Soil physical degradation is one of the main factors responsible for water erosion. The conventional tillage, usually, acellerates soil degradation process because it involves an intense soil tillage, whereas no-tillage is considered a soil conservation management system because it preserves crop residue on the soil surface, and increase soil organic matter. However, no-tillage may also increase soil surface density and decrease surface total porosity. This study was conducted in Lebon Régis, Santa Catarina State, Brazil, on a Hapludox soil, from June 1995 to May 1999. Two soil tillage treatments were used: conventional tillage (animal traction plowing) and no-tillage. Each tillage treatment was replicated four times. The crops used were oat and maize in no-tillage system and maize and fallow in conventional tillage system. Soil bulk density, organic carbon, macroporosity, microporosity, total porosity, phosphorus and potassium were evaluated in the soil layers of 0-2.5, 2.5-5.0, 5.0-10.0 and 10.0-15. 0cm depth. The values of soil bulk density, macroporosity and microporosity did not differ in all layers studed. The organic carbon, phosphorus and potassium values were higher for no-tillage than conventional tillage, for the 0-5.0cm layer.
no-tillage; animal traction plowing; soil density; soil porosity, organic carbon.
