Determinação dos parâmetros de transporte do potássio em solos fertirrigados com vinhaça

Abstract

The rapid growth of the population has increased the demand for bioethanol and other sugarcane products in Brazil, and this, in turn, raises concern for the care of the environment, starting to use techniques in the process that improve the environment, destination of by-products of these activities. Vinasse is one of the residues generated from alcohol distillation and due to its physicochemical characteristics, it has nutrient contents such as potassium (K+), calcium (Ca2+), magnesium (Mg2+), phosphorus (P), among others. Can act on the soil and plant when being fertigated. The objective of this work was to evaluate the interaction and transport of potassium ion (K+), applied via vinasse, in a dystrophic yellow Ultisol cultivated with sugarcane, in soil columns, thus identifying the possible interactions of adsorption, retention and leaching of this element. The assays were performed in soil columns at the LACS / UFPE Soil Contamination Assessment laboratory. To evaluate the interaction, we used the convection dispersion model (CDE) and the CDE - two site (CDE-2S) sorption model using the CXTFIT program, which allows the experimental data to be adjusted to the model. The CDE-2S model represented well the experimental data of the K+ elution curves for both columns, indicating the existence of chemical non-equilibrium, that is, sorption kinetics. The evaluation model allowed to determine the retention and dispersion capacity of the K+ ion in the soil, which showed that the vinasse dosage for a 0-20 cm layer must be controlled, to avoid its leaching and consequent groundwater contamination.