Atributos químicos dos solos sob diferentes usos e manejos em uma sub-bacia no noroeste do Estado de S?o Paulo

摘要

Changes resulting from the soils use and cropping affect the structure and biological activity, then interfeing on the chemical attributes. This research had the objective of evaluating the soil chemical attributes of sub-river basin Jardim Novo Horizonte, in order to verify the effect of different soil uses and management. Soils in the sub-river basin are Red Oxisol and Red-Yellow Alfisol. Six and four spots were evaluated in the first and second soils, respectively, totaling 10 spots along the sub-river basin with five replications each. The following systems were sampled from the Oxisol: area cropped with mango, four areas under pasture and area with annual crop. Two areas under pasture, one with annual crop and another with forest fragment area were sampled in the Alfisol. The Alfisol showed better chemical attributes compared with Oxisol, higher content of organic matter, providing better support capacity and, consequently, greater the soil vegetal cover. Annual crops area had better conditions soils fertility for both, and the pastures worst, due to inadequate management. The chemical degradation of the Oxisol by the use and management, mainly in the areas cultivated with pasture, causes more susceptibility of soil erosion for the sub-river basin studied.