Spatiotemporal diversification enables sustainable cotton-soybean production with enhanced yield and reduced emissions

Abstract

Conventional monoculture and static intercropping systems exacerbate soil degradation, greenhouse gas emissions, and yield stagnation, failing to reconcile productivity with environmental sustainability. To address these challenges, we developed a novel alternate strip intercropping (ASI) system that integrates annual row-swapping between cotton and soybean, leveraging spatiotemporal diversification to optimize resource use and soil functionality. Through a six-year field experiment in the North China Plain, we tested the hypothesis that ASI enhances productivity, soil health, and nitrogen cycling efficiency while reducing greenhouse gas emissions. Compared to monoculture, ASI increased cotton and soybean yields by 28 % and 21 %, respectively, achieving a land equivalent ratio of 1.26—surpassing traditional intercropping (1.13)—through improved light, water, and nutrient partitioning. Soil organic carbon rose by 21 %, driven by microbial restructuring (e.g., 83–87 % higher arbuscular mycorrhizal fungi colonization), which enhanced aggregate stability and nutrient retention. Critically, ASI reduced cumulative N₂O emissions by 18–23 % (cotton) and 6–11 % (soybean) via optimized nitrogen cycling and microbial suppression of denitrification, decoupling yield gains from emission intensity. Economic returns increased by 24–122 % over conventional systems. Multidimensional sustainability indices, integrating agronomic, ecological, and socioeconomic metrics, revealed 40–188 % improvements under ASI compared to conventional practices. These outcomes were driven by complementary root architectures and rhizosphere interactions that fostered carbon sequestration and nitrogen use efficiency. This system supports Sustainable Development Goals 2 (Zero Hunger) and 13 (Climate Action) by demonstrating a pathway toward climate-resilient agroecosystem. Within the studied temperate environment, ASI reconciles yield-environment trade-offs, suggesting a scalable approach for cleaner production in similar agroecosystems.