The farmers have come back to Washington, but this time they've left their tractors at home. They are armed instead with neatly combed hair, faith in America and shame for their "radical" elders who snarled traffic and infuriated some politicians last winter.

The 104 leaders of the Future Farmers of of America, who represent more than 500,000 young farmers across the country, are meeting here this week at an Alexandria motel in a conference brimming with optimism about their future in farming.

Their mood is in sharp contrast to that of the American Agriculture Movement protesters who rolled their tractors into twashington last February and cursed the government for refusing to help them.

Those farmers, claiming that farming was driving them to bankruptcy, hauled a white outhouse down Pennsylvania Avenue and dubbed it "Carter's White House." When Agriculture Secretary Bob Bergland accused some of them of "old-fashioned greed," an AAM leader branded Bergland as the source of "unmitigated lies."

But yesterday, the young leaders from rural America were addressed by President Carter and could only call his speech "inspiring." They spoke with Bergland and said his knowledge of farming was "amazing."

At a breakfast yesterday morning with members of the House and Senate, a General Motors vice president described the FFA leaders as "clean, neat and courteous." He said they are the kind of young people who say "Sir" and trace of sarcasm."

While small farms in the nation continue to go broke at the rate of 800 a week, the FFA leaders from 50 states and Puerto Rico have waxed enthusiastic about careers in agribusiness. The small farm is on the way out, they agreed.

"I'm a firm believer in the laws of supply and demand," said Kevin Drain, an Indiana farmer's son and FFA national vice president. "Some people may be cut out - in a way that's a weeding out of the weaker."

Maynard Augst, the FFA's "Star Farmer of America," would rather be forced out of farming than take a government handout. At 22, he is muscular, blond, highly successful Minnesota cattle raiser who paid cash last year for his $42,000 house. A farmer must be frugal, Augst says, unlike some of the AAM protesters who overspent themselves on land and equipment. Augst refuses to buy the airconditioned tractors owned by many of last winter's protesting farmers.

Like his fellow FFA leaders, Augst says he is sure that careful planning and smart farming will give him a good living.

But the FFA leaders, who include 50 state presidents and other officers, say they are aware that all is not well in american agriculture. They say they know about the failure of hardworking farmers who cannot cope with skyrocketing costs for fuel, machinery and fertilizer.

They say they're familiar with Agriculture Department figures showing that 60 percent of the nation's food and fiber is produced by six percent of the nation's farms - mostly corporate farms. They've also heard that the Agriculture Department estimates about 20 percent of the nation's small farmers live below official poverty limits.

"Those figures are discouraging to us. Small farmers are not making it," said Kelly Grant, 20, FFA national secretary. "But the economics just don't stack up so that small farms are possible. We realize that."

Only 30 of the 104 leaders of America's farm future say they plan to work their own farms. Only eight say they can afford to buy land to get into farming.

The rest of the leaders, as well as the majority of the half million FFA members, say they will make their living in agribusiness - working for large farm corporations, marketing farm machinery, designing urban landscapes, managing green houses.

Many of those who plan careers in agribusiness or who will inherit profitable farms from their parents refused this week to discuss the farmers who protested hbre last winter.

"It is our objective to learn how to be leaders of agriculture, leaders of the world. We do not get involved in political affairs," said Tom Linthicom, 18, who helps run his father's dairy farm in Boyds, Md.

FFA members who would talk about the American Agriculture Movement said the protests did some good by drawing attention to farm problems. but they said the protesters went too far.

"Like my dad says, the farmer who really buckled down and farmed didn't raise all this ruckus," said Randy O'Connell, 18, who lives on a 1,200-acre wheat and barley farm near Kalispell, Mont.

"The protesters in Washington took too drastic action. They offended the public," O'Connell said.

There were a few FFA leaders here this week, however, who said they know why some of the protesters last winter went "too far." They said they have listened many times to angry middle-aged men who work long hours and still find themselves falling deeper in debt every spring.

"A lot of farmers are plain, outright discouraged," said Doug theins, a young Rupert, Idaho, farmer who last year hauled sugar beets to market at an average $200 loss per truckload.

"They are put in a bind. They want to quit, but they can't. They owe so much money and farming is their lifeblood," Heins said. Yet, Heins echoed the feeling of many FFA leaders when he said government isn't the solution.

"With government subsidies, comes government control," Heins said. CAPTION: Picture, no caption, By Lucian Perkins - The Washington Post