WASHINGTON - Some farmers are worried that a federal court ruling requiring the Agriculture Department to come up with stricter standards for organic food will slow the fast-growing industry.

But consumers advocates are cheering the decision, saying it will ensure people get higher-quality food when they purchase products with the organic label.

Earlier this month, the U.S. District Court in Maine finalized a court ruling that bans dozens of synthetic ingredients that the USDA had allowed in products labeled organic.

Of particular interest in the upper Midwest, the court also ruled that dairy farmers must give their herds 100 percent organic feed for a full year before being certified organic. They had been able to get by with 80 percent organic feed.

The ruling came after a Maine organic blueberry farmer, Arthur Harvey, sued the USDA, arguing the current regulations violate the Organic Foods Production Act of 1990.

The organic dairy industry says that the regulations the USDA will have to implement will make it more expensive for dairy farmers to conform to organic standards. That's because organic feed can be two or three times the price of conventional feed, which can be grown using pesticides and other chemicals.

Advocates are considering going back to Congress for a legislative fix.

"We think this will discourage dairy farmers from becoming organic," said George Siemon, chief executive of Organic Valley, a national farmer-owned organic cooperative based in La Farge, Wis. "I think it will slow down supply, and buyers will have to contribute more to the cost."

Demand for organic milk has been steadily rising, as consumers seek products that are free from pesticides and antibiotics. The Organic Trade Association has projected a 17.3 percent increase in sales between 2004 and 2008.

The court gave the USDA one year to come up with new regulations; the agency will then have one year to phase those in.

Current regulations allow dairy farmers who want to go organic to feed their cows 20 percent conventional feed and 80 percent organic feed in the first nine months of the year before going organic; and 100 percent for the last three months.

Siemon said that most farmers take advantage of the 80 percent rule, which he called a workable standard. "We do hope there is some consideration for a legislative fix," he said.

Members of the U.S House Organic Caucus, including Wisconsin Democrat Ron Kind, wrote a letter to Agriculture Secretary Mike Johanns recently warning that the decision "could decimate every sector of the organic industry." The lawmakers did not call for a change in law, but did say they wanted to work with Johanns to resolve the conflict.

Meanwhile, six agriculture, retail and food safety groups, including the Center for Food Safety, have sent a petition to USDA urging it to come up with strict standards in the wake of the court ruling. The USDA declined to comment for this story.

Jerome Walch, who has a 50-cow dairy near Rochester, Minn., about 90 miles south of Minneapolis, is in the process of bringing his herd into compliance with organic labeling rules.

He said he still hopes to go through with the conversion, but worries about the economics in light of the court ruling.

"We'll be selling milk at conventional prices, but buying feed at organic prices," Walch said. "I can buy conventional corn feed for $1.78 a bushel; organic corn costs $5 to $6."

Urvashi Rangan, an environmental health scientist at Consumers Union in Yonkers, N.Y., argued that both farmers and consumers will benefit from the ruling in the long run.

"It's a big victory for consumers, as far as the integrity of the organic label and what it means," Rangan said. "This will increase the value of the organic label."

She said that fears about slowing the growth of the industry are shortsighted.

"What we don't want to get into is lowering standards so more of the market can meet the standards," Rangan said. "We want to see a steady increase in strength and rigor of the standards over time. Those who do meet those higher standards will ultimately be rewarded in terms of premium (prices) for their product."