Efeito residual da aplicação de fosfato monoamônio revestido por diferentes polímeros na cultura de milho/Residual effect of monoammonium phosphate coated with different polymers on maize

The use of phosphate fertilizers coated with polymers can reduce losses by phosphorus fixation in the soil, providing the element for a longer period of time. The objective of this study was to evaluate the residual effect of phosphorus rates, and forms of monoammonium phosphate coated with different polymers on production components and grain yield of maize in the first and second harvest. The experiment was conducted in Selviria-MS, in a loamy Oxisol. A randomized block design in a 4 x 4 factorial scheme with four repetitions was used in the experiment: four P2O5 rates (0, 50, 100 and 150 kg ha^sup-1^) applied at sowing, in four forms: conventional monoammonium phosphate and monoammonium phosphate coated with three different polymers. To evaluate the residual effect of these treatments on the maize successor crop, the new crop was sown in the same line of the previous crop. The residual level of phosphorus in the soil increased linearly up to 150 kg ha^sup -1^ P2O5.