Risky Business?
Pivot irrigation on corn in West Tennessee

The number of irrigated cornfields in West Tennessee is increasing, and researchers with the University of Tennessee Institute of Agriculture are releasing study results to help producers determine whether irrigating their fields would be profitable. Image by B. Brown, courtesy UTIA. Download image. 

KNOXVILLE, Tenn. — Driving through West Tennessee, you may have noticed more cornfields with center-pivot irrigation; after all, corn prices and demand have recently been at historic highs, and irrigation increases and stabilizes corn yields. However, researchers at the University of Tennessee Institute of Agriculture conducted a study to determine whether it is profitable for West Tennessee producers to be irrigating their cornfields.
“There are many agronomic benefits from irrigating corn in Tennessee, but the profitability of irrigating corn is unclear,” says Chris Boyer, assistant professor in UT’s Department of Agricultural and Resource Economics and lead researcher for this study.
The recent rise in corn prices has some farmers running numbers to see if corn irrigation is profitable for their operations. Irrigation of grain crops in humid regions in the Southeast has grown in the past several years. Most humid regions in the U.S. receive enough annual rainfall to produce corn without irrigation; however, the purpose of irrigation is to supplement rain-fed corn production during periodic short-term droughts.
Timely supplemental irrigation in humid regions can provide benefits such as:
·         stabilizing yields or reducing downside yield risk
·         increasing yields
·         helping to reduce crop disease.
Farmers have reaped the benefits of increased corn prices in recent years, but why have prices increased? Boyer says the upward shift in corn prices since 2006 has been the subject of much debate, but most analysts agree that multiple factors were involved:
·         growing demand for grains
·         rising meat consumption
·         expanding biofuel production
·         increasing cost of production
Only 3 percent of harvested corn area was irrigated in Tennessee in 2007. One potential reason for this is center-pivot irrigation systems are more expensive to install on smaller, irregularly shaped fields that are common in Tennessee.
The UT study reveals that corn price and field size are vital factors in determining profitability for corn irrigation in West Tennessee.
“We find that corn irrigation has only recently become profitable for fields over 125 acres with the rise in corn prices since the late 2000s,” says Boyer.
However, investing in corn irrigation in Tennessee is still a gamble. The UT study also concluded that corn prices would need to stay high for extended periods of time for irrigated production to remain profitable after investment in center-pivot irrigation.
The UT Institute of Agriculture provides instruction, research and outreach through the UT College of Agricultural Sciences and Natural Resources, the UT College of Veterinary Medicine, UT AgResearch, including its system of 10 research and education centers, and UT Extension offices in every county in the state.

Chris Boyer, Assistant Professor, Department of Agricultural and Resource Economics, 865-974-7468, cboyer3@utk.edu