Long-Term Effects of Agricultural Practices on Microbial Community

Abstract

In Brazil, efforts to increase soil organic matter and to reduce soilnutrient losses through erosion have been made including the adoption ofthe no-tillage system and cover/rotation/intercropping practices withlegumes. The better results obtained within these systems could beattributed to erosion control, improved plant residue management, higherrates of biological N-2 fixation, increased contribution of mycorrhizalfungi, nutrient cycling and decreased organic matter mineralisation, aswell as lower nutrient leaching and runoff losses. Benefits of thelong-term effects of legume crops and no-tillage system on microbialcommunity have been reported, including beneficial effects onmycorrhizal fungi colonization, on common bean rhizobia and soybeanbradyrhizobia diversity, nodulation and N-2 fixation rates. Theinoculation of grain legume crops every crop season has resulted inincreases in nodulation; N-2 fixation rates and grain yield of importantlegume crops, such as soybean (Glycine max) and common bean (Phaseolusvulgaris).