Objective  Arbuscular mycorrhiza fungi (AMF) is a kind of endophytic fungi belonging to Ascomycota, which can not only promote the growth of host plants, improve the stress resistance of plants and maintain the stability of soil ecosystem, but also increase soil erosion resistance by glomalin-related soil protein produced by its hyphae and spores. The growth and development of AMF are affected by planting patterns. Therefore, this study revealed the effects of intercropping on the physical and chemical properties of crop rhizosphere soil, glomalin-related soil protein content and AMF community, and provided a theoretical basis for the selection of planting patterns in red soil sloping farmland in southern China.

  Method  The red soil sloping farmland was taken as the research object, and three treatments of maize monoculture, potato monoculture, and maize-to-potato intercropping were set to analyze the changes of rhizosphere soil physical and chemical properties, glomalin-related soil protein content, AMF community composition and diversity of each crop under different planting patterns, as well as the relationship between each index.

  Result  Compared with monoculture, maize and potato intercropping significantly increased the contents of total glomalin and extractable glomalin in rhizosphere soil of two crops, with an increase of 10.5% - 30.1%. Rhizosphere soil organic matter content of maize intercropping decreased by 10.6% compared with maize monoculture, while rhizosphere soil organic matter and available phosphorus content of potato intercropping increased by 13.5% and 46.5% compared with potato monoculture. Compared with maize monoculture, the number of operational taxonomic units specific have increasing trend to rhizosphere soil AMF community of maize intercropping, while the potato intercropping has a decreasing trend compared with potato monoculture. Nonmetric multidimensional scaling analysis results showed that planting patterns significantly changed the community composition of AMF in maize rhizosphere soil, but did not significantly change the community composition of AMF in potato rhizosphere soil. Compared with monoculture maize, Chao1 of AMF community in rhizosphere soil of intercropping maize significantly increased by 9.3%, Shannon index increased by 1.3%, Simpson index decreased by 7.6%. Compared with potato monoculture, the Simpson index of AMF community in rhizosphere soil increased by 53.3%, Chao1 index significantly decreased by 10.8%, and Shannon index decreased by 10.6%. In each treatment of maize and potato, the dominant genera of rhizosphere soil AMF community were Gigaspora, Acaulospora and Rhizophagus. Redundant analysis showed that pH was the main factor affecting the abundance of AMF community, α diversity index and GRSP content in crop rhizosphere soil.

  Conclusion  The intercropping of maize and potato significantly increased the glomalin-related soil protein content and the diversity of AMF community composition in maize rhizosphere soil. The results can provide a theoretical basis for the selection of planting patterns of red soil sloping farmland in Yunnan Province.