Effects of Management Practices and Land Use on Biological and Enzymatic Attributes of an Agricultural Area

A series of anthropogenic approaches, including burning practices and soil disturbances as soil cover removal, plowing and harrowing were experimentally undertaken to mimic land conversion for agricultural production in northern Amazonia. These manipulations led to changes in soil biological and biochemical properties. To reduce knowledge gaps concerning land conversion in the Amazon, the study objective was to evaluate the influence of land use and management practices on the biological attributes and enzymatic activity of the soil in Tepequem, a settlement in north of the Amazon, Brazil. Tepequem was chosen for being highly representative in terms of land use and management patterns in the region. Microbial biomass carbon (MBC), soil basal respiration (SBR), metabolic quotient (qCO2) and enzymatic activity were analyzed. Land use changes resulted in alterations to soil quality. The spontaneous plants found on degraded pasture ensured system diversification, protection and organic contribution, facilitating resumption of ecological balancing of the soil. Good soil quality in managed pasture was attributed to the maintenance of soil cover, provided by grasses, and the absence of soil rotation. Burning, soil disturbances and lack of cover negatively influenced the biological and enzymatic activity in sites that were preparation, deforested and burnt. Chemical attributes are significant factors influencing soil quality and health at subsistance plantation. MBC, qMIC and qCO2, acid phosphatase, Beta-glucosidase and urease were the most sensitive parameters of differentiation of sites in preparation from those of native vegetation and pastures.