Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: 1/15/2015
Publication Date: 11/10/2015
Citation: Trout, T.J., Dejonge, K.C. 2015. Deficit Irrigation of field crops does not increase water use efficiency. Proceedings article for the joint ASABE/IA Irrigation Symposium, Long Beach, CA Nov 10-12, 2015 (ASABE) none.
Technical Abstract: Deficit irrigation is often proposed as a method to stretch limited irrigation water supply and increase water use efficiency. A field study of field crops in the high plains shows that water use efficiency, in terms of irrigation water applied, often increases with deficit irrigation. However, in terms of water consumed (ETc) water use efficiency decreases with deficit irrigation. This results from an initial consumption of about 250 mm to produce yield, and the ability of crops to efficiently increase yield with incremental ETc increases up to the potential yield. This result implies, for growers whose irrigation water supply allocation is based on consumptive use, deficit irrigation would not produce the best economic return.