Supercalagem: alterações em atributos químicos de um latossolo vermelho-amarelo distrófico

Abstract

Latosols correspond to the great part of the cerrado soils, naturally presenting high acidity, being necessary the liming to correct these soils. However, liming, if performed improperly, can promote overliming. Therefore, the objective of this work was to evaluate the effect of overliming on the chemical attributes of a frank sandy clay texture, Dystrophic Red-Yellow Oxisol. Five treatments were obtained from doses of calcium carbonate p.a. (CaCO3). The experiment was carried out in a completely randomized experimental design with five replicates. Doses of calcium carbonate equivalent were used; 0.0, 1.5; 3.0; 4.5 and 6.0 t ha-1. The following soil chemical attributes were evaluated: exchangeable calcium (Ca2+), potential acidity (H+Al), base sum (SB), base saturation (V%), phosphorus (P), potential cation exchange capacity (CTCpotential) and pH in H2O. The evaluated attributes presented a significant increase as a function of the calcium carbonate doses in the supercaling, except for potential acidity. Overliming increased soil pH to values above 6.5. Liming with high doses of limestone with low Mg causes soil nutritional imbalance.