Improving crop water use efficiency and water conservation

A better understanding of plant water use is necessary for irrigation systems that improve efficiency. The objective of this project is to increase crop water use efficiency without sacrificing yield or quality by using regulated deficit irrigation (RDI) based on crop developmental stage and evapotranspiration data. The approach is to monitor soil moisture depletion patterns and weather variables like solar radiation, temperature, wind and humidity. Irrigation is then scheduled based on crop evapotranspiration (ETc) using modified FAO crop coefficients. The effects of irrigating at 25, 50, 75 or 100% ETc on leaf gas exchange, and water relations, yield, quality, water use efficiency and water savings are measured. Benefits from this research are improved on-farm water conservation; reduced production costs related to water supply; increased water availability for non-agriculture uses; improved knowledge of drought effects on plant physiology, development and yield.