Published on 10/11/00

UGA, Farmers Seek to Replace Chemical

With help from University of Georgia experts, Georgia farmers think they may have found a simple replacement for a chemical they hoped they'd never lose.

Farmers would keep on using methyl bromide to control soil-borne diseases of vegetable crops if they could. But they can't. Now defined as a chemical that depletes the ozone layer, methyl bromide will be phased out by 2005, a government ruling that worries farmers.

Replacing Methyl Bromide

"Methyl bromide is very important to us," said Bill Brim, a Tifton, Ga., farmer. "Right now, we're just trying to figure out what we're going to do when they take it away from us."

In a joint effort with the UGA Coastal Plain Experiment Station in Tifton, Ga., Brim and other farmers believe they've found a safer replacement: compost.

A high-quality compost of the perfect mixture of yard waste, gin trash, culled vegetables and poultry litter, they say, could help protect plants from disease. The compost could make fertilizer and irrigation more effective and help the environment, too.

Because of the warm climate and long growing seasons in the Southeast, vegetable crops are highly susceptible to disease. If vegetable growers can't control those diseases, they can't continue to farm, said David Langston, an Extension plant pathologist with the UGA College of Agricultural and Environmental Sciences.

Composting to Increase Beneficial Organisms

Soil in the Southeast, particularly in south Georgia, is extremely sandy. Nutrients can leach quickly through this soil.

The sandy soils have little organic matter. And intensive tilling speeds the breakdown of the little there is. "Most soil in this area has less than 1 percent organic matter," said Keith Rucker, a Tift County extension agent.

Soil contains microscopic pathogens that can damage plants, Rucker said. But it also contains beneficial organisms that can suppress the pathogens. Research has shown that compost can increase the number of beneficial organisms, improve the soil and suppress diseases.

"Compost increases the organic matter and nutrient-holding capacity of sandy soil," said Darbie Granberry, a UGA Extension Service vegetable horticulturist. "And it helps stretch the farmer's fertilizer dollars."

Granberry said compost also extends the use of waste material, such as municipal waste and poultry litter, that would otherwise be a burden on the environment.

Two years ago, Brim and other farmers around Tifton, Ga., became interested in the benefits of applying compost to vegetables grown on plastic-film mulch. They can now produce as much as 8,000 tons of compost annually, at a cost of $30 per ton.

On-Farm Research Plots

Brim allocated part of his land to create research plots. CAES scientists will collect data from these plots and help in further studies to find economical ways farmers can manage to their crops.

Early data shows that transplants grown in greenhouses with compost tend to be larger and more robust. By using compost, Brim said he has reduced irrigation by as much as 30 percent and increased the fertility of his soil.

With help from UGA, Brim applied for a Southern Region Sustainable Agriculture Research Education (SARE) grant to fund the research on the farm.

The federal grant allows farmers to develop their ideas into viable practices and technologies with the help of CAES faculty. Information from the research is then shared with other farmers.

"It's an opportunity for researchers and extension people to work with the farmer," Granberry said, "and to help solve a particular problem he has on the farm."

"We've worked really close with the researchers and the extension office with this," Brim said. "Research is the most important thing that can happen to agriculture right now. We're just trying to find a way to keep a positive cash flow."

A field day Oct. 24 will showcase the on-farm plots. For more information, call the Tift County Extension Service office at (229) 391-7980. Or e-mail

Brad Haire is the former news editor with the University of Georgia College of Agricultural and Environmental Sciences.