EVAPOTRANSPIRATION AND YIELD OF CORN GROWN ON 3 HIGH-PLAINS SOILS

Soil properties that vary within a production area present management challenges to producers when mater supplies are limited. We conducted three experiments to determine the influence of soil type and differen t water management levels on corn (Zea mays L,) yield, evapotranspirat ion (ET), and water use efficiency. Short-season corn was grown at low population density in lysimeters containing monolithic soil cores of Pullman (fine, mixed, superactive, thermic Torrertic Paleustoll), Ulys ses (fine-silty, mixed, superactive, mesic Aridic Haplustoll), and Ama rillo (fine-loamy, mixed, thermic Aridic Paleustalf) soils, at a rain shelter facility in Bushland, TX. Dryland conditions were simulated in 1994 and 1995, with the soils receiving irrigations totaling either 5 0 or 150 mm in 1994 and either 120 or 200 mm in 1995. In 1996, water m anagement levels were expanded, with the soils receiving weekly irriga tion equivalent to 20, 50, 80, and 110% of measured ET, Grain yields f or the 3 yr ranged from 389 to 804 g m(-2) for the Pullman soil, 559 t o 899 g m(-2) for the Ulysses soil, and 438 to 736 g m(-2) for the Ama rillo soil. Low grain yields from corn in the Pullman soil were due to limited water extraction from the lower soil profile, El en under ful l irrigation (110%), grain yield and leaf area were lower for corn in the Amarillo soil than with the two other soils, possibly due to limit ed water availability, Soil type effects on corn water use and yield m ag require different water management strategies for optimum water use efficiency.