Produtividade e qualidade física de grãos : resposta da cultura do milho à aplicação de adubo em diferentes doses

Abstract

The importance and expansion of corn cultivation has been expressive in recent years, due to the appreciation of the market. In this sense, producers have sought to increase productivity through investments in the production system, given the good prospects. With this, the objective was to evaluate the profitability of the corn crop and some qualitative aspects of the grains as a function of increasing doses of N-P-K (20-00-20) fertilizer. The experiment was carried out in a commercial field, in Lucas do Rio Verde-MT, in a randomized block design, with four treatments with three replications. The cultivar evaluated was the 30s31 hybrid of Pionner intercropped with Brachiaria (Brachiaria ruziziensis) with early growth. The doses used were: 300 (producer standard); 400; 500 and 600 kg ha-1 , in two applications (seeding and in V4-V6), the first being 150 kg ha-1 . After cultivation, productivity was quantified, physical and physiological quality of grains and gross profitability, considering productivity, corn price and fertilizer expenses. The results showed that higher doses of fertilizer result in higher yields. The same did not occur for the physiological quality, which is influenced by several factors. There was a water deficit in the stages of formation and filling of the grains, affecting the physical properties evaluated. The higher dose of fertilizer resulted in higher gross profitability.