Due to the dynamic nature of soil microorganisms, the study of microbial biomass quantity and activity can furnish important information for the planning of adequate land use. The objective of this work was to verify alterations in biological attributes of soil quality indicators after the adoption of management systems in originally native cerrado areas, and to select the attributes with the best performance of indicating such alterations. Soil samples were collected at three depths (0-10, 10-20, and 20-40 cm) in a clayey texture, typic Dystrophic Red Latosol (Oxisol) in Morrinhos county, Goiás State. Five farms were chosen, based on their representativeness for the region in relation to their history of use and the characteristics of the adopted management systems. These systems included: native cerrado, pasture, no-till, no-till with a history of superficial harrowing, long-term conventional tillage, and recent conventional tillage following pasture. The native cerrado was considered reference, once all test areas had originally been covered by this vegetation type. The following attributes were evaluated: carbon of microbial biomass (Cmic), basal respiration, metabolic quotient (qCO2) and Cmic/OC ratio. In addition, the total organic carbon (OC) and some soil fertility attributes were evaluated. The introduction of agricultural systems and pasture reduced the Cmic amounts in the surface layer in comparison to the native cerrado. Without considering the site under cerrado, the highest Cmic value was observed in the pasture and the lowest one in the long-term conventional tillage soil. No significant differences in basal respiration and qCO2 values were observed among the management systems. The Cmic indicated significant alterations caused by the implantation of management systems in relation to the native cerrado. Though it had revealed differences only between two of the five cultivated systems, the Cmic was an indicator for a higher microbiota equilibrium in the soil under cerrado.
sustainability; conventional tillage; no-till; soil organic matter