Influence of Soil Management and Crop Rotation on Physical Properties in a Long-Term Experiment in Paraná, Brazil

This work aims to evaluate the soil physical properties affected by cover crop rotation and soil management in a long-term experiment in southern Brazil. The experiment was established in 1986, with treatments combining six winter treatments and two tillage systems (conventional and no tillage). Bulk density, porosity, aggregate-size class distribution, and organic carbon content of the aggregates were determined at six depths. Bulk density was not affected by tillage systems and winter treatments. The soil disturbance by plowing enhanced the macroporosity, decreased the microporosity, and promoted the formation of smaller aggregate size, in comparison to no tillage. Apart from the soil management, all winter species increased the greater aggregate-size classes, mean weight diameter, geometric mean diameter, and aggregate stability index compared to the fallow treatments. At the no-till treatments, the greater part of sequestered carbon into the soil was stored into the lower and bigger soil aggregates.