Record-high U.S. farm-support costs, a food production machine that is sharply out of kilter, nagging worries about failing farms and slumping exports are generating calls throughout American agriculture for a serious look at federal farm policies.

Those seeking the review range from Agriculture Secretary John R. Block to members of Congress, from heads of disparate farm and trade organizations to farmers and from governors to state agriculture directors.

"I believe farm policy soon will be at a crossroads," Block said recently. "The direction we take during the next few years will largely determine the nature and scope of the U.S. food and agriculture system as well as its role in the world economy for years to come."

With an eye toward directing the debate, Block has scheduled a "summit" meeting of about 60 farm and food industry leaders for July 12-13 to begin what he calls a "dialogue" on future farm policy. He is considering a second session toward the end of the year, he said.

"This will be broad-based and nonpartisan," Block said. "My idea is to talk about where agriculture is and where it should be in three or four years. USDA doesn't have all the answers."

The main concern is life after PIK: how to adjust U.S. farm policy to domestic and global realities after--and if--Block's payment-in-kind (PIK) program has worked its intended magic of cutting overproduction, aligning supply and demand and stanching farm-support budget costs that are expected to hit $21 billion this year.

Block and other top agriculture aides have stressed in recent statements that post-PIK policy must be considered now, while there is time, lest farmers return to their recent habit of market-depressing overproduction.

Another obvious but unstated motivator is 1984 congressional and presidential politics. For months, plainly nervous farm-state Republican legislators have pressed the Reagan administration for more help for farmers. Sen. Roger W. Jepsen (R-Iowa), facing reelection, has started an unusual round of farm-policy hearings at the Joint Economic Committee.

Democrats are responding with their own political PIK. The Democratic National Committee is planning a nationwide series of farm-policy forums, headed by Texas agriculture commissioner Jim Hightower. Small-farmer supporting Democrats have formed a Populist caucus in the House. And a small group of moderates led by Rep. Dan Glickman (D-Kan.) has formed to speak out on policy issues.

Beyond that, politicos and agricultural leaders are looking to 1985, when Congress will have its next major opportunity to deal with farm policy. The current farm legislation, which authorizes the price support programs that many feel have contributed to budgetary and overproduction problems, expires then.

Those calling for change include such disparate groups as the American Farm Bureau Federation, the National Farmers Union, the National Governors Association and agribusiness concerns such as Cargill Inc., a worldwide trading company.

And with the backing of a dozen or more House members, including Agriculture Committee Chairman E (Kika) de la Garza (D-Tex.), the Agriculture Council of America is moving ahead with its plans for a national forum on farm-policy alternatives.

"The key is that we are not trying to develop a consensus. We are looking for alternatives," said Allen Paul, council president. "What we have now is an absolute stalemate, a policy equivalent of gridlock. There is such a high level of confusion and disagreement in agriculture that the hard decisions keep being bucked to the top, where they are made in a crisis atmosphere.

"But I think some very big changes are brewing. I've never seen a time when this much ferment was going on. There is a high level of sensitivity that something is wrong with today's programs."

The governors are taking a similar view, according to Joseph A. Kinney, NGA staff advisor on agriculture. "We're in the process of restructuring our policy, developing a whole new one," he said. "There is a recognition that things have changed, a recognition that our policy tools have failed us. The need for a PIK program has demonstrated that."

But while there is general agreement that farm policy needs changes, there is bitter disagreement over what they should be. When the ACA announced its plan for forums, it was criticized by the Farm Bureau and the American Soybean Association.

When Farm Bureau President Robert B. Delano of Virginia called for an "all-out drive" to alter federal farm programs, he was blasted by Farmers Union President George W. Stone as "irresponsible."

That kind of intramural sparring, once uncommon in the farm bloc, intensified during congressional debate over the 1981 farm bill as different commodity groups perceived they were being picked on and set against each other by the Reagan administration.

But Block now is talking conciliation. "We're missing the boat in telling the country how broad-based this industry is. We need to be united. We are interdependent. We need a closer relationship. USDA doesn't have all the answers," he said.