Effect of cover crops on common bean yield and soil physical properties under no-till system

The aim of this study was to evaluate dry matter production of cover crops (oats, turnip, vetch and spontaneous plants) and their effect on bean yield and physical properties of soil after succession. The experimental design was randomized blocks, and treatments consisted of four species of cover crops: oat, turnip, vetch and spontaneous plants, with five replications. The cover crops were sown in winter; when in full bloom, they were cut close to the ground and left underground. The bean crop was then sown underneath this residue in a no-till system. The results show that the cover crop that yielded the most dry matter was oats with 4,900 kg ha(-1), which did not differ statistically from turnip with a yield of 4,000 kg ha(-1). The spontaneous plants produced the least amount of dry matter and differed from the other treatments. The development of vetch was hampered by the environmental conditions of Marechal Candido Rondon, State of Parana, with dry matter yield of 2,375 kg ha(-1). The highest bean yield (1,204 kg ha(-1)) was found for the planting carried out in succession to oat, and the lowest after succession of vetch (697 kg ha(-1)) and spontaneous plants (575 kg ha(-1)). Cover crops had no effect on macroporosity and total porosity of soil depth from 0.05 to 0.20 m. There was a statistical difference in soil bulk density in the layer from 0.05 to 0.10 m, and bulk density (1.18 kg dm(-3)) was obtained in the treatment where the bean crop was cultivated after spontaneous plants.