We used the Decision Support System for Agrotechnology Transfer - Cropping Systems Model to compare yield and water productivity of common cropping systems in western Kansas. The study compared continuous corn, wheat, and grain sorghum, as well as rotations of corn-wheat, corn-wheat-grain sorghum, and corn-wheat-grain sorghum-corn.
Continuous crops and crop rotations were grown under various levels of irrigation, then yield and crop water productivity of continuous crops and crop rotations were then simulated through the model.
Corn water productivity was improved when grown in rotation with other crops. Furthermore under deficit irrigation corn grown in crop rotation with wheat produced higher yields, water productivity, and irrigation water use efficiency than continuous corn.
Under full irrigation, wheat in rotation produced higher simulated yields than continuous wheat. However under deficit irrigation, continuous wheat yielded better than wheat in rotation.
Grain sorghum under deficit irrigation had higher irrigation water use efficiency in both continuous cropping and crop rotation.
Publication: Araya, A., I. Kisekka, and P. H. Gowda. (2017). Evaluation of water-limited cropping systems in a semi-arid climate using DSSAT-CSM. Agricultural Systems.