Ederson Antonio Civardi
Abstract:
Urea applied to soil surface presents high N losses due to NH3 volatilization. The use of polymers covering urea granules is a management alternative to reduce volatilization losses. The present work was developed in a commercial corn crop (Zea mays L.), in a 6% clay Quartzarenic Neossol, in the 2007/2008 crop in Jataí, GO. The objective of this work was to evaluate the efficiency of combining two types of fertilizers: common urea and polymer coated urea; with the application form: incorporated and superficial and of different doses of these nitrogen fertilizers. In addition to the use of two commercial products used to supply seed micronutrients (MVS) to maize. The experimental design was a randomized complete block design with 4 replications and 6 treatments. The MVS were applied at the time of corn sowing, while the treatments with urea were applied at maize V5 stage. Production components, production cost estimate, gross revenue, profit obtained and the ratio between revenue on production costs (RRCP) were evaluated in order to contribute to the decision making about the best management. There was no influence of treatments with MVS on all variables studied. The highest grain yield (8,278 kg ha -1) was obtained with common urea incorporated into the soil at its highest dose and where it presented the best profit 779.44 R $ ha-1 and the best RRCP of 1.37. This same treatment provided an increase of R $ 365.94 ha-1 compared to polymer-coated urea in
its highest dose is applied to the surface.
