Complementary Use of Cow Dung and Mineral Fertilizer: Effect On ...

PAT June 2011; 7 (1): 36-48 ISSN: 0794-5213Online copy available atwww.patnsukjournal.net/currentissuePublication of Nasarawa State University, KeffiComplementary Use of Cow Dung and Mineral Fertilizer: Effect On SoilProperties, Growth, Nutrient Uptake And Yield of Sweet Potato (Ipomea batatas)Asawalam, D. O and Onwudike, S. U.Department of Soil Science and MeteorologyMichael Okpara University of Agriculture, Umudike,PMB 7267, Umuahia, Abia State, Nigeriaasawaldo@yahoo.comAbstractThis study evaluated the effect of cow dung and mineral fertilizer (NPK 15 -15 -15) on soilproperties, growth, nutrient uptake and yield of sweet potato (Ipomoea batatas) at twolocations (Uturu and Umudike) in southeastern Nigeria. The experiment was a randomizedcomplete block design (RCBD) with four replicates. The treatments consisted of 3.7 t/ha cowdung, 400 kg/ha NPK fertilizer, 1.9 t/ha cow dung + 200 kg/ha NPK fertilizer, 0.9 t/ha cowdung + 300 kg/ha NPK fertilizer, 2.8 t/ha cow dung + 100 kg NPK fertilizer and a control.Combined application of cow dung and NPK fertilizer significantly (P < 0.05) increasedorganic matter, available P, exchangeable K and Effective Cation Exchange Capacitycompared to the control in both locations. Uptake of N, K, Ca and Mg were higher withtreatments in which cow dung was combined with NPK fertilizer compared to the control atboth locations. Also, combined application of cow dung and NPK fertilizer significantly (P

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 37The objectives of this study therefore, were to: (a) determine the effect of cow dung andNPK fertilizer on soil properties, and (b) determine the influence of varying proportionsof NPK fertilizer and cow dung on growth, nutrient uptake and yield of sweet potato.Materials and methodsThe study was conducted at two locations, namely Umudike (Long 7 o 32 / E andLat 5 o 29 / N) and Uturu (Long 7 o 20 / E and Lat 5o 45 / N), both in Abia State,Southeastern Nigeria. Soils of the experimental fields are sandy loam in texture,strongly acid in reaction (pH 4.82 – 4.93), medium in organic matter content (2.10 –2.29 %) and low in nitrogen and potassium contents but marginal in availablephosphorus (Table 1). The experiment was a randomized complete block design(RCBD) with four replicates. The treatments consisted of 3.7 t/ha cow dung (T1), 400kg/ha NPK fertilizer (T2), 1.9 t/ha cow dung + 200 kg/ha NPK fertilizer (T3), 0.9 t/hacow dung + 300 kg/ha NPK fertilizer (T4), 2.8 t/ha cow dung + 100 kg NPK fertilizer(T5) and a control (no manure and no fertilizer) (T6).Land preparation, including slashing, ploughing and harrowing were carried outbetween May to June 2004. The field was marked out into plots of 5 m x 5 m separatedby 1 m alley. Before the treatments were applied, a composite soil sample of one augerborings (0 – 30 cm depth) per plot was collected at each location. At the end of thestudy, a soil sample from each of the experimental plots was also collected to the samedepth. The samples were air-dried, ground and passed through 2mm-mesh sieve andused for laboratory analysis. Cow dung obtained from cattle market at Okigwe, was airdried,weighed and appropriate quantities applied on plot by broadcasting and workedinto the soil with hand hoe. The composition of the cow dung is shown in table 2. Sweetpotato vines (variety TIS 87/0087), obtained from National Root Crops ResearchInstitute, Umudike was cut into 20 cm length, and planted at a spacing of 60 cm x 90cm on flat, giving a plant population of 19,200 plants /ha. Sweet potato vines wereplanted two weeks after cow dung incorporation at an angle of 45 o . Mineral fertilizerwas applied three weeks after planting. Hoe weeding was carried out at 5 and 8 weeksafter planting. In each experimental plot, five plants were tagged for measurement ofnumber of leaves, leaf area, number of branches and length of vines on weekly basesfrom 3 – 13 weeks after planting. Vine length was measured using meter rule. Leaf areawas calculated by using the formula adopted by Asiegbu (1991):A = 0.56 x P x 6.20 .Where A = leaf area and P = length x breath. 0.56 and 6.20 areboth constants, which account for the spaces created due to irregular shape of sweetpotato leaves.At eight weeks after planting, vines and leaves of two plants per plot wereharvested, oven dried at 65 o C, weighed to determine dry matter, ground in a hammer

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 38mill and analyzed for nutrient concentrations. At 19 th week after planting, when theleaves have turned yellow, the plants were harvested and tuber weights were recorded.Soil samples collected were analyzed for particle size distribution by hydrometermethod (Gee and Bauder 1996) using sodium hexametaphosphate as dispersant. Soil pHwas determined in water and IN KCl at soil to liquid ratio of 1:2.5 using a combinedelectrode pH meter (Thomas 1996). Total nitrogen was determined by semi- microkjeldahl method (Bremner 1996) using selenium tables as catalyst. Organic carbon wasdetermined by chromic acid wet oxidation method of Nelson and Sommers (1996)while organic matter was determined by multiplying percentage organic carbon by1.724. Available phosphorus was extracted by Bray No 1 method, and determined bythe molybdenum blue method (Kuo, 1996). Exchangeable bases were determined by 1Nneutral NH 4 OAC saturation method of Grant (1982), exchangeable acidity by themethod of Mclean (1965). Effective cation exchange capacity was determined bysummation of total exchangeable bases and exchangeable acidity. Nutrient uptake bysweet potato plant was analyzed by dry ashing methods. Sweet potato plant tissues weredried at 65 o C for 72 hours, ground with milling machine and subjected to ashing usingporcelain crucible. The ashes were dissolved in 5ml of 20% HCl. The solution obtainedwas used for plant nutrient uptake determination.Statistical AnalyisisData obtained were subjected to analysis of variance (ANOVA) procedure ofStatistical Analysis System (SAS, 1989) and significant means were separated usingstandard error of the difference between means.Results and discussionEffect of Cow Dung And NPK Fertilizer on Soil PropertiesSignificant differences in soil chemical properties such as soil pH, organic matter, soilnitrogen, available phosphorus, exchangeable potassium, calcium and magnesium wereevident. At Umudike, combined application of cow dung and NPK fertilizer increasedsoil pH in water from 4.8 (T 6 ) to 5.0 (T 4 ) and (T 3 ) (Table 3). Also in Uturu, combinedapplication of cow dung and NPK fertilizer increased soil pH from 4.6 (T6) to 5.1 (T3)and (T4) (Table 4). Complementary use of cow dung and NPK improved the pH of thesoil more than application of either cow dung or NPK fertilizer. Okigbo (2000) reportedthat application of NPK fertilizer on soil that have experienced leaching can lead todeficiency of some nutrient elements such as Zn and Mg, which may lead to soilacidification. The results from the two locations confirm that combined use of organicand inorganic fertilizer increases soil pH more than application of either cow dung orNPK fertilizer.

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 39Application of 3.7t/ha cow dung at Umudike location significantly increased soilorganic matter more than other treatments (Table 3). At Uturu, soil organic matterincreased in the plots that received cow dung and NPK (Table 4). Increase in organicmatter of the soil due to application of cow dung could be attributed to the potential oforganic waste to enrich soil organic matter. Benckiser and Simarmata (1994) reportedthat 5.0 t of solid manure contains on the average about 900kg of organic matter.Sommerfeldt and Chung (1985) showed also that applying 1ton /ha cow dung increasessoil organic matter by 0.025% per annum.At Umudike location, combined application of cow dung and NPK fertilizersignificantly increased soil nitrogen from 0.09% to 0.16%. Application of only mineralfertilizer did not significantly increase soil nitrogen. This could be attributed to high rateof nutrient release in NPK fertilizer which makes N readily available and easily leached.The result also showed that complementary use of cow dung and NPK reduces N lossfrom the soil thereby increasing available nitrogen in the soil. This is in agreement withan observation (Reijintjes et al, 1993, cited in Okigbo 2000) that joint application oforganic and inorganic fertilizers reduces, among other things, losses of nutrients byleaching.The highest available phosphorus was recorded with application of 3.7t/ha cowdung, which increased available P from 9.05 to 12.58 ppm in Umudike. The same trendwas observed in Uturu location. Complementary use of cow dung + NPK fertilizershowed higher increase in P availability than application of NPK alone. Virekanandanand Fixen (1990) have reported that the build up of phosphorus through application ofcow dung is as a result of the mineralization of organic phosphate due to microbialpopulation and the production of organic acids, which make soil P available. Sincephosphorus is not as mobile as nitrogen or potassium, some available phosphorus,which was not used up by sweet potato, may not experience leaching (Fixen et al,1990).Compared to the control, there was significant increase in effective cationexchange capacity of the soil when complementary use of cow dung and NPK wasapplied. Application of 0.9t/ha cow dung + 300kg/ha NPK fertilizer increased ECECfrom 6.49 to 8.25 cmol/kg in Umudike (Table 3). The same trend was recorded in Uturulocation (Table 4). Increase in ECEC of the soil with addition of cow dung may beattributed to the better buffer capacity of the soil as a result of the high organic mattercontent of the added manure (Meelu and Gill, 2001).Effect of Cow Dung and Mineral Fertilizer on Sweet Potato GrowthThe results in Fig. 1(a) showed that combined application of cow dung and NPKfertilizer (T 4 ) gave a significantly (p

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 40of cow dung alone (T 1 ) NPK fertilizer alone (T 2 ) or the control (T 6 ). At Uturu location,the treatments increased leaf area more than the control (Fig. 1b).Treatment effects on number of leaves of sweet potato in Umudike and Uturuare presented in Fig. 2a and 2b respectively. Application of 0.9 t/ha cow dung + 300kg/ha NPK gave the maximum number of leaves. This was followed by application of1.9 t/ha cow dung + 200 kg/ha NPK. At Uturu location, no much difference wasrecorded when compared to control. However, applications of 0.9t/ha cow dung +300kg/ha NPK fertilizer gave the largest number of leaves.Sweet potato vine length was longer with combined application of cow dung andNPK fertilizer than the control (Fig. 3). Application of 1.9 t/ha cow dung + 200 kg/haNPK produced the longest vine length at Umudike (Fig. 3a) while application of 0.9t/ha cow dung + 300 kg/ha NPK produced the longest vine length at Uturu (Fig. 3b).Application of either 1.9 t/ha cow dung + 200 kg/ha NPK or 0.9 t/ha cow dung +300 kg/ha NPK produced equal number of branches in Umudike (Fig. 4a). Nosignificant difference was recorded when either 3.7 t/ha cow dung or 400 kg/ha NPKfertilizer was applied when compared to control. At Uturu, application of 0.9 t/ha cowdung + 300 kg/ha NPK produced the highest number of branches. Other treatments didnot differ significantly (P

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 41At Umudike, combined application of cow dung and NPK fertilizer significantlyincreased P uptake more than the control (Fig 6). The highest P uptake was recordedwith application of 1.9 t/ha cow dung + 200 kg/ha NPK at Umudike (Fig. 6a) and atUturu (Fig. 6b).In potassium uptake, application of 0.9 t/ha cow dung + 200 kg/ha NPKfertilizer recorded the highest potassium uptake in Umudike while in Uturu, applicationof 1.9 t/ha cow dung + 300 kg/ha NPK fertilizer recorded the highest uptake (Fig. 7).Uptake of calcium, was highest with application of 0.9 t/ha cow dung + 300 kg/ha NPKfertilizer (Fig. 8). Magnesium uptake was significantly (P

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 42cow dung + 300 kg/ha NPK fertilizer recorded the highest nutrient uptakes, growth andyield of sweet potato in Umudike while application of 1.9 t/ha cow dung + 200 kg/haNPK fertilizer recorded the highest nutrient uptakes and sweet potato tuber weight inUturu. From the results of the study, application of 1.9 t/ha cow dung + 200 kg/ha NPKfertilizer improved soil properties, nutrient uptakes, growth and yield of sweet potato inUmudike while application of 0.9 t/ha + 300 kg NPK fertilizer recorded significantly(P

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 43Maclean, E. O. (1965). Soil pH and lime requirement. In : A. L. Page et al (Ed.).Methods of Soil Analysis Part 2. 2 nd (Ed.) Agron. Mono. ASA and SSSAMadisson, W. I Mono. 9.Meelu, O. P. and Gill, H. S. (2001). Studies on the substitution of inorganic fertilizerwith organic manure and their effect on soil fertility in rice – wheat rotation.Fertilizer Res. 3: 303 – 314.Nelson, D. W. and L. E. Sommers 1996. Total Carbon, Organic Carbon and OrganicMatter. In: D. L. Sparks (Editor) Pp 961 – 1010. Methods of Soil Analysis Part 3– Chemical Methods, SSSA Book Series 5, Madison, Wisconsin, USA.Okigbo, B. N. (2000). Enhancing the development of research in Agricultural root cropsand natural science. Paper presented at the National Workshop on SustainableAgriculture, Food Self Sufficiency, Poverty Alleviation and Rural Developmentheld from 22 – 26 May, 2000. NRCRI Umudike, Nigeria.Reijntjes, C; Haveskort, B. and Waterbayer, A. (1992). Farming for future. Anintroduction to low external inputs and sustainable Agriculture. The McMillanPress, Leuden ; ILEIA. Netherlands, pp.250.SAS Institute, (1989). Statistical Analysis System. User’s guide. Statistics ASAInstitute, Cary N. C.Sommerfeldt, T. G. and Chung, C. (1985). Changes in soil properties under annualapplications of feed lot manure and different tillage practices. Soil SocienceSociety. Annual Journ. 49 : 983 – 989.Thomas, G. W. 1996. Soil pH and Soil Acidity. In: D. L. Sparks (Editor) Pp 475 – 490.Methods of Soil Analysis Part 3 – Chemical Methods, SSSA Book Series 5,Madison, Wisconsin, USA.Woolfe, J. A. (1992). Sweet potato and untapped food resources. Pub. in collaborationwith the CIP, Peru, Cambridge, University Press.Vivekananda, M. and Fixen, P. E. (1990). Effect of large manure application on soil Pintensity. Comun. Soil Plant Analysis 21 : 287 – 293.

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 44Table 1 Physico-chemical properties of the soil at the two locations before the studySoil Properties Umudike UturuSand (%) 82.0 82.1Silt (%) 11.0 4.0Clay (%) 8.2 13.9Texture Sandy-Loam Sandy-LoampH (H 2 O) 4.82 4.93pH (INKCl) 3.99 4.32Organic Carbon (%) 1.33 1.22Organic Matter (%) 2.29 2.10Total Nitrogen (%) 0.11 0.084Available P (ppm) 11.01 7.11Exchangable CationsPotassium (Cmol + kg -1 ) 0.133 0.070Sodium (Cmol + kg -1 ) 0.30 0.26Calcium (Cmol ++ kg -1 ) 3.11 4.11Magnesium (Cmol + kg -1 ) 1.20 2.80Exchangeable Acidity (Exch. Al & H) 1.82 0.81Effective CEC 6.21 5.33Base Saturation 70.35 80.31Table 2Some chemical composition of cow dung used in the studyCow dung Composition ConcentrationNitrogen (%) 1.61Phosphorus (%) 0.70Potassium (%) 0.53Magnesium (%) 0.91Calcium (%) 2.71Sodium (%) 0.50

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 45Table 3. Effect of cow dung and NPK fertilizer on the chemical properties of the soil atUmudike location.Soil properties T 1 T 2 T 3 T 4 T 5 T 6 SE +pH (H 2 O) 4.9 4.8 5.0 5.0 4.9 4.8 0.1pH (INKCl) 4.2 4.0 4.2 4.3 4.2 4.1 0.1OC (%) 2.29 2.87 2.82 2.87 2.79 2.17 0.029OM (%) 2.61 2.18 2.35 2.32 2.28 2.16 0.119N. (%) 0.12 0.10 0.14 0.16 0.12 0.09 0.021P (ppm) 12.58 11.55 12.15 12.10 11.61 9.05 1.182K (Cmol + kg -1 ) 0.12 0.13 0.14 0.14 0.13 0.09 0.009Na (Cmol + kg -1 ) 0.29 0.32 0.30 0.30 0.29 0.28 0.058Ca (Cmol ++ kg -1 ) 4.46 3.20 3.85 3.75 4.39 2.61 0.341Mg (Cmol ++ kg -1 ) 3.12 2.60 2.41 2.39 2.39 2.04 0.385EA 1.32 1.00 1.17 1.09 1.27 1.31 0.148ECEC 7.19 6.96 7.90 8.25 7.84 6.49 0.485BS 65.59 65.10 63.48 65.56 64.40 60.26 0.762T 1 = 3.7t/ha cow dung, T 2 = 400kg/ha NPK, T 3 = 1.9t/ha cow dung + 200kg/ha NPK, T 4 = 0.9t/ha cow dung + 300kg/ha NPK, T 5 =2.8t/ha cow dung + 100kg/ha NPK, T 6 = control (no treatment)Table 4. Effect of cow dung and NPK fertilizer on the chemical properties of the soilat Uturu location.Soil properties T 1 T 2 T 3 T 4 T 5 T 6 SE +pH (H 2 O) 4.8 4.7 5.1 5.1 5.0 4.6 0.1pH (INKCl) 4.4 4.3 5.0 5.1 5.0 4.2 0.1OC (%) 3.32 3.06 3.03 3.00 3.08 2.60 0.031OM (%) 2.60 1.59 2.78 2.63 2.15 1.05 0.111N. . (%) 0.21 0.19 0.32 0.30 0.29 0.09 0.032P (ppm) 12.68 10.70 12.60 12.65 12.48 10.63 1.176K (Cmol + kg -1 ) 0.14 0.16 0.20 0.21 0.19 0.07 0.010Na (Cmol + kg -1 ) 0.28 0.29 0.28 0.25 0.28 0.27 0.055Ca (Cmol ++ kg -1 ) 3.59 3.40 3.75 3.61 3.60 3.40 0.296Mg (Cmol ++ kg -1 ) 3.09 3.00 3.41 3.40 3.33 2.68 0.359EA 1.28 1.21 1.18 1.15 1.14 1.20 0.163ECEC 7.96 6.88 8.66 8.63 7.00 6.40 0.329BS 60.55 65.10 73.40 70.64 70.45 61.08 0.950T 1 = 3.7t/ha cow dung, T 2 = 400kg/ha NPK, T 3 = 1.9t/ha cow dung + 200kg/ha NPK, T 4 = 0.9t/ha cow dung +300kg/ha NPK, T 5 = 2.8t/ha cow dung + 100kg/ha NPK, T 6 = control.

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 46450400350s.e(a) UMUDIKE (b) UTURUsUMUDIKEUTURU454035( a) UM UD I KE (b) U TU RU LEGENDUM UDIKEs.eUTU RULeaf area (cm) 2300250200150Number of L eaves30252015s.100105050T1 T2 T3 T4 T5 T6 T1 T2 T3 T4 T5 T6Fig. 1 Effect of different rates of cow dung and NPKTreatmentsfertilizers on leaf area of sweet potato in (a)Umudike and (b) Uturu0T1 T2 T 3 T4 T5 T6 T1 T 2 T3 T4 T5 T6Fig. 2 Effect of different Treatments rates of cow dung and NPKfertilizer on number of leaves of sweet potato in (a)Umudike and (b) UturuVine length (cm)10 09080706050403020100s.e(a) UMUDIKE (b) UT URUT1 T2 T3 T4 T5 T6 T1 T2 T3 T4 T5 T6Treatmentss.eUMUDIKEUTURUNumber of branches8765432s.e(a) UMUDIKE (b) UTURUs.LEGENDUMUDIKEUTURU1Fig. 3 Effect of different rates of cow dung and NPKfertilizer on length of sweet potato vines at (a)Umudike and (b) Uturu0T1 T2 T3 T4 T5 T6 T1 T2 T3 T4 T5 T6TreatmentsFig. 4 Effect of different rates of cow dung and NPKfertilizer on number of branches of sweet potato in(a) Umudike and (b) UturuWhere;T1 = 3.7t/ha, T2 = 400kg/ha NPK, T3 = 1.9t/ha cow dung + 200kg/ha NPK, T4 = 0.9t/ha cow dung +300kg/ha NPK, T5 = 2.8t/ha cow dung + 100kg/ha NPK, T6 = Control

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 47Nitrogen uptake (kg /h a)121086420(a) UMUDIKE (b ) UTURU LEGENDUMUD IKEUTURUs.es.T1 T2 T 3 T 4 T 5 T 6 T 1 T2 T3 T4 T5 T6Phosphorus uptake (kg/ha)43. 532. 521. 510. 5s.e(a)UMUDIK(b)s.UMUDITreatments0T1 T2 T3 T4 T5 T6 T1 T2 T3 T4 T5 T6TreatmentsFig. 5 Effect of different rates of cow dung and NPKfertilizer on nitrogen uptake by sweet potato in (a)Umudike and (b) UturuFig. 6 Effect of different rates of cow dung andNPK fertilizer on phosphorus uptake by sweetpotato in (a ) Umudike and (b) Uturu14(a) UMUDIKE (b) UTURU LEGEND10(a) UMU D IK E ( a) U TUR U LE GEN DUMUDIKEPotassium uptake (kg/ha)98765432s.es.UM UDIK EUT UR UCalcium uptake (kg/ha)1210864s.es.UTU RU10T1 T2 T3 T4 T5 T6 T1 T2 T3 T4 T5 T62Treatments0T1 T2 T3 T 4 T5 T 6 T1 T 2 T3 T 4 T5 T 6TreatmentsFig. 7 Effect of different rates of cow dung and NPKfertilizer on potassium uptake by sweet potato in (a)Umudike and (b) UturuFig. 8 Effect of different rates of cow dung and NPKfertilizer on calcium uptake by sweet potato in (a)Umudike and (b) Uturu

PAT 2011;7 (1): 36-48 ISSN: 0794-5213; Asawalam and Onwudike, Complementary Use of Cow Dung....... 488(a) UM UD IK E ( b) UT UR U L EG EN DLEGENDMagnes ium uptake (kg/ha)76543210s.es.eUMUDIK EUTURUT1 T2 T3 T4 T5 T6 T1 T 2 T 3 T 4 T 5 T 6TreatmentsTuber weight (t/ha)98765432s.e(a) UMUDIKE ( b) UTURUs.UMUDIKEUTU RU10T1 T2 T3 T4 T5 T6 T1 T2 T 3 T 4 T 5 T6TreatmentsFig 9 Effect of different rates of cow dung and NPKfertilizer on magnesium uptake by sweet potato in(a) Umudike and (b) UturuFig. 10 Effect of different rates of cow dung andNPK fertilizer on the tuber weight of sweet potato in(a) Umudike and (b) UturuWhere;T1 = 3.7t/ha, T2 = 400kg/ha NPK, T3 = 1.9t/ha cow dung + 200kg/ha NPK, T4 = 0.9t/ha cow dung +300kg/ha NPK, T5 = 2.8t/ha cow dung + 100kg/ha NPK, T6 = Control