Uso de resíduos com potencial neutralizante de acidez do solo

Abstract

In Brazil there are naturally acidic and nutrient-poor soils, factors that directly affect agricultural production. The practice used to mitigate such impacts is liming, in which calcium and magnesium-based products are added to the soil, however, the acquisition costs of these products can be high, which requires smaller and as efficient added value sources as the commercialized ones. The aim of this study was to evaluate the effect of applying alternative sources of calcium oxides, which in turn act on the formation of ions and anions that act to reduce acidity in a Yellow Latosol. The study was carried out at the Trace Metals Laboratory of the Federal University of Recôncavo da Bahia (UFRB), Bahia, Brazil. The Oxisol was sampled at a depth of 0-20 cm in an area under eucalyptus cultivation and characterized for: pHH2O, pHKCl, Ca2+, Mg2+, Al3+, H+Al, Na2+, K2+ and P. SB, CTCpH7 were also determined, CTCe, V% in%. An experimental design in a 6 x 4 x 4 factorial scheme was established with five sources of calcium carbonates (eggshell, oyster shell, marble residue, calcitic and dolomitic limestone and a control treatment) in four incubation periods (30, 60, 90 and 120 days). During each incubation period, the same soil characteristics before incubation were evaluated. The results indicated that after the treatments incubation, the pH increased in all treatments in the first 30 days, highlighting the Oyster Shell and Egg Shell sources, which obtained the best results. For the availability of Ca2+, Egg Shell, Oyster Shell and Calcitic Limestone stood out in the supply of this element, an expected result due to their composition, and dolomitic limestone followed the supply pattern of marble. The application of oyster shell was the most effective treatment to increase pH and Ca2+ and Mg2+ content, in addition to reducing Al3+ activity in the soil.