Drip Irrigation of Corn in Northeast Arkansas

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 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 mapped primarily Convent fine sandy loam. 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 study period. Although the results of this study suggest that replacing 60% of the estimated soil water deficit with subsurface drip irrigation is sufficient for maximum corn yields, additional observations will be needed to develop drip irrigation recommendations for corn production.