Crop Rotation Diversity and Climate Change Impacts on Water Use Efficiency in two Contrasting Soil Textures

Cover cropping and diversifying corn-soybean rotation by including a wheat crop is recommended as a best management practice for promoting soil ecosystem services but can affect water use efficiency (WUE). Water can be the most limiting resource in agriculture, and predictions are for precipitation patterns to become affected by climate change. To measure the impact of crop rotation and climate change on evapotranspiration, yield, and WUE, direct measurements of the water budget are required, which are best done with high precision weighing lysimeter. This thesis is a study of the short-term impact of diversification and warming on evapotranspiration, yield, and WUE. Soybean yields were 19% higher, and growing season evapotranspiration was 14% higher after 3 years of crop rotation diversification, but WUE was not significantly affected. Winter warming caused a 14% and 19% reduction in corn and soybean yields, and a 12% reduction in soybean WUE.