This study was carried out to assess the influence of winter plant cover on the chemical soil properties in a Structured Terra Roxa soil in Santa Catarina, Brazil. The plant cover consisted of an association of black oats (Avena stirgosa Schreb) with pasture turnip (Raphanus sativus L.) and organic fertilization using poultry manure and mineral fertilization. Soil samples collected in August 1994 and January 1995, at depths of 0-10, 10-20 and 20-30 cm, were analyzed for an experiment initiated in 1990. The winter plant cover was efficient in maintaining nutrients (especially potassium) and the organic carbon levels within the limits of the plowable layer. The use of the organic fertilizer provided high nutrient accumulation in the soil, while the nutrients tended to be reduced by the organomineral and mineral fertilizers, mainly the levels of soil potassium.
organic residue; nutrient maintenance