The scientists performed their experiments on the "Old Rotation," a cotton-growing experiment started by Auburn University professors more than 100 years ago.

Throughout those years, there were consistent yields of cotton, but the professors currently managing the study thought they could increase per-acre yields. So they asked for help from ARS' Conservation Systems Research Team at the agency's Soil Dynamics Laboratory, located on the Auburn campus.

The specialized deep tillage, which was also used with new herbicide-resistant varieties of cotton, corn and soybeans, gave the researchers dramatic results. With the new system, cotton yields increased an average of 22 percent. A record yield of 1,600 pounds of cotton lint per acre--more than 3.3 bales — was measured on one plot in 2001. The previous record, before no-till was introduced to the fields, was 1,490 pounds of cotton lint per acre.

In addition, yields of corn and wheat grown in rotation with cotton also increased. A record corn yield of 236 bushels per acre was harvested from one plot in 1999, and record wheat yields were harvested in 1999, 2000 and 2001.

Conservation-tillage farming provides many economic and environmental benefits to the farmer. Since the soil is not touched after the harvest until the next growing season, there is less erosion because of the residue left on the fields. Conservation-tillage also requires less machinery and less labor than conventional-tillage.

ARS is the U.S. Department of Agriculture's chief scientific research

agency.