Legume intercropping in tea plantations modulates soil microbiome for enhanced profitability: A mechanistic link to economic returns

While legume intercropping is known to improve soil health in tea plantations, the economic benefits mediated through soil microbial mechanisms remain unquantified, limiting evidence-based agricultural decisions. Through field experiments comparing clover-tea and peanut-tea intercropping systems with monoculture controls, we demonstrate that both intercropping systems significantly reshape soil bacterial communities and enhance nutrient cycling functions. These ecological improvements translate directly into measurable economic gains: peanut-tea intercropping generates substantial additional revenue through peanut sales, while clover-tea intercropping significantly reduces production costs through decreased irrigation and weed management requirements. Economic analysis confirms both systems maintain financial advantage under market price fluctuations, establishing the first direct evidence linking soil microbiome restructuring to economic benefits in tea plantations. Our findings provide farmers with science-based intercropping strategies that enhance profitability while reducing chemical inputs, supporting the global tea industry's transition toward sustainable intensification practices. • Crop rotation enhances soil fertility, promoting tea yield & quality. • Soil improvement benefits enzymatic activity and bacterial community. • Intercropping optimizes soil ecosystem and productivity. • Sustainable farming practices yield economic and environmental benefits.