Adubação antecipada na cultura da soja com superfosfato triplo e cloreto de potássio revestidos por polímeros

Abstract

The objetive of this work was to compare times and application rates of triple superphosphate (TSF) and potassium chloride (KCl) with and without polymer coating on soybean yield performance in the cerrado environmental conditions. The experiment was conducted in Rio Verde, GO, in an Oxisol. Treatments were arranged in a randomized block design, in factorial 2x2x2+1. The first factor consisted by fertilizer TSF and KCl coated or not by polymer, the second by two doses of phosphorus and potassium (40 + 40 and 80 + 80 kg ha-1 P2O5 and K2O, respectively), and the third by two times of application fertilizer (15 days before sowing and at sowing). It also includes a treatment control without fertilization. Biomass yield, grain yield and yield components were evaluated. There was a response to the application of fertilizer P and K in fresh mass production and productivity, with the absence of fertilizer detrimental to the development of soybean. The broadcast application of superphosphate and potassium chloride coated polymer 15 days before sowing promoted dry matter yield, number of pods per plant and grain yield of soybeans compared to conventional fertilizer. When applied at sowing, the conventional fertilizer and slow release fertilizers promoted the same dry matter yield and grain yield of soybeans.