Atributos químicos do solo aos três anos após a calagem e produtividade da soja na quarta safra

Abstract

The use of liming as an agricultural corrective is widespread and it is important that it is carried out correctly in order to obtain maximum benefits. This study raises the hypothesis that higher than usual doses have a significant residual effect at a depth of up to 20 cm. The objective was to evaluate the chemical conditions of the soil and productive alterations of the soybean crop (Glycine max), in the fourth harvest, three years after the correction, in a Dystrophic Red Yellow Latosol, in an area of consolidated no-tillage, in Sinop/MT, 350m of altitude. The treatments had doses ranging from 2.46 to 12.34 t ha-1 with calcitic and/or dolomitic limestone, on the surface and/or incorporated in September 2018. A chemical analysis of the soil was carried out at depths of 0-5 cm, 5-10 cm, 10-20 cm and 0-20 cm, by the trench method for knowledge of changes three years after application, evaluating the pH, Ca, Mg and V%, as well as plants were harvested, threshed and weighed to know the mass of a thousand grains and the grain yield of the soybean crop. The results were compared by the Scott-Knott test at a 10% probability level, showing significant changes in pH (CaCl2) and Mg in the 0-5 cm soil layer. Calcitic limestone application significantly increased the Ca content at the highest rate used (12.34 t ha-1) for the entire profile, 0-5cm, 5-10cm, 10-20 and 0-20 cm. And the V% in layers 0-5, 5-10 and 0-20 cm. There was an increase in productivity, however, not significant.