Subsolagem, calagem e adubação mineral em um Latossolo amarelo coeso de tabuleiro costeiro e Conseqüências em pastagem degradada de brachiaria Decumbens

Abstract

Degradation of pasture is an evolving process of loss of vigor, productivity and resilience of natural pasture, preventing the production cost and quality of forage required by animals. This process can be caused by physical and /or chemical and /or biological. The aim of this study was to evaluate the effects of subsoiling, correct acidity and mineral fertilizer on a Typic Cohesive Coastal Board and the consequences of a degraded pasture of Brachiaria decumbens. This evaluation was performed using the following indicators bulk density, porosity and soil resistance to penetration) chemical (pH, hydrogen, aluminum, phosphorus, potassium, calcium, magnesium, sum of base, base saturation, CTC) and biological (root growth and root density). The experiment was installed on campus UFRB in the city of Cruz das Almas, with a split plot experimental design. It was found that subsoiling increased total soil porosity - mainly macroporosity - decreased density and soil resistance to root penetration and contributed to greater movement of nutrients through the soil profile. Associated with subsoiling, liming decreased the concentration of Al+3, increased pH, exchangeable base saturation (V% value) and CTC (effective). The combination of subsoiling, liming, nitrogen, phosphorus and potassium improved the rooting environment of plants, increasing growth and root density. The nutrients nitrogen and potassium were responsible for the highest yields of green mass and dry grass, in the periods. Subsoiling when associated with nutrients, nitrogen, phosphorus, potassium and lime, provided increases in levels of phosphorus, potassium and calcium in the plant canopy.