MINNEAPOLIS – Secretary of Agriculture Secretary Tom Vilsack has announced that the U.S. Department of Agriculture will conduct a four-week general sign-up for the Conservation Reserve Program (C.R.P.), beginning May 20 and ending on June 14.

The 27-year-old C.R.P. is the U.S.D.A.’s largest conservation program and aims to enroll and withdraw from production highly erodible or otherwise environmentally sensitive farmland. Producers bid acres into the program during competitive sign-ups, and if the land bid meets program criteria, the government essentially rents the land from the producer under 10-to-15-year contracts. Producers accepted in the sign-up also may receive cost-share assistance to plant long-term, resource-conserving covers.

During its life, the C.R.P. often has been criticized for withdrawing from production land that was not highly erodible or sensitive and that could be farmed in an environmentally responsible manner. The criticism has had the effect of reforming the program over time.

Current enrollment in the C.R.P. is about 27 million acres. Under the current farm act, no more than 32 million acres may be enrolled in the program at any one time. Under previous farm acts, up to 36.4 million acres could be enrolled.

The farm bill passed by the Senate last year would have lowered the cap on acres enrolled in the C.R.P. to 25 million acres, and if Congress is able to pass a farm bill this year, it is expected that lower cap may be included in the legislation.

The U.S.D.A. announced the upcoming general sign-up pointing out C.R.P. contracts on 3.3 million acres expire on Sept. 30, 2013. Additional sign-ups for continuous C.R.P. programs such as the Highly Erodible Land Initiative and the Initiative to Restore Grasslands, Wetlands and Wildlife, will be announced in the spring, the U.S.D.A. said.

"Since the 1980s, the C.R.P. program has established itself as a benchmark in voluntary conservation efforts, providing American producers with assets to address our most critical resource issues," said Mr. Vilsack. "Last year, during one of the worst droughts in generations, the C.R.P. proved vital in protecting our most environmentally sensitive lands from erosion. Emergency haying and grazing on C.R.P. lands also supplied critical feed and forage for livestock producers due to the drought. And the program continues to bring substantial returns to rural areas, attracting recreation and tourism dollars into local economies while sustaining natural and wildlife habitat for future generations."