Submitted to: Trade Journal Publication
Publication Type: Trade Journal
Publication Acceptance Date: 2/1/2010
Publication Date: 2/15/2010
Citation: Trout, T.J., Bausch, W.C., Buchleiter, G.W. 2010. Water Production Functions for High Plains Crops. Trade Journal Publication. Colorado Water 27(1):19-20.Colorado Water Institute, Fort Collins, Colorado
Technical Abstract: Water Production Functions for High Plains Crops Water consumptive use by a crop can be reduced through limited (deficit) irrigation. If the reduced consumptive use (CU) can be quantified, the saved water can be transferred to other users. If the value of the transferred water is greater than the farmer’s loss of income due to lower yields, limited irrigation provides a means to sustain irrigated agriculture and meet other water needs. The ARS Water Management Research Unit is conducting field studies to determine the water production functions for 4 crops common in the High Plains – corn, wheat, dry beans, and sunflower. Water production functions show the yield:water relationship based on the quantity of water consumptively used, and thus the marginal productivity of water used for crop production. Initial data on corn grown near Greeley, CO shows that the marginal productivity of consumed water is fairly constant as the deficit increases. This implies that, in terms of consumed water, there is no economic advantage to deficit irrigation and farmer profits would likely be higher fully irrigating a portion of a field rather than deficit irrigating the whole field. This information will help farmers decide how to respond to offers to sell or lease a portion or all of their irrigation water supplies to other uses.