Projecting Future Crop Yields under Impending Climate Change: A Study into the Importance of Soil Moisture and Soil Organic Carbon

This study presents a top-down, bottom-up modeling framework to investigate the effects of future climate on crop production in an intensively managed watershed of the Mississippi River Basin, a world leading crop producer. Specifically, this study will examine how climate modification will alter soil moisture, soil organic carbon, and ultimately crop yields in the Obion River, TN. Representative hydrologic response areas in the Obion River watershed are identified using the Variable Infiltration Capacity regional hydrologic model. This identification criterion considers both soil properties and changing hydrology, through the runoff coefficient and slope. Select hillslopes are further chosen in the representative areas and the physically based, hillslope-scale model, Water Erosion Prediction Project, is used to examine the cause-effect relations between management and climate. This includes changes in soil moisture, soil organic carbon loss, and soil erosion until 2050 under established climate scenarios to aid in the development of sustainable solutions. Results will indicate that effects from this changing climate are visible through a decrease in the utilization of available water and a decrease in soil organic carbon, with negative consequences to soil and water quality. Furthermore, these effects have a projected decrease to crop yields. Foreseeing potential impacts, through improvements to current management practices, could help improve future outcomes.