One aim of soil management systems research is the definition of production systems adequate to crop produtivity, soil conservation and amelioration. The objective of this study was to evaluate the effect of legume cover crops utilization and incorporation or not of their residues in the soil on corn yield. Two experiments were carried out, including soil tillage methods (conventional, reduced and no tillage), crop systems (fallow/corn, oats/corn, oats+vetch/corn, oats+vetch/corn+cowpea, vetch+spergula/corn and lablab+corn), and rates of nitrogen (0 and 120kg/ha), installed seven and nine years ago, both at the Experimental Station of the Federal University of Rio Grande do Sul in Eldorado do Sul, RS, Brazil. Soil tillage methods had no effect on corn yield. The crop systems affected corn yield only in absence of mineral N application. For these crop systems, without N application, corn yield varied between 1.46t/ha and 5.02 t/ha. The different cover crops increased corn yield in a magnitude equivalent to the addition of 4 to 90kg/ha of mineral nitrogen. Legume crops associated with no tillage had the greatest corn yields and residue production, saved nitrogen mineral, and may accelerate the soil amelioration process.
corn yield; cover crops; soil tillage; soil amelioration
