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Purpose: This study aimed to investigate the effects of different shrub plants on the structure and diversity of inter-root soil bacterial communities, in order to provide scientific support for ecological restoration and revegetation of the Mu Us Desert. Methods: Three major shrub plants (Artemisia ordosica, Salix psammophila, Caragana microphylla) in the Mu Us Desert were selected for this study. Using high-throughput sequencing technology, the bacterial community structure and diversity in the inter-root soils of these plants were analysed in depth, and combined with the determination of soil physicochemical and microbiological properties, the response characteristics of the bacterial diversity in the inter-root soils of the different plants were assessed comprehensively. Results: It was found that although the soil pH did not show significant differences among different plant growths, the SOC, TN and TP contents were higher in Salix psammophila sample plot and Artemisia ordosica sample plot, which indicated that the plant growths had a positive effect on the soil nutrient contents. Through Venn diagram analysis, it was observed that the number of OTUs of bacteria in the soils of different shrubland sites varied, and all of them were higher than those in the soils of the sample sites where no plants grew, which indicated that plants had an effect on soil bacterial diversity. The bacterial Chao1 index were higher in the Artemisia ordosica sample plot sample site, suggesting that the growth of Artemisia ordosica contributes to the enhancement of soil bacterial richness. Soil bacterial communities showed compositional differences among different sample plots, especially the higher relative abundance of Betaproteobacteria in the Artemisia ordosica sample plot sample plot, which may be related to the increase of soil organic matter content. Conclusion: The results of the study revealed that specific plants, such as Artemisia ordosica, can significantly improve the soil nutrient status of windy sandy soils, increase soil organic matter and nitrogen content, and thus enhance the diversity and abundance of soil microorganisms. The bacterial community structure in the inter-root soils of different plants differed significantly, with changes in the relative abundance of the dominant phyla, such as Alphaproteobacteria, Betaproteobacteria and Actinobacteria, reflecting the differences in soil nutrient status. These findings emphasise the important role of plants on soil chemical properties and microbial community structure, providing an important basis for soil management and ecological restoration. [ABSTRACT FROM AUTHOR]

The Mu Us Sandy Land is a region characterized by wind-blown sand and soil erosion in northern China. To enhance the soil quality of this area, various organic materials were incorporated into the mixed soil at a volume ratio of 1:2 for feldspathic sandstone to sand. Culture was conducted in the field and under constant temperature conditions in laboratory culture chambers. Four treatments were established in the experiment, each calculated based on weight ratio and controlled (with no organic material added, CK); single application of straw (5% straw, P1); single application of biochar (5% biochar, P2); combined application of biochar and straw (5% biochar + 5% straw, P3). After 90 days of culture, soil samples were collected for analysis of various indicators such as soil aggregate particle size distribution, water stability of soil aggregates, mean weight diameter, mean geometric diameter, and fractal dimension using dry sieving and wet sieving methods. The objective is to establish a scientific basis and provide technical support for addressing the challenges associated with compound soil and implementing rational fertilization measures. The research results indicate that: (1) The quantity of aggregates > 0.25 mm under different treatments follows the order CK < P1 < P2 < P3, and the differences between treatments are significant (P < 0.05); (2) Soil water stability, mean weight diameter (MWD), mean geometric diameter (GMD), and fractal dimension of soil aggregates in compound soil with different organic material additions are superior to the control, and the effect of biochar on improving soil aggregates is better than that of corn straw. The combined application of both significantly improves the effect compared to single applications. In both culture modes, under wet sieving, the P3 treatment shows the highest MWD and GMD of soil aggregates, with an increase ranging from 3.45% to 85% and 4.55% to 38.46%, respectively, compared to other treatments. (3) The trend of fractal dimension among treatments is consistent: P3 < P2 < P1 < CK, and the differences between treatments are significant (P < 0.05). Moreover, there is a good negative correlation linear equation relationship between the fractal dimension (y) and WR > 0.25 (x) of compound soil, with a correlation coefficient of up to 0.9851. In conclusion, the incorporation of organic materials can effectively enhance the proportion of macroaggregates in compound soil consisting of Feldspathic sandstone and sand, thereby improving soil stability and erosion resistance. The optimal outcome is achieved through the combined application of biochar and straw. Indoor culture proves to be more effective than field culture, while wet sieving accurately reflects the structural characteristics of compound soil under both dry and wet sieving treatments. [ABSTRACT FROM AUTHOR]