Representative Collin Peterson of Minnesota, ranking member on the House Committee on Agriculture, has called for a wide expansion in C.R.P. enrollment.

WASHINGTON — As congressional agriculture committees begin the process of drafting the 2018 farm bill, proposals for increasing acres idled under the Conservation Reserve Program or even establishing a new voluntary acreage reduction program have been raised. Representative Collin Peterson of Minnesota, ranking member on the House Committee on Agriculture, has called for a wide expansion in C.R.P. enrollment, and in the Senate, Senator John Thune of South Dakota, member of the Senate Committee on Agriculture, Nutrition and Forestry, has proposed a new income protection program based on reducing cultivation of less productive acres and diverting the land to conservation uses but under terms less restrictive to producers than the C.R.P.

The C.R.P. was created by the 1985 farm act with the aim of encouraging producers to idle their most environmentally sensitive cropland and devote the acres to conservation uses in exchange for federal rental payments under 10-year or 15-year contracts.

By the end of fiscal year 2007, 36.8 million acres were enrolled in the C.R.P. But in each of the nine subsequent fiscal years, acres idled under the program declined. The declines reflected rising crop prices that made planting many of the C.R.P. acres profitable once again and reforms to the program that allowed early withdrawals. By the time the 2014 farm bill was being drafted, C.R.P. enrollment had dropped more than 10 million acres from 2007.

In the Agricultural Act of 2014, Congress established a cap on C.R.P. enrollment at 24 million acres, and C.R.P. enrollment as of Sept. 30, 2016, the end of fiscal year 2016, totaled 23.88 million acres.

When the 2014 farm bill was debated, farm crop prices had been on the rise for several years. Farm income reached historic levels peaking in 2013 at more than $120 billion. But farm income since has fallen nearly 30% in real terms, marking the largest four-year drop in farm income in 40 years.

Historically, the federal government has sought to support farmer incomes and crop prices in difficult times by establishing a safety net requiring government payments in various forms to producers and by reducing acreage with the aim of limiting supply and raising prices. Since 1985, the C.R.P. has provided the principal means of reducing acreage in production while supporting national environmental goals.

Mr. Peterson on Feb. 28 said before the agriculture committee’s subcommittee on conservation and forestry, “At the committee’s recent hearing on the farm economy, I expressed my intent to take a good look at the C.R.P. and simplify, reform and increase program acres. We lowered the cap on C.R.P. in the 2014 farm bill because we were losing the acres anyway due to high commodity prices. So, because of the way the budget process works, we reduced C.R.P. acres to protect the conservation baseline and help offset some of the cuts in Title 2.

“But now, I would like to see us get back to 35 million or even 40 million acres in this next farm bill,” Mr. Peterson said. “This increase will improve water quality and address the declining wildlife populations we’ve experienced in my region of the country. I think we can find a way to get there, but we will need to simplify and reform the program. I wouldn’t support an increase in acres without some changes. I’m going to be looking at ways to make C.R.P. less complicated and more affordable on rental rates. I’m also interested in steps we can take to bring the program up to date, perhaps by repealing the requirement that program, or base, acres are needed to sign up.”

Right-sizing the C.R.P. by ensuring only the most environmentally sensitive acres are enrolled has been a principal food industry priority through the program’s history, and it was expected the food industry once again may be put in the position of opposing an expansion in C.R.P. not justified by conservation priorities alone.

Mr. Thune on March 2 unveiled a new voluntary income protection program, the Soil Health and Income Protection Program (SHIPP), meant not to replace but rather to complement the C.R.P. Mr. Thune indicated he planned to introduce a number of proposals during the farm bill debate.

“The first proposal I’m unveiling would create a new voluntary farm bill program that would provide a short-term option to conserve acreage while protecting farm income,” Mr. Thune said. “Unlike C.R.P., which requires a long-term commitment of 10 to 15 years, SHIPP would require only a three-to-five-year commitment. SHIPP would give farmers the flexibility they need to enroll their least productive acreage in this new program in return for a rental payment and additional crop insurance assistance.”

Under SHIPP, acres would be enrolled for three, four or five years. Enrolled acres must be planted to a low-cost perennial conserving use cover at the enrollee’s expense. Acres may be harvested for seed after wild bird nesting and brood rearing periods but may not be insured. (The annual rental rate would be reduced 25% if the acres are harvested for seed.) SHIPP acres also may be hayed or grazed outside the nesting and brooding periods established for the county as long as adequate stubble is left standing to protect the soil. The annual SHIPP payment rate would be one-half of the C.R.P. general signup rental per-acre rate for the county.