Dinâmica e disponibilidade de nutrientes e metais pesados em área de Planossolo tratado com resíduos industriais

Abstract

As a consequence of the industrial progress in the last decades it has been generated great amount and variety of residues. An alternative for the final disposition of this matérial has been your application to the soil. With the increase of the costs of the commercial fertilizers and the shortage of close available areas to the great urban centers for the spilling of the industrial and urban residues, the use of these matérials in the agriculture became an attractive alternative so much of the point of view of recycling of nutrients as of the economical point of view. This research had for objective: (i) to Study of the nutrients dynamic in the soybean culture due to the addition of the residues generated for the Petroflex Industry and Comércio S/A (residue LETRIP) and PURAC Síntese Industry and Comércio Ltda (residue Ferkal) (ii) to verify the solubility of heavy metals in soil treated with the industrial residues LETRIP and Ferkal. The experiment was conducted in area of a Planosols Haplic where was applied the residues, LETRIP and Ferkal in the doses 0, 25, 50 and 100 Mg ha-1 and 0, 3 and 6 Mg ha-1, respectively. The treatments were composed of the combination of Ferkal and LETRIP. Soybean was cultivated (cultivar celeste). The experiment was constituted of 12 treatments and three repetitions, totaling 36 plots arranged in blocks. Soil samples were collected in the depths 0-10, 10-20, 20-30, 30-60 and 60-90 cm, in the time zero (before the application of the residues) and to the 30 and 120 days after the application of the residues. In those samples were determinated pH, aluminum, calcium, magnesium, sodium, potassium, phosphorus, carbon and determination of concentrations totals of Mn, Fe, Cu, Zn, Cd and Pb. In the soybean culture were evaluated the following parameters: production of grains and the concentrations totals of Mn, Fe, Cu, Zn, Cd and Pb, in the soil, root, shoot and grain of the soybean. The application of the Ferkal and LETRIP residues caused increase of the macronutrients and of the concentrations of heavy metals, however the tenors of these heavy metals were below the level critic of contamination of the soil. The concentrations of heavy metals in the soybean were maintained in the normal range of the plants in the treatments where the doses of 6 Mg ha-1 of Ferkal and/or 100 Mg ha-1 of LETRIP. The application of LETRIP residue increased the yield of grains of the soybean significantly.