ASHINGTON, June 15 — A coalition of more than 100 environmental and hunting organizations, from the Sierra Club to the National Rifle Association, is trying to turn the measure that will set farm policy for the coming years into the major conservation act of this Congress.

With the recently enacted $1.3 trillion tax cut squeezing out most new spending programs, the conservationists are focusing on what is typically known as the farm bill as their best bet for recovering millions of acres of wetlands, prairies, grassland and forests and protecting the wildlife that live on the land.

Few other bills offer both the money — $79 billion in new financing over the next five years — and the assurance that the legislation will become law. The bill pays for the subsidies that have for decades underwritten farmers who grow major crops like corn, wheat, rice and soybeans.

But in the last 15 years, since conservation programs were added to the farm program, farmers have lined up for cash payments in return for taking their land out of production and letting it return to the wild.

Already, farmers have voluntarily set aside more than 35 million acres as nature reserves and another million acres of wetlands as part of the two major conservation programs supported by the farm program. There is a backlog of farmers and ranchers who have applied for $3.7 billion in payments for setting aside an additional 68 million acres, but the programs have run out of money.

Conservation and hunting groups support payments to farmers for returning some of their acreage to a natural state because it not only helps sustain wildlife but also helps farmers hold on to their property. In addition, it slows the encroachment of suburbs into the countryside.

"The conservation programs in the farm bill have really helped the farmer hold the line against developers," said Susan Lamson of the National Rifle Association, making points more often associated with the Friends of the Earth.

The environmental and hunting groups are asking that a new farm bill include money for the protection of another million acres of wetlands and 10 million more acres of land through the conservation reserve program. They are going up against the powerful farm and agribusiness lobbies that have helped persuade Congress to keep increasing crop subsidies, which last year reached a record $22 billion in commodity payments to farmers.

Environmental groups argue that these subsidies encourage overproduction of the major crops, which not only keeps prices flat but also pollutes rivers and soil with chemicals.

"When farms go into overproduction you have dirty water and dirty air," said Brett Hulsey of the Sierra Club. "With conservation programs, you have clean water, reduced flooding and more open space."

In Congress, these environmentalists, as well as the hunting and fishing groups, the so-called hooks-and- bullets crowd, have found natural allies among senators and representatives from states where farmers receive little of the $20 billion annual subsidies for the major crops. More than 120 House members wrote to the Agriculture Committee chairman this week asking for support for the conservation programs.

"We could turn this farm bill into the great conservation bill of the 21st century," said Representative Ron Kind, Democrat of Wisconsin, who is leading the movement in the House to rewrite the farm bill with conservation as its centerpiece.

Congress has begun considering how to rewrite the farm bill, which was last passed in 1996 as the Freedom to Farm Act. Representative Larry Combest, Republican of Texas and chairman of the Agriculture Committee, has concluded that the major commodity subsidy programs should be more predictable, with farmers receiving less money when their crops fetch higher prices. He has yet to recommend how much money should go to conservation.

"This is a work in progress," said an aide to Mr. Combest. "When the environmentalists discovered the farm bill, they made it trendy. Now the conservation programs are more oriented to Eastern farmers. Mr. Combest prefers the more traditional point of view of protecting soil banks that would give more money to the Western areas."

That geographic split is evident throughout Congress. In the Senate, a group of 43 Republican and Democratic senators from New England and mid-Atlantic states have formed an informal caucus to support farm conservation programs. Most of their farmers from Maine to Maryland either grow vegetables and fruits or are dairy farmers and therefore ineligible for the major commodity subsidy programs. But they can and have taken advantage of the conservation programs.

In the current farm bill, conservation payments have become so popular they rank third, behind payments for growing corn and wheat. Over five years, government payments to corn farmers were $24.3 billion, to wheat farmers $13.2 billion and to conservation programs $8.24 billion.

"In many parts of farm country, conservation is now the single most important source of government assistance to agriculture, especially for small and medium-size farms," said Ken Cook, president of Environmental Working Group.

During the Republican revolution in which Newt Gingrich was House speaker, the conservation programs were nearly lost. When the House wrote the initial Freedom to Farm Act of 1996, the bill excluded financing for conservation. But Representative Sherwood Boehlert, Republican of New York, offered an amendment to reinstate the programs, and the measure won by a vote of 372 to 37, establishing the now classic divide between Eastern and Western farm states over financing.

"Conservation used to be considered the purview of the Midwest and its eroded soil," Mr. Boehlert said in an interview. "With the expanded programs it has worked wonders for our Eastern farmers who were on the edge."

With so much money at stake in the new revision of the farm bill, Mr. Combest has vowed to present a new farm bill to the House by the end of July, nearly a year in advance of the Senate. For their part, the environmentalists in the House say they will offer legislation this month to expand the conservation programs.

"Our competition is the commodity payments, and there is only so much money in the bill," said Scott Sutherland of Ducks Unlimited, a conservation group supported by hunters. "We want funding put back for the wetlands and we know there are members of Congress who are hunters and anglers who will want to preserve those wetlands."