatano, R. (2005). Evaluating river water quality through land use analysis and N budget 

approach. J. Jpn. Soc. Soil Phys., 99, 21-28 (in Japanese with English abstract). 

Kuroda, H., Tabuchi, T., Kikuchi, H., & Suzuki, M. (1991). Nutirent outflow for a forest area. 

Trans. JSIDRE, 154, 25-35 (in Japanese with English abstract). 

Mariotti, A., Landreau, A., & Simon, B. (1988). 15 N istope biogeochemistry and natural 

denitirification process in groundwater: Application to the chalk aquifer of northern France. 

Geochemca et Cossmochimica Acta, 52,1868-1878. 

Mitsch, W.J., Day, J.W., Zhang, L., & Lane, R.R. (2005). Nitrate-nitrogen retention in wetlands 

in the Mississippi River Basin. Ecologic. Eng., 24, 267-278. 

Morita, A. (2002). Searching the origin of N outcome using δ 15 N. In S. Hasegawa (ed.) 

Predicting environmental loads (pp. 75-94). Tokyo: Hakuyusha Inc. (in Japanese). 

Rabalais, N.N., Turner, R.E., & Scavia, D. (2002). Beyond science into policy: Gulf of Mexico 

hypoxia and the Mississippi River. BioSci., 52,129-142. 

Shlesinger, W.H. (1997). Biogeochemistry. An analysis of global change. (2nd ed.). San 

Diego: Academic Press. 

Tabuchi, T., Yoshino, K., Shimura, M., Kuroda, S., Ishikawa, M., & Yamaji, E. (1995). 

Relationship between land use and nitrate concentration of outflow water from watersheds of 

agricultural and forest areas. Trans. JSIDRE, 178, 129-135 (in Japanese with English 

abstract). 

Tabuchi, T., Kuroda, H., & Shinoda, Y. (2005). On the decrease of NO 3 -N concentration of 

flow water in paddy field plots. J. Jpn. Soc. Soil Phys., 99, 65-72 (in Japanese with English 

abstract). 

Takamura, Y., Tabuchi, T., Harikae, Y., Otsuki, H., Suzuki, S., & Kubota, H. (1977). Study on 

mass balance in a rice paddy field (II). Jpn. J. Soc. Soil Sci. Plant Nutr., 48, 431-436 (in 

Japanese).

Assessment of Antibiotic Resistance in Water Systems 

Maria P. Amador 1* , Ruben M. Fernandes 2 , Isabel M. Duarte 1 , Maria L. Brito 3 , Mário 

P. Barreto 4 , Maria C. Prudêncio 2 

1 

Departamento de Ambiente, CERNAS, Escola Superior Agraria de Coimbra, Instituto 

Politécnico de Coimbra, Bencanta 3040-316 Coimbra, Portugal. 

2 

Ciências Químicas e das Biomoléculas, Escola Superior de Tecnologia de Saúde do Porto, 

Instituto Politécnico do Porto, R. Valente Perfeito, 322, 4400-330, Vila Nova de Gaia, 

Portugal 

3 Laboratório de Microbiologia, CBAA/DRAT, Instituto Superior de Agronomia, Universidade 

Técnica de Lisboa, Tapada da Ajuda 1349-017 Lisboa, Portugal 

4 Águas Mondego e Bairrada, S.A. – ETA da Boavista, Av. Dr. Luís Albuquerque, 3030-410 

Coimbra, Portugal. 

*Corresponding author. E-mail: paula_amador@esac.pt 

Abstract 

The awareness that the intensive use of antibiotics in human health, intensive animal 

husbandry led to the presence of a broad range of antibiotic residues, detected by 

environmental monitoring, increased the public concern on this issue. Studies report that this 

selective pressure favours the growth of bacteria increasingly multiresistant. Mobile genetic 

elements, such as plasmids, enable the exchange of antibiotic resistance genes among 

bacteria of different taxonomic groups. This horizontal transference occurs more frequently in 

sites highly concentrated in microbes, such the tract gastrointestinal, wastewater treatment 

plants. The increase of resistant bacteria and resistance genes are the more direct support 

for the expansion of resistance. In order to provide knowledge of antibiotic effects, it is 

required to undergo local and regional environmental surveys. Although soil studies are more 

abundant then those in water, these are important due to the wider coverage of water bodies 

and the potential impacts of lower levels of antibiotic. This paper describes a research project 

to characterize the emergence of resistant bacteria and resistance genes disseminated in 

microbial community in different water environments, namely upstream and downstream 

hospital, rural and agricultural areas. This project addresses two key areas: i) impacts of 

livestock farming on water quality for domestic supply, ii) impacts of diverse sources as 

livestock or hospitals on water and soil quality in agriculture, particularly to irrigation and 

livestock supply. 

Key words: Antimicrobial Resistant Bacteria, Gene Transfer, Public Health, Agricultural 

Water Resources, Livestock Wastewater. 


In the latest years there was an exhaustive and unrestrained consumption of antimicrobials 

for human medicine, veterinary, intensive livestock production, aquaculture, horticulture and 

other human activities (Aminov, 2009). The occurrence of several classes of AB have been 

reported in various aquatic environments, such as Wastewater and Sewage Treatment 

Plants (WWTP), to where some are excreted in their active forms, since only a few are 

partially metabolised (Jury et al., 2010). The two main issues for the acquisition and 

proliferation of antibiotic-resistant bacteria (ARB), responsible for a serious worldwide public 

health and environmental problem, are the selective pressure generated by sub-lethal 

concentrations of those AB in the environment and the co-occurrence of high concentrations 

1

of faecal bacteria (Kummerer, 2004; Ding & He, 2010; Jury et al., 2010); although, the causal 

relationship between the entry and spread of antibiotic resistance remains undetermined 

(Ding & He, 2010). 

The horizontal gene transference is the most common mechanism of prokaryote cells to 

obtain and disseminate antibiotic-resistance genes (ARG) between microbial populations (Xi 

et al., 2009). Resistance genes to different AB classes are usually gathered in cassettes 

inserted in mobile genetic elements, such as plasmids, transposons and integrons, being 

transferred together. This feature causes a progressive increase of multidrug-resistant 

bacteria in the environment, such as vancomycin-resistant Enterococcus (VRE), methicillin 

resistant Staphylococcus aureus (MRSA), particularly in clinical settings, where the available 

AB are losing effectiveness (Finch & Hunter, 2006) and therefore the control of these hospital 

infections is increasingly difficult (Kummerer, 2009b). Moreover, since 1962, the development 

of novel classes of AB is almost stationary, which leads to the need of developing innovative 

and effective therapies and pharmacological agents (Livermore et al., 2011). 

The gastrointestinal tract of animals and humans (Falk et al., 1998) and the aquatic 

ecosystems, generally contaminated with raw human and animal sewage, are reservoirs of 

antibiotic resistance determinants (ARD) (ARG and ARB), having favourable conditions for 

ARB exchanging their genes (Kummerer, 2004). It is not thus surprising that faecal coliforms 

and enterococci are the eligible bacterial groups to study antibiotic resistance in aquatic 

environments (Schwartz et al., 2003; West et al., 2010), neither that WWTPs are the selected 

sampling locations. In fact, WWTP collect wastewaters rich in bacteria previously exposed to 

AB, originated in hospitals, nursing homes, livestock, agriculture or industry, (Schluter et al., 

2003) reflected potential sites for horizontal ARG transference due to its microbial richness 

and high nutritional. Some studies in the WWTP have identified mobile genetic elements 

both in bacteria isolated from wastewater and in the activated sludge tanks, demonstrating 

that even with the decrease of bacteria in treated wastewaters there is an increased 

proportion of multiresistant bacteria to AB in effluent water (Silva et al., 2006; Kummerer, 

2009b; West et al., 2010; Moura et al., 2011). 

In Portugal, the water quality legislation for treated wastewater reuse (Marecos do Monte & 

Albuquerque, 2010) or human consumption (DL 306/2007, August 27) has no mention to the 

detection and quantification of ARD. The latter, although controlling other pesticide residues 

used in agriculture does not refers to bactericides, which application is illicit (Oliveira & 

Henriques, 2011). However, Kummerer (2009b) refers to AB as one of the most significantly 

consumed pharmaceutical groups, which explains the recognised widespread distribution of 

AB and their residues in different environmental ecosystems. It is also known their high 

toxicity to algae and bacteria, the ability to interrupt bacterial life cycles responsible of 

biogeochemical processes and its potential for cause resistance among environmental 

bacterial populations (Watkinson et al., 2009). Due to this awareness, AB has being recently 

classified as a priority risk group. 

The consciousness of the scientific community to the gravity of this problem caused by the 

uncontrolled discharges of urban and agricultural wastewater has resulted in an increase of 

studies evaluating the spread of ARB in aquatic environments in the last decades (Xi et al., 

2009; Moore et al., 2010; West et al., 2010). Despite the knowledge on AB genetic 

resistance mechanisms, their transference among bacteria and on mechanisms of ARG 

entrance, maintenance and spread in the environment; the accurate global ecological impact 

of ABs and ARD and the inherent risks to human and animal health is still undetermined 

(Kummerer, 2009a; Ding & He, 2010; Moore et al., 2010; West et al., 2010). The prevention 

of the ARD spread is sustained on two main strands: i) on the pre-emission side, the prudent 

use of AB, the development of new effective and environmentally degradable drugs, and ii) 

2

on the post-emission side, the monitoring of effluent discharges from WWTP in the aquatic 

environment (Kummerer, 2009a; Jury et al., 2010). 

This paper describes a research project to assess the impact of hospital, urban, rural and 

agricultural activities in the spread of ARB in the water supply and drainage in urban and 

agricultural systems. This project addresses two key areas: i) impacts of livestock on water 

quality for domestic supply, ii) impacts of diverse sources as livestock or hospitals on water 

and soil quality in agriculture, particularly to irrigation and livestock supply. The research 

team already developed successfully ARB research in other matrixes, such as: ready-to-eat 

foods (Amador et al., 2011), hospital samples (Fernandes & Prudêncio, 2010). Additionally, 

the enterprise (Águas Mondego e Bairrada, S.A.) that supplies water to Coimbra integrates 

this team, having the know-how to provide infield the means to access and collect water 

samples and characterise the regional water networks. The results achieved encourage 

developing new application to water research. 


The field and laboratorial work is idealized to be executed in four main steps (Fig. 1). At first, 

water samples collection in Coimbra Region, Portugal, follows a defined sampling 

methodology in relation to: (i) the sites selection in the water network of distribution and 

drainage, upstream and downstream the location of some human activities, namely hospital, 

WWTP and livestock farm, to enable evaluating the effect of each activity in the spread of 

ARB; (ii) the definition of a sampling schedule throughout the year, to monitor the putative 

seasonal contribution of each activity to ARB dissemination and (iii) the edapho-climatic and 

hydraulic characterisation of sampling sites. 

Sampling is followed by the microbiological analysis of water samples, which includes: (i) the 

determination of their microbial charge, through quantitative methods and (ii) the screening of 

Enterobacteriaceae, through differential and selective media. After bacteria isolation and 

biochemical identification, the patterning the antibiotic susceptibility of the isolates is carried 

out through the Minimal Inhibitory Concentration (MIC) tests by the disk diffusion method on 

Mueller Hinton agar with antibiotic disks, according to the Clinical Laboratory Standards 

Institute (NCCLS, 2005). The antibiotic selection involves the main antibiotic classes used in 

Portugal, namely β-lactams, Quinolones, Chloramphenicol, Sulphonamides, Tetracycline, 

Aminoglycosides, Glycopeptides, Macrolides, Lyncosamide. 

Afterwards, the isolated antibiotic-resistant bacteria are molecularly characterised aiming: (i) 

their identification and (ii) the detection and identification of the antibiotic-resistance genes 

that they harbour. Briefly, the total and/or plasmidic bacterial DNA is extracted and the 

resistance genes detected with specific PCR primers and identified by sequencing of PCR 

amplicons. 

Next, the antibiotic-resistant bacteria are used to perform horizontal transference assays with 

the liquid mating method (Amador et al., 2011), to assess their ability to transmit the 

antibiotic-resistance genes among bacteria. 

Finally, the last step of the project is carried out through the integration of all data gathered in 

the previously described steps, to assess the impact of human activities (hospital, WWTP 

and livestock farm) in the spread of ARB into water. 

3

FIGURE 1 – Project tasks and links 

3. Discussion and Conclusions 

The intended research constitutes an evolution of the state of the art relative to the ARB risk 

assessment in Coimbra Region. It will provide the first survey for ARB in the distribution and 

drainage waters in this Area. The expected results per sampling site as well as their spatial 

and temporal variability throughout the model watercourses selected are: (i) total numbers of 

cultivable bacteria; (ii) biochemically identified antibiotic-resistant bacteria to family or genus 

level; (iii) the antibiotic resistance profile per isolate towards different classes of antimicrobial 

agents; (iv) detection and identification of different classes of ARG, responsible for 

antimicrobial resistance; (v) putative evidences of the ability to antibiotic resistance gene 

horizontal transference among strains, through transconjugants assays. These data will be 

analysed to infer about the inputs and outputs of ARB and their resistance genes along the 

waterway and therefore clarify the contribution of different activities in the widespread of 

these genes in the environment. 

The project will reveal the percentage of multidrug resistant bacteria (and specifically of 

Enterobacteriaceae) in water networks and Mondego River and therefore will inform about 

the exposure risk through contact with surface waters. This contact may occur during animal 

drinking or crops irrigation with contaminated water. Conversely, as antibiotics are needed 

for animal infections treatment, the ARB can end up in surface water, through runoff of 

manure. Another expectable source is the discharge of treated or untreated wastewaters 

coming from hospitals, where people also are treated with antibiotics. This research will 

contribute for public health and environmental risk assessment, providing information about 

the real impact of each activity to environmental exposure and vice-versa. 

Concluding, this survey will allow inferring about the impact of hospital, urban and rural 

activities in the spread of ARG in the water network, namely in the distribution and drainage 

systems and water for agricultural uses. Those activities are expected to load ARB into water 

environments, as they are originated from human and animal sources. Such detailed 

4

information is required to establish the control measures to reduce ARB load in wastewaters 

and thus its environmental dissemination. 

4. Acknowledgments 

This work is funded by National Funds through the FCT (Portuguese Foundation for Science 

and Technology) under the project PEst-OE/AGR/UI0681/2011. 

5. References 

Amador, P., Fernandes, R., Duarte, I., Brito, L. & Prudêncio, C. (2011). In vitro transference 

and molecular characterization of bla TEM genes in bacteria isolated from Portuguese 

ready-to-eat foods. World Journal of Microbiology and Biotechnology, 27, 1775-1785. 

Aminov, R.I. (2009). The role of antibiotics and antibiotic resistance in nature. Environmental 

Microbiology, 11, 2970-2988. 

Anónimo (2007). Decreto-Lei No 306/2007 de 27 de Agosto de 2007. Diário da República, 1ª 

série. Nº. 164 - 27 de Agosto de 2007. Pp. 5747-5765. 

Ding, C. & He, J. (2010). Effect of antibiotics in the environment on microbial populations. 

Applied Microbiology and Biotechnology, 87, 925-941. 

Falk, P., Hooper, L., Midtvedt, T. & Gordon, J. (1998). Creating and maintaining the 

gastrointestinal ecosystem: what we know and need to know from gnotobiology. Microbiol 

Mol Biol Rev, 62, 1157-1170. 

Fernandes, R. & Prudêncio, C. (2010). Post-surgical wound infections involving 

Enterobacteriaceae with reduced susceptibility to β-lactams in two Portuguese hospitals. 

International Wound Journal, 7, 508-514. 

Finch, R. & Hunter, P.A. (2006). Antibiotic resistance-action to promote new technologies: 

report of an EU Intergovernmental Conference held in Birmingham, UK, 12–13 December 

2005. Journal of Antimicrobial Chemotherapy, 58, Suppl. S1, i3-i22. 

Jury, K.L., Vancov, T., Stuetz, R.M. & Khan, S.J. (2010). Antibiotic resistance dissemination 

and sewage treatment plants. In: Current Research, Technology and education Topics in 

Applied Microbiology and Microbial Biotechnology. Ed. Méndez-Vilas, A. Formatex. pp 

509- 519. 

Kümmerer, K. (2004). Resistance in the environment. The Journal of Antimicrobial 

Chemotherapy, 54, 311-320. 

Kümmerer, K. (2009a). Antibiotics in the aquatic environment – A review – Part I. 

Chemosphere, 75, 417–434. 

Kümmerer, K. (2009b). Antibiotics in the aquatic environment – A review – Part II. 

Chemosphere, 75, 435–444. 

Livermore, D. M. & British Soc, A. (2011). Discovery research: the scientific challenge of 

finding new antibiotic. Journal of Antimicrobial Chemotherapy, 66, 1941-1944. 

Marecos do Monte, H. & Albuquerque, A. (2010). Reutilização de Águas Residuais. Série 

Guias Técnicos-14. Eds: Entidade Reguladora dos Serviços de Aguas e Resíduos e 

Instituto Superior de Engenharia de Lisboa. ISBN: 978-989-8360-01-4 

Moore, J.E., Moore, P.J.A., Millar, B.C., Goldsmith, C.E., Loughrey, A., Rooney, P.J. & Rao, 

J.R. (2010). The presence of antibiotic resistant bacteria along the River Lagan. 

Agricultural Water Management, 98, 217–221. 

Moura, A., Carolina Pereira, C., Henriques, I. & Correia, A. (2011). Novel gene cassettes and 

integrons in antibiotic-resistant bacteria isolated from urban wastewaters. Research in 

Microbiology, 163, 92-100. 

NCCLS (2005). Performance standard for antimicrobial susceptibility testing; Clinical and 

Laboratory Standards Institute, Wayne, PA, USA, Supplement M100-S15. 

5

Oliveira, A.B. & Henriques, M. (2011). Guia dos produtos fitofarmacêuticos. Lista dos 

produtos com venda autorizada. MADRP. DGADR. 

Schlüter, A., Heuer, H., Szczepanowski, R., Forney, L.J., Thomas, C.M., Pühler, A. & Top, 

E.M. (2003). The 64 508 bp IncP-1beta antibiotic multiresistance plasmid pB10 isolated 

from a waste-water treatment plant provides evidence for recombination between 

members of different branches of the IncP-1beta group. Microbiology, 149, 3139-3153. 

Schwartz, T., Kohnen, W., Jansen, B. & Obst, U. (2003). Detection of antibiotic-resistant 

bacteria and their resistance genes in wastewater, surface water, and drinking water 

biofilms. FEMS Microbiology Ecology, 43, 325-335. 

Silva, J., Castillo, G., Callejas, L., López, H. & Olmos, J. (2006). Frequency of transferable 

multiple antibiotic resistance amongst coliform bacteria isolated from a treated sewage 

effluent in Antofagasta, Chile. Electronic Journal of Biotechnology, 9, 533- 540. 

Watkinson, A.J., Murby, E.J., Kolpin, D.W. & Costanzo, S.D. (2009). The occurrence of 

antibiotics in an urban watershed: from wastewater to drinking water. Science of the Total 

Environment, 407, 2711-2723. 

West, B.M., Liggit, P., Clemans, D.L. & Francoeur, S.N. (2010). Antibiotic Resistance, Gene 

Transfer, and Water Quality Patterns Observed in Waterways near CAFO Farms and 

Wastewater Treatment Facilities. Water, Air, and Soil Pollution, 217, 473-489. 

Xi, C., Zhang, Y., Marrs, C., Ye, W., Simon, C., Forman, B. & Nriagu, J. (2009). Prevalence 

of antibiotic resistance in drinking water treatment and distribution systems. Applied and 

Environmental Microbiology, 75, 5714-5718. 

6

ENERGY SAVINGS IN DISTRICT IRRIGATED USING FREQUENCY 

INVERTER 

Andre L. C. Mendes 1* , Jorge H. A. C, Damião 1 , Gerson O. L. Pedruzi 1 , Delly Oliveira 

Filho 1 , Maria J. Moraes 2 

1 UFV-DEA, Av. P. H. Holfs, Viçosa-MG, 36570-000, Brazil 

2 UEG-UnuCET, Br 153, km98, Anápolis-Go, 75132-400, Brazil 

*Corresponding author. E-mail: andre.mendes@ufv.br 

Abstract 

The area of irrigated agriculture in Brazil in 2009 was approximately 4.453.925 hectares, and 

has increased on average 4% per year. According to experts the demand for food in the world 

will have an growing increase being 80% of the food needed to satisfy the needs of the world 

population in the next 25 years, will be provided by irrigated crops. The irrigation makes it 

possible to increase production in 3 times in compared to the production without irrigation in 

the same area, thus, prevents the increase in planting area to expand production, contributing 

to environmental preservation. The energy consumption in irrigated agriculture is 

approximately 25% of the cost of production, while much of this cost is generated by the 

pumping system. With this the growing use of irrigation is required systems more efficient and 

economic, for this should invest in higher quantities in the development of technology applied 

in irrigation. Particularly for public irrigation districts, that has a variation in irrigated area 

throughout the day where the pumping system works out the optimal point of operation. 

Following this trend, is aimed with the carry out this work the simulation of the pumping system 

of irrigation district using frequency inverter aiming at energy savings. Was chosen as base 

districts irrigated containing 4 lots of 2 ha, with 25 meters in front and 2 meters of incline 

between them, 2 meters of suction, 73 meters distance from the pump to the first lot, with a 

pressure of operating in each lot of 15 MCA and flow of 3 m 3 h -1 . With these characteristics 

was simulated the economic of electric power consumption with the use of frequency inverter 

in districts irrigated, using the EPANET program, that it is a free software. In order to validate 

the simulation of the perimeter, was assembled a prototype in the hydraulics laboratory of 

Universidade Federal de Viçosa (Minas Gerais-Brasil) in reduced in size and with register 

drawer to induce the loss of load and outputs of water simulating the lots, activated by a 5 cv 

motor. First was activated the motor and adjusting the records to cause the loss of load applied 

to the real districts, and then measured the performance of the system with 4, 3, 2, 1 open 

records in different settings. In next was placed frequency inverter activating the motor and the 

test was repeated again, but regulating the motor speed to provide the minimum pressure 

required (15mca) in the last lot on avoiding excessive energy consumption. With the use the 

frequency inverter we obtained a percentage reduction in consumption of 8.1% for all records 

connected from 44.1% to 20.6% for 3, 48.4% to 35.5% for 2 and 55.6% to 40.7% to 1 record 

connected. These values are similar to the simulation using EPANET software, where verified 

to be an efficient tool for simulation of energy savings in irrigated districts. 

Key words: Energy, EPANET, Pump

1 Introduction 

To irrigate is to supply water to crops in order to attend their water needs, allowing 

efficient water use to maximize the productivity/quantity of water applied. But to make the 

irrigation is necessary a set of techniques that, if properly planned and put into operation at the 

right time, will contribute significantly to increase productivity. 

The irrigation use promotes the increase of production, on average, 2.5 to 3.0 times, 

compared to the same area not irrigated, generating an increase in the property value and the 

gain from agriculture, that in terms of gross value can be around 5.0 times greater than in nonirrigated 

areas (BERNARDO, 2008). 

The irrigation may cause environmental impacts when not used properly. Besides this, 

the irrigation is responsible for a great part of the energy consumption in rural areas. 

According to Moraes et al (2011), in a study of energy saving in Minas Gerais, it was 

found that the irrigation could save 10% of the power consumed. For Turco et al (2009), if the 

irrigation system were better proportioned, could have a saving about 20% of water and 30% 

of energy consumed, and from these 30% of energy savings, 20% due to the unnecessary 

application of water and 10% due to performance and optimization of the equipment. This 

economy is based on: (i) adaptation in design and management of the water pumping system, 

(ii) location, (iii) distance from the source to irrigation, (iv) type of material used in pipes and (v) 

use of flow controllers. 

Generally, irrigation systems are projected to provide maximum flow required. Thus 

the pump system is also designed to supply this flow. However, not always the system needs 

to provide the maximum flow, which is defined by the irrigation management techniques and 

that depends on irrigation demand of the time of year, culture type, among other factors 

(Araujo et al., 2004). Oliveira et al. (2011) studying frequency inverter, found a significant 

contribution to energy savings. 

The use of inverters minimizes the electricity cost in the control of the starting current 

and in the acceleration and deceleration time, thus expect to decrease maintenance costs, 

because with the use of this equipment, the engines will be subject to minor electric "stress" 

(caused by high starting currents), i.e., less heating and smaller demands of departure. They 

can be operated by means of automated systems. 

According to Testezlaf (2002), irrigation control automated systems become an 

essential tool for applying water in the required amount and in the right time, contributing to 

increase production and decrease the cost of it. 

Much of the technological innovations have as basic principles electronic devices. Over 

the past few years electronics has undergone a very rapid evolution, occupying a prominent 

position among all the other technologies (Braga, 1999). As stated earlier, the objective of this 

work was to evaluate the reduction of electricity cost for pumping in irrigated districts by 

applying different levels of automation with the use of a frequency inverter. 

1.1 Materials and Methods 

First, it was done a simulation using the EPANET software to a hypothetical field 

situation as shown in Figure 1. To perform the simulation, it was considered a unitary 

continuous flow of 1.66 L/(s/ha) for 20 hours, to area and slope uniforms. The dimensions of 

each lot were 25 meters in front by 200 meters long, totaling 0.5 acres per lot, 2 acres of total 

area, with a pumping rate of 3.33 L/s (12 m3/h), as the distance from the pump to the record of 

the first lot was 73 meters. It was considered 8 meters as difference of level or geometric 

height (Hg) from the pump shaft to the highest point, the suction height was 2 meters, the 

working pressure for the record of each lot was 15 mca.

Figure 1: irrigated district with 4 lots. 

The pump was chosen based on head and flow rate found the optimal operating point, 

for this it was used an electronic form, where the model IMBIL-INI 32-125.1 was determined, 

which presented better performance, subsequently determined the electric motor to couple 

with the pump of 5 cv. 

After the simulation using the EPANET software, was assembled in laboratory an 

experiment to simulate the four irrigated lots. Figure 2 shows the equipment and connections 

of the prototype of the irrigation line which supplies the 4 lots. 

0,7 m 

0,4 m 

+ + 

ABB ABB ACS 

Drives 500 

+ 

+ 

d 

p 

H H H H 

Figure 2. Scheme of the prototype assembled in the laboratory 

Source: (Ribeiro, 2008) 

To carry out the perimeter automation, it was used a system with a PIC (Programmable 

Interface Controller) to do all the system control. Thus is possible to program it, so it can 

perform various tasks, such as controll an electro-mechanical device, take measurements, 

exhibit information on a display, or simply flash lights. The simplicity, availability and low cost 

are the main attractions of the PIC. 

In this way, it was used the PIC to control a stepper motor, which is a type of electric 

motor used when something must be precisely positioned or rotated in a precise angle. Each 

configuration has a predetermined speed which is set through a variable resistor connected to

the inverter that provides a reference voltage, which regulates the motor speed proportional to 

this reference voltage. 

After the system installation of Figure 1 be implanted in the laboratory, a test was 

performed to verify energy consumption with the use of the main line for all possible 

combinations (15 in total) of the four lots according to be irrigating (on) or not (off), due to the 

fact that the irrigation system without the use of the inverter, in general, have a constant 

energy consumption. 

For each combination was checked the flow and pressure for each outlet pressure after 

the pump and before each record of the lot. Later, it was performed again the 15 combinations, 

but this time using the frequency inverter that, due to the rotation decrease, kept the pressure 

of 15 MCA for the more critical lot of the combination. For the situations was recorded the 

power consumed, reactive power, power factor and rotation of the motor shaft by means of a 

tachometer. 

1.2 Results and Discussion 

With the simulation were found the values of pressure for motor-pump and for each 

outlet pressure before leaving the lots, being these values obtained for each combination of 

open and close of the record possible in the assembled district, as shown in Table 1. 

After found the pressures that could be in a real perimeter using the simulation, in a 

laboratory assembled a prototype and by the pressure drops register, assembled these 

pressures for each combination. As far as using only the engine or using motor coupled to the 

frequency inverter, always with a flow rate of 2.5 m 3 .h -1 . 

Table 1- Values found with the simulation for each point of record of each possible 

combination. 

Open Records in 

Points of outlet pressure (mca) 

the lots 

Combinations 

1 2 3 4 Pump Record 1 Record 2 Record Tomada 31 

Record 4 

1 X X X X 32.08 22.73 19.87 17.46 15.34 

2 X X X - 33.16 26.05 23.64 21.52 19.52 

3 X X - X 33.16 26.05 23.64 21.52 19.41 

4 X - X X 33.16 26.05 23.64 21.23 19.12 

5 - X X X 33.16 26.05 23.18 20.77 18.66 

6 X X - - 33.92 29.96 27.85 26.35 24.35 

7 X - X - 33.92 28.46 26.35 24.24 22.24 

8 X - - X 33.92 28.46 26.35 24.24 22.12 

9 - X X - 33.92 28.46 26.05 23.94 21.94 

10 - X - X 33.92 28.46 26.05 23.94 21.83 

11 - - X X 33.92 28.46 26.05 23.65 21.53 

12 X - - - 34.36 29.96 27.96 25.96 23.96 

13 - X - - 34.36 29.96 27.85 25.85 23.85 

14 - - X - 34.36 29.96 27.85 25.74 23.74 

15 - - - X 34.36 29.96 27.85 25.85 23.85 

(X )for opened record, (-) for closed record

Energy cost (R$/day) 

Notes that for the combinations where we had the same number of opened records, the 

power suffers no change, but when it is used the frequency inverter; there is a variation of the 

power consumed. It is observed that with the inverter, the consumption is reduced when have 

lower energy losses, i.e. when the opened records are closer to the pump, it can be checked 

by observing Figure 1. The lower energy consumption for both systems was in the combination 

13, which also provided the largest difference in energy consumption, being 40% lower for the 

use of a frequency inverter. 

24.0 

20.0 

16.0 

12.0 

8.0 

4.0 

0.0 

With Frenquecy Inverter without Frequency Inverter 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 

Combination of records opening in the lots 

Figure 2 – Energy consumption for different combinations with or without frequency inverter 

1.3 Conclusions 

After evaluation of the pumping system in the laboratory, there was a reduction in the 

cost of electricity for pumping in irrigated districts applying different levels of automation, using 

the frequency inverter. 

The use of the frequency inverter demonstrated to be an effective tool in reducing the 

cost of electricity in pumping system for irrigated districts, in the case study, its use 

represented 40% of energy savings. 

1.3 References 

ARAUJO, J. A. B.; SERAPHIM, O. J.; SIQUEIRA, J. A. C., Avaliação de um sistema irrigação 

por aspersão com aplicação do inversor de frequência. In: ENCONTRO DE ENERGIA NO 

MEIO RURAL, 5., 2004, Campinas. 

BERNARDO, S., SOARES, A. A., MANTOVANI, E. C. Manual de Irrigação. 8 ed. Viçosa: UFV, 

2006. 611p. 

BRAGA, N.C. Curso básico de eletrônica. São Paulo: Editora Saber, 1999.v.1 140p. 

MORAES;, M. J.; FILHO;, D. O.; VIEIRA;, G. H. S.; SCARCELLI, R. D. O. C. Gerenciamento 

do lado da demanda no bombeamento de água para perímetro irrigado. Revista Brasileira de 

Engenharia Agrícola e Ambiental, v. 15, n. 9, p. 150-165, 2011.

OLIVEIRA FILHO, D. ; SAMPAIO, R. P., MORAES, M. J., PIZZIOLO, T. A.; DAMIÃO, J. H. A. 

C. Metodologia de diagnóstico energético em estação de captação de água. Revista Brasileira 

Engenharia Agrícola Ambiental [online]. 2011, vol.15, n.10, p. 1097-1103. 

RIBEIRO, M. C. Eficientização e gerenciamento do uso de energia elétrica em perímetros 

irrigados Viçosa, MG: DEA/UFV, 2008. Dissertação (Doutorado em Engenharia Agrícola) – 

Universidade Federal de Viçosa, Viçosa. 

TESTEZLAF, R. Impactos da irrigação no agronegócio brasileiro. I Curso de Cafeicultura 

Irrigada. Universidade de Uberaba. 2002. 9p. 

Turco, J. E. P.; Rizzatti, G. S.; Pavani, L. C., Custo de energia elétrica em cultura do feijoeiro 

irrigado por pivô central, afetado pelo manejo da irrigação e sistemas de cultivo. Revista 

Brasileira de Engenharia Agrícola, v 29, n2 , p.311-320, 2009.

Inefficiency an Index for Drought Analysis 

Hamidbabaei*, Shahab Araghinejad 

University of Tehran, Deparetment of water respurce manegement, karaj, 31587-77871, Iran 

*Corresponding author. E-mail: hamidbabaei1@gmail.com 

Abstrat 

Drought is a natural hazard that has significant impact on economic, agricultural, environmental, 

and social aspects. The central regions of Iran (Zayandeh Rud Basin) have suffered with severe 

droughts at many times in the past. The basin has a predominantly arid or semi-arid desert 

climate. The SPI, SWSI and PDSI are used for temporal and spatial analysis of meteorological, 

hydrological and agricultural droughts. Drought duration and drought severity are often 

calculated by used univariate index. Results showed that using traditional univariate for drought 

analysis cannot distribe drought characteristics. Then for the drought assessment must be 

bivariate indices insted of univariate analysis index. 

Key words: Drought, SPI, SWSI, PDSI, Bivariate indices, Zayandeh Rud Basin. 


Drought is a disastrous natural phenomenon that has significant impact on socio-economic, 

agricultural, and environmental spheres (Obasi 1994, Bruce 1994, Wu et al., 2000). The 

occurrences of droughts are generally linked to deficit precipitation, low soil moisture, deficit 

river flows or groundwater as compared to their corresponding normal values. Drought is 

defined as the deficiency of available water that injuriously affects the usual crops, causes 

temporary scarcity of water for mankind consumption and influences the economic renewable 

resources (Komuscu, 1999). Several approaches have been proposed for univariate index for 

drought analysis. These include Standardized Precipitation Index (SPI), Palmer Drought 

Severity Index (PDSI) and Surface Water Supply Index (SWSI). The SPI has been used to 

monitor meteorological drought. The SPI is an index based on the probability of precipitation for 

any time scale. The SPI is used operationally to monitor conditions across Colorado since 1994 

(McKee et al., 1995). The Palmer Drought Severity Index (PDSI) is a meteorological drought 

index, which provides a standardized measurement of moisture conditions to compare between 

locations and over time. The PDSI estimates duration and intensity of drought events by 

measuring departure of the moisture supply based on a supply-and-demand concept of the 

water balance equation (Palmer, 1965). The SWSI is calculated by river basin, based on 

snowpack, stream flow, precipitation, and reservoir storage. The objective of the SWSI is to 

incorporate both hydrological and climatological features into a single index value for each 

major river basin in the west (Shafer & Dezman, 1982). The aim of this study was to show one 

drought index cannot provide a comprehensive evaluation of droughts. Instead of using 

traditional univariate analysis for drought assessment, this study employs bivariate drought 

characteristics. Drought duration and drought severity, to dene and assess droughts.

1.1 Description of the Study Area 

The Zayandeh Rud Basin is located in central of Iran with a semidry area of 41.500 km 2 (Fig. 1), 

a relatively small basin that has experienced several severe droughts (1960–68,1981–90, and 

1999–2001) over the past years. 

FIGURE 1. Zayandeh Rud basin, Iran 

2. Data and methodology 

Climate data of the study region were extracted and modelled for the SPI, SWSI and PDSI 

calculations. For this study, the observational surface temperature (°C) and monthly 

precipitation (mm/day) data cover the time period from 1968 to 2001 in a monthly time step. The 

SPI is an indicator of meteorological drought, which is mainly caused by a deficiency of 

precipitation. When SPI is below 1.5, the drought condition is considered severe; when it 

reaches below 2 it is considered extreme. A long-term precipitation record is needed in order 

to calculate SPI. The PDSI is an indicator of prolonged soil moisture deficiency (Palmer, 1965). 

While it estimates soil moisture using a simple two layer soil description, it has been shown to 

be strongly correlated (r= 00.5–0.7) with measured soil moisture (Dai et al., 2004). The SWSI is 

a predictive indictor of total surface water availability within a watershed for the spring and 

summer water use season. The index calculated by combining pre-runoff reservoir storage with 

forecast of stream flow which are based on current snowpack and other hydrologic variable. 

3. Results and Conclusions 

Drought monitoring in the basin indicated that this phenomenon occurred in different periods. 

Time scale 12-month of SPI, the frequency of occurrence of severe drought shows in during 

1968 to 2001. Similarly, results based on hydrological, drought analysis shows that the severest 

drought events occurred in the Basin during October 1998 to September 2001 but indicators 

magnitude, severity and duration droughts was showed no same characteristic (Fig. 2).

Oct-1998 

Sep-2001 

FIGURE 2. Comparison drought indices 

Also result shows that Multidimensional characteristics of a drought make univariate index 

analysis unable to reveal the significant relationship among drought properties.

Refrences: 

Bruce J.P. (1994). Natural disaster reduction and global change. Bulletin of the Amer Meteorolo 

Soc, 75, 1831-1835. 

Dai, A., Trenberth, K.E., & Qian T. (2004). A global data set of Palmer Drought Severity Index 

for 1870–2002: relationship with soil moisture and effects of surface warming. Jornal of 

Hydrologic Engineering, 5, 1117–1130. 

Komuscu A.U. (1999). Using the SPI to Analyze Spatial and Temporal Patterns of Drought in 

Turkey. Drought Network News, 11, 7-13. 

McKee, T. B., Doesken, N. J., & Kleist J. (1995). Drought monitoring with multiple time scales. 

Proceedings of the Ninth Conference on Applied Climatology (pp. 233–236). American 

Meteorological Society, Boston. 

Obasi GO P (1994) WMO‘s role in the international decade for natural disaster reduction. Bull of 

the Amer Meteorolo Soc 75:1655-1661 

Palmer, W.C. (1965). Meteorological drought. Research Paper No 45, US Department of 

Commerce Weather Bureau, Washington. 

Wu, H., Hayes, M.J., Wilhite, D.A., & Svoboda M.D. (2005). The effect of the length of record 

on the standardized precipitation index calculation. International Journal of Climatology, 25, 

505-520. 

Shafer, B.A., & Dezman, L.E. (1982). Development of a Surface Water Supply Index (SWSI) to 

assess the severity of a drought conditions in Snowpack Runoff Areas, the western snow 

conference (pp. 164-175). Colorado State University, Fort Collins, Colorado.

Identification of Free-form Parameterized Soil Hydraulic Properties 

in Non-isothermal Subsurface Water Flow Using Inverse Technique 

Tomoki Izumi 1 *, Masayuki Fujihara 2 

1 Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, 790-8566 Japan 

*Corresponding author. E-mail: t_izumi@agr.ehime-u.ac.jp 

Abstract 

An inverse modeling to identify the soil hydraulic properties in a variably saturated water flow 

in non-isothermal soil based on field observation is proposed. The governing equations are 

the mixed form Richards equation and the heat conduction equation to consider the soil 

surface water movement significantly affected by the soil temperature. After the soil water 

retention curve function is given in advance, the relative hydraulic conductivity which is the 

major unknown parameter here is determined using inverse technique. For the 

representation of RHC function, a free-form parameterization appraoch using a sequence of 

piecewise cubic spline function is employed to express the flexible function form of the 

parameter. The inverse problem is solved using a simulation-optimization method after 

defined as the minimization of errors between the observed and computed pressure heads. 

The validity of the model is shown from the validation results of the model developed through 

its practical application to in-situ soil. 

Key words: Parameter identification, Simulation-optimization method, Mixed form Richards 

equation, Heat conduction equation, Field observation. 


Understanding of water movement through soil is quite important in agriculture. The water 

flow in soil is governed by Richards equation (RE). Generally, analytical solutions of RE are 

not possible except under very restricting assumption due to the strong nonlinearity of the 

parameters involved. Instead, there have been many attempts to develop numerical methods 

(Hillel, 1998). The success of these numerical methods depends on the parameter 

identification which is a critical step in modeling process, as well as the model structure given 

by governing equations. 

Most of the earlier works on parameter identification have commonly treated the well-defined 

models describing the soil hydraulic properties (SHPs), i.e. the unsaturated hydraulic 

conductivity and the soil water retention curve, by a fixed-form function such as the van 

Genuchten-Mualem model (Mualem, 1976; van Genuchten, 1980). 

Although the fixed-form functions make the inverse modeling relatively easy-to-handle due to 

the limited number of unknown parameters, drawbacks are caused in employing this type of 

the function. Alternatively, Bitterlich et al. (2004) proposed an inverse method using a freeform 

parameterization approach. In the approach, the unknown parameters, SHPs, are 

represented by a sequence of piecewise polynomial functions. Iden and Durner (2007, 2008) 

suggested the modified method proposed by Bitterlich et al. (2004). In their works, the 

validity of the methods is examined based on synthetic data sets and measurements through 

the multistep outflow or evaporation experiments in laboratory scale. 

On the other hand, Izumi et al. (2008) proposed a field-oriented approach for the inverse 

estimation of SHPs based on the free-form parameterization because the laboratory 

experiments cannot be performed under fully natural conditions. Izumi et al. (2009) also 

proposed an inverse method to estimate SHPs in non-isothermal soil since the soil surface 

water movement is significantly affected by the soil temperature. Additionally, Izumi et al. 

(2011) presented an inverse modeling for the mixed form of RE which is one of three forms of

RE because it has the advantages over the other forms in applicability. However, the method 

presented by Izumi et al. (2011) does not consider the effect of soil temperature on water 

movement in soil. 

The purpose of this paper, thus, is to develop an inverse modeling for the mixed form RE in 

non-isothermal soil. Firstly, the governing equations (forward problem, FP) are described, 

and SHPs which are model parameters included in the equations are parameterized. The 

relative hydraulic conductivity (RHC) which is a major unknown parameter to be identified in 

this study is described by a free-form parameterized function which is a sequence of 

piecewise cubic spline functions over the whole effective saturation domain. For the 

representation of the soil water retention curve (SWRC), van Genuchten model (VG model) 

is employed due to being time-proven. Secondly, the inverse problem (IP) is defined as 

minimizing errors between the observed and computed values of the pressure head. The 

solution procedure is then described based on a simulation-optimization algorithm with the 

aid of the Levenberg-Marqurdt method to determine the function shape of RHC. Finally, the 

validity of the inverse modeling developed is examined through in-situ experiments in terms 

of reproducibility for observed water movement. 

2. Governing Equations 

2.1 Water Movement Model 

In order to obtain the mass-conservative numerical solutions, the mixed form of RE is 

employed for the water movement. Additionally using the Boussinesq assumption to consider 

the dependency of density and viscosity of water on soil temperature, the equation in onedimensional 

vertical flow where the liquid phase is considerable magnitude, i.e. neglecting 

the vapor fluxes, is described as follows (Huyakorn and Pinder, 1983); 

∂S 

ψ ⎛ ⎛ ρ ρ ⎞⎞ 

w 

∂ ∂ ∂h 

T 

− 

ρ 

φ + WSwSs 

= − − K ⎜ + 

⎜ 

⎟ 

(1) 

∂t ∂t ∂z ∂ ρ ⎟ 

⎝ ⎝ z 

ρ ⎠⎠ 

with 

⎧⎪ 1 ( ψ ≥ 0 ), 

p 

W = ⎨ 

Ss = ρρg( βs + φβw) , K = Kρ ( Se) KT ( Ts) 

Ks, 

h = + z = ψ + z (2) 

⎪⎩ 0 ( ψ < 0 ), 

ρρg 

where φ is the porosity, S w the saturation, S s the specific storage, ψ the pressure head, K the 

unsaturated hydraulic conductivity, h the hydraulic head, t the time, z the height defined as 

positive upward, ρ T the water density at the soil temperature T s , ρ r the reference water density 

at the reference soil temperature T r , g the gravitational acceleration, β s and β w the 

compressibility coefficients of soil and water, respectively, K r the relative hydraulic 

conductivity, K T the correction-factor function of soil temperature, K s the saturated hydraulic 

conductivity, S e the effective saturation and p the water pressure. 

2.2 Thermal Transport Model 

The heat flux due to the water movement in soil is smaller than the heat conduction by the 

solid soil and thus can be neglected. Accordingly, the heat conduction equation is employed 

for the thermal transport, and described as follows; 

∂ ( CT 

h s) 

∂ ⎛ ∂Ts 

⎞ 

= − ⎜ −λ 

∂ ∂ ∂ ⎟ 

(3) 

t z⎝ 

z ⎠ 

with 

0.5 

( 1 φ) θ , λ θ θ 

C = − c + c = r + r + r 

(4) 

h s w 1 2 3 

where C h is the volumetric heat capacity of soil, θ the volumetric water content, c s and c w the 

volumetric heat capacity of soil particles and that of water, respectively, and λ the thermal 

conductivity of soil expressed by a simple empirical equation with the regression parameters 

r 1 , r 2 and r 3 (Chung and Horton, 1987).

2.3 Parameterization of SHPs 

The unsaturated hydraulic conductivity is described as the product of three variables shown 

in Eq.(2). The correction-factor function of soil temperature and saturated hydraulic 

conductivity are represented as follows; 

µ ρ κ 

= ρ 

g 

K = ρ 

T 

, K 

s 

(5) 

µ 

T 

µ 

ρ 

where µ r and µ T are the dynamic viscosity coefficient at temperature T r and T s , respectively, 

and κ the intrinsic permeability. Because the dynamic viscosity is the function of the 

temperature and the saturated hydraulic conductivity can be determined through laboratory 

experiments by definition, the parameterization of RHC is needed. 

To represent RHC, a free-form approach using a sequence of piecewise cubic spline 

functions is employed and is then described as follows; 

I − 

= ∑ 1 

K S K S (6) 

( ) ( ) 

r e r, i e 

i = 1 

with 

2 3 

( ) ( ) ( ) , , 

+ 

⎧ 

⎪ai + bi Se − Se, i 

+ ci Se − Se, i 

+ di Se −Se, i 

Se ∈⎣⎡Se, i 

Se, i 1⎦⎤ 

Kr, i ( Se 

) = ⎨ 

(7) 

⎩⎪ 0, Se ∉ ⎡⎣Se, i, 

Se, i+ 

1⎤⎦ 

where a i , b i , c i and d i are coefficients in the cubic splines, and i (1 ≤ i ≤ I) a nodal number. 

Hereinafter, the values of K r (S e ) at a node i are simply denoted by k i . 

To represent SWRC, various models have been proposed. VG model has been more 

frequently used among them and, thus, VG model is employed for the representation of 

SWRC. Additionally, to account for the effect of soil temperature when calculating θ using VG 

model, the value of ψ obtained from Eq.(1) is corrected as follows; 

S 1 θ − θr 

e ( ψ ) = = 

vg 

vg θ − θ 

(8) 

r 

n 

m 

1+ 

αψ 

s r 

( ( r ) ) 

with 

1 σ ρ 

= − ψ = ρ T 

m 

vg 

1 , 

ρ 

ψ 

(9) 

nvg 

σT 

ρρ 

where θ r is the residual water content, θ s the saturated water content, α, m vg and n vg the 

unknown parameters, ψ r the pressure head at a reference soil temperature T r , and σ T and σ r 

the surface tension at soil temperature T s and a reference temperature T r , respectively. 

2.4 Numerical Procedure 

After discretization with the standard Galerkin finite element method for space and the finite 

difference method for time, Eqs.(1) and (3) are subjected to initial and boundary conditions 

and numerically solved with the iterative partitioned method. 

3. Parameter Identification Procedure 

The unknown parameters to be identified are RHC and SWRC. RHC, in general, cannot be 

determined by the direct measurement while SWRC can be obtained from the time-series 

data of the pressure head and volumetric water content with relative ease. Hence, RHC is 

treated as the unknown parameter and is identified using inverse technique. 

3.1 Inverse Problem (IP) 

IP in terms of k={k i , 1≤i≤I} is defined as the minimization problem of errors between the 

solution of FP (ψ com (k)) and the observed data (ψ obs ), and thereby described as follows; 

opt 

( ) minJ ( ) 

opt 

J k = k , k , k∈K 

(10) 

ad

with 

L 

1 

2 

com 

obs 

J ( k ) = ∑{ fl 

( k )} , fl ( k ) = ( ψl ( k ) −ψl 

) 

(11) 

2 l = 1 

where J(k) is the objective function, k opt the set of optimal solutions, K ad an admissible set of 

k opt and k, and L the total number of observed data available in space and time. 

The decision variables, k, are iteratively modified or updated while step by step solving FP 

with their assumed or previously estimated values. In this respect, identification of RHC 

function (Eq.(6)) requires a sort of simulation-optimization technique. 

3.2 Optimization Algorithm 

Levenberg-Marquardt method is employed for the optimization algorithm to search for the set 

of optimal solution with following search sequence through the iteration (Sun, 1994); 

( γ+ 

1) ( γ ) ( γ ) 

k = k +∆k (12) 

with 

γ γ 

γ γ γ γ 

( η ) 

− 1 

⎡ L 

∂ ∂ ⎤ 

∆ = − + ∇ = ⎢∑ ( ) ( ) 

k ( ) H ( ) I J ( ) ( ) 

, H fl 

fl 

⎥ 

⎢⎣ 

l = 1 ∂ki ∂k 

(13) 

j ⎥⎦ 

where γ is an iteration number, η a coefficient which controls search strategy between the 

Gauss-Newton and the steepest decent direction, and I the I×I unit matrix. 

4. Validation 

The validity of inverse modeling proposed is assessed in terms of reproducibility for observed 

water movement in test soil. The time-series observed data is obtained through in-situ 

experiments (sandy soil) in Matsuyama, Ehime Prefecture in the following way. 

4.1 Field Observation and Computational Domain 

The observation system and computational domain for parameter identification are illustrated 

in Fig.1. The observation system consists of three sets of instruments: tensiometer (UIZ- 

SMT), soil moisture probe (UIZ-SM-2X) and thermometer (TMC20-HD). To reduce the 

influence of direct solar radiation on the observed pressure heads, the sensors of 

tensiometers attached above ground are shielded by white-colored box with slits for 

ventilating air. Each set of instruments is buried at three different depths in soil: -10 cm, -20 

cm and -30 cm. A pair of pressure head and volumetric water content data at the same depth 

is used to determine SWRC. The observed values of the pressure head at -20 cm are used 

to determine RHC and to assess the fitness of estimated RHC function in the simulationoptimization 

runs. The pressure head and soil temperature observed at both top and bottom 

(-10 cm and -30 cm) of soil are utilized as Dirichlet boundary values for solving FP to 

intentionally avoid measuring flux like evapotranspiration whose measurement is generally 

difficult in the field experiments. The time-series soil temperatures at -20 cm are used as the 

benchmark data for confirming reproducibility of forward solution for the heat transport. 

The computational domain, therefore, is the surface soil of 20 cm thick, and is divided into 

four equal elements with five nodes for computations. 

In this study, a one-way process of desorption is considered for estimation of SHPs to 

exclude the hysteric phenomenon like in most of the earlier works on parameter 

identification. Hence, the time-series observed data during no-rainfall period—November 25 

to December 2, 2010—as shown in Fig.2 is used. 

4.2 Identification of SWRC 

SWRC is should be determined before estimating RHC in this inverse modeling. To obtain 

θ −ψ relations expressed by Eq.(9), SWRC fit developed by Seki (2007) is used. For the 

implementation, observed data of θ and ψ are corrected for a reference temperature based 

on the soil temperature at the same depth, using the coefficient of thermal expansion and

z 

5 cm 

-10 cm 

-20 cm 

5 

4 

3 

Pressure 

head 

Volumetric 

water content 

m 

0.0 

-0.4 

-0.8 

-1.2 

-1.6 

0.25 

0.15 

-10cm -20cm -30cm 

-30 cm 

2 

1 

Tensiometer 

Soil moisture 

probe 

Thermometer 

FIGURE 1: Schematic illustration of observation 

and computation 

Soil 

temperature 

0.05 

o 

C 

20 

10 

0 

11/26 11/27 11/28 11/29 11/30 12/1 12/2 

Time in day 

FIGURE 2: Observed data 

Eq.(10), respectively. Additionally, the saturated water content θ s is defined as the value of θ 

in case that ψ is equal to zero while the residual water content θ r as the minimum value in 

observed data of θ. Thus, θ s and θ r are determined to be 0.30 and 0.05 from all observed 

data series including them shown in Fig.2, respectively. As the reference soil temperature, 

the average value of observed data is adopted which equals to 12.4 degrees Celsius. 

Conclusively, a best fitting curve for θ −ψ relation at the reference soil temperature is 

obtained with the value of α and n vg being 28.9 m -1 and 1.43, respectively. 

4.3 Identification of RHC 

Firstly, the number of identified unknown parameters is determined. Since the optimal 

number of parameters is approximately from seven to nine according to Bitterlich et al. 

(2004) and Iden and Durner (2007), the number of unknown parameters is set to be 10 in 

this study. 

Secondly, the manner of division on the definition domain (effective saturation domain) is 

determined. The function shape of RHC generally has steeper gradient near the saturated 

zone. In the context of accuracy, the range with steeper gradient should be divided into finer 

subdomain. Therefore the effective saturation range from 0.8 to 1.0 where RHC function 

rapidly changes is partitioned into sub-range in the manner of geometric series. 

Eventually, RHC function is identified as shown in Fig.3 after the saturated hydraulic 

conductivity at the reference temperature is determined to be 5.18×10 -5 m/s through 

laboratory experiment. 

4.4 Reproducibility of Calibrated Forward Simulation Model 

The validity of the inverse modeling proposed is assessed in terms of reproducibility for the 

time-series observed data by calibrated forward simulation model through comparing the 

observed and computed values. The result of reproducibility for water movement is shown in 

Fig.4. In the lower half of Fig.4, the absolute errors |ψ obs -ψ com | are also shown to demonstrate 

the time-varying difference in solution reproducibility. From the results, it is found that water 

movement is reproduced with high accuracy. 

5. Conclusion 

An inverse modeling in variably saturated and non-isothermal subsurface water flow is 

developed. To consider the water movement depending on the soil temperature, a couple of 

the mixed form RE with heat conduction equation is employed as the governing equation.

Relative hydraulic conductivity r 

1.0 

0.8 

0.6 

0.4 

0.2 

r 

0.0 0.2 0.6 1.0 

Effective saturation 

FIGURE 3: Identified RHC 

e 

Pressure head (m) 

Fitting error (m) 

0.0 

-0.2 

-0.4 

-0.6 

0.16 

0.08 

0.0 11/26 11/27 11/28 11/29 11/30 12/1 12/2 

Time in day 

FIGURE 4: Reproducibility of forward solution 

for water movement 

RHC function is represented using a free-form approach and determined by solving IP with 

the simulation-optimization technique after SWRC which can be determined through 

experiments with relative ease is given in advance. The validity of the inverse modeling 

proposed is confirmed from the practical application with in-situ soil near the surface soil. 

obs 

com 


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estimate soil hydraulic properties in saturated-unsaturated groundwater flow. J. of 

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conductivity of unsaturated soils. Soil Sci. Soc. Am. J., 44, 892-898.

Develop A Simple Economical Evaporation Pan 

Mohamed A. Rashad 1 , and El-Sayed E. Omran 2 * 

1 Agricultural Engineering Department, Faculty of Agriculture, Suez Canal University, Egypt. 

2 Soil and Water Department, Faculty of Agriculture, Suez Canal University, Egypt. 

* Corresponding author. E-mail: ee.omran@gmail.com - e.omran@scuegypt.edu.eg 

Abstrat 

The objective of the current study was “to develop a Simple Economical Evaporation Pan 

(SEEP)”. The pan made using inexpensive materials which are simple, low cost, and can easily 

be placed in several locations of an irrigated field. Four different pans sized very small (16cm), 

small (32cm), medium (40cm) were compared to the standard large (57cm) pan. The pan 

consists of a galvanized washtub with standard brass toilet bowl floats. Twelve pans (3 

replicates for 4 diamter) were evaluated and tested to determine if the pans of the same size 

responded similarly to each other, and how the variation was different between pan sizes. For 

the test, 432 different readings were available over a period of time. The results show that pan 

size 57 cm was the nearest from the standard class (A) in evaporation rate. But that not mean it 

is the best one. The final decision for the best pan is based on the economical and many other 

factors. The medium pan (M= Ф 40) did not respond exactly the same as the larger pan (L= Ф 

57). However, the small pan (S= Ф 32) responded in a similar manner to the medium pan (M= 

Ф 40) when compared to the large (L= Ф 57) pan. The very small pan (VS= Ф 16) representing 

the evaporation that occurs from the large pan. Overall based on this study, the very small 

sized pan (VS= Ф 16) offers a potentially less expensive alternative to irrigation scheduling. The 

advantages of economical evaporation pan are facial in measurement and in transportation and 

lower in cost of installation which make it easy for farmers to have evaporation pan and 

calculate water requirement for all plant. 

Key words: Economical Pan, Evaporation, Irrigation Scheduling. 


The current available methods for measuring rates of evaporation are limited. Unfortunately, 

the three accurate direct methods of measurement available, i.e. weighing lysimeters, Bowen 

ratio and eddy flux instrumentation, are unsuitable for monitoring evaporation as a routine direct 

measurement at meteorological enclosures (Strangeways, 2001). 

Field devices that integrate environmental effects and measure evaporation can be used to 

schedule irrigation. These devices respond to water removal and water addition, like rainfall or 

irrigation. Crop water use is commonly predicted using weather data to estimate reference 

evapotrationspiration (ET 0 ). Evapotranspiration is not easy to measure. Specific devices and 

accurate measurements of various physical parameters or the soil water balance in lysimeters 

are required to determine evapotranspiration. The methods are often expensive, demanding in 

terms of accuracy of measurement and can only be fully exploited by well-trained research 

personnel. Although the methods are inappropriate for routine measurements, they remain 

important for the evaluation of ET estimates obtained by more indirect methods. 

The only two practical methods suitable for routine use in meteorological station networks are 

measurements using evaporimeters and calculations based on other meteorological 

measurements. The second is the approach, introduced by Penman in 1948 to estimate open 

water evaporation (Penman, 1948) and extended by Monteith in 1965 to directly estimate 

evaporation from vegetation covered surfaces (Monteith, 1965) which is now the method 

recommended by the FAO to calculate reference crop evapotranspiration (Allen et al., 1998). 

However, to apply the Penman–Monteith equation to natural vegetation or agricultural crop

surfaces requires information on their surface resistance to water loss. The use of the 

Penman–Monteith equation in irrigation practice requires empirical coefficients to modify in 

general to reduce but sometimes to increase the estimates of reference crop 

evapotranspiration. It is of course the need for such empirical crop coefficients that is the major 

criticism of the use of evaporimeters. 

One meteorologically based device used for irrigation management is the evaporimeter, which 

can be any evaporation measuring device such as an atmometer (Broner and Law, 1991) or 

evaporation pan, whose data can be related to crop water use by applying crop coefficients as 

are used to modify evapotranspiration models. The World Meteorological Organization (WMO) 

has recommended that the evaporation pan be adopted as the standard instrument for crop 

water use determination. The best known of the pans are the "Class A" evaporation pan and 

the "Sunken Colorado Pan". The pan has proved its practical value and has been used 

successfully to estimate reference evapotranspiration by observing the evaporation loss from a 

water surface and applying empirical coefficients to relate pan evaporation to ET O (Stanhill, 

2002, Thomas, et al., 2002). The problems involved in the use of Class A pan as expensive 

and not easy movable were recognized. 

According to our knowledge, no reports are available on using the economical and flexible 

evaporation pan. The objective of this study is to develope a simple economical 

evapotranspiration pan. The aim is to assess the feasibility of and also to provide guidelines for 

setup and use of the evaporation pan for irrigation 


Experiments were conducted at the soil and water department’s farm, Faculty of agriculture, 

Suez Canal University. The main aim of this research is to propose evaporation pan and 

calculate its K pan and compare it with the K pan of evaporation pan class A. 

2.1. Pan Development Stages 

Four galvanized steel pans with 16, 30, 39, and 57 cm diameter and 30 cm height were built-in. 

The pans were from available materials in the market and at affordable prices. The pan 

constructed with mesh covers and install unit to determine the increase and the decrease in the 

water level (figure 1). 

2.2. Field Experimental setup 

The first field experiment was conducted from 15/04/2011 to 05/05/2011 and the second 

experiment was conducted from 7/6/2011 to 21/6/2011. In order to calibrate the different pans 

and determine k pan compared to k pan of the evaporation class A pan (120 cm diameter and 25 

cm height) at the same condition, the following steps are considered (Figure 1). First, three of 

the pans were distributed and put on wood base exept for the fourth size (16) which is installed 

vertically at a djustable height of 150 cm above the soil. After that the horizontal of pans was 

adjust by using water leveling apparatus to ensure the accuracy of prototype obtained. Second, 

every three pans of the same type were distributed in one place to standardize the conditions 

applicable to them. Third, the evaporation class A pan was Put with different pans to compare it 

with the different pans. Finally, wind speed was measured by Anemomete (accuracy 0.1 km 

/hr) for used in equations to calculate the K pan . Also, the temperature and humidity were 

measured by digital temperature and humidity device at the time of sunrise and noon. The 

water level reading in pans was started in same time from first day until last day.

Example of the manufactured pans of 

galvanized steel with 57 cm diameter 

and 30 cm height 

Cover using wire mesh fixed on 

steel frames and pieces of wood 

base its height is 10 cm 

The water level measured by ruler 

scale and a pointer mounted on a 

steel rod ended by a float on water. 

Class A pan Defferent types of pan: very small pan (VS= Ф 16), small pan (S= Ф 32), 

medium pan (M= Ф 40), larger pan (L= Ф 57) 

FIGURE 1: Examples of the different pan sizes and class A pan used in the Pan development 

and field experimental setup. 

Measuring the Pan Water Levels 

Water levels in an evaporation pan can be most accurately measured using a stilling well (as 

illustrated in Figure 1) with a hook gauge and micrometer. The stilling well provides a fixed 

reference point for accurate measurements even if the pan is not perfectly level. The hook 

gauge and micrometer permit depths to be measured to the nearest 0.001 inches, which is 

much greater accuracy than required for irrigation scheduling. Accuracies sufficient for irrigation 

scheduling can be obtained using a finely-graduated ruler or meter stick. However, the water 

depth measurement must always be made at the same location, and care must be taken to 

assure that the ruler is held vertically when measurements are made. For ease of 

interpretation, evaporation measurements should be made at about the same time each day. 

Normally, early morning or late evening measurements are most convenient. Early morning 

measurements permit yesterday's ET to be estimated and today's irrigations to be scheduled. 

Late evening measurements can be used to estimate today's ET for irrigations to be scheduled 

tonight or early tomorrow morning. 

Determination of K pan (Pan Coefficients) 

When using the evaporation pan to estimate the ET o , in fact, a comparison is made between 

the evaporation from the water surface in the pan and the evapotranspiration of the standard 

grass. Of course the water in the pan and the grass do not react in exactly the same way to the

climate. Therefore a special coefficient is used (K pan ) to relate one to the other. ET o and E pan 

are required to calculate (K pan ) coefficients. K pan values depend upon the location of the 

evaporation pan, the average daily relative humidity, the average daily wind speed, and the 

type of area surrounding the pan. The pan evaporation rate (and thus the value of K pan ) is 

different if the pan is surrounded by bare soil as opposed to a vegetated surface. 

ET o = K pan × E pan 

ET o : reference crop evapotranspiration, K pan : pan coefficient, E pan : pan evaporation 

If the water depth in the pan drops too much (due to lack of rain), water is added and the water 

depth is measured before and after the water is added. If the water level rises too much (due to 

rain) water is taken out of the pan and the water depth before and after is measured. 


3.1 Overall Daily Reading of Atmosphere Data 

Daily averaged meteorological data recorded in the study field (Ismailia city) from (15/4) to (5/5) 

are shown in Table 1. The rate of evaporation is the amount of water evaporated over a given 

period of time. On open bodies of water, the rate is affected by several ground and atmospheric 

factors of which the main ones are: Solar radiation, Relative humidity, Winds, temperature. It is 

important to note that the effects of ground and atmospheric conditions on large water bodies 

can be different to the effects on an evaporation pan. 

TABLE 1: Meteorological data recorded during the experiment: air temperature, relative 

humidity (RH), and average wind speed. 

Day Julian Day 

Temperature 

Hummidity 

MAX TEMP MIN TEMP MAX RH MIN RH 

AVG Wind SPEED 

15 April 106 28.6 12.0 83 35 9.5 

16 April 107 29.4 14.4 85 38 7.9 

17 April 108 30.7 12.5 84 28 6.3 

18 April 109 34.0 14.4 71 23 7.3 

19 April 110 36.5 16.8 69 22 8.9 

20 April 111 35.3 17.0 65 26 6.0 

21 April 112 29.1 15.9 80 38 8.0 

22 April 113 22.6 13.9 81 48 9.2 

23 April 114 26.0 13.0 88 35 7.0 

24 April 115 28.1 12.9 80 35 9.3 

25 April 116 30.9 14.0 80 32 9.2 

26 April 117 31.0 14.8 82 35 7.2 

27 April 118 34.3 14.8 80 25 6.1 

28 April 119 26.8 14.7 85 44 9.1 

29 April 120 28.1 14.9 87 39 6.4 

30 April 121 28.8 15.2 81 36 7.2 

1 May 122 27.4 13.5 83 35 6.6 

2 May 123 26.0 12.4 88 37 6.4 

3 May 124 28.5 12.9 83 32 6.3 

4 May 125 29.9 13.9 84 31 6.2 

5 May 126 30.8 14.4 84 30 6.2 

7 June 159 34.9 14.7 86 33 8.3 

8 June 160 29.3 14.6 87 46 6.9 

9 June 161 30.5 12.5 85 38 6.5 

10 June 162 33.8 13.1 78 30 8.4 

11 June 163 35.3 14.9 79 28 6.8 

12 June 164 31.3 15.8 86 43 7.4 

13 June 165 32.5 16.1 86 40 6.3 

14 June 166 32.7 14.9 85 35 6.3 

15 June 167 31.5 14.4 84 37 7.1 

16 June 168 34.8 18.0 81 40 7.4 

17 June 169 36.8 19.6 83 37 8.0 

18 June 170 36.5 17.2 82 39 7.9 

19 June 171 36.1 15.0 86 37 9.1 

20 June 172 40.1 15.0 73 27 8.9 

21 June 173 42.4 14.5 70 22 6.2

3.2 Description of the Tested Pans 

The variability in pan level readings within a particular treatment was analyzed using the 

coefficient of variation (Table 2). The expectation is that the smaller pans would respond to 

evaporation rates (change in water level) in a similar manner to the larger pans. The analysis 

was made to determine if the pans of the same size and same screen material responded 

similarly to each other, and how the variation was different between pan sizes. For the test, 432 

different readings were available over a period of time that did not include a refill of a pan or a 

significant rainfall event (where a pan overflowed through the drain hole). 

TABLE 2: Description of pans that were tested. 

Label– diameter, cm Description SD Mean Variance CV** 

VS- 16 Very Small 2.3553 8.75 5.547 26.91 

S-32 Small 0.900029 5.63 0.810 15.97 

M-40 Medium 0.918361 6.08 0.843 15.11 

L-57 Large 1.008692 6.48 1.017 15.58 

Class A Pan 1.150611 7.01 1.324 16.42 

**CV is the coefficient of variation calculated for the three replications of each treatment based on the average of the individual 

reading CVs (SD/Mean difference in water level for the three replications) over the entire period of study. 

3.3 Relation between Kpan and Epan and different pans dimensions 

Figure 2 shows the E pan , ET O and K pan results. At the same period, the water level of four 

different pans was measured by using the schematic prsented in figure (1). Moerover, 

measuring water level in pan class (A) was prsented. 

These different results in K pan and E pan were according to different between pans in dimensions and 

materials and zero point from pan to pan adding to different in daily atmosphere data. ET O is 

constant to all pans in day. But, it's variable from day to day according to the different in daily 

atmosphere data that entered in crop water program. 

3.4 Response of the smaller pans in comparison to the larger pan 

To get an idea of the overall performance of developed pan, the relashionship and linear 

correlation line for the average wáter loss or gain between the large pan and the small pan 

were plotted together. The results show that there are a linear correlation between the small 

(Ф 16cm) and large pan (Ф 57cm). At last from the resulting data, pan Ф 57cm was the nearest 

from the standard class (A) in evaporation rate. But that it is not mean Ф57 cm is the best. K pan 

(Ф16- Ф32- Ф40) has no large difference between them. But the best pan limits according to 

price and many parameters, so Ф16cm is the most simple economical evaporation pan. The 

very small pan did a better job of representing the evaporation that occurs from the large pan. 

The pan is suitable for the small holder farms (i.e., window screen and a short rod length). The 

very small pan may be a reasonable alternative. Statistical results did not show any significant 

differences (based on P

FIGURE 2: The relation between K pan , E pan and different pans diameters.

4. Conclusion and Eyes to the Future 

The objective of the current study was to determine K pan for each type of pans and comparing it 

with the standard method in order to choose the most simple (design and use) economical pan. 

The results indicate that K pan was from (0.6-0.85). Different sized pans were evaluated for their 

potential to be used as simple and economical Pans for scheduling irrigations. Medium and 

small pans were compared to the standard large pan as more economical alternatives. The 

results show that pan Ф 57 was the nearest from the standard class (A) in evaporation rate. But 

that not mean the Ф57 is the best one. The medium pan responded quite similarly to the large 

pan under the same conditions. K pan (Ф16- Ф32- Ф40) at the same range from the standard. But 

the final decision for the best pan is based on the price and many other factors. The 

advantages of economical evaporation pan are easy in measurement and in transportation and 

lower in cost which make it simple for farmers to have evaporation pan and calculate water 

requirement for all plant. In conclusion, the very small (VS) sized pan offers a potentially less 

expensive alternative to irrigation scheduling. Overall based on this study, the VS sized pan 

offers a potentially less expensive alternative to irrigation scheduling through the Pan approach. 

The VS pan has some limitations based on the conditions of this test which will be managed in 

future research. 

References 

Allen, R.G., L. S. Pereira, D.Raes, & Smith M. (1998). Crop evapotranspiration - Guidelines for 

computing crop water requirements. FAO Irrigation and Drainage Paper 56. Food and 

Agriculture Organization of the United Nations, Rome, Italy. Available at 

http://www.fao.org/docrep/X0490E/x0490e00.htm#Contents 

Broner, I & Law R.A.P. (1991). Evaluation of the modified atmometer for ET estimation. 

Irrigation Science, 12:21-26. 

Harrison, K.A. & Thomas D.L. (2001). How-to brochure – Step by step instructions for using the 

EASY Pan. University of Georgia Cooperative Extension Service. 

Monteith, J.L. (1965). Evaporation and environment. Symp.Soc. Exp.Biol. 19:205-234. 

Stanhill, G. (2002). Is the Class A evaporation pan still the most practical and accurate 

meteorological method for determining irrigation water requirements? Agricultural and 

Forest Meteorology 112: 233-236. 

Thomas, D.L., K.A. Harrison, J.E. Hook, & Whitley T.W. (2002). UGA EASY pan irrigation 

scheduler. Available online at http://pubs.caes.uga.edu/caespubs/pubcd/B1201.htm. 

Strangeways, I. (2001). Back to basics: the ‘met.enclosure’. Part 7. Evaporation Weather, 56 

(2001), pp. 419–427 

Penman, H.L., (1984). Natural evaporation from open wáter, bare soil and grass, Proc. R. Soc. 

London, Ser. A., 193, 120-146

Coagulation using Moringa oleifera and filtration for removal of 

Cryptosporidium ssp. oocyst by simulation with polystyrene 

microspheres 

Francisco, A.R. 1 ; Silva, M.J. 1 ; Paterniani, J.E.S. 1* 

1 Faculdade de Engenharia Agrícola – Universidade Estadual de Campinas, Av. Candido 

Rondon, 501, Campinas SP, CEP 13083-875, Brazil 

*Corresponding author. E - mail: pater@feagri.unicamp.br 

Abstract 

In regions where there is no conventional water treatment, waterborne diseases are 

common, increasing the proliferation of most living organisms. Among many disease-causing 

organisms, Cryptosporidium spp. is a protozoan that survives various barriers to water 

treatment, mainly due to its forms of oocysts with size, strength and hydrophobic 

characteristics. For locations that lack conventional treatments, the best way to avoid 

contamination by oocysts and other organisms is to search alternative treatments easy to 

apply and economically available. The use of natural coagulants enables the cost of 

synthetic coagulants, so the Moringa oleifera seed is an appropriate choice to be used in 

locations without conventional treatments. The Moringa oleifera associated to filtration may 

be a promising alternative to prevent organisms such as Cryptosporidium spp. ooscysts 

present in water for human consumption. This study aimed to use a combined treatment by 

coagulation / flocculation procedure using Moringa oleifera seed solutions followed by a 

filtration in non-woven synthetic fabrics for the reduction of Crytosporidium ssp. oocysts. To 

avoid manipulation of oocysts in the laboratory, many studies have used fluorescent 

polystyrene microspheres, which have the same characteristics of the oocysts, so they could 

be used to observe the combined treatment in these systems. The results showed a 

reduction of 99% polystyrene microspheres, which may have reached 100% in some 

sampling intervals. 

Keywords: water treatment, Cryptosporidium spp, natural coagulants, fluorescent 

polystyrene microspheres 


The water treatment plants face increasing challenges to ensure adequate levels of potability 

and to protect their systems against microorganisms that cause diseases, which are usually 

resistant to chlorine or can overcome barriers in the previous stages of water treatment 

(BAEZA, 2004). One of the most frequent protozoa is Cryptosporidium spp., which can be 

found in water for human consumption if at the stage of oocysts (a dispersed form in the 

environment). As a consequence is the cryptosporidiosis, a gastrointestinal disease that 

causes acute diarrhea (FERNANDES et al., 2010). 

Cryptosporidium oocysts are responsible for major outbreaks related to failures in water 

treatment plants. The best example occurred in Milwaukee (USA, 1993), resulting in a total of 

739 people presenting oocysts in feces tested by 14 laboratories. In addition, more than 

4000 people were hospitalized and cryptosporidiosis contributed to approximately 104 

deaths (MORIS et al., 1996).

Therefore, there is great importance on studying this parasite and understand its dispersal 

ability, strength and resistance to the stages of water treatment (XIAO et al., 2004). Thus, it 

is necessary to improve the systems of coagulation / flocculation or create filtration barriers 

for retention of oocysts in water. In locations with no conventional treatment, it is necessary 

to find alternative methods to improve the water treatment conditions. 

Many studies aimed to verify the removal of Cryptosporidium using oocysts as a means of 

checking the efficiency of the water treatment. However, the great problems are the high 

costs of reagents, the methodological difficulties of detection and the risk of contamination of 

handlers with inactive oocysts. Therefore, many studies have addressed the use of 

indicators, or even synthetic substitutes with similar characteristics to the oocysts. 

The polystyrene microspheres are an alternative substitute of Cryptosporidium oocysts 

widely used by many researchers in the evaluation of water treatments (BROWN & 

EMELKO, 2009). 

Natural coagulants are used as an alternative treatment to improve the quality of water in 

regions where there are no conventional water treatments. Moringa oleifera Lam is a tropical 

tree from Northwestern Indian cultivated because of nutritional, medicinal and industrial value 

and in the water treatment for human consumption. It belongs to the plant family 

Moringaceae, whose seeds present coagulation properties for treating water in regions 

without conventional treatments. 

So far, other types of natural coagulants such as based on the Moringa oleifera seeds were 

not tested for the removal of polystyrene microspheres, simulating the removal of 

Cryptosporidium spp. 

Due to the importance of testing the coagulation with Moringa oleifera seeds for the removal 

of polystyrene microspheres simulating Cryptosporidium spp., this study aimed to evaluate a 

system of coagulation / flocculation using a coagulant solution based on seeds of Moringa 

oleifera, followed by slow filtration in non-woven synthetic fabrics for the reduction of 

fluorescent polystyrene microspheres. 


The experiment was conducted in a bench scale, with the intent of employing water with both 

low turbidity and concentration of fluorescent polystyrene microspheres. To obtain water with 

low turbidity, on range of 18 NTU, the optimum dosage of coagulant solution of Moringa 

oleifera to the treatment was 25 mg L -1 (FRANCISCO et al. 2011). Tests of coagulation and 

flocculation in static reactors (Jar Test) were performed followed by filtration with non-woven 

synthetic fabrics. 

The system received water synthetically prepared with bentonite, which generated an 18 

NTU turbidity value, and the jars from the equipment Jar Test were filled with 2 liters of this 

sample. In sequence, it was inoculated approximately 2 x 10 6 polystyrene microspheres 

previously counted in hemacytometer. The microspheres had a size of 3 m and were stored 

in a vial with 2.5% aqueous suspension (1.69 x 10 9 particles / ml), as informed by the 

manufacturer (Polysciences). The microspheres viewed under a microscope exhibited 

excitation maximum at 441 nm and emission maximum at 486 nm (Cerqueira, 2008).

After the assembly of the experimental apparatus, a 25 mg.L -1 (2% w/v) coagulant solution 

prepared from the seeds of Moringa oleifera was added to the system according to the 

procedure described by Arantes (2010). The unit was turned on and intervals of fast and 

slow mixing were conducted, being programmed for a stirring velocity gradient at 400s -1 for 

15 seconds and 40s -1 for 1800 seconds, respectively. After this interval of mixing, Jar Test 

equipment was adjusted to recover the maximum volume of sample to the filtration. The 

upper output was sealed and another output was placed at 1.5 up from the bottom of the 

jars. In addition, the jar was suspended so that the homogenization blades reach the bottom, 

and thus prevent the floc sedimentation. After the jars were suspended, the homogenization 

occurred until the end of filtration of the sample. 

The samples were directed into a single output which was connected by rubber hoses. This 

output was directed towards the filtration system, which employed a simple filter system in 

PET (polyethylene terephthalate) bottle, with the filter medium composed by 5 layers of nonwoven 

synthetic fabrics with a thickness of 4 mm each, and a gramature of 600 g/m 2 . The 

filtration rate was 4 m 3 / (m 2 .day), within the values established by Di Bernardo (2003). Other 

characteristics of slow filtration was not adopted because the proposed system operated at a 

bench scale, with a limited flow conditioned to operate in a total of 4 hours and a half, 

approximately. 

Samples were collected after an interval of mixing (fast and slow) in the jars, after leaving the 

filter every 30 minutes for a total period of 240 minutes (4 hours). Samples were sent for 

turbidity determination and separation by vacuum filtration followed by the mechanical 

extraction, according to procedures carried out for the extraction of Cryptosporidium oocysts 

employed by Hong et al. (2001). In the case of microspheres, there was no need to add the 

reagent Fluorescein Isothiocyanate (FITC), since they have its own fluorescence 

(CEQUEIRA, 2008). At the end of the process, the slides of microspheres were obtained and 

the counts were performed in the epifluorescence microscope (Motic Mod BA410) with 100- 

fold increase lens. 

The negative control test (without inoculation of microspheres) was performed both to 

demonstrate the possibility of contamination between the tests and indicate the presence of 

false positives results in the positive control test (without addition of Moringa oleifera 

coagulant solution). The positive control test was conducted to check the amount of recovery 

of polystyrene microspheres, especially because there is no Moringa oleifera coagulant 

solution added to this test. 


The results showed that the coagulation with Moringa oleifera followed by filtration in 

synthetic non-woven fabrics retain polystyrene microspheres throughout the filtration, with 

removal efficiency of 99% and 100% removal in some sampling intervals.

TABLE 1: Average count of microspheres in the sampling intervals and efficiency (%) of 

treatment. 

Sampling 

Average count of 

Efficiency (%) 

Intervals (min) 

microspheres 

0 3000 99.85 

30 2000 99.9 

60 1500 99.925 

90 500 99.975 

120 2500 99.875 

150 500 99.975 

180 3500 99.825 

210 0 100 

240 0 100 

Total filtrate 

(240 min) 12000 99.4 

The retention capacity of polystyrene microspheres is entirely due to the use of Moringa 

oleifera coagulant solution. Ndabigengesere et al. (1995) showed that the coagulation active 

agents in aqueous extracts are dimeric cationic proteins and the clotting mechanism can be 

represented by adsorption and neutralization of colloidal charges. The microspheres adhere 

to the surface of the floc formed during the process. This adhesion may be explained by 

means of mechanisms that occur during the flocculation step. 

In the filtration process, the floc is almost fully retained in the first and second layer of the 

non-woven synthetic fabric, and white sediment is formed on the surface layer as a result of 

the adhered flocs. The adhesion of the microspheres on the floc and the material retained in 

the fabric can be seen in microscopic image (FIGURE 1). 

A 

B 

Figure 1: A - Microscopic image of post-test non-woven synthetic fabric with microspheres 

and Moringa oleifera. B - Post-test image of non-woven synthetic fabric visible to the naked 

eye. 

The negative control test showed that there was contamination in some sampling intervals, 

but these values are considered minimum to detect in slides, presenting 1% contamination 

only for the sampling intervals at 30, 60, 120 and 240 minutes.

For the positive control test, the microspheres presented more than 100% recovery. This 

value can be considered acceptable and according to SANTOS et al. (2011), it is related to 

the standardization of the inoculums used in the evaluation. In this test, the polystyrene 

microspheres were not retained in the fabric, but in the final filtrate. Furthermore, some 

factors as the batch experiments using a simplified system such as static reactors, the small 

volume and the facility to observe the microspheres in the microscope allowed few losses 

occurred, thus the recovery is greater when compared to full-scale systems, besides the use 

of oocysts instead of microspheres decreases the chances of recovery. Figure 2 shows a 

microscopic image of non-woven synthetic fabrics of the negative (FIGURE 2-A) and positive 

control tests (FIGURE 2-B), demonstrating that the microspheres are not retained in both 

wires of the fabric. 

A 

B 

FIGURE 2: A - Microscopic image of non-woven synthetic fabric after negative control test. B 

- Microscopic image of non-woven synthetic fabric after positive control test. 

The turbidity values of the samples in the sampling intervals correspond to the same 

reduction of microspheres relative to baseline values. The first point observed at the 

beginning of the sampling obtained 85.5% reduction efficiency. During the sampling intervals 

the efficiency increased and reached 95%. 

In the negative control tests, the turbidity values exhibited the same behavior of the tests 

carried out with coagulant and microspheres, as in this case there was the coagulant 

Moringa oleifera, and therefore the floc formation and the turbidity reduction remained the 

same. For the negative control test, the absence of coagulant Moringa oleifera proved 

ineffective in reducing turbidity, as the reduction values of turbidity did not exceed 17%. The 

turbidity values also confirm the importance of using the natural coagulant Moringa oleifera 

for water treatment. 


The coagulant based on the seeds of Moringa oleifera is the main responsible on the 

aggregation of microspheres during the floc formation. The non-woven synthetic fabric helps 

in retention the floc and therefore does not promote the passage of the microspheres in the 

treated effluent. However, the use of the fabric without the natural coagulant does not 

promote the retention of polystyrene microspheres, as shown in positive control test results, 

so it is not considered an alternative treatment for reduction of polystyrene microspheres.

The turbidity values show that Moringa oleifera can be used as an aid to the preliminary 

filtration, since it was possible to achieve an efficiency reduction of up to 95% in the final 

effluent, and the efficiency indexes did not exceed 17 % in the absence of coagulant. 

As it is still preliminary tests of a future experiment, it is possible to standardize other criteria 

for the tests so that the microspheres are not seen in negative control, even in insignificant 

amounts, in order to have a greater reliability in the tests. 

5. Acknowledgements 

The authors thank the Faculty of Agricultural Engineering, for yielding the structure and 

laboratories, CAPES (Coordination for the Improvement of Higher Education Personnel), for 

granting the scholarship, and FAPESP (Foundation for Research Support of São Paulo) for 

supporting the research project (process No. 2010/16223-0) and scholarships processes No. 

2010/07649-4 and No. 2010/16118-2. 

6. References 

ARANTES, C.C. (2010). Utilização de coagulantes naturais à base de sementes de Moringa 

oleifera e tanino como auxiliares da filtração em mantas não tecidas. Faculdade de 

Engenharia Civil, Universidade Estadual de Campinas, Campinas, SP. 129 f. (Dissertação 

de Mestrado). 

BAEZA, C.; DUCOSTE, J. (2004). A non-biological surrogate for sequential disinfection 

processes. Water Research, 38, 3400-3410. 

CERQUEIRA, D.A. Remoção de oocistos de Cryptosporidium parvum e de indicadores no 

tratamento de água por ciclo completo, filtração direta descendente e dupla filtração, em 

escala piloto. 2008.194p. Tese (Doutorado em Saneamento, Meio Ambiente e Recursos 

Hídricos) - Departamento de Engenharia Sanitária e Ambiental, Universidade Federal de 

Minas Gerais, 2008. 

Brown. T.J. & Emelko, M.B. (2009). Chitosan and metal salt coagulant impacts on 

Cryptosporidium and microsphere removal by filtration. Water Research., 43, 2, 331-338. 

FERNANDES, N.M.G.; GINORIS, Y.P.; RIOS, R.H.T.; BRANDÃO, C.C.S. (2010). Influência 

do pH de coagulação e da dose de sulfato de alumínio na remoção de oocistos de 

Cryptosporidium por filtração direta descendente. Engenharia Sanitária e Ambiental, 15, 

375-384. 

FRANCO, R.M.B.; ROCHA-EBERHARDT, R. & CANTUSIO NETO R. (2001). Occurrence of 

Cryptosporidium oocysts and Giardia cysts in raw water from the Atibaia River, Campinas, 

Brazil. Revista do Instituto de Medicina Tropical, 43, 109-111, 2001. 

MORRIS, R.D; NAUMOVA, E.N.; LEVIN, R. MUNASINGHE, R.L. (1996). Temporal variation 

in drinking water turbity and diagnosed gastroenteritis in Milwaukee, Amer. Journal of Public 

Health, 86, 237-239. 

NDABIGENGESERE, A.; NARASIAH, K.S.; TALBOT, B.G. (1995). Active and mechanism of 

coagulation of turbid waters using Moringa Oleifera. Water Research, 29, 2, 703-710, 1995. 

SANTOS, L.U.; CANTUSIO NETO, R.; FRANCO, R.M.B.; GUIMARÃES, J.R. (2011). 

Detecção de oocistos de Cryptosporidium spp. e cistos de Giardia spp. em amostras de 

esgoto bruto ou tratado: avaliação crítica dos métodos. Revista Engenharia Sanitária e 

Ambiental, 16, 2, 115-120. 

XIAO, L.; FAYER, R.; RYAN, U.; UPTON, S.J. (2004). Cryptosporidium taxonomy: recent 

advances and implications for public health. Clinical Microbiololy Rewiews, 17, 72-92.

MULTIVARIATE STATISTICAL OF PRINCIPAL COMPONENTS AND 

CLUSTER ANALYSES IN THE STUDY SUPPORT OF 

REGIONALIZATION OF FLOW 

Abrahão A. A. Elesbon 1 *, Demetrius D. Silva 2 , Gilberto C. Sedyiama 2 , Carlos A. A. S. 

Ribeiro 3 

1 Federal nstitute of Espírito Santo, Av. Arino Gomes Leal, 1700, Colatina-ES, 29700-558, Brazil. 

E-mail: abrahaoelesbon@gmail.com 

2 Federal University of Viçosa, DEA. Av. Peter Henry Holfs, s/n, Viçosa-MG, 36570-000, Brazil. 

3 Federal University of Viçosa, DEF. Av. Peter Henry Holfs, s/n, Viçosa-MG, 36570-000, Brazil. 

Abstract 

This study aims to identify: 1) the most representative variables hydrological regionalization 

studies, using principal component analysis (PCA) and 2) to optimize the identification of the 

hydrologically homogeneous regions in studies of regionalization of water flow using cluster 

analysis (CLUSTER) for the rio Doce basin. Fifteen variables were used in the study, 

individualized to 61 gauging stations: Q 7, 10 , Q 90 , Q 95 , Q mld , Q max10 , Q max20 , Q max50 , Q max100 , P a , 

P ss , P sc , A d , L p , L t and S L . The results of the principal component analysis pointed out that the 

variable SL was the least representative for the study. The first two principal components, Y 1 

and Y 2 , were responsible for 77.92% of the total variation of the data. The best divisions of 

hydrologically homogeneous regions were obtained using the similarity matrix of 

Mahalanobis and the complete linkage clustering method. The Cluster analysis enabled the 

identification of four hydrologically homogeneous regions in the watershed of the rio Doce. 

Key words: Principal Components, Cluster Analysis e Regionalization of flow. 


In general, it is understood by hydrological regionalization process the transferring 

information from one region of the hydrological behavior known to other sites, often without 

observations. 

In this context, multivariate statistical analyzes can help significantly in the studies of 

hydrological regionalization, reducing processing time from the database and increasing the 

reliability of results. At the international level can prove this statement by the development of 

numerous studies addressing the hydrological regionalization based on multivariate 

statistical analyzes (Assani et al., 2011; Kahya et al., 2007; Mwale et al., 2010, Samuel et al., 

2010; Engeland & Hisdal, 2009; Castiglioni et al., 2009). 

The principal component analysis (PCA) aims to examine the correlations between variables, 

summarize a large set of variables into a smaller one and the same meaning, evaluate the 

importance of each variable and promote the elimination of those that contribute little in 

terms variation in the group of individuals evaluated (WILKS, 2006). In recent years, many 

applications of this technique have been studied in various fields of knowledge such as: 

genetics (Price et al., 2006; Haider et al., 2008), chemistry (Bellomarino et al., 2010), 

environment (Reid & Spencer, 2009), among others. 

Multivariate statistical analysis of Cluster is a tool of exploratory data with the aim of 

classifying homogeneous groups (Wilks, 2006), which has been used in numerous areas of 

knowledge, for example, medicine (Mezer et al., 2008 ), geomorphology (Melchiorre et al., 

2008) and environmental engineering (Pires et al., 2007; Hatvani et al., 2011). In hydrology, 

the cluster analysis is a technique often used to define classes or for grouping stations into 

homogeneous climatic regions. 

In view of this, this study aimed to develop a methodology based on multivariate statistical of 

principal components and cluster analysis for the identification of variables most 

representative studies of hydrological regionalization and optimize the achievement of 

1

hydrologically homogeneous regions for Doce river basin. This work is part of the doctoral 

thesis of Professor Abrahão Alexandre Alden Elesbon. 

2. MATERIAL AND METHODS 

2.1. REGION STUDY 

The Doce river basin is located in Southeastern Brazil, between parallels 17° 45'and 21° 15'S 

and longitudes 39°30 'and 43°45' W, with an average altitude of 578 meters. It has drainage 

area of approximately 83,400 km ², of which 86% belong to the state of Minas Gerais and 

14% for the state of Espírito Santo (PIRH, 2010). Figure 1 shows the geographical location of 

the study area and 61 stations selected fluviometric monitoring. 

2.2. DATABASE AND APPLICATIONS 

The study was conducted using data from 61 gauging stations in the network of 

hydrometeorological National Water Agency - ANA. The series used consisted of daily data 

flow corresponding to the base period 1976 to 2005. It is emphasized that it was limited to 

use of data by the year 2005 because, at the outset, it constitutes the most recent year with 

available data consisted by ANA. 

Figure 1 : Geographical location of the Doce river basin and the gauging stations 

selected. 

Were used the vector base elevation (contour lines and point elevations) and hydrography of 

the river basin obtained from the Brazilian Institute of Geography and Statistics - IBGE, scale 

1:250,000 (IBGE, 2010). The vector base ottocodificada the Doce river Basin was obtained 

from the IGAM (MINAS, 2010). The multivariate statistical analyzes were performed using 

the Statistica ® 7.0, developed by "StatSoft." 

For the generation of digital elevation model hydrographically conditioning (MDEHC), 

automatic retrieval of morphometric variables, average rainfall and spatial distribution of 

results we used the Geographic Information System, ArcGIS ® 10.0, developed by the 

"Environmental Systems Research Institute - ESRI," as geoprocessing tool of vectors and 

spatial data. 

2

The multiple regression equations were obtained using the application SisCORV 1.0.3 

(Sousa et al. 2008) developed by the Research Group on Water Resources - GPRH, linked 

to the Department of Agricultural Engineering - DEA, Federal University of Viçosa - UFV. 

In the present study were considered 15 variables, eight dependent variables to be 

regionalized (minimum flow average of seven consecutive days with a return period of ten 

years - Q 7,10 ; minimum flow associated with stays at 90% - Q 90 and 95 % - Q 95 ; long-term 

average flow - Q mld ; maximum flow with a return period of 10 years - Q max10 , 20 years - Q max20 , 

50 years - Q max50 and 100 years - Q max100 , in m 3 s -1 ) and seven independent variables (total 

annual rainfall - P a , total precipitation in the dry semesters - P ss and rainy - P sc , in mm, area 

drainage basin - A d , in km², length of the main river - L p in km, total length of watercourses 

basin - L t in km and average Slope basin - S L in%). 


3.1. PRINCIPAL COMPONENTS ANALYSIS 

Based on seven independent variables (Pa, Pss, Psc, Ad, Lp, Lt and S L ) for each of the 61 

gauging stations adopted, proceeded to the principal component analysis. The total variance 

in the existing set of multivariate data analysis is equal to the number of variables, given that 

the data was standardized with an averageand variance equal to 0 and 1, respectively. The 

summary of the main components of the variables studied are presented in Table 1. 

Table 1 – Principal Components of the study variables 

PC's 

Variance 

Coefficients of standardized variables - eigenvectors 

% Var. % acum. 

eigenvalue Z 1 (P a ) Z 2 (P ss ) Z 3 (P sc ) Z 4 (A d ) Z 5 (L p ) Z 6 (L t ) Z 7 (S L ) 

Y 1 2,9628 42,33% 42,33% 0,1216 0,1310 0,1035 -0,5679 -0,5544 -0,5679 0,0700 

Y 2 2,4911 35,59% 77,92% 0,6025 0,4858 0,5889 0,1074 0,1207 0,1072 -0,1286 

Y 3 0,9950 14,21% 92,13% 0,1430 -0,1534 0,1628 0,0519 0,0427 0,0497 0,9605 

Y 4 0,4733 6,76% 98,89% 0,2541 -0,8447 0,4032 -0,0463 -0,0139 -0,0362 -0,2361 

Y 5 0,0755 1,08% 99,97% 0,0222 -0,0123 0,0068 0,3960 -0,8220 0,4082 -0,0124 

Y 6 0,0020 0,03% 99,996% -0,7317 0,0976 0,6726 0,0369 -0,0144 -0,0330 0,0108 

Y 7 0,0003 0,004% 100,000% 0,0379 -0,0108 -0,0307 0,7092 -0,0066 -0,7032 -0,0039 

Based on the results presented in Table 1, were considered only the first two components 

(Y1 and Y2), by simultaneously meet the two selection criteria (the cumulative variance 

explained a value greater than or equal to 75% of the total variation of data and eigenvalues 

being greater than or equal to 1). The other components, which together accounted for 

22.08% of the total variation, weren’t considered. Table 2 shows the load factors or 

correlations among the seven standardized variables and the first two principal components. 

Table 2 – Factors loads between the standardized variables (VP's) and the principal 

component (PC's), and the variance (λi) of each main component (i = 1, 2) 

X 

VP’s 

Y 1 

CP's 

Y 2 

P a Z 1 0,209226 0,950899 

P ss Z 2 0,225520 0,766821 

P sc Z 3 0,178086 0,929543 

A d Z 4 -0,977547 0,169484 

L p Z 5 -0,954338 0,190567 

L t Z 6 -0,977535 0,169216 

S L Z 7 0,120541 -0,202970 

(%) λ i 42,33 35,59 

It is noted in Table 2 that the standardized variables Z 4 , Z 5 and Z 6 have higher correlation 

with the first principal component (Y 1 ), while the variables Z 1 , Z 2 and Z 3 show higher 

correlations with the second principal component (Y 2 ). The variable Z 7 can be discarded from 

3

the study for contributing little in terms of variation for the group of individuals assessed 

confirming the results obtained by analyzing the correlation matrix R. 

Physically, the main component Y 1 represents the most representative morphometric 

principal component and Y 2 represents the average rainfall areas of each of the upstream 

drainage gauging station. 

3.2. CLUSTER ANALYSIS 

Discarded the variable S L , from the results obtained in principal component analysis were 

obtained by homogeneous regions for the eight flows, considered separately, based on 

standardized variables that showed higher correlations with the first two principal 

components (A d , L t , L p , P a , P sc and P ss ) from the matrix of Mahalanobis distances and the 

method of grouping the farthest neighbor. 

From the method of grouping the farthest neighbor were obtained for the Doce river basin 

four regions with homogeneous characteristics of flow. Figure 2 shows the spatial 

configuration of the four hydrologically homogeneous regions for theflows Q 7, 10 , Q mld , Q 90 and 

Q 95 , which had a hydrological applicant. For the delineation of homogeneous regions, the 

catchment areas of gauged stations that composed it were extended to the section of the 

river outflow of higher order, downstream, as described by Marques et al. (2009). 

Figure 2 – hydrologically homogeneous regions obtained for the Doce river basin. 

It is emphasized that drainage áreas less than 160 km² and greater than 82,000 km² were 

included in the hydrologic regions I and IV, respectively. Importantly, however, that most of 

the Doce River basin does not have adequate monitoring fluviometric (drainage areas less 

than 160 km²), and one should adopt additional criteria for extrapolation of results in these 

regions. 

3.3. MULTIPLE REGRESSION ANALYSIS 

From the multiple regression analysis between the dependent variables and independent 

variables of greatest importance for the study was obtained from the results presented in 

Table 3. 

4

Table 3 - Regression models that best adjusted to the minimum flow characteristics obtained 

settings 

Flow (*) Region Model Equation r²a E.P. F 0.05 

Q 7,10 

Q 90 

Region I Potencial 0,72 0,313 3,5x10 -4 

Region II Potencial 0,82 0,491 0,3x10 -4 

Region III Potencial 0,74 0,455 4,8x10 -4 

Region IV Potencial 0,92 0,367 0,0 







Q 95 



(*) Flows in m³ s -1 , A d in km² and P sc in mm. 

Analyzing the Table 3 it can be observed that: 

• The regression model that best fits the data flow has the potential. The same 

behavior for the regional equations was found by Ribeiro et al. (2005) and Marques et al. 

(2009) for the Doce river basin; 

• The most important independent for the study was the catchment area (A d ) follow 

then the average rainfall in rainy season (P sc ); 

• The regional equations presented for the four hydrologically homogeneous regions 

defined by the methodology proposed in this study had coefficients of determination higher 

than 0.70, standard error of estimate less than 0.5 and a significance level of 5% by F test. 

4. CONCLUSIONS 

Based on the results obtained in this paper, we can conclude that: 

• A principal component analysis showed satisfactory results for the exclusion of some 

variables representative for the identification of hydrological homogeneous regions. 

• The first two principal components, Y1 and Y2, were responsible for 77.92% of the 

total variation of the data. 

• The similarity matrix of Mahalanobis and method of grouping the farthest neighbor 

showed good results in the identification of hydrologically homogeneous regions for all flow 

rates studied. 

• We obtained four hydrologically homogeneous regions for all studied flow characteristics. 

• The regionalization of equations obtained by multiple regression analysis for the 

minimum characteristics flow were considered satisfactory, validating the methodology 

presented in this study. 

• The proposed methodology for identifying the number of homogeneous regions 

showed good results, allowing the elimination of subjectivity in the identification of 

hydrologically homogeneous regions. 

5. ACKNOWLEDGEMENTS 

The authors thank the Coordination of Improvement of Higher Education CAPES), the 

Foundation for Research Support of Minas Gerais (FAPEMIG), the Viçosa Federal University 

(UFV) and the National Council for Scientific and Technological Development (CNPq ), for 

financing this work. 

6. REFERENCES 

ASSANI, A. A.; CHALIFOUR, A.; LÉGARÉ, G.; MANOUANE, C.; LEROUX, D. (2009). 

Temporal regionalization of 7-day low flows in the St. Laurence watershed in Quebec 

(Canada). Water Resources Management, v. 25, p. 3559-3574. 

5

BELLOMARINO, S. A.; PARKER, R. M.; CONLAN, X. A.; BARNETT, N. W.; ADAMS, M. J. 

(2010). Partial least squares and principal components analysis of wine vintage by high 

performance liquid chromatography with chemiluminescence detection. Analytica Chimica 

Acta, v. 678, p. 34-38. 

CASTIGLIONI, S.; CASTELLARIN, A.; MONTANARI, A. (2009). Prediction of low-flow indices 

in ungauged basins through physiographical space-based interpolation. Journal of Hydrology, 

v. 378, p. 272-280. 

ENGELAND, K.; HISDAL, H. (2009). A comparison of low flow estimates in ungauged 

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HAIDER, S.; PARKINSON, G. N.; NEIDLE, S. (2008). Molecular dynamics and principal 

components analysis of Human Telomeric Quadruplex Multimers. Biophysical Journal, v. 95, p. 

296-311. 

HATVANI, G. I.; KOVÁCS, J.; KOVÁCS, I. S.; JAKUSCH, P.; KORPONAI, J. (2011). Analysis of 

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Turkey. Journal of Hydrologic Engineering, v. 13. 

MARQUES, F.A.; SILVA, D. D.; RAMOS, M. M.; PRUSKI, F. F. (2009). Sistema multi-usuário 

para gestão de recursos hídricos. Revista Brasileira de Recursos Hídricos, v. 14, n. 4, p. 51-69. 

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and cluster analysis in landslide susceptibility zonation. Geomorphology, v. 94, p. 379-400. 

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of resting-state fMRI time series. NeuroImage, v. 45, p. 1117-1125. 

MINAS GERAIS, Governo do Estado. (2010) Redes e bacias hidrográficas ottocodificadas de 

Minas Gerais. Belo Horizonte, Base vetorial. DVD. 

MWALE, D.; GAN, T. Y.; DEVITO, K. J.; SILINS, U.; MENDOZA, C.; PETRONE, R. 

(2010).Regionalization of Runoff Variability of Alberta, Canada, by Wavelet, Independent 

Component, Empirical Orthogonal Function, and Geographical Information System Analysis. 

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PIRES, J. C. M.; SOUSA, S. I. V.; PEREIRA, M. C.; FERRAZ, M. C. M.; MARTINS, F. G. 

(2008). Management of air quality monitoring using principal component and cluster analysis: 

Part II – CO, NO 2 and O 3 . Atmospheric Environment, v. 42, p. 1261-1274. 

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Available in: . In march, 2010. 

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REICH, D. (2006). Principal components analysis corrects for stratification in genome-wide 

association studies. Nature Genetics, v. 38, p. 904–909. 

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estuarine sediment datasets: The effect of data pre-treatment. Environmental Pollution, v. 157, 

p. 2275-2281. 

RIBEIRO, C. B. M.; MARQUES F. A.; SILVA D. D. (2005). Estimativa e regionalização de 

vazões mínimas de referência para a bacia do rio Doce. Engenharia na Agricultura. Viçosa – 

MG, v.13, n. 2, p. 103-107. 

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in Ontario Ungauged Basins: Comparison of Regionalization Methods. Journal of Hydrologic 

Engineering, v. 16. 

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Computacional para Regionalização de Vazões – SisCoRV 1.0. Universidade Federal de 

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WILKS, D. S. (2006). Statistical Methods in the Atmospheric Sciences. Academic Press, 630 p. 

USA. 

6

Is Imaging Analysis Quantifying the Impacts of Solute Transport? A 

New Approach to Assess Wetting Front Map under Trickle Irrigation 

El-Sayed E. Omran 1 *, Gamal M. ElMasry 2 and Mohamed A. Rashad 2 

1 Soil and Water Department, Faculty of Agriculture, Suez Canal University, Egypt. 

2 Agricultural Engineering Department, Faculty of Agriculture, Suez Canal University, Egypt. 

* Corresponding author. E-mail: e.omran@scuegypt.edu.eg 

Abstrat 

To investigate solute transport in soils, detailed information about the spatial distribution of 

solutes is required. Many attempts have been made to determine wetting pattern under 

trickle irrigation using sophisticated mathematical and numerical models. These methods 

require detailed information concerning soil physical properties besides too complicated 

calculations for routine use. This study was carried out to investigate the feasibility of using 

image-analysis technique to derive soil wetting area and depth and to develop an image 

processing algorithm to derive soil wetting front map. A digital image analysis technique is 

proposed as a potential alternative method for visualizing and quantifying flow patterns in 

soils with a high spatial resolution. The method was applied in two soil types (sandy and 

sandy clay loam). The results of the proposed method showed that the image analysis 

technique gives reasonably good estimates of the wetting front map (depth and area). This 

potential approach to characterize flow patterns allows an objective comparison of soil 

infiltration patterns in the field. This proposed method could be generalized to quantify and 

easily derive soil flow patterns which are an important issue for precision irrigation farming 

and agricultural management. 

Key words: solute transport, image analysis, trickle irrigation, precision irrigation. 

Introduction 

Agricultural management, soil remediation and groundwater protection require ways of 

quantifying solute transport processes. Soil heterogeneity is responsible for the difficulty in 

predicting the movement of mass (solids, liquids and gases) in field situations at most scales 

[Lin & Zhou, 2008; Jamieson et al., 2002]. Solute transport in the unsaturated zone which is 

difficult to predict remains an important research topic in soil science [Vanderborght et al., 

2002 and Omran, 2008]. The concern is mainly about the impact of solute transport on the 

water use efficiency. One of the methods that can provide high water use efficiency is trickle 

irrigation but only if the system is designed to meet the soil and plant conditions [Phene, 

1995; Cook et al., 2006]. 

One of the pre-requisites for better trickle irrigation design is more information about the 

moisture distribution patterns. Trickle irrigation involves applying low quantity of water at low 

pressure via an emitter. The wetted-soil volume under a point source trickle systems must be 

known to determine the total number of emitters required to wet a specific volume of soil to 

meet plant water requirements [Ainechee et al., 2009]. The volume of wetted soil and its 

shape is primarily a function of the soil texture and structure, application rate, and number of 

emitters. So, it is essential to know the effect of the water application technique (discharge 

rate, continuous or intermittent application) on the amounts of water distributed to the various 

parts of the wetted soil volume [Elmaloglou & Diamantopoulos, 2007]. Water trickling from a 

point source takes place in the soil and moves downwards and sideways. As a result, three 

dimensional transient flows occur. 

There has been much speculation on the shape of the wetted soil volume. One of the 

important criteria when designing trickle irrigation systems is the geometry of the wetting 

pattern generated by the emitters [Cook et al., 2006]. Many attempts have been exerted to 

determine the wetting pattern under trickle irrigation using sophisticated mathematical and

numerical models which require detailed information about soil physicochemical properties 

[Li et al., 2003, 2004; Elmaloglou & Malamos, 2006]. Traditional used procedures to monitor 

water flow into soil are in situ extraction of soil solution using suction samplers or extracting 

soil samples taken from the field and laboratory columns. An alternative for soil solution 

samplers is the Time Domain Reflectometry (TDR) technique that infers the concentration 

from the in situ measured bulk soil electrical conductivity [Vanclooster et al., 1993; Ward et 

al., 1994]. Analytical models also provide a rapid means of determining the wetting front 

position [Thorburn et al., 2003; Cook et al., 2003]. These models are based on the 

assumption of a point source and certain forms for the soil physical properties [Revol et al., 

1997a,b]. The main problem with these models is that the spatial arrangement and 

distribution of these wetting volumes is not known. These wetting volumes must be 

detectable with a high spatial resolution. 

According to our knowledge, no reports are available on using the image analysis technique 

to assess soil flow patterns. The objectives of this study are to assess the feasibility of using 

image analysis technique to determine soil wetting area and depth; and to develop an image 

processing technique to derive soil wetting front map. This potential approach to characterize 

flow patterns allows an objective comparison of soil infiltration patterns in the field. Using 

spatial imaging processing techniques for soil wetting pattern monitoring may open a new 

avenue for precision irrigation farming. 


2.1. Experimental Set-up and Soil Image Acquisition 

The procedure for using image analysis in estimating soil wetting front map under trickle 

irrigation is accomplished by placing the soil column inside an illumination chamber shown in 

Figure (1). Digital images were acquired sequentially every 30 sec. The digital color image 

with a full resolution of 22721704 pixels was acquired for the soil column by using the 

experimental set-up and image acquisition unit shown in Figure (1). The schematic diagram 

shown in Figure (1) outlines the different components of the experimental set-up used to 

estimate the soil wetting front map. The system consists of two (irrigation and imaging) units. 

The irrigation unit consists of a main line (cast-iron pipe) 24.5 mm diameter, which have two 

pressure regulators to regulate the supply pressure at 100 kPa during the experimental 

period. Three Bourdon gages (range 0-250 kPa accuracy 0.1 kPa) and water meter were 

used to approximate the desired pressure and discharge, respectively. Three valves were 

constructed: at the outlet of the reservoir tank and at the entrance of recycling line (PE pipe 

diameter 1.9 cm) to control the pressure at the main line, meanwhile the third valve mounted 

on the main line before the water meter. Lateral line constructed one COER 100 emitter has 

nominal discharge of 4 l/h. mounted on PE lateral lines (14.5 mm inside diameter). A plastic 

cylinder (127 liters) was used to store irrigation water. At the main pipe inlet a screen filter 

100 mesh was deployed only with mixed water, a pump with discharge of 1.2 – 6.0 m 3 /h, and 

pressure head of 200 - 320 kPa was used. On the other hand, the imaging unit consists of a 

digital color camera, PowerShot A580 model (Canon Corporation, USA). Illumination source 

composed of two 50W halogen lamps to illuminate the camera's field of view. Illumination 

chamber made from a white nylon box to equally disperse and distribute the light around the 

soil column and a computer to record images acquired by the camera. 

The lamps were placed on each side of the illumination chamber at approximately 0.5-m 

distance and 45° angles. The placement of the lamps was adjusted to make sure that no 

reflections were visible to the camera. The camera was placed on a tripod at the same level 

as the soil column, at approximately 1.5-m height and 1-m distance. The camera was 

connected to a laptop computer via the USB port. The software Canon Photo Record (Canon 

Corporation, USA) was used to remotely control the camera and capturing the digital images. 

Using this software, the images taken by the camera are directly transferred to the hard disk

of the computer. All additional image analyses for extracting different parameters from each 

image were programmed using Matlab7.1 (Release 14, The MathWorks Inc., MA, USA). 

10 

9 

8 

6 8 6 

7 

3 

12 

5 

11 

13 

4 

15 

14 

1 

2 

3 

1- Reservoir tank 2- Filter 3- valve 4- Pump 

5- Main line 6- Pressure gage 7- Water meter 8- Pressure regulated 

9- Lateral lines 10- Emitter 11- Nylon box 12- Illumination Lamps 

13- Fiberglass column 14- Digital camera 15- Computer 

FIGURE 1: Schematic of the experimental and image acquisition setup 

2.2. Soil Samples 

Two cylindrical Plexiglas containers (20 cm in diameter) were filled with two different soil 

textures (Table 1). The soils were taken from the agriculture faculty farm of Suez Canal 

University, Ismailia, Egypt. The first cylinder was filled with sandy soil meanwhile the other 

cylinder was filled with sandy clay loam soil. Each Plexiglas container with soil column was 

placed vertically inside the illumination chamber. The drip sprinkler was placed exactly 5 mm 

above the soil surface and mounted on the center of the soil column. An emitter flow rate of 

0.60 Lh -1 and 0.67 Lh -1 for sandy and sandy clay loam soil respectively was chosen, as this 

had been used by Thorburn et al. [2003]. 

Soil Type 

TABLE 1: Soil physical characteristics of the selected soils 

Bulk density Particle Size Distribution, % 

x 10 3 Kgm -3 Sand Silt Clay 

Sandy 1.64 95.0 2.3 2.7 

Sandy Clay Loam 1.19 51.5 19.5 29.0

2.3. Image Processing and Extraction of Wetted Area 

Image acquired at a certain moment describes the soil conditions at this moment. Since the 

wetted area will increase when time elapsed, therefore the main aim of image analysis step 

was to accurately estimate this wetted area of soil column under specified operating 

conditions. The acquired color image was expressed by the average value of red (R), green 

(G) and blue (B) for all pixels in the image. The digital color image (called RGB image) 

consists of pixels at red, green and blue channels in the range of 0–255 and stored using 

eight bits per color component. Figure 2 outlines the image processing steps to derive 

wetting area map from the image. The acquired color image was first resized to a smaller 

size to subset only the soil cylinder in the center of the image and to hasten computational 

time of image processing. Thereafter, the color image was then converted to a grayscale 

image called intensity image. 

Image was then enhanced by several processes to ideally isolate the wetted area from the 

background. Image enhancement is the process of making an image more interpretable for a 

particular application. Contrast enhancement is a process that makes the image features 

stand out more clearly. The main advantage of contrast enhancement was that wetted area 

having the small size was well preserved in the images. Other image enhancements are also 

applied to the image, such as sharpening. Sharpening is an image filter that makes images 

appear sharper by increasing contrast near edges. 

Start 

Original RGB Image 

Subsit Image to 

Interest Area 

Intensity Image 

Contrast 

Image 

Enhancement 

Sharpening 

Yes 

Enhanced 

Image 

No 

Segmentation 

Binary Image 

Feature extraction 

Wetted Area 

Wetted Depth 

End 

FIGURE 2: Schematic diagram for image analysis algorithm to extract wetted area

The final enhanced images were segmented by choosing suitable thresholds to separate the 

wetted area of the soil column from the background. A threshold value is selected to provide 

a binary image. When the value of the pixels in an image is greater than the threshold, the 

image becomes white and when the value of the pixels is smaller than the threshold, the 

image becomes black. The resulting image is called the binary image. A binary image 

consists only of black and white pixels representing background and the wetted area, 

respectively. At zero time the wetted area equals zero since there is no wetted area in the 

column. After few seconds, water starts to distribute and penetrate inside the soil column and 

the column starts to be wet consequently. The same algorithm for image analysis to extract 

wetted area was carried out for all images captured at different time by using routine script 

developed using Matlab 7.1 and its image processing toolbox (Release 14, The MathWorks 

Inc., MA, USA). 

2.4. Model Validation 

In order to apply the model validation, field experiment were conducted at the experimental 

farm, agriculture faculty of Suez Canal University. The experiment was setup to allow testing 

of 4 emitters. The system consists of main lines (3 inch.), pressure regulator, pressure gage, 

water meter, valves, lateral lines (20 mm. diameter), and emitters. The design discharge 

rating of emitter was verified for the installed system. The coefficient of variation of the 

discharge was found to be less than 0.5 which is considered to be good. Depth of wetting 

front and wetted soil volume was observed in the field by measuring radius and depth of the 

soil from point source of trickle irrigation. 


Image analysis of the soil images has only involved separation between dry and wetting area 

of the soil column. A depth-dependent relationship was found between the time, discharge 

and the wetting areas. Figures 3 and 4 show the change in wetting front under drip irrigation 

at different times for both the sandy and sandy clay loam soils. 

After 25 min 174 min 60 min 380 min 

Sandy soil 

Sandy clay loam soil 

FIGURE 3: Change in soil wetting area under drip irrigation at different times 

In case of sandy soil, the wetted area reached 50% from the whole area of the column after 

only 74 min; meanwhile it takes 130 min to wet the same area of the sandy clay loam soil 

column. The time taken to wet the whole column (100%) was 174 and 380 min in case of 

sandy and sandy clay loam soil respectively indicating that the sandy soil has high infiltration 

rate compared to the sandy clay loam soil. Moreover, as shown in Figure (4) the relationship 

between wetted area and time is not linear. The best fit line for both types of soil texture is

polynomial relationship of second order. Figure (5) shows the wetting depth at different times 

for the sandy soil. 

FIGURE 4: Wetting areas at different times for both the sandy and sandy clay loam soil 

20.00 

Depth, cm. 

15.00 

10.00 

5.00 

0.00 

0 50 100 150 200 

Time, min. 

FIGURE 5: Wetting depth at different times for the sandy soil 

4. Validation of the Proposed Method 

To test and validate the proposed model, field experiment for the sandy soil only in the 

faculty farm, Suez Canal University was conducted. A direct comparison is complicated by 

the inability to use the same function in both the image analysis and field study. Therefore, 

we would not expect the two models to give exactly the same results. However, the models 

should give similar results as they are both describing the same physical process. 

Results from the image analysis and field study models on predicting wetting front position 

are compared (Table 2). Wetting front patterns generated with either image analysis or field 

study were shown (Figures 6 and 7) to give similar results. 

5. Overall Discussion 

Competition for water, high pumping costs, and concerns for the environment are making 

good water management more important. Irrigation water management requires timely 

application of the right amount of water. Managing irrigation water needs to combine an 

easily and cheap method of measuring soil wetting front with some method of irrigation 

scheduling. The most difficult task in the field, however, is to determine the spatial variability 

of infiltration process, which is of great importance for precision agriculture. Field 

determination of wetting front patterns is time consuming, laborious and expensive. 

Therefore, the present study assesses the feasibility of using image-processing technique to 

derive soil wetting area and depth and to develop an image-processing technique to derive 

soil wetting front map for sandy soil (equation 1 and 2). The results showed that digital image 

analysis is well suited for visualizing and quantifying solute infiltration into the soil. Digital

image analysis is well suited and focuses on developing a method to quantify flow patterns 

which allows an objective comparison of infiltration patterns observed at different sites or 

under different treatments. 

Predicted Wetting Area, cm2 

400 

350 

300 

250 

200 

150 

100 

50 

0 

y = 1.037x ‐ 7E‐14 

0 50 100 150 200 250 300 350 400 

Actual Wetting Area, cm2 

FIGURE 6: Actual and predicted wetting front area for sandy soil 

Predicted 

wettingdepth, cm. 

50 

40 

30 

20 

10 

0 

y = 2.2x 

0 5 10 15 20 

Actual wetting depth, cm. 

FIGURE 7: Actual and predicted wetting depth for sandy soil 

Actual wetting area, cm 2 = 1.037 * predicted wetting area, cm 2 – 7x10 -14 .……… 1 

Actual wetting depth, cm = 2.2 * predicted depth area, cm …………….………….2 

Overall, using image analysis as a non-contact measurement technique is recommended for 

the determination of wetting front patterns in the field or as a source of information for soil 

management and eventually agricultural management. 

6. Conclusion and Eyes to the Future 

Is imaging analysis quantifying the impacts of solute transport? Yes of course it is. The 

results showed a general advantage of column experiments, which was save money, effort 

and time. This study demonstrated that the proposed image analysis system is feasible for 

wetting front patterns. The method allowed us for the first time to quantify soil flow with high 

spatial resolution and sufficient accuracy. The results show that the image analysis models 

give reasonably good estimates of the wetting front position. Imaging analysis acquires both 

spectral and spatial information to detect some subtle features for visualizing and quantifying 

solute infiltration into soil. Using imaging techniques with image processing algorithms may 

opens a new avenue for inferred useful information from soil characteristics and soil quality 

for sustainability. Consequently, the next step will be to propose a predictive soil properties 

methodology.

References 

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Pattern Under Point Source Trickle Irrigation. Journal of Applied Sciences, 9(6), 

1170-1174. 

Cook, F.J., Fitch, P., Thorburn, P.J., Charlesworth, P.B., & Bristow, K.L. (2006). Modelling 

trickle irrigation: Comparision of analytical and numerical models for estimation of 

wetting front position with time. Environmental Modelling & Software 21, 1353-1359. 

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buried point sources: the average wetting water content. Water Resources Research, 

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Elmaloglou, S., & Diamantopoulos, E. (2007). Wetting front advance patterns and water 

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irrigation. Agricultural Water Management, 90, 160-163. 

Elmaloglou, S., & Malamos, N. (2006). A methodology for determining the surface and 

vertical components of the wetting front under a surface point source, with root wateruptake 

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111. 

Forrer, I. N., Papritz, A. Kasteel, R. Flühler, H. & Luca, D. (2000). Quantifying dye tracer in 

soil profiles by image processing. European Journal of Soil Science, 51, 313-322. 

Jamieson, R.C., Gordon, R.J., Sharples, K.E., Stratton, G.W., & Madani, A. (2002). 

Movement and persistence of fecal bacteria in agricultural soils and subsurface 

drainage water: a review. Canadian Biosystems Engineering, 44, 1.01–1.09. 

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fertigation strategy from a surface point source. Agricultural Water Management, 67, 

89-104 

Li, J., Zhang, J., & Ren, L. (2003). Water and nitrogen distribution as affected by fertigation of 

ammonium nitrate from a point source. Irrigation Science, 22(1), 12-30 

Lin, H., & Zhou, X. (2008). Evidence of subsurface preferential flow using soil hydrologic 

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Michigan. 

Revol, P., Clothier, B.E., Mailhol, J.C., Vachaud, G., & Vauclin, M. (1997b). Infiltration from a 

surface point source and drip irrigation. 2. An approximate time-dependent solution 

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Reflectometry. Soil Science Society of America Journal, 58, 1031-1039.

EVALUATION OF CROP CANOPY EFFECT ON THE MICRO- 

ADVECTIVE CONDITION AND SOIL WATER MOVEMENT IN MICRO- 

IRRIGATED FIELDS 

Kozue Yuge 1 *,Mitsumasa Anan 2 , Yoshiyuki Shinogi 1 

1 Faculty of Kyushu University, 6-10-1 Hakozaki Higashi-ku,Fukuoka, 812-8581, Japan 

2 Takasaki Sogo Consultant, Co. Ltd., 3-7-5 Higashiaikawa, Kurume, 839-0809, Japan 

*Corresponding author. E-mail: yuge@bpes.kyushu-u.ac.jp 

Abstrat 

The objective of this study was to evaluate the soil water content under micro-advective 

conditions considering the airflow turbulence generated by the crop canopy. A numerical 

model was developed to quantify the soil water movement under micro-scale advection, 

considering the spatial variation of the air moisture, heat, and flow generated by the crop 

body. In this study, the thermal and humidity environments of air and the air flow were 

simulated based on the assumptions that drip-irrigation is conducted in a crop field and wet 

portions appear partially on the soil surface. Using the thermal, humidity, and flow conditions 

of air, the soil moisture content and temperature were estimated using the soil surface 

boundary representing the energy budget. The accuracy of the model relative to the soil 

moisture content was verified in a wind tunnel experiment. Spatial changes of the soil 

moisture content, simulated by this model, were reproduced by the experiment. This 

indicates that the numerical model for estimating the soil moisture content under micro-scale 

advection considering the crop body is fairly satisfactory. 

Key words: 5 words or items at maximum must be included as key. 


Spatial distribution of the soil surface evaporation is observed in micro-irrigated fields 

because the water content on the soil surface is spatially varied. The wind effect, i.e., 

advection, complicates the spatial variation of the soil surface evaporation in micro-irrigated 

fields. Micro-scale advection plays a significant role in the energy budget on the soil surface 

and soil surface evaporation. Quantification of the water consumption in the micro-irrigated 

field is very difficult because of these phenomena. 

Bonachela et al. (2001) evaluated the micro-scale advective effect on daily soil surface 

evaporation in olive orchards. The occurrence of micro-advection was illustrated using a 

micro-lysimeter filled with well-irrigated or dry soil and arranged in a grid-pattern (Daiz- 

Espejo et al., 2005). Yuge et al. (2005) introduced a numerical model to estimate the 

evaporation from the bare soil under micro-scale advection. These studies focused on 

quantifying the soil surface evaporation considering the energy budget variation and the 

difference between conditions in the wet and dry portions of the micro-irrigated field. 

Additionally, the wind conditions, which varied because of the crop canopy, influenced the 

micro-advective effect and soil surface evaporation. Wilson and Shaw (1977), Raupach and 

Shaw (1982), Yamada (1982), and Uno et al. (1989) developed numerical models to simulate 

the turbulent airflow around an isolated plant canopy. Ohashi (2004) evaluated the 

effectiveness and limitation of various plant canopy turbulence models. These studies could 

be useful in the evaluation of the air flow turbulence caused by the crop canopy. However, 

the air flow turbulence effect on the soil surface evaporation or soil water content was not 

mentioned in these studies. 

The objective of this study was to evaluate the soil water content under micro-advective 

conditions considering the airflow turbulence generated by the crop canopy. A numerical

model was introduced to estimate the air flow turbulence. Using the wind velocity predicted 

by this model, the vapor pressure and air temperature in the vicinity of the soil surface were 

estimated by the numerical model describing the air heat and vapor transfer in the microadvective 

condition. The energy budget on the soil surface was estimated using the wind 

velocity, vapor pressure, and air temperature simulated by these models. The soil water 

content and temperature were predicted using the simulation model describing the water and 

heat transfer in the soil. Using the energy budget, the accuracy of this model was verified by 

a wind tunnel. 


2.1. Analysis of airflow field around an isolated crop 

The governing equations describing the wind flow around an isolated crop can be written as 

follows: 

∂u 

∂v 

+ = 0 

∂x 

∂z 

∂u 

∂u 

∂u 

1 ∂p 

∂ ⎛ 

+ u + v = − + ⎜ K 

∂t 

∂x 

∂z 

ρ ∂x 

∂x 

⎝ 

∂v 

∂v 

∂v 

1 ∂p 

∂ ⎛ 

+ u + v = − + ⎜ K 

∂t 

∂x 

∂z 

ρ ∂z 

∂x 

⎝ 

a 

a 

∂u 

⎞ ∂ ⎛ 

⎟ + ⎜ K 

∂x 

⎠ ∂z 

⎝ 

∂v 

⎞ ∂ ⎛ 

⎟ + ⎜ K 

∂x 

⎠ ∂z 

⎝ 

a 

a 

∂u 

⎞ 

⎟ − C 

∂z 

⎠ 

∂v 

⎞ 

⎟ − C 

∂z 

⎠ 

where u and v are the wind velocity in horizontal and vertical directions (m·s -1 ), ρ is the air 

density (=1.293kg/m 3 ), p is the air pressure (g·m -1·s -2 ), K a is the eddy diffusion coefficient 

(m 2·s -1 ), C m is the resistance coefficient by crop canopy, S is the leaf area density(m 2·m -3 ) , t 

is the time, x is the fetch, and z is the height. 

Eddy coefficient described in eqs. (2) and (3) can be estimated as follows: 

K 

a 

2 ∂u 

= λ 

m 

(4) 

∂z 

The parameter λ m , inside and outside of the crop canopy can be represented as the following 

equations, respectively. 

3 

2κ 

λ 

m in 

= (5) 

C m 

S 

( z − ) 

λ = κ 

(6) 

m out 

d 0 

The parameter of inside of the crop canopy λ m in can be estimated as follows: 

( z − d ) 0 m in : = κ ( z − ) 

κ > λ 

m in 

d 0 

m 

m 

S 

S 

u 

u 

2 

2 

+ v 

+ v 

λ (7) 

2 

2 

v 

u 

(1) 

(2) 

(3) 

κ z > λ 

m 

in 

: λ = κz 

(8) 

m in 

2.2. Heat and vapor transfer under micro-scale advection 

The equations that describe the air heat and vapor transfer in the advective condition can be 

written as follows:

∂e 

∂e 

∂e 

+ u + v 

∂t 

∂x 

∂z 

= 

∂ ⎛ ∂e 

⎞ ∂ ⎛ ∂e 

⎞ 

⎜ K 

a ⎟ + ⎜ K 

a ⎟ 

(9) 

∂x 

⎝ ∂x 

⎠ ∂z 

⎝ ∂z 

⎠ 

∂T 

a 

∂t 

∂Ta 

+ u 

∂x 

∂Ta 

+ v 

∂z 

∂ ⎛ 

= ⎜ K 

∂x 

⎝ 

a 

∂Ta 

∂x 

⎞ ∂ ⎛ 

⎟ + ⎜ K 

⎠ ∂z 

⎝ 

a 

∂T 

∂z 

where, T a is the air temperature(°C), and e is the vapor pressure(hPa). 

K a can be given using eq. (4). 

a 

⎞ 

⎟ 

⎠ 

(10) 

2.3. Soil moisture and heat transfer 

The moisture and heat transfer at the soil surface can be described as follows: 

∂θ 

∂ ∂θ 

∂ ∂θ 

∂ ∂T 

∂ ∂T 

∂K 

= ( Dw 

) + ( Dw 

) + ( DT 

) + ( DT 

) + 

∂t 

∂x 

∂x 

∂z 

∂z 

∂x 

∂x 

∂z 

∂z 

∂z 

C 

v 

∂T 

∂t 

(11) 

∂ ∂T 

∂ ∂T 

⎧ ∂ ∂θ 

∂ ∂θ 

⎫ 

= ( λ ) + ( λ ) + Lρ 

w ⎨ ( Dwv 

) + ( Dwv 

) ⎬ 

(12) 

∂x 

∂x 

∂z 

∂z 

⎩∂x 

∂x 

∂z 

∂z 

⎭ 

where C v is the volumetric heat capacity(J·m -3·ºC -1 ), D θ is the isothermal water 

diffusivity(m 2·s -1 ), D θv is the isothermal vapor diffusivity(m 2·s -1 ), D T is the thermal water 

diffusivity(m 2·s -1·ºC -1 ), K is the hydraulic conductivity(m·s -1 ), L is the latent heat of water 

vaporization(J·kg -1 ), T is the soil temperature(ºC), t is the time(s), λ is the thermal 

conductivity(W·m -1·ºC -1 ), ρ l is the water density(kg·m -3 ), and θ is the volumetric soil water 

content(m 3·m -3 ). 

2.4. Model structure 

Figure 1 shows the schematic view of the numerical model used to simulate the air-flow field, 

vapor, and heat environment around an isolated crop and the moisture and heat transfer in 

soil. 

z 

Above soil 

surface 

∂ ⎛ 

⎜ K 

∂z 

⎝ 

∂ ⎛ 

⎜ K 

∂z 

⎝ 

a 

a 

∂e 

⎞ 

⎟ = 0 

∂z 

⎠ 

∂Ta 

⎞ 

⎟ = 0 

∂z 

⎠ 

風 Wind 

e and T a are uniform. 

∂Ta 

∂Ta 

∂Ta 

∂ ⎛ ∂Ta 

⎞ ∂ ⎛ 

+ u + v = ⎜ K 

a ⎟ + ⎜ K 

∂t 

∂x 

∂z 

∂x 

⎝ ∂x 

⎠ ∂z 

⎝ 

∂e 

∂e 

∂e 

∂ ⎛ ∂e 

⎞ ∂ ⎛ ∂e 

⎞ 

+ u + v = ⎜ K 

a ⎟ + ⎜ K 

a ⎟ 

∂t 

∂x 

∂z 

∂x 

⎝ ∂x 

⎠ ∂z 

⎝ ∂z 

⎠ 

a 

∂Ta 

∂z 

⎞ 

⎟ 

⎠ 

⎛ ∂θ 

∂T 

⎞ 

E = Lρ 

w ⎜ − D 

w 

− D 

T 

− K ⎟ 

⎝ ∂z 

∂z 

⎠ 

∂T 

∂θ 

G = −λ 

− Lρ 

w 

D 

wv 

∂z 

∂z 

x 

v 

u 

The values of e and 

T a are the same as 

the adjacent node. 

Subsurface 

∂θ 

∂ ∂θ 

∂ ∂θ 

∂ ∂T 

∂ ∂T 

∂K 

= ( D 

w 

) + ( D 

w 

) + ( DT 

) + ( DT 

) + 

∂t 

∂x 

∂x 

∂z 

∂z 

∂x 

∂x 

∂z 

∂z 

∂z 

∂T 

∂ ∂T 

∂ ∂T 

⎧ ∂ ∂θ 

∂ ∂θ 

⎫ 

C 

v 

= ( λ ) + ( λ ) + Lw 

ρ 

w ⎨ ( D 

wv 

) + ( D 

wv 

) ⎬ 

∂t 

∂x 

∂x 

∂z 

∂z 

⎩ ∂x 

∂x 

∂z 

∂z 

⎭ 

Dry 

Wet 

Dry 

θ,T are same value as 

the adjacent node. 

FIGURE 1: Schematic view of the numerical model used to simulate the air-flow field, vapor, 

and heat environment around an isolated crop and the moisture and heat transfer in soil.

3. Wind tunnel experiment 

The accuracy of the numerical model for estimating soil surface evaporation under microscale 

advection was verified using the wind tunnel. The schematic view of the wind tunnel is 

shown in Figure 2. To simulate the field conditions where wet portions are generated partially 

by drip-irrigation, a rectangular tank filled with saturated soil and oven-dried soil was used. 

Crop canopy architectural models were arranged as shown in Figure 2 to describe row 

planting. The height of the crop canopy architectural model was 0.25m. 

The wind flowed at a velocity of 1.5 m/s at a height of 0.8m. The profile of the wind velocity in 

the vicinity of the soil surface was observed using one anemometer (Anemomaster, MODEL 

6071) upwind and downwind of the crop canopy architectural model. The height of the 

anemometer was variable, and the profile of the wind velocity was measured at 7 levels (0.01, 

0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.10, 0.12, 0.15, 0.17, 0.20, 0.25, and 0.30 m). The air 

temperature and humidity in the tunnel were observed at a height of 1m. The soil surface 

evaporation was measured by weighing the micro-lysimeters set at the wet portion, as shown 

in Figure 3. Soil moisture sensors (SM200, Delta-T) were set 1 point upwind of the dry 

portion, 4 points upwind of the wet portion, and 2 points downwind of the dry portion (Figure 

2). The soil moisture sensors were buried at a depth of 5cm. To measure the soil 

temperature, thermocouples were set at depths of 0cm, 5cm, 10cm, 15cm, and 20cm. The 

thermocouples were buried at dry and wet portions, as shown in Figure 3. In addition, the soil 

moisture profile was measured by sampling the soil at the points shown in Figure 4. 

Crop canopy architectural 

model 

Wet portion 

Dry portion 

0.2m 

Wind 

0.3m 0.4m 0.3m 

FIGURE 2: Schematic view of the wind tunnel 

TDR 

5cm 

5cm 

0.4m 

Micro-lysimeters 

Thermocouples 

0.3m 0.4m 

0.3m 

FIGURE 3: Plan view of wind tunnel and measurement condition 

20cm 

FIGURE 4: Cross-section of the subsurface and soil sampling points


4.1. Spatial distribution of soil moisture content 

Figure 5 shows the spatial distribution of soil moisture content measured by sampling soil 3 

hours after the beginning of the wind flow at the points shown. The soil moisture content at 

the upwind dry portion was lower than that found downwind. Soil water loss by soil surface 

evaporation was prevented because of the interception of wind flow by the crop model body. 

At the wet portion, the soil moisture content at the shallow layer was lower than that at the 

deep layer. 

Depth(m) 

0.00 

0.05 

0.10 

0.15 

0.20 

Fetch(m) 

0.2 0.4 0.6 0.8 

Volumetric water 

content(%) 

30 

25 

20 

15 

10 

5 

0 

FIGURE 5: Spatial distribution of soil moisture content 

4.2 Model accuracy 

Figure 6 shows the comparison of the simulated and observed volumetric water content 3 

hours after the beginning of the wind flow. At the upwind dry portion, the volumetric water 

content was constant. The volumetric water content at the wet portion increased gradually as 

the fetch increased and reached a peak. After peak, the volumetric water content decreased 

gradually. 

At the upwind edge of the wet portion, the volumetric water was low because the soil water 

moved to the upwind dry portion. Soil water was lost due to increased soil surface 

evaporation caused by the relatively dry airflow from the upwind dry portions. The gradual 

decrease of the soil moisture content after peak in the wet portion occurred because dry air 

from the dry portions mixed with the relatively humid air in the wet portions. Downwind of the 

dry portion, the volumetric water content decreased abruptly and reached a constant value. 

The simulated volumetric water content reproduced the variation of the soil moisture content. 

25 

Volumetric water content (%) 

20 

15 

10 

5 

Simulation 

Observation 

0 

0.0 0.2 0.4 0.6 0.8 1.0 1.2 

Fetch (m) 

FIGURE 6: Comparison of the simulated and observed volumetric water content 3 hours 

after the beginning of the wind flow


A numerical model was developed to quantify the soil water movement under micro-scale 

advection, considering the spatial variation of the air moisture, heat, and flow generated by 

the crop body. In this study, the thermal and humidity environments of air and the air flow 

were simulated based on the assumptions that drip-irrigation is conducted in a crop field and 

wet portions appear partially on the soil surface. Using the thermal, humidity, and flow 

conditions of air, the soil moisture content and temperature were estimated using the soil 

surface boundary representing the energy budget. The accuracy of the model relative to the 

soil moisture content was verified in a wind tunnel experiment. The soil moisture content at 

the upwind dry portion was lower than that found downwind. Soil water loss by soil surface 

evaporation was prevented because of the interception of wind flow by the crop model body. 

At the wet portion, the soil moisture content at the shallow layer was lower than that at the 

deep layer. Spatial changes of the soil moisture content, simulated by this model, were 

reproduced by the experiment. This indicates that the numerical model for estimating the soil 

moisture content under micro-scale advection considering the crop body is fairly satisfactory. 

The numerical model introduced in this study is effective for estimating soil moisture 

conditions under micro-scale advection in the drip-irrigated fields. This method will allow 

researchers to increase irrigation efficiency in crop fields. 


Bonachela, S., Orgaz F., Villalobos, F. J., & Fereres, E. (2001). Soil evaporation from dripirrigated 

olive orchards. Irrigation Science, 20, 65-71 

Daiz-Espejo, A., Verhoef, A., & Knight, R. (2005). Illustration of micro-scale advection using 

grid-pattern mini-lysimeters. Agricultural and Forest Meteorology, 129, 39-52 

Raupach, M. R., & Shaw, R. H. (1982). Averaging procedures for flow within vegetation 

canopies. Boundary-Layer Meteorology, 22, 79-90 

Ohashi, M. (2004). A study on analysis of airflow around an individual tree. Journal of 

Environmental Engineering (Transaction of Architectural Institute of Japan), 578, 91-96 (in 

Japanese with English abstract) 

Uno, I., Ueda, H., & Wakamatsu S. (1989). Numerical modeling of the nocturnal urban 

boundary layer. Boundary-Layer Meteorology, 49, 77-98 

Wilson, N. R. & Shaw, R. H. (1977). A Higher order closure model for canopy flow. Journal of 

Applied Meteorology, 16, 1197-1205 

Yamada, T. (1982). A numerical model study of turbulent airflow in and above a forest 

canopy. Journal of the Meteorological Society of Japan, 60(1), 439-454 

Yuge, K., Haraguchi, T., Nakano, Y., Kuroda, M. & Anan, M.(2005). Quantification of soil 

surface evaporation under micro-scale advection in drip-irrigated fields. Paddy and Water 

Environment, 3(1), 5-12

Benchmarking of Irrigated Agriculture: The Case of Thessaly 

(Greece) 

Constantinos Kittas 1 , Thomas Bartzanas 2 , Nikolaos Katsoulas 1 Evaggelini 

Kitta 2 , Adrianno Batilliani 3 

1 University of Thessaly, Department of Agriculture Production and Rural 

Environment, Fytokou St. N. Ionia Magnisias, 38500, Volos Greece 

2 

Center for Research and Technology-Thessaly, 1 st Industrial Area of Volos, 38500, 

Volos, Greece 

3 Consorzio di bonifica per il Canale Emiliano Romagnolo CER Via E. Masi, 8 - 

40137 Bologna (Italy) 

Abstract 

*Corresponding author. E-mail: ckittas@uth.gr 

We develop a computerized data base for benchmarking irrigated agriculture. 

Indicator values in the summary worksheet are calculated automatically after the 

basic data are entered into the data base worksheet without user intervention. For 

each targeted district, protocols for data collection were defined which were provide 

the information and data required for a comprehensive diagnosis and valuation of the 

actual management rules for water allocation and distribution, and for proposing 

changes and improvements in the organizational structure and the day-to-day 

management of the irrigation district. The proposed database provides farmers and 

other relative with irrigated water stakeholders, with a suitable method of irrigation 

performance assessment through the process of ‘benchmarking’, propose district 

best management practices. The proposed indicators and benchmarking exercises 

can be used by farmers and water authorities to identify ways to reduce inputs such 

as fertilizer or electricity, or to more effectively use irrigated water in order to increase 

production, achieving a better water use efficiency. In the present paper we present 

the first data from the Region of Thessaly – Greece, the main agriculture region of 

Greece. 

Key words: water use efficiency, evaporotranspiration, web database 


Water resources management is today regarded as an integrated procedure and in 

this context incorporates technical, political, legislative, and organisational 

components. Examples of most of the world’s water resources problems can be 

found around the Mediterranean basin particularly in the Southern and Eastern parts 

of the region. In many watersheds of the Mediterranean Countries, water resources 

are presently fully or overcommitted. Demand for water is likely to continue 

increasing due to population growth as well as increased demand from in-stream 

users. Irrigators are the largest consumers of fresh water in Mediterranean Countries: 

either individually or as members of irrigation districts, using up to 80% of all 

allocated water in some regions. With the increasing water demand of other sectors 

and environmental constraints, water resources available for agriculture will decrease 

in the next decades

Agriculture is still by far the greatest consumer of water in the region, and is well 

above the world average. More than 80% of water resources are allocated to 

irrigation, with relatively high losses that exceed 50%. With the intensification of 

water stress and the limited potential for additional water supply, in recent years 

great emphasis has been given to improving water use efficiency. In the agricultural 

sector, this has been expressed as “more crop and higher value per drop” (FAO, 

2000). In the last decade the EU Commission produced several documents 

addressing the integration of environmental concerns into the agricultural policy. 

Particularly was highlighted the needs of reliable indicators to monitor, measure and 

evaluate the real impact of proposed innovation on the environmental sustainability. 

Although the need is evident, still are missing practical indicators that farmers and 

water authorities can use to achieve their goals by taking note of and controlling 

changes occurring on-farm and on-irrigation district. Benchmarking tools and 

performance indicators can be efficient used for this purpose. 

Benchmarking may be defined as the identification and application of organisation 

specific best practices with the goal of improving competitiveness, performance and 

efficiency. It is a continuous process that involves (a) internal assessment of the 

organisation, (b) comparing it with the best practices of more successful similar 

businesses in the market, (c) determining performance gap between current practice 

and best practice, and (d) selecting best practices, tailoring them to fit the 

organisation and implementing them. Guidelines for benchmarking in the irrigation 

sector were proposed recently (Malano et al., 2004; Farmani et al., 2003). 

Performance assessment is based on performance indicators that are specifically 

identified to enable the comparison and to monitor progress towards closing the 

identified performance gap. Comparison between performance indicators is widely 

used in irrigation systems, very much as a tool for water management policies. 

Previous applications and checks have shown that performance indicators and 

benchmarking can be successfully applied using the common general guidelines, 

taking into account the special features of every zone, because not all irrigation 

zones of the world are similar. The core of any benchmarking exercise is data 

collection. In order to enable comparison between irrigation districts, data used for 

benchmarking need to be consistent and comparable. 

In the present paper a first set of data including both historic and pilot (experimental) 

data is presented and relative performance indicators were calculated. 


2.1. Data collection 

The core of any benchmarking exercise is data collection. In order to enable 

comparison between irrigation districts, data used for benchmarking need to be 

consistent and comparable. There are three types of data collection: 

• data collected for day-to-day management, operation and maintenance of the 

irrigation systems, such as pumping costs, reservoir and canal level, flow 

rate, etc. 

• data collected for benchmarking and comparison with other systems. 

• data collected as part of the diagnostic process within the benchmarking 

exercise to identify causes of performance. 

To enable irrigation districts with different levels of data available to participate in the 

benchmarking process, a range of benchmarking indicators will be proposed. 

2.2. Performance indicators

Indicators can be thought of as statistical constructs which support decision-making, 

through benchmarking analysis, by revealing trends in data and subsequently, they 

can be used to analyse the results of policy actions. Indicators of sustainability seek 

to describe and measure key relationships between economic, social and 

environmental factors with sustainable development being seen as a better balance 

between all three dimensions. 

Successful indicators must be readily understandable, representative of key 

environmental policies and concerns, and capable of illustrating trends over time. In 

addition, indicators could provide an early warning of potential economic, social or 

environmental damage 

A further type of indicator is a derived indicator, which is used when it is either 

impossible or impractical to directly measure an impact. For example, soil 

productivity can be described by a large list of physical, chemical or biological soil 

characteristics that would be expensive and time-consuming to measure. 

Water productivity performance measures are at the very basis of most of the 

indicators utilised in benchmarking exercises. The water productivity concept 

grounds on the performance ratio between the amount of resource entering into a 

process and the process output. There are several definitions of water productivity, 

so we have to precise which crop and which drop we are referring to (Table 1). 

TABLE 1 Some examples of stakeholders and definitions in the water productivity 

framework. 

Stakeholder Definition Scale Target 

Plant physiologist Dry matter / 

transpiration 

Agronomist Yield / 

evapotranspiration 

Plant 

Field 

Utilize light and water 

resources 

Sufficient food 

Farmer Yield / supply Field Maximize income 

Irrigation engineer Yield / irrigation Irrigation Proper water 

supply 

scheme allocation 

Groundwater policy € / groundwater Aquifer Sustainable extraction 

maker 

extraction 

Basin policy maker € / evapotranspiration River Basin Maximize profits 

Water Authorities Diverted Water/ River Basin Safeguard or restore 

Existing water 

water quality and/or 

consents 

biodiversity into river 

and wetlands 

Measurements of production from irrigated agriculture can be used in several ways to 

compare across the irrigation systems the effectiveness of the actual governance or 

to assess the impact of recently implemented technologies, strategies, 

infrastructures. However, compare different crops, in different regions, cultures and 

markets is not an easy task. The difficulties arises when comparing measurement 

which have the effect of more than one variable embedded in itself, as e.g irrigation 

methods and strategies, climate, intermittent water availability, etc. A large number of 

authors attempted at standardize the comparisons through performances indicators, 

that are now available in literature and in some cases also tested in specific

enchmarking exercises. Nevertheless, there is not a single set of performance 

indicators that can satisfy the standardization criteria from every standpoint. 

Therefore, primary data can be used to produce a large number of secondary data 

and performance indicators, then can be analysed in different ways following the 

prevalent standpoint (e.g. economic instead of environmental, etc). In the present 

paper we will present results based on the following indicators: 

a) Measured yield normalized on the local potential yield (t ha -1 / t ha -1 ). 

Actual crop yield 

Relative yield = 

Potential crop yield 

b) Relative water productivity (t/m 3 ) 

Potential crop production 

Relative water productivity= 

Total water supplied 

c) Production value of land (kg/ha) 

Total yield (kg) 

Productive efficiency = 

Irrigatedarea ( ha) 

The above three indicators were calculated based on experimental data from a pilot 

farm. The experimental work was carried out in a single- span, arched roof, 

greenhouse covered by a single polyethylene film (type PE-EVA-film TUV 3945, film 

thickness of 180 μm) N-S oriented, near Volos (Velestino: Latitude 39º 22΄, longitude 

22º 44΄, altitude 85 m). The internal of the experimental greenhouse was properly 

adjusted so that the closed hydroponic system to be installed. The geometrical 

characteristics of the greenhouse were as follows: eaves height of 2.4 m; ridge height 

of 4.1 m; total width of 8 m; total length of 20 m; ground area of 160 m 2 , and volume 

of 572 m 3 . The greenhouse soil was totally covered by a plastic covering permeable 

to water. 

The tomato crop (Licopersicon esculentum, cv. Belladonna) was transplanted during 

23 December 2010 and will remain in the greenhouse until mid July 2011. The plants 

are grown hydroponically in rockwoll bags (1 m long, 0.2 m wide, 0.075 m high). The 

plant density is 2.4 plants∙m -2 . Plants are laid out in four double rows; the two outside 

rows are used as borders while the six internal lines are used for the treatments 

studied. 

Three treatments were studied: 

a) open system, no recirculation of the nutrient solution 

b) closed system, complete recirculation of the nutrient solution, addition only of 

water and nutrients absorbed by the plants 

c) semi-closed system, recirculation of the nutrient solution until certain set 

points are reached. 

The set points were: EC of the nutrient solution higher than 5 dS m -1 or Na+ 

concentration in the nutrient solution higher than 15 mmol l -1 . The first time to drop 

out of the system drainage solution was when Na+ concentration in the system was 

higher than 25 mmol l -1 and after this set point was reached, Na+ concentration was 

set to be lower than 15 mmol l -1 . If the above set points were not reached, the system 

added water and nutrients absorbed and recycled the solution. 

3. Results 


Thessaly is located in central Greece and is a plain region surrounded by Mount 

Kisavos and Mount Pelion in the east, along the coast of the Aegean Sea. Thessaly’s

total area is about 13,700 km2. The two larger basins of region are the Pinios River 

and the Lake Karla basins. Thessaly plain is the most productive agricultural region 

of Greece with an area of about 4,000 km2. The main crops cultivated in the plain 

area are cotton, wheat and maize whereas apple, apricot, cherry, olive trees and 

grapes are cultivated at the foothills of the eastern mountains. Lake Karla occupied, 

until 1962, most of the eastern part of Thessaly plain in central Greece. It was one of 

the most important wetlands in Greece and a natural reservoir, which provided 

significant water storage and recharge to groundwater. The basin surface runoff and 

the overflowing floodwaters of the Pinios River sustained Lake Karla. The lake area 

fluctuated from 40 to 180 km2 due to the very gentle land slope and the inflow– 

outflow balance. For this reason, significant area of the surrounding farmland was 

often inundated facing soil salinity problems 

3.2. Water needs 

Evapotranspiration is a key indicator for water management and irrigation 

performance. The agricultural water demand for irrigation per sub-basin was 

estimated as follows. Firstly, data of the irrigated agricultural areas per crop and 

municipality for the year 2008, provided by the Cooperation of Agriculture Farmers of 

Larisa, were used to estimate the irrigated agricultural areas for each sub-basin and 

each crop. The major crops in the study area were cotton, wheat, legumes, and 

orchards. The monthly reference evapotranspiration for each crop (ETo) was 

estimated using the Blaney–Criddle method (Blaney and Criddle 1950) and the 

monthly crop coefficients proposed by FAO (Allen et al. 1998) for Mediterranean 

climate conditions. Fig. 1 presents the potential evapotranspiration of main crops and 

the relative water needs. 

1000 

Evapotranspiration / water needs, mm/year 

900 

800 

700 

600 

500 

400 

300 

200 

100 

0 

Sugar beat Corn Vineyiards Orchands Vegetables Wheat Tomato Legumes 

Crop 

FIGURE 1: Potential evapotranspiration (blue) and water needs (red) of basic crops 

in the region of Karla basin 

Taking into account the total area of each crop in the area the maximum water needs 

for irrigation are 165.943.916,24 m3/year (based on climate date for the reference 

year 2008). Here we should state that practical (actual) water needs maybe vary from 

what has been calculated since the above calculation did not take into account the 

potential water losses during the transfer of water from the water both from irrigation 

channels to the fields and also the application or irrigation method used in the field. 

The efficiency of the system of water transfer and distribution depends on the type of 

network. For example the open channel surface distribution networks (mainly used in 

the studied area) have efficiencythat ranges from 0.20 to 0.75 (Papazafiriou 1999).

The efficiency of the irrigation methods ranges from 0.50 to 0.80 for the surface 

irrigation methods, from 0.60 to 0.90 for the sprinkle irrigation methods, Esprinkle, 

and from 0.80 to 0.95 for the drip irrigation, Edrip (Papazafiriou 1999). 

3.3. Performance indicators calculation 

Table 2 presents the values of the performance indicators for the three different 

cases applied in the pilot study in the experimental greenhouse with the tomato crop. 

It should be noted here that all values are per m 2 . It is clear that the close hydroponic 

systems have the best indicators in the three tested categories. Close hydroponic 

systems can lead to higher yields with low irrigation needs, but at the same time they 

need state of the art equipment and irrigation systems and experience greenhouse 

managers. 

Case Relative yield Relative water productivity Production value of 

land 

Open system 0.62 0.024 0.038 

Close system 0.71 0.037 0.044 

Semi close 0.66 0.032 0.041 

References 

Allen, R.G., Pereira, L.S., Raes, D., & Smith, M. (1998). Crop evapotranspiration - 

Guidelines for computing crop water requirements - FAO Irrigation and drainage 

paper 56. FAO, Rome, 290 pp 

Blaney, H.F., & Criddle, W.D. (1950) Determining water requirements in irrigated 

areas from climatological and irrigated data, SCS-TP96. US Soil Conservation 

Service, Washington DC 

FAO (2000). Food and Agricultural Organization of the United Nations (FAO) (2000). 

Crops and drops: making the best use of water for agriculture. On-line publication, 

www.fao.org. FAO, Rome 

Farmani, R., Savic, D.A. & Walters, G.A. (2005). Evolutionary multi-objective 

optimization in water distribution network design. Engineering Optimization, 37, 167- 

183. 

Malano H., Burton, M., & Makin, I. (2004). Benchmarking performance in the 

irrigation and drainage sector: a tool for change. Irrigation and Drainage, 53, 119- 

133. 

Papazafiriou ZG (1999) Water demands of crops. Ziti, Thessaloniki (in Greek)

poster - International Conference of Agricultural Engineering

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