Arthur Harvey, the blueberry farmer, persuaded a federal court in 2005 that some regulations on organic milk were too lax, including those governing how a dairy farmer can convert to organic status.

As a result, hundreds of dairy farmers decided to switch last spring so they could complete the yearlong conversion before the more stringent ‘‘Harvey’’ rule takes effect in June.

‘‘When this court case was decided, we said, ‘Now’s the time for us. Let’s do it,’’’ said Edward Walldroff, a farmer in La Fargeville, N.Y., who said that five other dairy farmers nearby were doing the same thing. ‘‘It’s really kind of exciting to see that happen, and know that six smaller-type farmers have some real viability now.’’

On a larger scale, Organic Valley, a cooperative based in Wisconsin that sells dairy products, is adding 269 farmers this year for a total of 972; it will process 45 percent more milk this spring than a year earlier.

Horizon Organic, the biggest organic dairy company in the country, added 64 organic dairy farmers in 2006 for a total of about 350, and about 230 more are in transition, said Sara Unrue, a spokeswoman.

‘‘It looks like we will have a serious oversupply in the next two months,’’ said George Siemon, Organic Valley’s chief executive. ‘‘We are now telling people, ‘Please stop thinking that there is a bottomless market.’’’

The sudden glut would be remarkable because there is usually a chronic shortage of organic milk. Demand has been growing 20 percent or more a year, so much so that in 2005, some retailers posted signs in their dairy cases apologizing for not having enough of it.

While the increase should correct the supply problems, consumers probably will not see lower prices. Several manufacturers and retailers said they did not plan to reduce prices, in part because the oversupply would be quickly absorbed by increasing demand. Organic milk can cost twice as much in stores as regular milk.

Source: Helena Independent Record