Submitted to: Proceedings of the Central Plains Irrigation Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/11/2011
Publication Date: 2/22/2011
Citation: Colaizzi, P.D., Evett, S.R., Howell, T.A. 2011. Corn production with Spray, LEPA, and SDI. In: Proceedings of the Central Plains Irrigation Conference, February 22-23,2011, Burlington, Colorado. p.52-67. Interpretive Summary: Irrigated crop production in the semi-arid Southern High Plains is dependent on the Ogallala Aquifer, which is declining because pumping for irrigation greatly exceeds natural recharge. This has resulted in declining well capacities, forcing producers to adopt irrigation management strategies using increasingly limited water. Most irrigation in the Southern High Plains is with center pivots equipped with low pressure spray nozzles; however, drip irrigation has been shown to produce greater cotton lint yield, with limited water compared with center pivot systems. Although drip irrigation costs almost twice as much as center pivots to install per acre, it continues to be adopted by producers seeking to stretch their water supplies. Corn is a relatively water sensitive crop and requires irrigation for profitable production. However, no data exists that directly compares corn response under drip and spray irrigation, which was the objective of this study. We found that in most cases, corn yield and water use were the same for drip and spray irrigation. Drip irrigation resulted in less water evaporated from the soil compared with spray, but this was not always enough to impact final grain yield. These results will assist producers in selecting the most appropriate irrigation technology, which has a significant impact on their profitability.
Technical Abstract: Corn, a major irrigated crop in the U.S. Great Plains, has a large irrigation requirement making efficient, effective irrigation technology important. The objective of this paper was to compare corn productivity for different irrigation methods and irrigation rates in 2009 and 2010 at Bushland, Texas. Irrigation methods included mid-elevation spray application (MESA), low elevation spray application (LESA), low energy precision application (LEPA), and subsurface drip irrigation (SDI). Each irrigation method was evaluated at four irrigation rates, which were 25, 50, 75, and 100% of meeting the full crop water requirement. There were no significant differences in grain yield and water use efficiency for MESA, LESA, and SDI for the 100% irrigation rate in 2009 and for all irrigation rates in 2010. In 2009, SDI resulted in significantly greater grain yield and water use efficiency compared with all other methods at the 50 and 75% irrigation rates; little measurable grain yield resulted for all methods at the 25% rate. However, 2009 was not a typical production year because an irrigation system failure occurred just before anthesis, and unusually high atmospheric demands followed, resulting in soil water shortages in all plots during the most water-sensitive development stages, with consistent lowering of grain yield. In both years, LEPA resulted in lower yield, soil water content, and water use efficiency compared with the other methods at the 75 and 100% rates, which was partially attributed to furrow dike erosion and plot runoff. The relative response of corn to MESA, LESA, LEPA, and SDI was much different compared with other crops that were evaluated in previous experiments; these included grain sorghum, soybean, and cotton.