As part of the most farm political protest since the Great Depression, angered American farmers Wednesday are to begin their long-promised strike against the federal policies they say are destroying not only their well-being but also a way of life.

The number of farmers nationwide who plan to commit themselves to selling no more and buying no more until they get higher prices for their crops and livestock is unknown. Born only 90 days ago it is the latest in a string of 20th-century farm withholding actions, none of which has succeeded in achieving higher prices.

This one, which follows scores of farmer rallies and tractor parades designed to win public support for the cause, comes at a time of dwindling farm population, of diminished farm political power and what the farmers see as insensitivity to their plight on the part of the 56 people fed by each American farmer.

This strike reaction is to economics and emotion, and many of the farmers see their plight as largely based in their reduced numbers as well as in the increased harvests that have depressed prices.

"Many American farmers feel they are forgotten," said Agriculture Department historian Wayne Rasmussen. "They still feel there is something different about farming - that they are producing what everyone needs and they are the butt of jokes and low prices."

"We're not second-rate citizens," says Wayne Ballard, 31, who has lost $15,000 on the past two grain crops. "And we're not gonna live like one."

"You're damned right," affirms Terry Freed, a 27-year-old seed dealer who says he was driven out of farming "What burns me up is the priorities in this nation are all out of shape. People buy mobile homes and take vacations and go to the mountains on weekends - now just how bad do you need to go skiing and how bad do you need to eat?"

But outside of the headquarters of the American Agriculture Movement here and the supporters it has won over, there is little belief that this strike will seriously affect food supplies or prices and that it is more of a political act designed to win higher prices in federal farm programs.

"The point is this," said Theodore Salutos, a historian on farm organizations at the University of California at Los Angeles. "If this were a withholding movement, this is one poor time of year to have a withholding movement. You do it in the spring of at harvest time. Not at Christmas time."

Even as a movement to take foodstuffs off the market, such actions have historically proven ineffective. From the 1904 burning of cotton in Texas every Saturday cover a period of weekd to the potato burning and calf slaughters of the 1970s, no effort has been successful in obtaining higher prices for more than short periods, according to a history of farm strikes prepared by Rasmussen.

Even the Farm Holiday Strike of the early 1930s, led by Milo Reno, failed to raise prices, but apparently helped influence action by state and federal governments of help farmers.

The current strike movement, Rasmussen said, "has not matched the Farm Holiday, but it's getting there. They are the strongest political force since the Farm Holiday."

Undeterred, though, the farmers here made final preparations today for their strike, although no one could say what would happen immediately. This year's crops are either harvested or in the ground for spring reaping, and there is a two-year domestic supply of wheat in storage. Most farmers, too, apparently quit buying nonessentials months ago for lack of cash.

Several parades and raillies have been scheduled, and merchants in some rural communities plan to shut down to show their support for the farmers on whom they depend so much for their own livlihoods.

Ranchers with livestock fattened and ready for market are expected to keep selling, but American Agriculture hopes they will slow the feeding process to delay future deliveries to market.

What the farmers say they want is full party for their production - a price that would restore their purchasing power to what it was in the early 1900s.

The farmers bitterly attack the 1977 farm bill, saying that it provides price support levels well below what it costs to produce crops.

"We don't have no clout and they won't listen to us," said Vance Alfrey, 35, married and the father of four. "We feel they don't care about us back there [in Washington]."

The U.S. farm population, which was 25 per cent of the nation in 1940, now stands at less thean 4 per cent - 7.8 million people and falling.

Calvin Beale, the Agriculture Department's rural population expert, said, "There are just scores of urban and suburbun members of the House of Representatives who do not have to worry about farmers. They have pressures from consumers to keep food at as cheap a price as possible."

But, says William Nordhaus, a member of the Presidents' Council of Economic Advisers, the farm bloc won major concessions from the administration, which agreed repeadtly to higher price supports in the farm bill.

"I dno't think we've treated thwm unfairly. From the consumers' point of view, we treated the farmer more generously than any other producers in the country." he said.

Sugar farmers, he adds, have received a tariff protection from imports as the steel and television industries have not. Nordhaus says that much of the farmers' agony today slems from readjusting to traditionlly low profits after the boon years of the early 1970s.

But the farmers here sadly realize that those who will benefit the most from the strike, at least in the short run, will be those who do not participate in it and continue to market their goods should prices rise because of the strike.

As Rasmussen, the historian, noted, farm strikes have traditionally failed for the same reason that farmers find themselves producing more than the market can absorb.

That is, no farmer nor any group of farmers, outside of a few specialty crop growers, has been able to control enough production to affect prices.