The soil quality of a crop-livestock system can change according to the pasture and soil management. This research was carried out in Otacilio Costa, Santa Catarina State, southern Brazil, on a Humic Cambisol previously used with native grass pasture for 9 years, desiccated in May 2003, for use with ryegrass (Lolium multiflorum) pasture in the winter and corn in the summer. A split plot design was used, consisting of pasture management systems and soil tillage systems prior to the summer crop, with the following treatments: ungrazed ryegrass, desiccated at the end of the cycle followed by corn under no-tillage; ungrazed ryegrass, mowed and removed at the end of the cycle followed by corn under no-tillage; grazed ryegrass followed by corn under no-tillage; grazed ryegrass followed by corn under conventional tillage; and grazed ryegrass followed by corn under reduced tillage. Animal grazing consisted of two periods of 14 and 10 days, with an animal weight of 6.0 Mg ha-1. Soil samples were collected on different dates for analyses of soil physical and total organic carbon. Soil tillage with plow or disking was the factor that influenced soil physical properties most, reducing organic carbon content, aggregate stability, bulk density and soil moisture, and increased total porosity, macroporosity and soil aeration capacity, compared to the no-tillage system. Under no-tillage, the effects of pasture management caused no modification of the soil physical properties. By converting from native grassland to an integrated crop-livestock system under no-tillage soil physical conditions were better preserved than under conventional tillage, while reduced tillage had a moderate performance.
animal trampling; compaction; pasture; soil structure; soil tillage
