Projected Changes in Nitrate Leaching and Crop Yield in the Northeastern Great Plains of the United States

One region of the USA increasingly important to national corn and soybean production is a portion of the northern Great Plains from central North and South Dakota eastward to western Minnesota. This region has seen substantial changes in cropping history and agricultural production in recent decades. Given the predominance of rain-fed agriculture in this region, evaluating the impact of projected climate change on crop production and nitrogen loss is critical for concerns involving food security and environmental quality. Using a process-based crop model, gridded soil, gridded climate projections, and a stability zone production management concept, we simulated a corn-soy rotation using existing production field boundaries at 30-meter resolution for two periods (2040-2059 and 2080-2099) for two emissions scenarios (RCP 4.5 and 8.5) in four Northeastern Great Plains 4-digit HUC watersheds. Preliminary results suggest substantially different responses to projected climate based on yield stability zone when compared with historical simulations and observations, with position in the landscape being a key determinant in crop yields and nitrogen losses. Ultimately, the results from these simulations can be used to inform, modify and develop long-term precision management plans for individual agricultural fields and could be a useful tool for ensuring food security and environmental quality through the upscaling of traditional point-based crop model simulations under changing climatic conditions.