UNIVERSITY PARK, Pa. -- Crownvetch, the pink-flowered perennial planted along highways to control erosion, is an effective living mulch for cropland, says an agronomist in Penn State's College of Agricultural Sciences.

Those interested in seeing research and demonstration plots of crownvetch are invited to a living mulch tour from noon to 3:30 p.m on July 14 at Penn State's Agronomy Research Farm. The farm is at Research Gate B of the Russell E. Larson Agricultural Research Center, Rock Springs, nine miles southwest of State College on Route 45. Lunch will be provided at no cost.

"Crownvetch can be used as an alternative to terraces, contour strips and dead residue mulch," says Nate Hartwig, professor emeritus of weed science.

"When managed correctly, crownvetch forms a vegetative cover, virtually eliminating runoff of rainwater, topsoil, nutrients and pesticides," says Hartwig. "It also allows farmers to plant agronomic crops, rather than planting sod crops to reduce soil erosion."

Hartwig has been studying the use of crownvetch as a living mulch for corn, small grains and soybeans since 1973. His research compares test plots with no soil cover, plots with surface crop residue and plots with crownvetch.

"Tilled plots with no soil cover on a 14 percent slope can lose about 12 to 14 tons of topsoil per acre per year," says Hartwig. "Plots with cornstalk residue lose an average of one-quarter to one-half of a ton of topsoil per year. That's about a 95 percent reduction in soil loss.

"Plots with crownvetch show the most dramatic reduction, losing only about 50 pounds of topsoil per acre per year. That's about a 99 percent reduction. At the same time, the plant's roots penetrate deep into the soil, improving tilth and water infiltration."

At $10 a pound, crownvetch costs about $10 per acre to establish. "But once in place, it should last forever," says Hartwig. "It's almost impossible to kill it accidentally with herbicides. At the same time, the plant is easy to suppress so that it doesn't compete with crops. In the long run, it can be less expensive than other conservation measures."

Crownvetch is compatible with all crop rotations, including corn, soybeans, small grains, alfalfa and alfalfa/grass mixtures. It doesn't decrease crop production, and it requires no special tools or chemicals to manage it. "In addition, it has nutritional value equal to alfalfa, so it can be used as a forage," says Hartwig.

Crownvetch normally takes two to three years to become well established. "Once established, it fixes nitrogen, a portion of which becomes available to crops such as corn," says Hartwig. "Our research shows that yields of 100 bushels of corn per acre are possible in fields with a crownvetch cover without any added nitrogen."

Registration for the free tour will be accepted until July 2. To register, send your name, organization (if applicable) and address to Nate Hartwig by e-mail at nlh@psu.edu, by phone at 814-865-1906 or by mail at 116 A.S.I. Building, University Park, Pa. 16802.

For more information about using crownvetch as a living mulch, contact your county Penn State Cooperative Extension office, district conservationist or Nate Hartwig. Information on how the system works can be found in the 1999-2000 Agronomy Guide, available on the World Wide Web at http://AgGuide.agronomy.psu.edu. Paper copies of the guide are available at county extension offices or from the College of Agricultural Sciences Publications Distribution Center (call 814-865-6713).

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EDITORS: Nathan Hartwig can be reached at 814-865-1906.

Contacts: Kim Dionis KDionis@psu.edu 814-863-2703 814-865-1068 fax