USDA Researchers Help Farmers Preserve Tennessee Valley Soils

By Tara Weaver-Missick
August 24, 1999

Auburn, Ala., Aug. 24—U.S. Department of Agriculture and Auburn University scientists are teaming up on a joint project to help cotton growers correct soil problems in the Tennessee Valley, which includes Tennessee and parts of Alabama, Mississippi, Kentucky, Georgia, North Carolina and Virginia.

“Although the land is very fertile, the soils in this area are heavily eroded and heavily compacted, and plant roots don’t extend very deep into the soil,” said Agricultural Research Service Administrator Floyd P. Horn. “About 60 percent of the soil in the Valley is highly erodible. Years of conventional tillage, coupled with little crop rotation, have severely depleted the soil organic matter, in some areas to less than 1 percent.”

Conservation agronomist Ben Moore with USDA’s Natural Resources Conservation Service in Troy, Ala., has worked with Valley farmers to help them comply with conservation management alternatives required by the Food Security Act of 1985. Growers who followed these conservation practices in earlier years had reduced yields. “That’s mainly because crops previously grown under conservation tillage were not as competitive as those grown under conventional tillage,” Moore said.

Agronomist D. Wayne Reeves and agricultural engineer Randy L. Raper, with ARS’ National Soil Dynamics Laboratory, in Auburn, Ala., were asked to help growers develop soil management systems that would protect the soil from erosion, which also allows them to maintain or improve cotton yields, reduce input costsand improve soil quality.

In field studies, Reeves found deep tilling to 17 inches and planting a rye cover crop in fall increases yields and reduces soil compaction. Three-year average yields for this system were about 1,040 pounds of lint per acre.

“Our best conservation tillage treatment gave yields that were 14 percent higher than conventional tillage and 18 percent higher than no tillage without using a cover crop, the system Tennessee Valley farmers adopted when they first went to conservation tillage,” Reeves said. "At current prices for cotton, fall deep tillage in combination with a rye cover crop paid for itself more than three times over."

An in-depth article appears in the August issue of Agricultural Research magazine. The story is also on the World Wide Web at:

/is/AR/archive/aug99/tenn0899.htm

Scientific contact: D. Wayne Reeves and Randy L. Raper, ARS National Soil Dynamics Laboratory, Auburn, Ala., phone (334) 844-4666 [Reeves], (334) 844-4654 [Raper], wreeves@acesag.auburn.edu, rlraper@eng.auburn.edu.