Warm-season forages for cattle herds and deficit irrigation to be studied


WASHINGTON — Two projects proposed by University of Tennessee Institute of Agriculture researchers have received nearly $685,000 in funding in the most recent round of USDA Conservation Innovation Grants. Announced on April 4, the prestigious grants are for projects geared toward innovative adaptations producers can make in response to drought.

UTIA awardees included Dr. Justin Rhinehart, an assistant professor and beef cattle specialist in the Department of Animal Science, and Dr. Brian Leib, an associate professor and irrigation specialist in the Department of Biosystems Engineering and Soil Science.

Rhinehart will lead a three-state effort to examine and
deliver a comprehensive and transformative approach to forage production to growers across the region. Cooperating with colleagues from the University of Kentucky and the University of Arkansas, Rhinehart expects the effort to impact producers’ ability to respond to drought over the long-term.

“Short-term drought response is important,” Rhinehart said, “But innovation in forage production systems is essential to ensure long-term sustainability and profitability. In our region, particularly Tennessee, Kentucky and Arkansas, we have the fundamental problem that our pastures are based primarily on cool-season perennial forages. These are normally challenged during summer months when they become semi-dormant.” Rhinehart goes on to explain that during periods of long-term drought, the challenge to these grasses is compounded when forages with poor drought-tolerance are repeatedly established following successive drought cycles.

The project will perform side-by-side comparisons of forages to demonstrate actual drought response, beef production, stocking rates, and economic outcomes based on field conditions over two summers. “Because the region is dominated by cow-calf production systems, and reproductive performance is critical, we plan to use heifers in grazing demonstrations,” said Rhinehart. Forages to be studied include switchgrass, eastern gamagrass, big bluestem and indiangrass (in a blend), bermudagrass and crabgrass. Information from the demonstrations will be used to enhance the understanding of how these forages options can fit into cow-calf, stocker, and grass-finishing operations in the fescue belt.

The project,
Coping with Drought in Beef Cattle Production: Long-term Innovation through Optimal Warm-season Forage Systems,” was awarded nearly $399,000, and Tennessee research sites will include the Highland Rim AgResearch and Education Center in Springfield and Ames Plantation in Grand Junction.

The focus of the second project receiving funding is deficit irrigation. Dr. Brian Leib explains that in West Tennessee and the Mid South – humid regions – deficit irrigation can be
a means to apply less water than standard irrigation during drought and thus improve the sustainability of row crop production. “Deficit irrigation in humid regions means not supplying the crop with all the water it could use and not keeping the soil-water profile at field capacity, a condition known as full irrigation,” said Leib. “Deficit irrigation makes use of what rainfall is available while full irrigation does not. In a full irrigation scenario, there is little or no storage capacity remaining in the soil and additional rainfall could saturate the soil, leach fertilizer, and/or run-off the soil surface." Leib explained that deficit irrigation does not cause soil saturation and related complications. It also alleviates water competition with nearby populations during periods of drought.

Leib says the purpose of his project is to promote deficit irrigation for humid regions as a means to apply less water for drought mitigation. He plans to work with cotton and soybeans at the West Tennessee AgResearch and Education Center in Jackson as well as with private producers at three Tennessee sites: 
Richard Jamison of Haywood County, Willie German of Fayette County and Eugene Pugh of Lauderdale County. The project, titled “Deficit Irrigation of Row Crops Provides Drought Mitigation, Environmental Protection, and Optimized Yield in Humid Regions,” was awarded nearly $285,000.



Dr. Justin Rhinehart, Department of Animal Science,

Dr. Brian Leib, Department of Biosytems Engineering and Soil Science, 865-974-8846


USDA Conservation Innovation Awards -

About the UT Institute of Agriculture
The UT Institute of Agriculture provides instruction, research and public service 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.