Concepts in Deficit Irrigation: Defining a Basis for Effective Management

Deficit irrigation can be defined as an agricultural water management system in which less than 100% of the potential evapotranspiration can be provided by a combination of stored soil water, rainfall and irrigation, during the growing season. As water supplies decline and the cost of water increases, it is clear that producers are being driven toward deficit irrigation management. The implication of this management system is that some level of plant water stress is unavoidable. The challenge is to define a management system that will minimize the negative impact of the expected stress. Irrigation management requires choosing the timing and amount of water to be applied. Deficit irrigation management requires optimizing the timing and degree of plant stress, within the restriction of available water. This third, critical, concept greatly increases the complexity of the decision process. This presentation will incorporate a wide discussion of deficit irrigation concepts, with a focus on emerging technologies that can be applied to the detection and management of plant stress, within production environments.