Efeito da calagem nas características físico-químicas do solo em área cultivada com soja

Abstract

Liming corrects the acidity of the soil, favoring the development of the plant's root system and ensuring that nutrients are used. However, excessive liming can affect clay dispersion, leading to changes in the soil's physical structure. The aim of this study was to evaluate the potential for clay dispersion and flocculation, doses of lime and soil pH, and residual Ca2+ and Mg2+. The experimental design was randomized blocks with limestone doses: 0, 3.3, 6.6, 9.9 and 13.2 t ha-1 and four replications. Liming was carried out in December 2022. Samples were taken at depths of 0 to 20 and 20 to 40 cm and submitted to regression equations. At depths of 0 to 20 cm, pH values increased with a maximum peak at a dose of 6.6 t ha-1. An initial decrease in the degree of flocculation was observed at a dose of 3.3 t ha-1 in the 0 to 20 cm layer. At depths of 20 to 40 cm, there was a reduction in the degree of flocculation as the doses of lime increased. The application of lime promotes an increase in pH values. The degree of flocculation varied with increasing doses of limestone in the 0 to 20 cm depth and decreased with increasing doses of limestone in the 20 to 40 cm depth. Residual Ca2+ and Mg2+ at depths of 20 to 40 cm were stable compared to depths of 0 to 20 cm. Ca2+ peaked at a dose of 6.6 t ha-1 and Mg2+ showed higher values at a dose of 9.9 t ha-1.