Aplicação de gesso de dessulfuração de gases de combustão na melhoria de atributos químicos de solos impactados pela mineração de carvão e efeitos sobre atributos de plantas

Abstract

FGD-gypsum is a solid residue from the removal of sulfur from exhaust gases in coal-fired plants. This residue is rich in CaSO4 and is very similar to agricultural gypsum, due to the ability to bring Ca and S to the soil, in addition to having the potential to change the pH of the soil due to the alkalizing agents used during the process of removing sulfur from the current gaseous.Thus, the objective of this work was to evaluate the use of FGD-gypsum as an acidity corrective in soils impacted by coal mining and in soils for agricultural use, as well as its effect on the chemical attributes of the soil, the chemical composition and the attributes of plant development. Two studies were carried out, the first study was conducted in a greenhouse using two soils impacted by coal mining, where oats and ryegrass were grown. The second study was carried out in the field in agricultural Ultisol under soybean cultivation, associating the application of lime and agricultural gypsum to FGD-gypsum.In study 1, FGD-gypsum reduced the active and potential acidity of both studied soils, as well as the exchangeable Al content and provided an increase in the levels of Ca, Mg, Zn and Cu, without an increase in the concentration of trace. In study 2, there was a synergy between the joint application of lime and agricultural gypsum n the variables pH SMP, K, S, Ca, C.E. and V% of the soil; FGD-gypsum increased the availability of P, decreased toxic Al, increased Ca and S in the profile, and increased the levels of Mg in depth. In this way, the application of FGD-gypsum is a relevant alternative for improving the chemical attributes of soils impacted by coal mining, as well as for agricultural soils in the lowlands of southern Brazil.