Comparing crop growth models across the contiguous USA with a focus on dry and warm spells

Efficient water use and sustainable crop production are vital for ensuring both food and water security amidst the growing global population and changing climate. With expected increases in hydroclimatic extremes under climate change, irrigated agriculture is projected to rise, further interlinking food and water security. Hence, the need for future crop yield projections has become more urgent, including knowledge about the accuracy of crop growth modeling in terms of crop yield and water consumption. To this end, our study evaluates two crop growth models—AquaCrop-OS and PCR-GLOBWB 2-WOFOST. The coupled hydrological-crop growth model PCR-GLOBWB 2-WOFOST was applied using both its original settings and harmonized with AquaCrop-OS input, resulting in two model experiments that were compared to the AquaCrop-OS results, allowing analyses of differences in both model structure and parametrizations. AquaCrop-OS and PCR-GLOBWB 2-WOFOST (with original and harmonized input) were used to simulate the yield of irrigated maize, soybean, winter wheat and spring wheat across the contiguous United States (CONUS) from 2001 to 2019. Model outputs were compared in terms of crop water consumption, biomass production, and crop yield and the model sensitivity under dry and warm conditions was evaluated.