Abstract
Aims Semi-arid region in northwest China is characterized by barren soil, high soil pH and high carbonate content.Methods In order to improve the soil health status in this area, we studied the effects of alfalfa/oat intercropping on rhizosphere soil nutrients and bacterial community by Illumina MiSeq technology in the 3rd year.Results The results showed that SOM significantly increased in the rhizosphere soil of intercropped compared with monoculture. AN, AP and AK of intercropping were significantly higher than those of monoculture of oat. Bacterial reads number, population taxonomic unit, richness and diversity all showed that intercropping were greater than monoculture. In terms of bacterial phylum, Proteobacteria, Bacteroidetes, Chloroflexi, Actinobacteria, Planctomycetes and Acidobacteria were dominant populations. The abundances of Proteobacteria, Acidobacteria, Cyanobacteria and Gemmatimonadetes were greater in intercropping systems than that in monoculture systems. At genus level, Opitutus, Pseudomonas, Gemmatimonas and Flavobacterium in intercropping were all higher than those in monoculture. At the same time, proteobacteria, bacteroidetes and actinobacteria were significantly positively correlated with SOM, TN and AN.Conclusions This result indicated that alfalfa/oat intercropping can reduce the pH and significantly improve the microbial environment and nutrients of rhizosphere soil in northwest semi-arid region. Meanwhile, the rhizosphere soil microbial community and nutrients interact and regulate each other. Therefore, alfalfa/oat intercropping is an effective measure that improve soil environment in northwest semi-arid region.