Resposta da cultura da soja a fontes e a doses de fertilizante fosfatado

Abstract

The soybean (Glycine max) crop is Brazil's main export agricultural product, accounting for most of the agribusiness in the country and of great importance in the development of our economy. The objective of this study was to evaluate the response of soybean cultivation to phosphorus sources and doses of protected phosphate fertilizer (Top-Phos [marca registrada]). The work was carried out in Ampére, community of the interior of the municipality of Honório Serpa - PR. Two experiments were carried out, both with a randomized block design, with 5 replicates of each treatment, totaling 40 plots. Experiment 1 was composed of phosphorus sources, distributed as follows: Witness (0 kg ha-1 P2O5); Simple Superphosphate (100 kg ha-1 P2O5); Thermophosphate (100 kg ha-1 P2O5); Top-Phos [marca registrada] (100 kg ha-1 P2O5). Experiment 2 was composed of doses of protected phosphate fertilizer (Top-Phos [marca registrada]), distributed as follows: 0, 25, 50, 75 and 100 kg ha-1 of P2O5. The evaluations were performed at harvest and the evaluated variables were: 1) plant population per ha-1, 2) number of pods per plant, 3) number of grains per pod, 4) mass of one thousand grains and 5) grain yield. The results were evaluated through analysis of variance using the statistical software SISVAR and when significant, the effects of quantitative treatments were compared through regression analysis. While the effects of qualitative treatments were compared by the Tukey test at a 5% error probability level. For the experiment of phosphorus sources, there was no statistical difference between the fertilizers used, only of these in relation to the control. For the experiment of doses of the fertilizer Top-Phos [marca registrada] there was a quadratic response to grain yield as a function of the P2O5 doses and maximum technical efficiency (MET) of the fertilizer is at the dose of 109 kg P2O5 ha-1.