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ARS Home » Southeast Area » Dawson, Georgia » National Peanut Research Laboratory » Research » Publications at this Location » Publication #246058
Title: Agronomic and economic effect of irrigation rate in corn

Author
item Lamb, Marshall
item Sorensen, Ronald - Ron
item Nuti, Russell
item Butts, Christopher - Chris
item Faircloth, Wilson
item EIGENBERG, DAVE - US Department Of State
item ROWLAND, DIANE - Texas A&M Agrilife

Submitted to: Plant Management Network
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/13/2010
Publication Date: 7/26/2011
Citation: Lamb, M.C., Sorensen, R.B., Nuti, R.C., Butts, C.L., Faircloth, W.H., Eigenberg, D., Rowland, D. 2011. Agronomic and economic effect of irrigation rate in corn. Plant Management Network. 114. Available: http://www.plantmanagementnetwork.org.

Interpretive Summary: Irrigation is essential to sustain corn yield and net returns during most years in the Southeast. Producers realize that irrigation is important as 79 percent of the corn acreage in Georgia is irrigated. Trends in increased irrigated acreage in Georgia for corn, cotton, and peanuts have been observed in recent years. However, demand for water resources due to urban expansion and interstate litigation coupled with repeated drought are collectively threatening irrigation water supplies in the Southeast. Next to land, abundant water for irrigation is arguably the most important natural resource in production agriculture. Data and information on corn grain yield, water use efficiency (WUE), water use efficiency from irrigation (WUEi), and the returns from irrigation in terms of water use efficiency (RWUEi) in corn is limited. A study was conducted at the USDA/ARS Multi-crop Irrigation Research Farm in Shellman, GA during the 2001-2008 crop years to examine the impact of irrigation amount rate on corn in Georgia. Irrigation amounts rates consisted of 100, 66, 33%, and a non-irrigated control. These data were separated based on precipitation received into average, below average, and above average precipitation groups. Irrigation consistently increased grain yield regardless of precipitation amount. Response for WUE, WUEi, and RWUEi was responded differently across irrigation rates depending on precipitation grouping. However, maximum yield, WUE, WUEi, and RWUEi resulted in the 100% irrigation treatment during the below average precipitation group. Thus, because of inconsistent rainfall distribution and resulting crop stress, corn in the humid Southeast region should be produced in fields with adequate irrigation capacity.

Technical Abstract: Although the Southeast U.S. receives an average annual precipitation of 1300 mm, corn (Zea mays L.) yield is often limited by erratic seasonal distributions. Irrigation is utilized to supplement precipitation during drought periods to sustain crop production. Studies were conducted from 2001 through 2008 at the USDA/ARS Multi-crop Irrigation Research Farm in Shellman, GA (84' 36' W, 30' 44' N) on a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults). Irrigation rates consisted of 100, 66, 33%, and a non-irrigated control. Grain yield, water use efficiency (WUE), water use efficiency for irrigation (WUEi), and net returns to WUEi (RWUEi) were separated based on precipitation received during the growing season into average, below average, and above average precipitation groups. Irrigation consistently increased grain yield regardless of precipitation amount. The highest grain yield resulted in the 100% irrigation treatment in the years of below average precipitation. Response for WUE, WUEi, and RWUEi was responded differently across irrigation rates depending on precipitation grouping. In the above average rainfall years, WUE responded inversely to irrigation amount. The highest WUE and WUEi occurred in the 100% irrigation rate during the below average rainfall years at 188.8 and 248.4 kg ha-1cm-1. The highest RWUEi also occurred in the 100% rate during the below average rainfall years at $17.62 ha-1 cm-1. Thus, because of erratic rainfall distribution and crop stress, corn in the humid Southeast region should be produced in fields with adequate irrigation capacity.