Soil Dynamics in Acacia mangium plots associated to Brachiaria humidicola in an ULTISOL of Panama

摘要

Acacia mangium (Willd.) is a robust leguminous tree, easily established in plantations. In fertile soils, it has high survival and good initial growth, although inferior to other fast growing trees. However, in degraded, compacted, acid (pH lower than5.5) soils with high aluminum contents it has overcome other species (CATIE, 1986). Experimental data of EDIAP, in acid Ultisols, classify it with better behavior, when comparing with other native and exotic species, such as Tectona grandis, Eucalyptuscamandulensis, Genipa americana (Name, Cordero and Bernal, 1987). The grass Brachiaria humidicola was introduced and selected as one of those of better adaptability under conditions of acid soils, deficient in macro and micronutrient (Urriola et. al. 1985). The objective of the present work, was to determine the effect of the association Acacia mangium-Brachiaria humidicola on an acid ultisol of Panama by means of the quantification of the variability and behavior in the soil parameters: quantity of organic matter, roots, variation in the number of soil organisms, infiltration, density, natural fertility and foliar content of elements of the plants in the subsystems under evaluation.