SOIL, ORGANIC MATTER AND NUTRIENTS LOSSES BY WATER EROSION IN A SLOPE WITH SUGARCANE STRAW, IN GUARIBA, STATE OF SAO PAULO

The interril erosion results of the disaggregation caused by the impact of the rainfall on the surface and by the superficial transport of the disaggregated soil particles, where there are the organic matter and the nutrients for the agricultural production. The present work aimed to evaluate the soil, organic matter and nutrients losses of a slope located in an area of distrofic Oxisol, cultivated with sugarcane and submitted to the automated crop. Experimental portions were submitted to the action of a simulated rain of 60 mm h(-1) intensity, for 65 minutes. Analyses of the erosion sediment were made to determine the solution volume and soil, organic matter and nutrients losses. There were larger soil, organic matter and nutrients losses in the sediment of the portions with 0% and 25% of sugarcane straw coverage. On average, the losses were significantly reduced in the portions with 75% and 100% of sugarcane straw coverage. The results allowed concluding that the sugarcane straw coverage above 50%, in the crop area, reduces the soil and organic matter loss as well as the concentration of nutrients in the erosion sediment.