Assessing cover crops' effect on resilience of the US Midwest Corn belt

Process-based model is an efficient tool for the analysis of agroecosystem's resilience to varying climate. The US Midwest corn-soybean agroecosystem is a key region for US agricultural economy. The changing climate could increase environmental degradation. Here we propose to assess cover crops as solution to improve the resilience in the US Corn Belt. Cover crops can be integrated into current corn-soybean rotation system, and effectively reduce nitrogen loss as well as reduce soil erosion. We use Ecosys, a mechanistically-comprehensive process-based model, to simulate effects of cover crops in seven agroecosystem sites in Midwest US. Ecosys contains a complete crop module, dynamically adjusts plants' nutrient allocation, includes microbial interactions with plants and integrates plant hydraulics that is closely related to photosynthesis, which makes Ecosys as a perfect model for the analysis of adoption of cover crops. We implement Ecosys for specific site with parameterization and calibration. The assessment of cover crops upon sustainability is shown in current and future climate, regarding crop yield, reduction of N-leaching and C sequestration. Our hypotheses are that cover crops can improve resilience and sustainability for corn-soybean rotation system.