Vinhaça como biofertilizante para fornecimento de potássio a soja com sucessão de milho e capim e impactos sobre o solo

Abstract

Vinasse is a liquid organic residue from the fermentation process to obtain ethanol, it is rich in potassium, an essential nutrient for plant development. Vinasse is a class II (non-hazardous) waste characterized by the absence of heavy metals and pathogenic contaminants so it can be used as a biofertilizer in several agricultural crops. The aim of this study was to study the effect of vinasse application in "in natura" and "concentrated" as a source of potassium in the succession of soybean to the corn and grass consortium, as well as to evaluate its impact on soil attributes. The experimental design used was a randomized block, with five treatments and four replications. The treatments were distributed according to the vinasse conditions (in natura and concentrate), applied at sowing and cover associated with mineral fertilization with potassium chloride at sowing. At the end of each production cycle, crops were evaluated to determine their productivity parameters. Soil samples were collected to evaluate the potassium content in the soil profile at the end of each soybean cycle. In the third year, the end of the experiment, sampling was carried out in the areas in order to evaluate the biological attributes of the soil after application of vinasse to soybean. Vinasse can be used as a biofertilizer to replace or supplement mineral fertilization with potassium chloride in soy, regardless of its application form (fresh or concentrated). The residual effect of the application of vinasse in soy provided increases in corn productivity and in the dry matter production of the aerial part of Marandu grass, without compromising the quality of the material, resulting in high levels of crude protein in the forage. The application of vinasse in soybean cultivation, after three years, caused a reduction in carbon and an increase in nitrogen in the soil's microbial biomass.