The National Park Service tried and failed yesterday to persuade D.C. police to urge protesting farmers to remove their tractors from the Mall during the weekend, according to park service spokesman George Berklacy.

Police rejected the request because of the likelihood of a confrontation with the farmers and the difficulty of moving so many tractors, police spokesman Lt. Larry Soulsby said yesterday.

"You just can't click your fingers and do away with 500 tractors," Soulsby said.

Meanwhile, protesting farmers, complaining about press coverage, marked the 12th day of their siege yesterday by driving 110 of their tractors across the city from the Mall to The Washington Post. "They are writing information in The Post that is not factual," claimed Don Murphy, a farmer from Wyoming, Ill., who led the tractorcade that choked off traffic on 15th Street in front of the Post building for more than two hours.

As a crowd of farmers milled about and burned newspapers in front of the building, five leaders of the American Agriculture Movement met for 1 1/2 hours in the fifth floor office of editorial page editor Philip L. Geyelin.

The Post "is sending the wrong thing back to our folks at home," South Dakota rancher Wayne Peterson told Geyelin and three other Post editors during the meeting.

While Geyelin said he was not as knowledgeable as the farmers on some of the issues in their protest, he restated The Post's editorial position that the farmers' demands for higher crop prices will increase the price of farm land and speed the demise of the family farm.

"We didn't come to town to have fun," Peterson told the editors. "If you people in The Post don't understand the problems this nation is in, then you are in the wrong business."

The five farm leaders argued that an increase in farm prices would have a relatively small effect on consumer prices. They also said that family farmers who get a fair price for their crops would not be tempted to sell their land, even if its value jumps dramatically.

The farmers said they reject as a violation of "free enterprise" any government plan to limit that sale of farm land to individuals who must promise to farm the land themselves.

On the street below, other farmers burned copies of The Washington Post and The Washington Star first as a protest and later as a means of keeping warm in the subfreezing temperatures.

At the nearby Madison Hotel, a woman in an expensive fur mistook a uniformed D.C. policeman, who was watching farmers and warming himself in the lobby, for a bellhop and asked him to call a cab for her.

Echoing the sentiments of many farmers who pulled their tractors up in front of the Post, Gary Wagner of Amarillo, Tex., said, "We can't get anything in the paper. We say one thing and it comes out distorted." Wagner said he could think of no specific complaints.

The Post has printed nearly 540 column inches of news, more than four pages, on the farm protest since the first of February. "It's easy to get headlines," said Illinois farmer Murphy, who carried a hammer into the meeting with Post editors. He said the problem is getting the "right kind" of coverage.

Because nearly all the farmers left the engines in their tractors running, diesel fumes rising from the exhaust pipes mixed with the burning newspapers to turn the air outside The Post a foul-smelling gray.

D.C. Deputy Police Chief Robert W. Klotz interrupted the farm leaders meeting at noon, saying that the tractors on 15th Street were polluting the area.

While the farmers waited outside, a hand-lettered sign went up in the Lee House Hotel that offered "free coffee for farmers." Inside, farmers and their wives huddled around a popcorn machine or wandered into Durdy Annie's, a bar where a jukebox played "Just One Look" by Linda Ronstadt.

"Why don't we just leave 'em here for a couple of days, mom?" one farmer said to his wife as they relaxed in the lobby and looked out at the tractors.

The tractors had left The Post by 1 p.m., turning left on L Street and onto 14th Street, where they rolled down to the Agriculture Department administration building on Independence Avenue. Again, the 110 tractors pulled to a traffic-snarling stop and the farmers gathered for a second meeting.

At that meeting, a 10-year-old Cummings, Ga., boy "clogged" (danced) on aploywood board inside the administration building to a record by "The Tennessee Mountain Cloggers."

The farmers watched Brian Reid, who has four years of experience as a clog dancer, go through two numbers, and then piled back into their tractor for the ride back to their barricaded compound on the Mall. Police said the farmers returned at 2:15 p.m. and that there were no arrests in yesterday's tractorcade.