BIOCHEMICAL ATTRIBUTES OF TWO SAVANNAH SOILS UNDER DIFFERENT MANAGEMENT SYSTEMS AND USE

Abstract

Soil biochemical attributes can be used as sensitive indicators of alterations promoted by the agricultural use, being a tool to guide tillage practices planning and evaluation to maintain soil sustainability. The objective of this study was to evaluate alterations in the soil organic carbon, biomass and microbial activity, urease and acid phosphatase activity, in two savannah soils, as affected by soil management systems. The study consisted of five soil management systems in a Typic Quartzipsamment, four in an Oxisol, and reference areas without alterations in the two soil types. The management systems changed the biochemical attributes of both soils. The Typic Quartzipsamment area under the soybean/Brachiaria decumbens sequence decreased the soil organic carbon and the microbial biomass carbon, and increased the respiration and qCO₂, while the Oxisol, in all the areas, except for pasture, promoted reductions in the biochemical attributes. Among the management systems studied,  the pasture provided improvements in the evaluated attributes, in both soils.

KEY-WORDS: Soil quality; microbial biomass; soil enzymatic activity.