The effects of vinasse sprinkling and vinasse plus nitrogen on sugarcane yield and soil chemical characteristics were evaluated over seven consecutive years. The trial was laid down on 08-11-1995 at Usina Sao Jose da Estiva, Sao Paulo state on Yellow-Red Latosol, allic, sandy texture (sandy loam allic, Typic Hapludox). The experiment was established in a second cut of RB72454 variety, and it was harvested for seven years up till 2002. The statistical design was a factorial 4x4 randomised blocks with four repetitions of vinasse doses (0, 100, 200 and 300 m~3/ha) and nitrogen (0, 50, and 150 kg/ha). The experimental plots were seven sugarcane lines 10 m long. The five central sugarcane lines were harvested for sugarcane yield (t/cane/ha). After each harvest, the same treatments were re-applied to the respective plots. The data analysis leads to the following conclusions: a) vinasse is a soil fertility improver that promotes deep root development; b) it promotes a nutrient lixiviation, specially, calcium to 75 cm deep, magnesium to 250 cm deep, sulfur and potassium in high concentrations to 350 cm deep; c) the sugarcane yield was significantly improved as vinasse doses increased; d) the interaction of vinasse and nitrogen doses proved to be more efficient than vinasse alone regarding sugarcane yield; e) nitrogen doses should be reduced as vinasse doses increase, and an economic evaluation is recommended to obtain the adequate nitrogen dose.
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