GAYS MILLS, Wis. - Jake Wedeberg and his brother, John, like the idea of producing some of their own biodiesel fuel for their four diesel tractors and protein meal for use in feed for the 43 dairy cows on the Wedeberg farm near Gays Mills.

They're among six Organic Valley member farms - in Crawford, Vernon, Grant and Monroe counties - participating in a test of a mobile biodiesel system that the organic farmer cooperative finished putting together last year.

Housed in a trailer, the system was displayed and demonstrated last year at several events, including the Vernon County Fair and the Kickapoo Country Fair. Demonstrations were given this year at nine regional meetings for Organic Valley members in Wisconsin, Minnesota and Iowa.

The system is being used to process oilseeds - including camelina, flax, sunflowers and soybeans - at the six participating farms. "But we're willing to try any type of oilseed crop," said Zach Biermann, Organic Valley's biodiesel coordinator.

Sunflowers have an exceptionally high oil yield.

This year, the Wedebergs raised 11 acres of sunflowers and four acres of flax for processing into biodiesel and protein meal. They work well with the equipment farmers already use and are easy to grow, Jake said. The Wedebergs are using a conventional combine to harvest the two crops.

Earlier this fall, the Wedebergs were using the system to process sunflower seeds they harvested last year. "It's really easy to do on your farm," Jake said.

The study involving the six farms began earlier this year and will continue into next summer. It will determine how many farms are needed to support each portable system.

In the future, it's possible small groups of farmers within Organic Valley would buy a portable system for their group, Biermann said. That would be less expensive than each farm buying its own system.

The trailer contains equipment needed to extract, filter and turn the oil into biodiesel, which is thinner than oil, and to separate feed meal. The system can produce about 100 gallons of oil a day, which takes about 2,000 pounds of seeds. That also will produce about 1,200 pounds of protein meal for livestock.

An acre of sunflowers can produce up to 100 gallons of biodiesel.

"I like the idea of making biodiesel that works on the farm" to fuel tractors and other equipment, Wedeberg said. "It's really easy to produce on your farm."

He is involved in the project in order to practice sustainable agriculture, as a hedge against rising fuel costs and as a source of livestock feed.

Wedeberg will blend the biodiesel with conventional diesel fuel for use in his four diesel tractors, or run them on 100 percent biodiesel, which he has done before. He has been using biodiesel in his tractors for about five years, buying some of it through Organic Valley and making some himself using other equipment.