Valorização agronômica da água residuária de suinocultura: uso de biofertilizante na cultura do milho de segunda safra

Abstract

Because corn requires a substantial amount of fertilizer, the high cost of the nutrients used throughout the corn production cycle has an impact on its final profitability. Therefore, using alternative fertilizers can increase production profit. A biofertilizer derived from the anaerobic digestion of swine wastewater, which is harmful to the environment if handled incorrectly, can be used as an alternative. Anaerobic digestion is a technology that can combine waste stabilization with the generation of a clean, renewable energy source and nutrient-rich agricultural input, namely, biogas and biofertilizer. Thus, the objective of this paper was to assess the use of biofertilizer derived from the anaerobic digestion of swine wastewater as a source of nutrients for the second-crop corn. The experiment was carried out on a 13x40m plotted area divided into 20 plots. In quadruplicate, five treatments were evaluated. The treatments included two doses of biofertilizer (100 and 50%) based on the corn’s nutritional requirement of nitrogen (N) and two forms of application, on the plant (P) and on the base (B), as well as a control treatment, that used only mineral fertilizers. When 50% of the plants displayed female inflorescences, productivity, growth analysis (five collections every 20 days), and foliar diagnosis were evaluated. In the productivity analysis, all treatments showed equal values (p<0.05), but in the growth analysis, the treatments that received 100 percent N via biofertilizer (100%NP, 100%NB) and mineral fertilization (control) stood out in most of the indexes. All treatments had satisfactory Nitrogen values among the values found in the foliar diagnosis, except for Phosphorus, which had values far below the standards established in the literature, but such values did not differ (p<0.05) between treatments. Finally, it is concluded that using biofertilizer to replace completely or partially nitrogen requirements for second-crop corn is feasible because it has no effect on crop yield.