Características estruturais e produtivas do Capim-Marandu sob efeitos de corretivos da acidez, gesso e compactação do solo

Abstract

This work was designed in order to evaluate the influence of soil amendments, gypsum and soil compacting on the structural and productive characteristics of marandu grass (Urochloa brizantha cv. Marandu). The experiment was conducted in pots in a greenhouse, utilizing samples of the B horizon of dystrophic Dark Red Latosol of clayey texture. The experimental design was completely randomized in a factorial scheme 4×6, with three replicates; that is, four treatments with different soil densities (1.0, 1.20, 1.40 and 1.60Mg·m-3 ) and six treatments related to soil improvement: control with no amendment; gypsum; limestone; calcium silicate; limestone + gypsum; and calcium silicate + gypsum. Five plants of marandu grass were grown per pot, performing three cuts of shoots, every 30 days. The number of tillers, leaf area and the dry mass of stems, leaves and shoots were evaluated in each cut. The results showed that the soil acidity amendment is of fundamental importance for the growth of the root system and shoots of marandu grass. Soil compacting to densities ≥1.2Mg·m-3 reduces growth of both roots and shoots of marandu grass. The use of lime diminishes the effects of soil compacting; however, this latter was the most limiting factor for the growth of marandu grass. Among the soil amendment treatments, the use of calcium silicate in combination with the gypsum leads to increased growth of marandu grass roots and shoots.