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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Publications at this Location » Publication #330296
Title: Crop water use by corn in the central high plains under full and deficit irrigation

Author
item TROUT, THOMAS - Retired ARS Employee
item DeJonge, Kendall

Submitted to: United States Committee of Irrigation and Drainage Engineering Conference
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2016
Publication Date: 10/11/2016
Citation: Trout, T.J., Dejonge, K.C. 2016. Crop water use by corn in the central high plains under full and deficit irrigation. United States Committee of Irrigation and Drainage Engineering Conference. Proceeedings on the 9th Int'l conf. on irrigation and drainage. pp.69-78.

Interpretive Summary:

Technical Abstract: Corn crop water use (evapotranspiration, ET) was measured during a four year study at the USDA-ARS Limited Irrigation Research Farm near Greeley, Colo. Replicated corn plots were irrigated by surface drip application to meet full water use requirements and at 5 reduced levels to measure the effects of deficit irrigation on crop response and yield. Crop water use was measured by water balance in which precipitation and irrigation inputs were carefully measured, irrigation was scheduled to avoid deep percolation loss, and soil water content was measured at least twice per week. Seasonal corn water use under full irrigation ranged from 616 to 648 mm and averaged 633 mm. With surface drip irrigation and reduced tillage, surface evaporation was only about 10% of total ET. Mid-season basal crop coefficients for a tall crop (alfalfa) reference varied between 1.0 and 1.1, which is about 10% higher than is recommended in the literature. Under deficit irrigation, deep percolation was largely avoided and seasonal change in soil water storage was relatively small, so crop water use was nearly equal to the amount of precipitation and irrigation water applied. The reduction in ET with deficit irrigation was related to soil water deficit and a reduction in crop canopy cover.