Nitrogen fertilization of maize with enhanced-efficiency fertilizer

Abstract

Urea fertilizers coated with polymers are used to optimize nitrogen (N) uptake by crops. However, there are many types of polymers that can be used for coating, leading to differences in observed results. Consequently, validation of this technology to guarantee its viability in agriculture is necessary. The objective of this study was to evaluate effects of ammonium- and nitrate-N levels in the soil, maize yield and nutritional status, N fertilization efficiency with Policote® urea coating, and different N doses under various soil and climatic conditions. Three field experiments were carried out to compare the performance of common urea with Policote® coated urea. A (2 x 4) + 1 factorial design with two N sources (common urea and Policote® coated urea), four N doses, and a control treatment (without N) was used. The results showed that Nitrate-N levels in the soil were not affected by the treatments. However, the ammonium-N levels was increased with N fertilization. Higher levels of soil ammonium-N contents were observed in treatments with Policote® coated urea. Foliar nitrogen levels were increased linearly with N doses only in one of the experiments. Nitrogen fertilization significantly increased maize yield. Higher yield and N fertilization efficiency were observed in treatments with Policote® coated urea than with common urea.