GRAZING AND NITROGEN ON RYEGRASS OVER SOIL PHYSICAL PROPERTIES AND BEAN YIELD

Knowing the interaction among factors that compound integrated crop-livestock system can provide a sustainable use of soil and pasture. It was evaluated grazing and nitrogen doses influence on soil physical properties including density, macroporosity, microporosity, total porosity, mechanical penetration resistance, and beans yield of an integrated crop-livestock system. The experiment was performed in a split-plot randomized block design, with three replications. Treatments were four nitrogen levels: 0, 75, 150 and 225 kg ha(-1) on ryegrass (Lolium multiflorum Lam) in winter with common bean (Phaseolus vulgaris Lam.) in summer. Additionally, subplots were grazing presence or absence. Sheep continuous grazing under adequate ryegrass forage maintenance and nitrogen fertilization did not compromise soil physical quality. Nitrogen fertilization at 150 kg ha(-1) rate during winter pasture (ryegrass) allows subsequent high bean yield, without the need of another nitrogen fertilization. Sheep treading effect on soil penetration resistance was greater at 0.10 m of depth. The winter grazing during allows high bean yield even at low nitrogen doses.