Agronomic performance of urea in pastilled compositions applied on maize fertilization

Abstract

Urea pastillation is a technology that allows the composite mixture with other elements like sulfur and zinc. This study aimed to provide recommendations of N rates, and to assess the agronomic performance of N fertilizers, including pastille urea and its composition associated with S and Zn, top-dressed on maize. Two experiments were set up in the harvests of 2014 and 2015 in an Acrisol and a Lixisol. The experimental design was the randomized blocks with three replicates in a split-plot arrangement and an additional treatment (no N). In the plot, three N applications rates were tested (75, 150 and 300 kg ha-1); while in the subplots, seven fertilizers were tested, including conventional and pastilled ones. The greater was the N rate applied, the higher were the leaf N content and grain yield of maize. The S content in the leaves increased with the increasing S doses applied with the tested fertilizers. Yields with ammonium sulfate were higher than with prilled urea, pastille urea and pastille urea with elemental S in the harvest mean on the Haplic Lixisol. The rate that corresponded to the maximum economic efficiency for UR was 128 and 119 kg N ha-1 for Haplic Acrisol and Haplic Lixisol, respectively. The recommended dose of ammonium sulfate was 119 kg ha-1, since it provided the greater incomes for both sites.