|Vories, Earl - Earl|
Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2008
Publication Date: 3/21/2009
Citation: Vories, E.D., Tacker, P., Lancaster, S.W., Glover, R.E. 2009. Subsurface Drip Irrigation of Corn in the United States Mid-South. Agricultural Water Management. 96(6):912-916. Interpretive Summary: Rainfall in the midsouthern US is sufficient to produce corn without irrigation in most years; however, timely irrigation has been shown to increase yields. The increased interest in ethanol fuels is expected to lead to increases in US corn production. However, corn has a relatively high irrigation requirement and drip irrigation is one possible way to reduce the water needs for producing corn. Research conducted at the University of Arkansas Northeast Research and Extension Center showed a large yield reduction without irrigation in 2002, the year with the least rainfall during the growing season. Because two of the three years of the study experienced wetter than average growing seasons, additional observations will be needed to develop drip irrigation recommendations for corn production. Improved guidelines for corn irrigation will help to meet the country's need for more ethanol fuel without exceeding our available water supplies, which will benefit everyone throughout the US and the world.
Technical Abstract: Rainfall in the midsouthern US is sufficient to produce corn (Zea mays L.) without irrigation in most years; however, timely irrigation of corn has been shown to increase yields. The recent interest in ethanol fuels is expected to lead to increases in US corn production, and subsurface drip irrigation (SDI) is one possible way to reduce water requirements. The objective of this study was to determine the response of SDI-irrigated corn produced in the Mid-South. Field studies were conducted at the University of Arkansas Northeast Research and Extension Center at Keiser during the 2002 through 2004 growing seasons. The soil was mixed, with areas of fine sandy loam, loamy sand, and silty clay. Subsurface drip irrigation (SDI) tubing was placed under every row at a depth of approximately 30 cm. The study was designed as a randomized complete block with a split plot arrangement of treatments. The whole plot treatment was irrigation with three irrigation levels. The split plot treatment was hybrid, with three hybrids of different relative maturities. Although the three-year means indicated significantly lower yields for a nonirrigated treatment, no significant differences were observed among the treatments in 2003 or 2004. A large difference was observed in 2002, the year with the least rainfall during the study period, but no difference was detected between the two irrigated treatments in any year. The treatment with the lower water application had the higher irrigation water use efficiency and irrigation water use efficiency was greatest in 2002, the year with the least rain during the growing season. Although the results of this study suggest that replacing 60% of the estimated daily evapotranspiration with SDI is sufficient for maximum corn yields, additional observations will be needed to develop drip irrigation recommendations for corn production. Improved weather forecasting and crop coefficient functions developed specifically for the region should also contribute to more efficient irrigation management.