Using Geotechnology to Estimate Annual Soil Loss Rate in the Brazilian Cerrado

Soil erosion is a serious environmental problem that has adversely affected the world’s food production through the reduction of land productivity and water availability. The present study estimated annual soil loss rate and its spatial distribution in the most important Brazil’s agricultural region, the Brazilian Cerrado, using Revised Soil Loss Equation (RUSLE) model into Geographic Information System (GIS) framework. For this purpose, the soil erosion annual rate was determined in function of RUSLE model factors: rainfall erosivity (R), soil erodibility (K), topography (LS), crop management (C) and supporting conservation practice (P). All factors were obtained from literature. They were processed and integrated into a GIS, resulting in a map of annual soil loss rate. The methodology applied showed acceptable precision and it was possible to identify the most susceptible areas to water erosion. The average estimated rate of soil loss for the entire Cerrado was 12.8 t∙ha−1∙yr−1. Large part of the Cerrado is under low soil loss zone corresponding to 79.91% of total surface area, while 15.70%, 3.74%, and 0.66% are under moderate, high, and very high, respectively. The average estimated rate of soil loss in areas used for silviculture was 52.1 t∙ha−1∙yr−1. In semi-perennial, perennial, and annual crops cultivation were 29.3, 23.9, and 9.8 t∙ha−1∙yr−1, respectively, while in the pasture was 13.3 t∙ha−1∙yr−1. Except for annual crops, all farm and silviculture areas showed average soil loss ranging from moderate to high rate. These results suggest that the implementation of more effective management techniques and conservation practices are necessary for the Cerrado to maintain and to improve land productivity by ensuring national and international food demands.