Impacts of Deficit Irrigation on Barley and Durum Wheat Production in Arizona: A Preliminary Report

Deficit irrigation is often considered an effective irrigation strategy to conserve water and has been tested in different crop production systems and under different environments. In this research study, we explored the impact of deficit irrigation in the arid Southwest region, particularly in central Arizona, on the production of durum wheat and grain barley using flood irrigation. The experiment was conducted at the University of Arizona Maricopa Agricultural Center in Maricopa, Arizona. We examined irrigation deficits of 12.5% and 25% and observed that a 12.5% deficit in irrigation led to 30% and 45% decline in grain yield for durum wheat and barley, respectively; however, the yield did not decline further under the 25% deficit irrigation treatment. Additionally, we did not record any changes in soil chemical properties or soil health. Our study concluded that under flood-irrigated durum wheat and barley, deficit irrigation may not be an economically viable strategy for water conservation in desert agroecosystems. However, this research also highlighted the need for similar research on drip- and sprinkler-irrigated small grain production systems.