ECONOMIC ANALYSIS OF MAIZE GROWN UNDER INCREASING NITROGEN DOSES IN SUCCESSION TO INTERCROPPED PASTURES

The aim of this work was to carry out an economic analysis of production systems with the use of cold season pastures followed by maize cultivation with surface application of increasing doses of nitrogen fertilizer. The treatments were: black oat + 200 kg of N ha-1 (Bo+N); black oat + white clover (Bo+Wc); black oat + vetch (Bo+Ve); black oat + red clover (Bo+Rc); and black oat + forage peanut (Bo+Fp). Experimental randomized block design was used, with four replications. The forage species were evaluated as to dry matter production, chemical-bromatological composition, estimated milk production (kg ha-1) and gross income (R$ ha-1). Maize was cultivated in succession, with doses of 0, 100 and 200 kg of N ha-1, in a split-plot design. Among the profitability indices evaluated, the gross margin (R$ ha-1) stands outs. The data were submitted to analysis of variance and the means were compared through Tukey's test at 5% probability. In the pasture phase, the Bo+N treatment presented higher gross income. In the cropping phase, the gross margin was higher in the Bo+Ve treatment, but it did not differ from the Bo+N treatment. In terms of system, the best economic result was obtained with the Bo+N treatment.