The telephone rings two, three, four times every day at the farm home of Jim and Barbara Adams near Noblesville, Ind. More often than not it's another Hoosier farmer calling with a new story of financial woe and wondering what he's to do.

These phone calls to the Adamses' farmer "hot line" are another of the signs that herald the hard times that grip American agriculture. Farm income has been down three straight years--in 1982 to its lowest point since 1933. There is only scant hope that things will be better this year.

"We've had a great response, but I feel we've only touched the tip of the iceberg," Jim Adams said the other day. "Farmers are in a whole different ballgame today . . . We haven't had this kind of situation for 50 years. The economy is killing us."

The U.S. Department of Agriculture uses different language, but it sounds much the same. Its latest forecast for 1983 puts it this way:

"The outlook for agriculture remains clouded by large crop supplies worldwide combined with a weak global economy--pointing to low crop prices and poor income prospects for many U.S. farmers . . . These huge stocks, plus the strong dollar, are expected to keep U.S. crop prices low."

Although most economists agree that no farm upturn will occur until general economic conditions improve, the Reagan administration is pressing ahead with a plan to expand the government's crop-reduction program--a move intented to align supply and demand and, the hope goes, increase farm prices.

The approach proposed by Agriculture Secretary John R. Block calls for giving farmers surplus corn, wheat, feed grain, rice or cotton, which they in turn can use or sell if they agree not to plant in 1983. Federal spending on farm programs would be reduced, surpluses would diminish and prices would rise, the theory goes.

But Block and his chief aides at USDA have stressed that the payment-in-kind (PIK) program could not be expected to have a major impact on prices until 1984. The chief impact in 1983 would be the drawdown on price-depressing surpluses.

This proposed government intervention, running counter to the administration's professed enthusiasm for free markets, was spurred by these events last year:

A second straight bumper crop of wheat, corn, cotton and other major commodities pushed surplus stocks to inordinate levels, which will mean 74 percent of the world's coarse grain supply and 44 percent of its wheat supply will be in U.S. granaries by the end of the next harvest.

Although the rapid inflation of production costs was slowed, net farm income fell for the third straight year. It was $19 billion in 1982; $19.6 billion in 1981, $24.4 billion in 1980.

For the first time in 18 years, national average farmland value dropped, seriously undercutting farmers' ability to get operating loans based on increasing worth of their assets. Loan foreclosures and bankruptcies, although not as dramatic as many had predicted, increased.

The sluggish world economy and continued strength of the dollar conspired against U.S. exports, upon which farmers have come to rely heavily. Exports tripled between 1971 and 1981, but last year fell to $39.1 billion from the 1981 record high of $43.8 billion.

Farmers like Jim and Barbara Adams, who raise corn, soybeans and wheat on 1,500 acres of their own and rent land in north-central Indiana, don't need computers or economists to tell them what this all means.

Their loan with the Production Credit Association (PCA) was due Dec. 30, and they didn't make the deadline. They laid off their two sons, aged 25 and 21, who had worked on salary as farmhands. They intend to reduce their active farm acreage this year to no more than 800 acres.

"Our cash flow ran out," Adams said, "and my assets are not too bright. We figure there has been a $1 million erosion in value of our land and equipment with these low prices. This happens, the lenders want out. They encouraged us to expand, stayed right in bed with us and now they want out."

The Adamses aren't sure where this year's operating capital will come from. Because details are not yet clear on the federal crop-reduction program, they aren't certain whether or to what degree they will take part.

Their uncertainty and their nervousness is like that of tens of thousands of other farmers who are stretched to the limit. And the Adamses are also part of a nascent national movement to get farmers together, thinking alike and acting together to cope with the economic squeeze.

Hot lines have been set up by farmers in about a dozen states, emulating an advice-giving, trouble-shooting call-in system that was started in Minnesota last year by Citizens Organization Acting Together (Coact), a Minneapolis-based rural-affairs group.

The Adamses have created an Indiana Coact and, through their hot line, are providing fellow farmers with a shoulder to cry on and a place to turn for advice on how to deal with increasingly hard-line lenders.

"The idea is to give the farmer support and to try to unite in an effort to survive as family farmers," Barbara Adams said. "We're getting through to people . . . . But we're finding that pride still stands in the way of a lot of them. They don't want to admit they're not making it, or they're afraid to rock the boat with their lender, hoping he'll stay with them one more year."

The hot lines and grassroots organizing activities have led to more militant activity in other states. In Minnesota and Illinois, for example, farmers have staged "penny auctions" to thwart or postpone closeout sales. The idea is to intimidate potential serious bidders, offer no more than a penny on each sale item and win extra loan-negotiating time for the troubled farmer.

In the latest of these efforts, several hundred farmers were tear-gassed after they had gathered at Springfield, Colo., hoping to mount a penny auction to stop a sale of holdings of Jerry Wright, a founder of the American Agriculture Movement, which led the protest tractorcade to Washington in the late 1970s.

In other shows of force, designed to pressure lenders into leniency with troubled borrowers, groups of farmers have converged on Farmers Home Administration and PCA offices while a neighbor negotiated extensions with lending officials.

Although represented by a variety of national organizations, farmers traditionally are lone wolves. And few are ready to predict how far their new militancy will go.

But fears of further crumbling in the nation's largest industry are leading many, inside farming and out, to urge new looks at the structure of agriculture and development of new government policies to buttress family farming.

Montana Gov. Ted Schwinden, a wheat farmer, echoed those feelings in a recent speech. He said that corporations, encouraged by farmers' current problems, are poised to take control of U.S. agriculture and eliminate the small independent grower. He called for creation of a "people coalition" to fight against farm policies that reward "bigness" rather than performance.

Thomas N. Urban, president of Pioneer Hi-Bred International Inc., of Des Moines, the world's largest seed company, wants farmers and agribusiness to link up to develop "more realistic" food policies.

"We are in danger of squandering our food production advantages because our political system seems unable to recognize change," he said.