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Water‐Yield Relationships for Irrigated and Dryland Wheat in the U.S. Southern Plains
Author(s) -
Musick Jack T.,
Jones Ordie R.,
Stewart Bobby A.,
Dusek Donald A.
Publication year - 1994
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1994.00021962008600060010x
Subject(s) - agronomy , evapotranspiration , sowing , water use efficiency , irrigation , dryland farming , environmental science , yield (engineering) , water use , precipitation , soil water , agriculture , biology , geography , soil science , ecology , materials science , meteorology , metallurgy
A climate with high evaporative demand and limited precipitation restrict yields of winter wheat ( Triticum aestivum L.) grown in the semiarid U.S. southern High Plains. Stress effects can be avoided or minimized by management practices that increase soil water storage at planting or by application of irrigation water. We analyzed a 178 crop‐year database of irrigated and dryland wheat data from Bushland, TX, to develop relationships that define the grain yield and water‐use efficiency (WUE) response to a wide range in seasonal evapotranspiration (ET) associated with water deficits and to evaluate yield response to stored soil water at planting. The ET‐grain yield relationship was determined as linear, with a regression slope of 1.22 kg grain per m3 ET above the ET threshold of 208 mm required to initiate grain yield. Maximum yields (>7.0 Mg ha −1 ) required 650 to 800 mm seasonal ET. Maximum yields observed in the combined database were 2.8 and 8.2 Mg ha −1 for dryland and irrigated wheat, respectively. The linear regression response of grain yield to soil water stored at planting, 1.57 kg m −3 , was significantly higher than the yield response to seasonal ET. Largely similar WUE values occurred over a wide range of seasonal ET within irrigated and dryland data sets; however, WUE values for irrigated wheat averaged about double the values for dryland wheat. A curvilinear relationship determined between WUE and yield emphasizes the importance of obtaining high yields for efficient water use.