Biochemical and Biological Properties of Soil from Murundus Wetlands Converted into Agricultural Systems

The implementation of conservationist systems that improve soil properties and reduce the impacts of the conversion of native areas is fundamental for feasible agricultural exploitation. This study aimed to evaluate the impact on soil biological properties caused by the conversion of murundus fields into agricultural systems and verify the ability of the no-tillage conservation system to recover these properties over the years. Treatments consisted of three agricultural areas subjected to the same management (no-tillage), in a chronosequence (7, 11, and 14 years of conversion) and a reference area (murundus field). To evaluate soil quality, we analyzed total soil organic carbon, microbial biomass carbon, soil basal respiration, metabolic and microbial quotients, and acid phosphatase activities, as well as the potential functionality of soil bacterial communities and the modifications in their genetic structure. The conversion of murundus field into agricultural systems negatively impacted soil biological properties, with expressive reduction in soil organic carbon content and microbial biomass carbon. The periods of adoption of the conservationist system (no-tillage) were not enough to recover the biological properties and/or to reverse the changes observed in the genetic structure of the soil bacterial communities of the managed areas, although stabilization trends were observed in the agricultural systems over the years.