A Crop Simulation Model for Predicting Yield and Fate of Nitrogen in Irrigated Potato Rotation Cropping System

3USDA-ARS, Crops Systems and Global Change Laboratory, Beltsville, Maryland Simulation models are valuable tools to evaluate soil processes, crop growth, and production responses under varied agroclimatic and input-management production conditions. In this study, an upgraded potato (Solanum tuberosum L.) crop growth simulation model (CSPotato) was integrated with a multi-year, multi-crop simulation model (CropSystVB). The integrated CropSystVB-CSPotato model facilitated prediction of soil processes, and growth and yields of different crops in a potato rotation system under center pivot irrigation. The integrated model was validated using two years (2001-2002) of field data on ‘Ranger Russet’ cultivar grown in a Quincy fine sand in the Pacific Northwest Columbia Basin production region under different nitrogen-management practices. This study showed good agreement between the measured and predicted yields as well as N uptake across different N management practices in both years. The predicted water as well as nitrogen drainage below the potato rooting depth (0.6 m) was greater in 2002 than that in 2001. This study demonstrated that the upgraded potato model integrated with CropSystVB can be used as a valuable decision tool to predict the crop yields, fate, and transport of N in irrigated potato rotation cropping systems.