Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/14/2015
Publication Date: 4/14/2015
Citation: Evett, S.R., Brauer, D.K., Colaizzi, P.D., Tolk, J.A., Oshaughnessy, S.A. 2015. SDI versus MESA Irrigation. Meeting Abstract. Presentation at NRCS irrigation workshop, 4/4/2015, Boise City, Oklahoma.
Technical Abstract: It is known that irrigation application method can impact crop water use and water use efficiency, but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through planting, early growth and yield development stages. Grain corn (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) were grown on four large weighing lysimeters at Bushland, Texas in 2013 (corn) and 2014 (sorghum). Two of the lysimeters and surrounding fields were irrigated by subsurface drip irrigation (SDI) and the other two were irrigated by mid elevation spray application (MESA). Crop evapotranspiration (ETc) was measured using the weighing lysimeters and soil water content was measured using the neutron probe and electromagnetic sensors. Periodic measurements of plant height, width, leaf area index and biomass were made, and final biomass and yield were measured. Micrometeorological measurements included incoming and outgoing short and long wave radiation, soil heat flux, precipitation, air temperature and humidity and wind speed. Irrigation amounts were metered. Compared with MESA irrigation, using SDI saved from 2.5 to 2.2 inches of water that was lost to evaporation early in the season (pre-plant to 25 days after planting) in 2013 and 2014, respectively. While sorghum, particularly short season sorghum, is not a crop ordinarily considered for SDI, it was grown successfully using SDI with yields averaging 120 bu/acre, comparable to others reported for short season sorghum at Bushland. In the relatively dry 2013 season, SDI increased corn yields by 35 bu/acre (20%) compared with MESA irrigation, while reducing overall corn water use by 3.6 inches. At pumping costs of $5 to $9 per acre-inch saving 5 inches of water with corn resulted in saving $25 to $45 per acre in pumping cost. Saving 4 inches of water with sorghum resulted in saving $20 to $36 per acre