Harnessing Rhizosphere Microbiota through Root-Root Interaction to Optimize Productivity in Maize-Soybean Intercropping
Intercropping system increase biodiversity and complementary interactions among crops to enhance ecosystem functions, thereby improving nutrient efficiency and grain yield. However, the belowground interspecific facilitation mechanisms between intercropped species remain poorly understood. In this study, we investigated the roles of microbiota shifting in maize growth and nutrient acquisition under root-root interaction conditions in a maize-soybean intercropping system. Through microbiota transplantation, gnotobiotic assays, and functional microbe validation, we demonstrated that microbiota shifting driven by root-root interaction was essential for interspecies facilitation. The interspecific shift of microbiota from soybean to maize confer the maize growth promotion and nutrient acquisition. Based on these discoveries, we optimize the existing maize-soybean strip intercropping system through reduce the distance from 70 cm to 30 cm. Under this the nutrient acquisition of maize was enhanced and the yield of maize was improved by 10.8%-11.2%, soybean grain yield by 30.6%-45.1%. Taken together, we revealed the essential roles of microbial community shifting at context of root-root interaction in the intercropping system, providing a feasible strategy and theory for the intercropping system optimization.