UVM tests aerial planting of cover crops

Winter rye cover crop seed is loaded into a helicoptor for aerial seeding on corn fields planted by Cottonwood Stables and Fitzgerald Farm in Colchester. From right are Jeff Senesac of Cottonwood Stables, Jeff Sanders of UVM Extension, and, at left, pilot for Mansfield Heliflight/Hard Time Helicopters. Photo by Kirsten Workman/UVM Extension

A test program by the University of Vermont Cooperative Extension to plant cover crops on northern Vermont farm fields by sowing seeds from the air is part of an effort by the state to help farmers lock nutrients into the soil and stop the flow of fertilizers into Lake Champlain, according to Heather Darby, an agronomics professor at the University of Vermont.

The pilot project was slated to seed 1,000 acres, but demand pushed the program to expand to 2,500 acres of cover crops in Addison, Chittenden, Franklin and Orleans counties. There is a waiting list for 2,000 acres, and much of that won’t be planted in time, Darby said. The cover crops are sown over ripening corn fields and the plants are established before the corn is harvested.

“The interest is there and the farmers that have had it done are really excited about it,” Darby said.

Some unexpected wrinkles slowed down the program’s first year, she said. The first contracted helicopter broke down. Eventually, the program’s coordinators contracted with Mansfield Heliflight in Milton, which found a helicopter with the necessary equipment in Texas, but it had to be transported to Vermont by land.

The helicopter was able to disperse 500 pounds of seed in a matter of seconds, but there was trouble keeping up with that pace on the ground. The spread-out geography of Vermont’s farmlands slowed the process, as the helicopter needed to return frequently to a central staging area to reload seed. And unusually high winds kept the operation grounded during otherwise good planting weather.

“We learned a lot, I will say that,” Darby said.

The program succeeded in helping northern Vermont farmers get a critical jump on planting cover crops. While aerial seeding has been used for years in warmer climates, it’s just beginning to be tested in northern farmland, said Paul Gross, an officer at Michigan State University Cooperative Extension, which is piloting a similar program. Many northern corn-growers can’t harvest their fields early enough to plant cover crops by hand before the killing frost comes, he said.

“We’re trying to get our cover crops established and we don’t have a lot of time,” Gross said.

The timing for aerial seeding seems to work out well for farmers, Gross said. While the corn is still standing in the field, cover crops get a chance to become embedded in the soil. Also, agricultural pilots are usually free during the late summer and early fall and can be hired fairly cheaply, he said. Once harvest time rolls around, cover crops are well established, thus avoiding a time when the soil might be bare and exposed to the elements.

Cover crops, which can include rye, switch-grass and oats, serve a three-fold purpose, said James Adams, a soil scientist with the Brattleboro branch of the Natural Resource Conservation Service: They add nitrogen to the soil, increase water retention in times of drought and curb topsoil erosion. This last function is vital to New England farmers, as there is little enough soil, as it is.

“Typically our topsoil at this part of the world is 6 inches,” Adams said. “It takes about 500 years to really develop an inch of soil.”

The aerial planting project is an extension of the state’s efforts to encourage the state’s farmers to use cover crops to build up soil health and to cut down on fertilizer use, Darby said. It’s especially important to plant cover crops in corn fields, as the fields often lay bare of vegetation after the growing season, she said. Currently, Vermont has some 90,000 acres in corn production.

In response to water quality issues in the Lake Champlain watershed, the state has been subsidizing cover cropping since 2007. The program has been wildly popular, Darby said. In its first year, the state subsidized roughly 1,000 acres of cover crops; this past year, it helped pay for some 8,000 acres. To test out planting by helicopter, the state kicked in some additional funds. Federal money is also available to help farmers plant cover crop.

The University of Vermont Cooperative Extension will spend the winter months assessing the program’s first year and finding ways to expand it in the future, Darby said.

Winter rye that was sown by air a month earlier onto a field of standing corn is well established a month later, after the corn has been harvested by farmer Harold DeGraaf of DeGraaf Dairy in Richmond. Photo by Kirsten Workman/UVM Extension