By Sharon Dowdy
University of Georgia

Corn and soybeans are excellent crops for use in ethanol and biodiesel production, but chickens, cows and people like to eat the crops, too. University of Georgia engineers are searching for non-food crops that can be used to make alternative fuels.

The oilseed radish is one crop that could be used to produce biodiesel in Georgia, said Dan Geller, a biological engineer with the UGA College of Agricultural and Environmental Sciences.

Canadian cover crop

The radish is widely grown in Canada as a cover crop, or one that is planted to improve the soil and prevent erosion in fields. But it isn’t typically grown for food.

Its seed is about 40 percent oil by weight, said Nicholas Chammoun, a CAES graduate student working with Geller. This makes it an excellent candidate for the biodiesel market.

For his research, Chammoun had oilseed radish seeds crushed by the U.S. Department of Agriculture National Peanut Research Laboratory. The oil was then converted into biodiesel by the CAES biological and agricultural engineering department.

“This sounds like a short and easy process,” he said. “But it actually took a long time since there was very little data on converting oilseed radish oil to biodiesel.”

Engine-tested

Next, he had to prove the new biodiesel would actually work in diesel engines and perform as well or better than No. 2 diesel and other existing biodiesels.

The oilseed radish biodiesel passed the engine tests, performing much like No. 2 diesel, he said.

With the help of the UGA Center for Agribusiness and Economic Development, Chammoun determined whether farmers would benefit economically from growing the crop.

“No matter the crop, it will take land to produce it,” said John McKissick, director of the center. “It’s still a battle for food production over fuel production on the same limited land. In Georgia, food is still more economically viable.”

The economic research data on the radish as a biodiesel crop was also used to assess its economic potential as a Georgia cover crop.

“They would harvest in the spring, and the crop would also protect the soil in the winter,” Geller said.

Roots aerate soil

And as a cover crop, its extra-long tap root breaks up and aerates soil and draws up nutrients for the following crop, or one grown for food or fiber.

Georgia farmers could grow peanuts and cotton in the summer months and follow with a crop of oilseed radish in the fall.

“Oilseed radish isn’t grown for the food market, but it can be grown for the fuel market,” Geller said. “And it can be grown cheaper with a greater oil yield per dollar than soybean, and with lower inputs.”

The economic evaluation showed the oilseed radish had potential to be an economically viable crop for Georgia, McKissick said. But more research is needed to determine the yield and costs of producing the crop.

Crushers needed

Geller calls the university’s research results promising but notes there is one large missing piece to the puzzle.

“We can get the seed, and the agronomic data is available,” he said. “The farmers just need someone to crush the seed. The big kicker is which comes first, the farmer or the crusher?”

Crushers are companies that process seeds to extract oil.

If crushers are found, Geller says Georgia farmers could begin growing these new crops in a few years.

CAES researchers are also studying the use of algae, switchgrass and sunflower as oil sources for biodiesel production.