Microirrigation for Sustainable Water Use (from W1128)
As the pressures on water resources continue, even microirrigation which is considered to be the most efficient irrigation method must be closely examined for additional water savings. The simplest and most common definition of irrigation scheduling is the determination of when and how much water to apply. Improvements in irrigation scheduling must be carefully balanced with the primary economic goal of microirrigation which is to improve crop yield and quality. Field testing of soil-based irrigation scheduling techniques will determine sensor location relative to plants and installation requirements for several the types of soil water sensors. Use of these sensors as appropriate irrigation scheduling tools will be evaluated. A web-based irrigation advisory program (http://oiso.bioe.orst.edu/RealTimeIrrigationSchedule/) developed at Oregon State
University will be evaluated under Idaho soil and climate conditions for sugar beets, malting barley, winter and spring wheat, silage corn, and alfalfa. Sustainable water use in the United States can be augmented by the use of non-potable waters through microirrigation systems. This requires careful selection of system components and appropriate system management. Use of non-potable water for irrigation has advantages since the water is often rich in nutrients beneficial to crops and use of the non-potable water for irrigation often reduces treatment costs and environmental impacts. Non-potable water use through microirrigation also has disadvantages since some of the water constituents may adversely impact soil quality and plant growth. One by-product of the dairy industry in Southern Idaho is a large quantity of lagoon water resulting from winter precipitation runoff, and wash
pen-milking center cleaning. Because this liquid effluent is high in N, P and K, it must be properly managed to avoid nutrient overloading. Removal of sediment-bound P by filtration would allow higher levels of effluent application per acre for more effective irrigation and N source utilization. Outcomes/Impacts: A grower-accessible, real-time measure of crop performance will be an invaluable tool as a check against any proposed microirrigation schedule. A technical session at a a national irrigation meeting will bring together experts representing different approaches to irrigation scheduling and will contribute to a more integrated approach to this field of research and education. Websites dedicated to soil- and plant-based irrigation scheduling approaches and delivery of ET-based information will allow growers to improve crop production and economics while reducing irrigation
withdrawals. Concentrated animal agriculture facility operators who use their effluent for irrigation will be able to determine whether microirrigation is a viable option. Selection of microirrigation equipment and components for livestock effluents will be easier for producers. Growers, scientists, and regulators will have increased knowledge about the safe reuse of reclaimed water.