AimsThis study aimed to develop microbial inoculants composed of functional strains isolated from the rhizosheath of Agropyron cristatum (L.) Gaertn., a pioneer species in desertified grasslands, and to evaluate their effects on root exudates, rhizosheath properties, and microbial community composition. The ultimate goal was to enhance rhizosheath functionality and promote plant growth.MethodsMicrobial inoculants were formulated by combining functional strains in various proportions. A short-term greenhouse experiment was conducted to assess changes in root exudates, including sugars, proteins, and organic acids, as well as key rhizosheath soil parameters: seedling height, soil weight, pH, electrical conductivity (EC), organic matter (OM), available phosphorus (AP), and available nitrogen (AN). Metagenomic sequencing was employed to analyze the microbial community composition and diversity in rhizosheath soil.ResultsMicrobial inoculants significantly increased the concentrations of sugars, proteins, and tartaric acid in root exudates, lowered rhizosheath soil pH, and enhanced seedling height, EC, and soil nutrient content (OM, AP, and AN). Metagenomic sequencing revealed that inoculation altered the composition of the rhizosheath microbial community, increasing the relative abundance of bacterial phyla such as Actinobacteria, Proteobacteria, and Firmicutes, as well as the fungal phylum Ascomycota. Root exudate composition, particularly soluble sugars and proteins, was closely associated with microbial community shifts.ConclusionCustomized microbial inoculants significantly improved rhizosheath properties, reshaped microbial community composition, and promoted plant growth in A. cristatum. These findings provide valuable insights into the application of microbial inoculants for ecological restoration in desertified grasslands by improving soil health and enhancing plant productivity.