WASHINGTON — U.S. Department of Agriculture Secretary Tom Vilsack announced the next general signup for the Conservation Reserve Program will begin March 14 and run through April 15. It was the second consecutive year a general C.R.P. signup was offered.

“Over the past 25 years, support for C.R.P. has grown thanks to strong backing from farmers, ranchers, conservationists, hunters, fishermen and other outdoor enthusiasts,” Mr. Vilsack said when he announced the signup Jan. 28 at the National Pheasant Fest 2011 in Omaha, Neb. “Today’s announcement continues the Obama administration’s effort to conserve sensitive areas and improve wildlife habitat.”

During the general signup period farmers and ranchers may offer eligible land for up to 15 years at county offices of the Farm Service Agency, which implements the program for the Commodity Credit Corp. Farmers may offer new land not currently enrolled or may make new offers on contracts expiring this fall. Awarded contracts become effective Oct. 1. Eligible landowners receive annual rental payments and cost-share assistance to establish long-term, resource conserving covers on enrolled land. The general C.R.P. sign-up does not affect cropped acres this season, the U.S.D.A. said, for which enrollment is this fall.

The U.S.D.A. was working with several conservation and wildlife groups to help make farmers aware of the signup period.

In addition to the general signup, there is an ongoing “continuous” signup for the most environmentally desirable and sensitive land, the U.S.D.A. said.

The U.S.D.A. said it estimates 3.3 million to 6.5 million enrolled acres will expire from the C.R.P. annually from now until 2014. The 2008 farm bill authorized maximum C.R.P. enrollment at 32 million acres with the intent of protecting topsoil erosion, safeguarding natural resources and increasing wildlife populations.