Deficit Irrigation

When the level of irrigation supply is less than crop ET, deficit irrigation (DI) programs are needed to optimize the use of the limited water. In annual crops where yield and transpiration are linearly related, DI aims at achieving maximum profits by minimizing application losses and maximizing the use of stored soil water and seasonal rainfall. Crops that respond positively to mild water deficits are good candidates for DI programs that decrease irrigation water use while maintaining yield. DI programs for fruit trees and vines aim at inducing water deficits when they are least harmful to yields, including high evaporative demand periods. Achieving optimal use of limited water is accomplished by solving an optimization problem using knowledge of water availability and cost and net farm profits.