|Evett, Steven - Steve|
Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: 4/10/2015
Publication Date: 11/10/2015
Citation: Tolk, J.A., Evett, S.R. 2015. Do soil textural properties affect water use efficiency?. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE). CDROM: Paper#152143931.
Interpretive Summary: Fresh water available for agriculture is decreasing world wide because of decreases in supply and increases in competition by non-agricultural uses. A better understanding of the interaction between crops and soil water is needed to better utilize the water available for crop production. Soil texture, defined by the percentages of sand, silt, and clay particles it contains, affects many soil qualities. It controls how much water a soil can contain and how easily it releases the water to the plant. It can make the soil warmer or colder. It can make it easier or harder for the plant to spread its roots to get food and water. We conducted many years of experiments on corn, cotton, grain sorghum, and sunflower to see how soil texture affects these crops' ability to produce grain or lint. We found that how easily a crop can release soil water is important in a dry, hot climate when the crop is not receiving much water. Temperature is especially important for cotton. For a plant to use water efficiently (water use efficiency), awareness of the soil’s texture qualities is important.
Technical Abstract: The Soil-Plant-Environment Research (SPER) facility at USDA-ARS, Bushland, TX, was conceived by Terry A. Howell, Sr., and developed by the evapotranspiration (ET) research scientists at Bushland. It consists of a rain shelter and 48 weighing lysimeters containing monolithic soil cores of four soil textural classes, which are the Pullman clay loam, Ulysses silt loam, Amarillo sandy loam, and the Vingo fine sand. Since its opening in 1990, numerous irrigation research projects have evaluated the effect of deficit irrigation and soil profile textural properties on the water use efficiency of corn, cotton, grain sorghum, and sunflower. This research has demonstrated how soil water evaporation and soil hydraulic characteristics have, or in some cases, have not affected crop production and water use efficiency (WUE) defined as the ratio of marketable yield (Y) to ET, or Y/ET. The most important overall findings are that: 1) soil textural class does in several cases have important effects on crop water use and yield, even with full irrigation; and 2) soil textural class effects on crop water use, yield, and WUE are increased when irrigation is limited, increasing the need for careful irrigation management