ESCOAMENTO SUPERFICIAL E RISCO DE EROSÃO DO SOLO NA ...

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SURFACE RUNOFF AND SOIL EROSION RISK IN THE SUB-WATERSHED JARDIM
NOVO HORIZONTE, ILHA SOLTEIRA-SP, BRAZIL. Botucatu, 2010. 88 p. Dissertação
(Mestrado em Agronomia/Irrigação e Drenagem) – Faculdade de Ciências Agronômicas,
Universidade Estadual Paulista.
Author: CARLA DEISIANE DE OLIVEIRA COSTA
Adviser: ANTÔNIO DE PÁDUA SOUSA
Co-Adviser: MARLENE CRISTINA ALVES
2 SUMMARY
The sub-watershed Jardim Novo Horizonte is located in Ilha Solteira-SP, Brazil, in the
northeast of São Paulo State. This region shows grave environment problems, such as soil
erosion and river sedimentation, as well as few native forests. Soils in the sub-watershed are
classified as Red Oxisol and Red-Yellow Alfisol. This research had the objective of studying
soil physical attributes that affect water dynamics, drainage capacity of the sub-watershed and
surface runoff in the sub-watershed Jardim Novo Horizonte, contributing to identify areas of
erosion risk and soil degradation. Soil physical and chemical properties were evaluated under
different cropping systems. Sampling took place in ten spots along the sub-watershed. Seven
and three samples were taken from the Oxisol and Alfisol, respectively. Five replications were
evaluated for each place. The following systems were sampled from the Oxisol: area cropped
with mango, four areas under pasture, area with annual crop and degraded area with fragments
of native forest in a transition between the Oxisol and the Alfisol. Two places under pasture
and annual crop were sampled in the Alfisol. Results of physical and chemical attributes, as
well as water dynamics in soil, were submitted to combined analysis for each soil class and to
the Tukey test, using the SAS program. The simulation of surface runoff was carried through
using the SIMHUNER program. Physical and chemical degradation of the Oxisol, caused by
soil use and management, lead to higher erosion risk in the sub-watershed Jardim Novo
Horizonte. Moderate and higher rates of water infiltration in soil cause low surface runoff. The
sub-watershed showed good drainage capacity and low surface runoff. However, some regions