Microbial Diversity in Rhizosphere Soil of Legumes and Forages under Different Sowing Methods in Alpine Cold Region

Background and Aims: In order to explore the characteristics of rhizosphere microbial community composition and diversity of legumes and forages under single and mixed cropping, the physical and chemical properties and microbial diversity of rhizosphere soil of Avena sativa L. and Vicia sativa L. in alpine cold region were measured and analyzed under single and mixed cropping. Methods: High-throughput sequencing technology. Results: There were no significant differences in pH, Total Nitrogen(TN), Total Phosphorus(TP), and Total Potassium(TK) between Avena sativa L. and Vicia sativa L. monoculture and mixed cropping treatments, but significant differences in the contents of Available Nitrogen(AN), Available Phosphorus(AP), Available Potassium(AK), and Organic Matter(OM) (P<0.05). The rhizosphere soil bacterial microbial diversity was the highest under Avena sativa L. monoculture, and the rhizosphere soil fungal microbial diversity was the highest under Vicia sativa L. monoculture. There were significant differences in rhizosphere microbial diversity under different cultivation methods (P<0.05). At the phylum level, the abundance of Alphaproteobacteria and Actinobacteria in the mixed cropping treatment was significantly higher than that in the Vicia sativa L. monoculture and Avena sativa L. monoculture, while the abundance of Gemmatimonadetes, Nitrospira, and Acidimicrobiia was significantly lower than that in the monoculture treatment. The Mortierellomycetes was the most abundant fungus under the mixed cropping treatment (32.66%), while the abundance of Sordariomycetes and Leotiomycetes was significantly lower than that in the monoculture treatment. There were significant differences in the species distribution of soil bacterial and fungal communities among the treatments. KEGG metabolic analysis showed that the functional genes of soil microbial communities under each treatment were basically similar in metabolic pathways.