From where he sits, in his back yard under the shade of a massive silver maple he planted from a seed, John Middleton can hear the mooing of his prize Holsteins and the rumbling of encroaching bulldozers, can see the hay bales piled high near his barn and the control tower at Dulles International Airport, a huge, Orwellian scarecrow looming over a distant field.

In 1951, there were 60 dairy farms like Middleton's in Fairfax County. Today, there are four. Back then, Middleton's farm, cleared of bushes and trees by his grandfather's own hands, was 255 acres. Today, 67 acres remain. The rest went to Dulles, $175 an acre whether John Middleton liked it or not.

Across Frying Pan Road from his property, the land is zoned for industrial development. Next door will be a subdivision. Back behind the silver maple, past the sagging frame house where he was born, the bulldozers make way for warehouses. "Hear them bulldozers? They want to run this way. And they would if they could, but I won't let them," says John Middleton, 86, a Fairfax County farmer all his life.

"Was a time when this whole area was nothing but farms. I guess it's just a few of us left now. It's nothing to be proud about that I'm still here. Some people might take it the other way, that I'm too dumb to sell out. I just always liked it here. Never lived no where else. I was born here, you know."

If the future is a question on the Middleton farm, it is not a nagging one. Life on this Fairfax County farm is like life on any farm, slow and deliberate, ruled by the rhythms of the clock and the calendar and of nature itself.

Up at dawn, down after dusk. Twice a day milking of 90 Holstein cows, three times a week pickup of 1,750 gallons of refrigerated milk. Once a week shipments of feed from Loudoun County Milling Company for the cows, 4,950 pounds, $475. It costs half the milk receipts just to feed them.

Plow and seed and fertilize and harvest and store the 200 rented acres of corn and hay, all of it done by Middleton, who had a stroke two years ago, and three hands, two of them part-timers. Seven thousand bales of hay, 25 acres of corn cut for silage. The corn goes in a 16 foot by 38 foot silo. That will last all winter. There used to be another silo for the summer silage on a rented farm nearby. Bulldozers got that recently.

And, at any moment, Middleton could lose his 200 acres of rented cropland. The development companies that lease them do so on six-month leases. One of the fields is zoned residential, the other industrial.

Plow and seed and fertilize and harvest and can the vegetables from the three-quarters acre garden, the apples and pears and peaches and plums from the trees. On a recent day, Middleton's first cousins, sisters Emma and Elizabeth Elmore, both white-haired, retired school teachers from Herndon, picked 39 pints of beans, a couple of bushels of apples and some raspberries. Sometimes Hilda Gillette, Middleton's niece and a great grandmother herself, helps out.

Wood to chop, tractors to service, eggs to gather, fences to mend, calves to feed, grass to cut.

"There's always something to do," says Middleton. "I'm just going to keep on doing it for as long as I can."

Once a major dairy and vegetable producer, a rural food basket for Washington, Fairfax has lost farmland steadily since World War II and the onset of asphalt and split-levels and the suburban way of life. Since 1969, when almost 23,000 county acres were being farmed, agricultural acreage has declined more than 40 percent.

The 1978 Census of Agriculture indicates there are 187 farms in the county, 10,777 acres of cropland, less than 8 percent of the county's total land. A full two-thirds of the county's farmers don't even consider themselves full-timers.

In Loudoun County, two-thirds of the land is in farms, said planner Milton Herd. Census figures for 1978 show 151,657 acres in cropland and the gross value of farm products sold is $29,022,000. In Fauquier, 137,665 acres are in cropland and the gross value of farm products sold is $27,488,000. In Stafford, 28,462 acres are in cropland and the gross value of farm products sold is $1,934,000.

To save Fairfax County's remaining farmland, the county board of supervisors recently approved a plan designed to offer special tax breaks to people who own 25 or more acres of working farmland. Under the terms of the program, which went into effect July 1, farmers can ask to be placed in a special agricultural district. In exchange, the landowners would have to agree to forgo developing their property for eight years.

This new plan could mean real estate tax savings of up to 90 percent for many of the county's farmers, who complain that rising expenses, in addition to the taxes, have just about made farming in Fairfax systematically unprofitable. Currently, farmers in the county pay taxes at the same rate as homeowners. The tax bill on Middleton's 67 acres, for example, valued at about $254,000, according to county records, is just under $4,000 a year.

Middleton says he doesn't plan to have his farm classified an agricultural district. "It just doesn't make much sense," says his daughter Clara Leigh, who drives daily from Herndon to help out on the farm. "Who knows what's going to happen in eight years?"

Is Middleton the last of the Fairfax farmers, one of a lone tribe of tan, wrinkle-necked men headed for extinction? "Maybe I am, maybe I ain't. I don't worry about it."

To Middleton, at least, the esoteric question about the future of farming in Fairfax is best left to the politicians. County supervisor Audrey Moore says the ag district bill is one answer. "I guess you can say this was one of those things that is better late than never. If the county had done it 15 years ago, we could have saved a lot more of the farms."

Debra Fielka, a Dranesville resident and member of a citizens committee that initially brought the ag district issue before the board of supervisors, says, "The issue is about saving farms, saving some of the county's beauty, some of the memory that this was once a rich, lush agricultural community."

From where John Middleton sits, in the chair under the maple he planted from a seed, Fairfax County is still a rich, lush agricultural community. Maybe the community only extends down his gravel driveway to his stone gate, but such is his world. As long as he has cows to milk and hay to bale and vegetables to plant, as long the bulldozers remain a distant throbbing and the jet planes a distant annoyance, John Middleton will remain.

"This is my life," Middleton says. "What more can I say?"