Soil erosion related processes in a small sugarcane watershed of Southeast Brazil

Abstract

Brazil is the world's largest producer of sugar and sugarcane ethanol, hence, sugarcane agriculture in the country is quite extensive, covering an area of about 10 million ha of arable land and ranking as the third largest crop after corn and soybean. Nevertheless, our knowledge about the impacts of sugarcane produced in Brazil is still limited, especially for water and soils, and presents a serious obstacle in assessing sugarcane production sustainability. Soil erosion and its implications are some of the neglected environmental problems in sugarcane fields. Thus, this project aims to investigate the erosion dynamics in a small sugarcane catchment of Southeast Brazil. To achieve this goal, a plot of 6 hectares cropped with sugarcane, encompassing a 30 meters of riparian forest bordering a stream was chosen. One pluviometer was installed in an open area near to crop in order to measure the amount and intensity of rain during the rainy season. Surface runoff generation and soil detachment were estimated by plots installed in cultivated and riparian areas. Bathymetry was carried out in the stream channel to estimate the soil mass settled on the stream bed. The sources of organic matter were investigated by carbon (´13C) and nitrogen (´15N) stable isotopic compositions. (AU)