A bitter wind whipped away the exhaust from their idling tractors' diesel engines yesterday but left untouched the bitterness of about 100 farmers gathered in a muddy pasture here to demand higher prices for their products.

Beneath farmer's demands for more money, however, lie other, deeper concerns. They are alone in an organized world, they say. Their long hours of work go unappreciated. They feel they cannot control their distinies.

"We want to know what we're working for," said C. C. Edwards, a 69-year-old farmers who had come up from Bealeton, Va., for the American Agriculture Movement protest, one of three held yesterday across the country.

Bill Dawson, 31, of Purcellville said, "If we can get together, folks will sit up and take notice. We can't shut down like the coal miners. This is the only way the farmer has to express his feelings."

They had 30 tractors and another 30 trucks and cars jumbled in the pasture, ready to drive about 15 miles through Fauquier County to Warrenton High School where organizer C. L. Ritchie was hoping for a bigger turnout at a nighttime rally. He had predicted earlier in the week that 300 vehicles would be there for the afternoon protest.

Ritchie had reached back to Dulles Airport where he had picked up Tom Kersey, a bull-voiced Georgia farmer who was to be the night's featured speaker, and Kersey was roaring toward the farmers - and toward television and still cameras - that "more people are going to be looking at you than ever before."

Earlier, Michael Susik, owner of a purebred cattle farm near Warrenton, had said "every farmer in Virginia support this."

The official position of the American Agriculture Movement calls for a strike Dec. 14 if prices are not pegged at 100 per cent of parity. Parity is an index of farmers' purchasing power now compared to what a unit of production - a bushel of grain, for example - would have bought in 1910-1914.

Nevertheless, many farmers yesterday said they knew the problem was not that simple.

Dawson expressed their main goal, saying, "It's the greatest opportunity the farmer has ever had to show he has a voice."

Ironically, as the farm protest has grown, farm commodity prices have risen and agricultural experts are predicting further improvements next year. Six weeks ago, for example, the price of wheat was $1.90, now it is $2.40.

This year, however, record production levels and existing surpluses caused many farmers to lose money on every bushel of corn and wheat they sold and farmers want non-farmers to know it.

Their tractors will start moving into a field near Chantill today for a Saturday drive on Washington. Protest organizers say they will put 30.000 tractors and other farm vehicles in the city that day.

"They're going to find out in there that something is wrong," Kersey told the farmers. "That tractor this weekend is going to be the most important vote you'll ever cast."