Avaliação dos atributos químicos e biológicos de um Planossolo Háplico tratado com resíduo industrial visando a produção de oleaginosas

Abstract

The development of large urban centers resulted in an inordinate increase in the generation of residues. Adequate disposal of the waste is a challenge that includes solving environmental and economical aspects. The objectives of this study were to assess impact on soil chemical attributes, plants nutrients availability and on heavy metals, and soil fauna. It was used an area cultivated with sunflower (Helianthus annuus L.), and soybean (Glycine max), of a Fragiudult soil, treated with sewage sludge generated by the company Petroflex (denominated LETRIP). The experimental design was in randomized blocks. The treatments consisted of control and equivalent doses of 50, 150 and 300 Mg ha-1 of LETRIP. The level in the soil of Ca, Mg, P, K, organic C and total N, and pseudo total levels of Cd, Fe, Mn, Pb, Cu and Zn, were determined. These measurements were made in samples taken before and after each planting (8, 195 and 600 days after the residue application), at depths of 0-15, 15-30, 30-60 and 60-90 cm. In the plants, the levels of nutrients and heavy metals were measured. The epigeous fauna (pitfall) and soil macrofauna (TSBF) were evaluated at 0-15 and 15-30 cm depths. The LETRIP usage resulted in an increase in the levels of organic matter, nutrients and heavy metals in soil, and in the concentration of macronutrients and heavy metals in the sunflower and soybean crops, with a consequent increase in their productivity. There was leaching of all chemical elements measured to deeper sections of the soil. The density of epigeous fauna and the diversity index were not affected by the addition of the residue. However, there was a positive effect on diversity, equitability, and richness of soil macrofauna.