Finally, in that rarest of rarities, Washington's political left, right and center agree on a burning issue: Federal farm programs are not working.

The agreement dissolves there, however. Proposed solutions are a dime a dozen. And as Congress gets down to writing a new farm bill, the future of federal agriculture policy is shaping up as one of the year's major fights.

The debate comes amid the most intense economic stress that U.S. farmers have felt since the Depression. Farm failures, spurred by stagnant prices, lower exports, high interest rates and falling land values, have brought a crisis air to the debate.

Heightening the intensity are the politics that usually envelop the farm debate and a growing Republican worry about losing Senate control in 1986, as Farm Belt resentment toward President Reagan mounts.

Three points have emerged clearly in early House and Senate hearings on new farm legislation:

Unlike years past, the playing field is more crowded. Farm groups that traditionally wrote their own ticket are competing with other farm groups, agribusinesses, consumers, food processors -- all of which will make legislative consensus more difficult.

Despite growing recognition that farm problems cannot be solved by a farm bill alone, lawmakers are showing little inclination to correlate farm policy with tax policy, science, energy use and other external factors. A major study of some of these issues, released by Agriculture Secretary Bob Bergland just before he left office in 1981, remains largely ignored, a rare book.

The radical surgery proposed by Reagan to return farmers to a "market-oriented" agriculture by reducing federal supports appears to be going nowhere. Farm-state lawmakers -- GOP and Democratic -- are attacking it as too drastic; even the conservative American Farm Bureau Federation opposes it.

At a House Agriculture Committee hearing last week, Rep. Leon E. Panetta (D-Calif.) was blunt with Agriculture Secretary John R. Block: "Your bill's dead on both sides House and Senate ; it ain't going anywhere."

Block said the administration's goals of cutting farm-program costs and pushing farmers toward more competition were "non-negotiable." But he conceded that compromises might be possible to reach those goals. Few, however, see the compromises coming easily.

The basic problem is that U.S. farmers produce more than they can sell. The unsellable surpluses have depressed prices and increased federal farm-support costs to more than $50 billion during Reagan's first term, but that is only a part of the problem.

More than a third of U.S. farm production is aimed at the export market. World recession and the strong dollar have cut export sales by about $8 billion since the 1981 peak of $43 billion. Block and the administration argue that the farm programs drive farmers to overproduce, rather than orient them to market realities.

Block's critics charge that the administration's approach will wipe out tens of thousands of farmers who are in economic difficulty due to events beyond their control. They urge more targeting of aid to the farmers who need it most and more aggressive U.S. export sales policies.

Much of this year's debate will focus on these basic elements of the farm programs:

Price supports, which tend to set a floor under market prices for cotton, rice and basic grains. When markets are low, the farmer can get a loan on his crop at the support level. If prices go up, he repays the loan and sells his crop. If not, he keeps the loan and the government keeps his crop. Reagan wants to cut support levels; his critics do not.

Target prices, income supplements for grain, rice and cotton farmers to make up the difference between low market prices and their production costs. Federal spending on these "deficiency payments" has increased as markets have stagnated. Reagan proposes a reduction of target levels.

Acreage controls, surplus-regulating tools available to the secretary for reducing the amounts of land farmers plant. The administration proposes an end to all forms of production controls; some critics want mandatory controls to keep supplies in line with demand.

Few say that there will be an easy resolution of the profound differences between the administration and its farm-country critics. And some are suggesting there may be no resolution.

"I think we may get to Christmas and then quit," said Rep. James M. Jeffords (R-Vt.), a key player in the farm debate. "We could end up just extending the current law for another year."