The Uncertainty of Crop Models in Irrigation Optimization

ABSTRACT THIS research concerns economic optimization of ir-rigation water use. Statistical decision theory is employed in the analyisis, and particular attention is given to questions of uncertainty and utility. The theoretical framework is applied to a case study involving farmers operating with a limited water supply. Uncer-tainty in predictions of crop yield were quantified. This uncertainty is shown to be substantial and pervasive. Decision theory was used to select optimal cropping pat-terns for each of six farmers. The cropping patterns con-sidered include various combinations of two different crops and fallow land. Case study results indicate that optimal irrigation strategies selected for individual farmers in the face of the uncertainty in crop yield models may differ substantially from strategies selected without regard for uncertainty and utility. These optimal strategies will be more consistent with the preferences of the individual farmers.