Effects of Maize and Soybean Intercropping on the Function and Structure of Rhizosphere Microbial Community

PurposeTo reveal the change rules of rhizosphere microbial community function and structure under the interaction of two crops in the intercropping system of maize (Zea mays L.) and soybean (Glycine max).

MethodFunction and structure of rhizosphere microbial communities in maize tasseling stage/soybean flowering pod stage were analyzed synchronously by BIOLOG and high throughput sequencing technology under maize and soybean intercropping field plot experiment.

Results1) Microbial community carbon source metabolic function diversity of soybean rhizosphere was higher than that of maize. Compared with monoculture of each other, Shannon index of intercropped maize was significantly increased by 3.5% (P<0.05), Simpson index significantly decreased by 13.1% (P<0.05), while Simpson index of intercropped soybean was significantly increased by 7.8% (P<0.05), which made the each other became similar. 2) Compared with monoculture, the total amount of detectable bacteria in maize rhizosphere increased significantly after intercropping (P<0.05), while the total amount of detectable bacteria in soybean showed a decreasing trend (P>0.05). However, there was no significant change in species diversity and genetic diversity (P>0.05). Under the influence of interspecific interaction, there were new species in the rhizosphere bacterical community of both species. As for species composition convergence and variation coexist. 3) Compared with monoculture, the relative abundance of Armatimonadetes in rhizosphere increased significantly in maize and soybean intercropping system (P<0.05), but there was no significant difference in other dominant groups (P>0.05). The relative abundance of Acidobacteria changed from insignificant (P>0.05) to significant (P<0.05) under the interaction of maize and soybean, while the relative abundance of Gemmatimonadetes, Gemmatimonas, Gaiella, Ktedonobacter and Rhodanobacter changed from significant (P<0.05) to insignificant (P>0.05) under the interaction of maize and soybean.

ConclusionThe function and structure of rhizosphere microbial community were changed by maize and soybean intercropping. Convergence coexists with divergence, mainly with convergence.