PORTLAND — Organic acreage has surged in Oregon even as the number of organic farms has shrunk in recent years, according to federal data.

The total number of organic farms in the state decreased 18 percent, from 657 to 525, between 2008 and 2014, according to the USDA National Agricultural Statistics Service.

Meanwhile, organic acreage nearly doubled in Oregon, from 105,600 to 204,000, the NASS report said.

The agency found a sharp decline in the number of farmers who earn less than $25,000 in annual revenue, while the number of those with sales of more than $250,000 grew, said Dave Losh, Oregon’s state statistician for NASS.

“The smaller folks are having a harder time and the larger operations are getting bigger,” Losh said, noting that the trend is occurring in overall agriculture as well.

In some cases, organic farms may not have gone out of business but opted to drop their organic certification for financial reasons, said Chris Schreiner, executive director of Oregon Tilth, an organic certifier.

At the time of the survey, a USDA cost-share program that helped pay for certification costs had lapsed, so some growers decided the organic label was no longer financially feasible, he said.

That program has since been restored with funding from the 2014 Farm Bill.

Even so, the 2008 survey was conducted shortly before the financial crisis, so some farms might have shut down during the ensuing economic downturn, said Ivan Maluski, policy director of Friends of Family Farmers, a nonprofit group.

“I think the recession during that five-year window had a lot to do with it,” he said.

The acreage increase is likely the result of larger conventional farms, as well as dairies with pasture, converting to organic production due to the associated price premium, Maluski said.

“As the organic industry matures, they tend to get bigger,” said Lindsey Eng, ODA’s director of market access and certification, which certifies organic farms.

Oregon has the fifth highest number of organic acres in the country, following California, Montana, Wisconsin and New York.

The state is also near the top of the list in sales of organic farm products, with $237 million in 2014.

Organic premiums have also attracted farmers who grow feed crops such as Timothy hay and alfalfa and who tend to have bigger operations than those growing vegetables, she said. Organic hay production in the state grew more than 20 percent, to 34,700 acres, between 2008 and 2014, according to NASS.

“It’s a relatively low barrier to entry because they grow well in Oregon without a lot of inputs,” Eng said.

Oregon’s acreage growth has bucked a national trend, as overall U.S. organic acreage contracted nearly 10 percent to 3.7 million acres between 2008 and 2014.

Regulatory problems were considered the primary production challenge nationally, with 34 percent of organic growers naming regulatory problems as their top concern.

Laura Masterson, an organic farmer and chair of the Oregon Board of Agriculture, said she was surprised that the number of organic farmers had dropped and that growers were worried about regulatory problems.

“When the price is in the right place, a lot of those production challenges are resolved,” she said.