Economic nitrogen rate for fertigation of green corn crop in the Brazilian semiarid

Abstract

Abstract: The objective of this work was to determine the nitrogen rate for fertigation associated with the maximum productivity of green corn (Zea mays) with a lower production cost, in two harvest seasons in the Brazilian semiarid region. The experimental design was a randomized complete block with four replicates, and the treatments consisted of four N rates (0, 80, 160, and 240 kg ha-1) in form of urea, applied via drip irrigation. The used cultivar was the Bt Feroz hybrid. The evaluated characteristics were: number and mass of marketable ears, gross income, net income, and rate of return. The greatest amounts of marketable ears were reached with 152.52 kg ha-1 N in summer (41,183.84 ears per hectare) and 190.31 kg ha-1 N in winter (53,291.25 ears per hectare). In the two harvests, there was a variation in production costs between R$ 2,422.12 ha-1 and R$ 3,320.95 ha-1 without N and with 240 kg ha-1 N, respectively. The winter harvest showed higher productivity and profitability of green ears with fertigation with 160 kg ha-1 N. In the Brazilian semiarid, the maximum productivity of green corn with the lowest production cost is reached with fertigation with 90 kg ha-1 N, in both harvests.