nfluence of land use on the conservation of carbono by microbial biomass in organic production systems

Abstract

The objective of this study was to evaluate the influence ofland use in microbial biomass and labile soil in the integrated agroecological production. We studied different crop areas under organic cultivation of vegetables (intensive cultivation, minimum tillage and crop rotation), three pastures, three forest remnants and three degraded. The pasture had the highest carbon content of soil microbialbiomass (384 mg C kg-1solo), about 60% above the level seen in the forest remnants. The metabolic quotient indicated a high metabolic activity of microbial biomass soil (BMS) in managed areas with agricultural crops, with value varying from 1 20 to 200 mg C kg-1soil and with an average reduction of 30% in the C-BMS content in relation to forest remnants. Major losses of C-BMS occur in under intensive cultivation of vegetables, due to the frequent use of plow and harrow, prompting the search for management systems that minimize soil disturbance and prioritize the maintenance of vegetation cover.