Soil plays an imperative role in building and maintaining sustainable and resilient food and water systems. Optimized soil management practices such as conservation tillage have been promoted to enhance soil health and sustain agricultural production in the context of climate change. However, most existing studies regarding conservation tillage were conducted at field and site levels, and its impacts on crop yields and water use patterns remain highly controversial, depending on diverse cropping systems and various environmental and ecological factors. The biogeochemical and hydrological responses of agroecosystems to conservation tillage are far from clear at broad scales, which has impeded our efforts to explore potential synergies among food security, soil health, and climate change adaptation and mitigation. In this study, we developed a conservation tillage module for a process-based agroecosystem model (DLEM-Ag). The improved model has been calibrated and evaluated against observations from a series of long-term conservation tillage sites. We then conducted a range of simulation experiments, driven by high-resolution environmental datasets, to investigate the effects of conservation tillage on crop yield, water productivity, and evapotranspiration under different climate scenarios across the Ohio River Basin.
Results/Conclusions
This study integrated model simulations and field-level data from several long-term conservation tillage sites across the Ohio River Basin. Our simulated crop yield, dry matter biomass, and soil water dynamics are favorably comparable with those from observations for both conventional tillage (CT) and no-tillage (NT) systems. Our preliminary results showed that NT could improve soil water storage relative to CT during the growing season. The grain yield and biomass were significantly improved in the NT system. Higher plant transpiration and lower soil evaporation were achieved in the NT system compared to the CT system. In general, the NT system could improve crop water productivity and soil water storage under different climate scenarios. Our results suggest that the NT practices could serve as a viable strategy for enhancing the resistance of agroecosystems to climate changes in the study region. The integrated modeling approach might be applied to other regions for assessing the impacts of conservation management practices on carbon and water budgets at broad scales.