Assembly changes of soil microorganisms during the transformation from native soil to alfalfa cultivation soil in Kunlun mountain sand area, Xinjiang

It is considered to be an effective means to improve desertified and degraded soil by biology, but it is still unclear how the effect is in high altitude desertified soil environment and how the microorganisms of soil and plants are assembled when the host plants of native soil are changed. We observed and analyzed whether the change from native soil to alfalfa soil affected the community aggregation of soil microorganisms and whether this led to the diversity of microorganisms. The results showed that alfalfa cultivation improved the quality of native soil, and with the extension of planting time, it promoted the recovery and homogenization of soil microbial diversity. This process is accompanied by the replenishment or expulsion of soil microorganisms, and soil organic matter and pH are the driving factors of microbial community change. Only 541/56 clusters of bacteria/fungi OTUs were always present in native soil, cultivated soil and rhizosphere soil, but this core microbial group accounted for a large part of all readings (bacteria: 28.70%, fungi: 40.37%). The complexity of microbial network structure and interaction between native soil and rhizosphere soil is higher than that of cultivated soil, and the performance of bacteria is more obvious than that of fungi. On the whole, the transition from native soil to cultivated soil by planting alfalfa has a positive impact on the local microbial diversity, and the assembly of microorganisms is affected by the recruitment and dispersion of alfalfa rhizosphere soil.