Location: Soil and Water Management ResearchTitle: Corn and sorghum performance are affected by irrigation application method: SDI versus mid-elevation spray irrigation
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/10/2015
Publication Date: 3/10/2015
Citation: Evett, S.R., Brauer, D.K., Tolk, J.A., Colaizzi, P.D., Oshaughnessy, S.A. 2015. Corn and sorghum performance are affected by irrigation application method: SDI versus mid-elevation spray irrigation. Meeting Abstract. Seminar at the USDA-ARS laboratory, March 10, 2015.
Technical Abstract: Irrigation application method can impact crop water use and water use efficiency (WUE), but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through the 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 (ET) was measured using the weighing lysimeters and soil water content was measured using the neutron probe. 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 53 to 85 mm of water that was lost to evaporation early in the season (pre-plant to 25 days after planting) in 2013 and 2014, respectively. Sorghum, not a crop ordinarily considered for SDI, was grown successfully using SDI with yields averaging 6.48 Mg/ha, comparable to others reported for short season sorghum at Bushland, and with WUE larger than or comparable to that achieved with MESA. In the relatively dry 2013 season, SDI reduced overall corn water use by 147 mm while increasing yields by 1.88 Mg/ha (20%) and WUE by 0.64 kg/m3 (61%) compared with MESA full irrigation. Sorghum yield under SDI was compromised by an inadvertent irrigation scheduling mistake that stressed the crop during flowering, which resulted in aborted ovules and fewer grains per head at harvest, even though number of heads was not different between SDI and sprinkler irrigation.