Physical characteristics changes on the topsoil caused by sheet flow in the subsistence agriculture with land rotation system: Guarapuava-PR

Abstract

This study has as its aim to monitoring a land use in the subsistence agriculture, in order to verify the physical change on the topsoil caused by tillage and sheet flow. Three areas with different regeneration phase were monitored. The main elements evaluated on the topsoil were resistance, bulk density and total soil porosity. Resistance was measured with soil pocket penetrometer and bulk density and porosity were evaluated through volumetric ring with 95,5 cm3. The results suggest that area 1, which remained with shrubs regeneration, kept the topsoil physical conditions. After the shrubs were burned (area 2), some sites showed clear change on the topsoil physical conditions. It was verified that the topsoil of abandoned area (area 3) had a different superficial physical condition as compared with the two previous areas. The physical changes that were observed in the topsoil were caused by sheet wash scars, due to diffuse flow (irregular patchy). This intermittent sediment transport process was a determinant cause for the topsoil physical changes.