Corn Yield and Grain Nutritional Status in a Crop-Livestock System with Winter/Summer Nitrogen Levels

Abstract

Winter pastures nitrogen fertilization in crop-livestock systems may provide effects not only on animal production during winter season, but also on corn grain yield and in its nutritive value cultivated after the grazing period. This paper assessed the effect of nitrogen levels and its management in a crop-livestock system with and without grazing by sheep on corn yield and its nutritive value. The experiment was established in 2006 in Guarapuava, PR, Brazil. Oats (Avena spp.) and ryegrass (Lolium multiflorum) were grown during winter season and corn and beans during summer season over the years, being this paper related to the 2009/2010 corn crop period. Treatments were composed of four nitrogen levels at the winter pasture (0, 75, 150 and 225 kg ha−1), with and without grazing by sheep, and five nitrogen levels on corn (0, 75, 150, 225 and 300 kg ha−1). Corn yield was positively influenced by nitrogen fertilization performed in the pasture, what characterized a residual effect of nitrogen applied in winter. Corn crude protein levels from the grazed areas were higher than ungrazed areas, and its levels increased as nitrogen levels increased.