Impacts of Cereal and Legume Cultivation on Soil Properties and Microbial Communities in the Mu Us Desert

This study aimed to evaluate the effects of different crop cultivation practices on soil chemical properties and microbial communities in the Mu Us Desert, with the goal of optimizing land management and promoting ecological restoration. A one-way randomized block design was used to establish experimental plots for a cereal (Setaria italica, SI), a legume (Glycine max, GM), and a control group with no crops (CK) in the central Mu Us Desert. Soil samples were collected to assess physicochemical properties and to analyze microbial community structures via high-throughput 16S rRNA gene sequencing. Results showed that crop cultivation decreased soil pH while increasing soil organic carbon (SOC), total nitrogen (TN), and available phosphorus (AP), indicating improved soil fertility and reduced soil alkalinity. The composition of soil bacterial communities varied significantly among treatments. Both SI and GM treatments increased the number of operational taxonomic units (OTUs), enhancing bacterial richness and diversity. Proteobacteria and Actinobacteria increased with crop cultivation, whereas Chloroflexi declined. These shifts were largely attributed to changes in pH and nutrient availability. Notably, SI treatment had a stronger positive effect on bacterial richness. Correlation analyses between soil chemical properties and microbial community composition highlighted the potential of crop cultivation to influence soil ecosystem services. These findings provide a scientific basis for sustainable agricultural practices and ecological restoration in arid regions such as the Mu Us Desert. Further studies are warranted to investigate the functional roles of microbial communities under different cropping patterns.