Caracterização química do solo adubado com doses de nitrogênio e enxofre após o cultivo do capim-marandu

Abstract

In Brazil, the cultivar Brachiaria brizantha cv. Marandu is one of the most cultivated grasses, so fertilization is extremely important to improve the chemical properties of the soil in pastures. The objective of this study was to evaluate the influence of combinations of fertilizers with doses of nitrogen (N) and sulfur (S) on the chemical characteristics of the soil after the cultivation of Marandu grass. The experiment was carried out in a greenhouse, using plastic pots with a capacity of 8 liters, between the months of November 2017 to January 2018. Five doses of N (0, 100, 200, 300 and 400 mg dm were combined) -3) with five doses of S (0, 10, 20, 30 and 40 mg dm-3), in an experimental design composed of a fractional 52 factorials. The statistical design was completely randomized, with four replications, totaling 52 vessels. Two cuts were made to the plants, 30 and 60 days after transplanting and soil samples were collected for chemical analysis. Soil contents of calcium (Ca), magnesium (Mg), aluminum (Al), S, pH in CaCl2 and pH in soil water were evaluated. Statistical analyzes were performed using the F test, adopting a 5% significance level. For the significant N x S interactions, the response surface study was performed and for the effect of N and / or S doses alone, the first and second degree regression study was performed. The highest levels of S, Ca and Mg in the soil were obtained by combining the highest doses of N and S. The highest doses of N favored acidification of the soil.