Deficit Irrigation Management: Concepts and Implementation

Deficit irrigation management is commonly used in regions with inadequate water supplies to meet the full crop seasonal consumptive use or to conserve irrigation water. Deficit irrigation management requires careful attention to both strategic and logistical decisions for successful implementation. In regions with limited irrigation supplies, deficit irrigation might simply be applying one or two irrigations targeted to meet known critical crop development growth stages. With center pivot or microirrigation systems, deficit irrigation is more often a form of planned soil water deficits to utilize the limited irrigation capacity (flow rate per unit area) most effectively. For several horticultural crops, deficit irrigation is intentionally used to improve or enhance crop quality while conserving irrigation water. We will review selected literature on limited and deficit irrigation and discuss concepts of regulated deficit irrigation and partial root zone drying and the physical constraints necessary for successful deficit irrigation management.