NITROGEN MANAGEMENT IN SUGARCANE AND ITS INFLUENCE ON YIELD, PROFITABILITY AND LEACHING LOSSES

Abstract

The excessive use of nitrogen (N) in sugarcane (Saccharum officinarum L.) is a source of contamination for aquifers. The objective was to evaluate sugarcane yield, as well as profitability and amount of N leached resulting from the application of different split N doses. Three N doses (250, 200 and 150 kg ha-1) and three different application numbers (2, 3 and 4) were evaluated using a factorial design in randomized blocks. When the N dose was divided in three and four applications yields higher than 125 ton ha-1 were obtained. The greatest benefit-cost-ratio (1.8) resulted from using 150 kg ha-1 of N divided in three applications. The lowest N losses due to leaching were obtained using 150 kg ha-1 of N divided in three (16.8 kg ha-1) and four (15.4 kg ha-1) applications. Low N doses divided in three or four applications did not reduce sugarcane production; furthermore, it was more profitable and had a lower environmental impact by reducing N leaching.