Chemical properties of a Red Latosol under notillage and swine manure utilization

In western Santa Catarina state, Brazil, swine manure is commonly used as nutrient source for crops. The aim of this study was to evaluate the effects of swine manure on chemical attributes of a Red Latosol (Hapludox), cultivated with corn under no-tillage conditions. Two experiments were carried out using different rates of liquid swine manure (0, 40 and 115 m(-3) ha(-1) year(-1)), applied annually at corn sowing, from 2000 to 2004, in Chapeco and from 2001 to 2004, in Guatambu. After the last corn harvest, crop season 2003/04, soil samples were collected from seven soil layers (0-5, 5-10, 10-20, 25-35, 40-50, 70-80 and 100-110 cm), in three replicates. The following chemical attributes were evaluated: pH in water, available P and K, exchangeable Ca, Mg and Al, Cation Exchange Capacity, clay and organic matter. The potential acidity and Al saturation were calculated. Surface-applied swine manure resulted in increments of available P in the top soil layer (0-10 cm). There was no movement of P from the topsoil layer with higher P concentration to the deeper soil layers. The other chemical attributes analyzed were not significantly influenced by the doses of swine manure. Higher K, Ca and Mg concentrations were also observed in the surface soil layers (0-20 cm).