Grain yield of common bean as affected by cover crops and soil management systems

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">A field experiment was carried out under no-tillage system (NT) and conventional tillage (CT) to assess the dry mass production, N accumulation and the decomposition rate of crotalaria (Crotalaria juncea) and sorghum (Sorghum bicolor L.), as well as, their effects on the grain yield of common bean (Phaseolus vulgaris L.). Results showed that soil management had no effect on the dry mass production of cover crop, however, the sorghum produced 60% more dry mass as compared with crotalaria. The largest N accumulation was observed under NT, which showed 45% more N than CT, however, no statistical difference between cover crops was observed. The straw rate decomposition under NT was 50% lower than under CT and, until 28 days, the decomposition of crotalaria under CT was faster than sorghum. The common bean grain yield was 40% higher under NT as compared with CT and it showed high correlation with N amount accumulated by the cover crops. Under Cerrado condition of Goiás state, NT promotes greater N accumulation and lower decomposition rate of the cover crops, leading to greater grain yield of common bean as compared with CT.