Erodibility factor and loss tolerance of soils of São Paulo state (Brazil)

Abstract

Erodibility factor (K) and soil loss tolerance (T) were determined for Sao Paulo State (Brazil) soils with base on the new Brazilian System of Soils Classification published in 1999. Twenty-five representative profiles from the new soils were studied. Bouyoucos’s expression was used for indirect determination of erodibility factor for A and B horizons. Soil loss tolerance was determined based on Smith and Stamey (1964). The extreme values of erodibility factor for A horizon were 0.4278 and 0.0044 t.ha.h/ha.MJ.mm, respectively for an Ultisol and a Dystric Gleisol. The extreme values of erodibility factor for B horizon were 0.5750 and 0.0038 t.ha.h/ha.MJ.mm, respectively for a Spodosol and an Oxisol. On the other hand, the extreme values of soil loss tolerance were 14.70 (Inceptisol/Entisol) and 3.00 (Ultisol) t/ha.year. It was determined that with the increase of the textural gradient there was a decrease in soil loss tolerance and increase in the soil erodibility factors