Abstract:

The growing tension between global cropland degradation and rising food demand has made agricultural soil health a central determinant of food security and agricultural sustainability. Rhizosphere microorganisms play key roles in this context by driving nutrient cycling, maintaining soil structure, and enhancing crop stress tolerance. In recent years, synthetic microbiomes have emerged as a controllable strategy for engineering microbial communities to achieve targeted regulation of rhizosphere functions. This review focuses on key rhizosphere interaction processes that underpin soil health in agricultural systems, highlighting how plant-microbe interactions and microbial community dynamics contribute to nutrient cycling, environmental stress responses, and disease suppression. We then summarize current approaches for constructing synthetic microbiomes, including functional strain selection and assembly, community synergistic design, and strategies to enhance persistence under field conditions. Building on this framework, we examine their applications in agriculture, with emphasis on improving nutrient use efficiency, mitigating soil degradation, remediating contaminated soils, and controlling plant diseases. We further discuss major barriers to field implementation, including limited environmental adaptability, insufficient ecological risk assessment, high application costs, and the lack of standardized evaluation systems. Addressing these challenges will be essential for advancing the practical deployment of synthetic microbiomes. This review provides a foundation for both mechanistic understanding and field application of synthetic microbiomes in soil health management.

Key words: synthetic microbiome, agricultural soil health, rhizosphere microbiome, rhizosphere interactions, field application