ON A COLD FEBRUARY MORNING two years ago, A. P. Thomson noticed that something strange was happening to his apple trees. The bark didn't look right. It seemed loose. On closer inspection, he saw that the underlying wood was stretching and tearing the bark, ripping it apart like Arnold Schwarzenegger in a too-tight shirt.

"I made a few phone calls, and I found out split bark means the trees were growing in the middle of the dormant season. Well sir," he says, shaking his head, "that just doesn't happen."

Nevertheless, Thomson's orchard is the sort of place where impossible events are frequent. In early spring last year, he tapped his trees with a refractometer, a device that measures the sugar content of the sap. "It was four times higher than is normal for these trees," he says. And then there is the alfalfa, planted around the base of the trees as a ground cover. Thomson pulls up a healthy-looking sprig. "Now, the agriculture boys will tell you that alfalfa only lasts three years. But this alfalfa here," he says with a slow smile, "we planted in 1946."

Weird, yes, but everything is weird about A. P. Thomson's 35-acre orchard in the foothills of the Shenandoahs five miles north of Front Royal, Va. For more than 41 years he has used no herbicides, no pesticides, no chemical fertilizers. He sprays the leaves with kelp and soap, and feeds the roots with an arcane mix of minerals, fish emulsions and grass clippings. He dispatches his own carefully tended bees to effect pollination above ground, and earthworms to aerate and fertilize below. He uses buffer zones of gravel to ward off mice, and has established "a bird in pretty near every tree" to patrol for harmful insects. Lately, he is even tapping low-frequency radio waves and broadcasting them to te trees to encourage growth, a method borrowed from sixth century Irish monks.

But tell A. P. Thomson how foolish it is to break every rule of modern commercial orchard husbandry and he'll show you an apple -- perhaps a massive Margold, or a Jonathan, or Winesap, York Imperial, or any of his vigorous, juicy apples that hang bunched on trees like grapes, swollen and heavy and pulling the branches down in swooping arcs that must rest their tips on the earth.

Even more to the point, he'll show you the people driving up his road. About a thousand visitors come here each year to hear Thomson patiently explain the particulars of "biological, regenerative farming." Many others subscribe to his newsletter or read his pamphlets, or belong to one of a half- dozen organizations he has set up to promote growing methods that work with nature rather than against it.

And those who come here to learn do not arrive in hippie vans or yuppie Volvos, seeking the secretsof organic gardening They come in rattling, dusty pickup trucks driven by tired, broke farmers -- men who watched their land, finances and self-esteem erode after decades of chemical farming left their fields scarred and sterile. They are men with enough humility to learn how to farm all over again, and Thomson is teaching them.

"I was driving past here during the bad drought year we had back in '64," says William Royston, who grows potatoes just three miles up the road. "Everything for miles around was brown and dying, except this place. It looked like an oasis. I figured I ought to stop in and find out what he was doing." Royston now farms as Thomson advised, and last year harvested 1,000 bushels of potatoes per acre, an amount Virginia agriculture officials say is more than five times the state average. Others trained by Thomson also report high yields.

Many farmers now regard Thomson as a point man in a move to profoundly alter American farming practice -- a role he gladly accepts. "I have learned a few things in my 40 years here through a lot of painful trial-and- error," he says. "I intend to spend the rest of my life trying to pass some along."

Royston, the farmer from up the road, is a tall quiet man with a perpetual sun squint. He leans against his pickup and says, "With costs what they are, this is just the only way to farm anymore." He sweeps a callused hand across the field. "This is gonna be the salvation of American agriculture, that's all."

AUGUSTUS PEMBROKE THOMSON is 75 years old, a southern gentleman who reads Greek philosophy and works dawn to dark but just as eagerly drops his hoe to chat about anything from the Civil War to particle physics. He lives in a house full of antiques that include a parchment deed signed by Thomas, Lord Fairfax, and a whiskey cabinet once owned by George Mason. He can make men half his age huff and puff as he beats the bounds of his spread, and he seems so at peace with himself that he makes growing old in the country seem like a terrific idea.

He is, above all, a farmer, with a passionate love for the land and a family history rooted deeply in this soil. His ancestors were granted the land by Lord Fairfax in the late 1600s, and on his mantelpiece are silver cups they won for high yields over two centuries.

But by the time Thomson's father took over the spread, the land was played out, eroded and barren as a moonscape. "It was washed down the river. There was just dead clay -- you could barely make a living on it."

So Thomson decided to cultivate human health instead and set out to be a physician. He graduated premed from Washington and Lee University in 1933 with high marks in organic chemistry and biology, and won a scholarship to Harvard Medical School.

"But along came the Depression, and my daddy couldn't get the money together for room and board," so Thomson worked as a chemist in the assay office at the U.S. Mint. "It was a good job, which you were right thankful for in those days.

"Then along came the war. and while I was in the Navy in Pearl Harbor, I was browsing around in the PX and I happened to pick up a book by Louis Bromfield called Pleasant Valley. It commenced to ring bells. He explained what the farmer was doing wrong, why our land was washing away, and I started to realize what had happened to the old home place.

"Well, then I read and read. I couldn't seem to get enough books." He also began a long correspondence with Sir Albert Howard, the English horticulturist considered the founder of organic gardening. He went to Pennsylvania to see early experiments conducted by J. I. Rodale, founder of Organic Gardening magazine. Thomson regards those contacts as crucial. "You must understand: it was a rare thing in those days. I was fortunate to meet up with the real pioneers."

Thomson decided to "go back to the old home place and make a go of it, using these methods." When he laid it out to his family, "they thought I was out of my mind," he recalls with a grin.

The scene spread before Thomson and Cliffie -- the young wife he had brought here -- was bleak. "There were gullies big enough to hide a house in. My daddy planted 15 acres of corn, and he couldn't raise enough to feed one milk cow -- it was that bad."

So before he planted a single tree, Thomson began to reclaim the soil. For two years he spread chicken manure and planted a mix of bromegrass and sweet clover to loosen the earth and provide nutrients. Each time the plants reached their nitrogen peak, he plowed them under and replanted.

Then in 1946, he set out the trees, and soon made his first big mistake. To correct the soil's natural acidity, he spread 10 tons of ground limestone per acre. The young apple trees promptly began "corking" -- producing fruit with a tough, corklike texture. The massive onslaught of limestone had apparently created a chemical imbalance. Thomson began working borax into the soil to correct it, "but it literally took years to get over that. If I could make a mistake like that with my knowledge of chemistry, it just shows how careful you must be with the soil's ecology."

Through the years, Thomson has experimented -- carefully -- with a variety of minerals and fertilizers for roots and leaves. Beneath his trees grows a lush carpet of erosion-preventing cover crops. After mowing the grasses, he sprays them with a bacteria to speed up decomposition of the fallen grass. He has also used fish emulsion, and the soil is continuously conditioned by several tons of hand-raised Red Wiggler earthworms.

He feeds above ground too, a twice-monthly dousing with a Norwegian seaweed emulsion that is absorbed through the leaves. And most incredibly, he supplies his trees with what he unabashedly calls "cosmic energy," channeled through two unlikely collections of copper tubing (see box, page 15). His pest management system is equally iconoclastic. The only insect spray he em- ploys is Basic H, Shaklee's coconut-oil soap. "It dries up the mucous membrane surronding the larvae," he says.

But Thomson tries not to "monkey" too much, believing that the strongest defense against insects is the chemistry of the tree itself. "Over millions of years, the trees developed these internal biotoxins, which either taste bad to the insect, or will actually kill it. You just need to keep the plant healthy."

Thomson says his yield has varied through the years, as he experimented with different fertilizers and pest control techniques -- usually, it has been slightly lower than that of nearby commercial orchards, "because they use a growth hormone and a lot of chemical nitrogen."

But he says in the last two years his yield has increased dramatically, through a technique called "biological ionization" developed by Dr. Carey Reams, a Florida biophysicist and citrus consultant. It consists of heavy doses of fertilizers: one ton potash, two tons phosphate and four tons aragonite (an ocean deposit of decomposed sea shells) per acre. Thomson says his tree's bark-splitting winter growth came after the minerals were applied, and the next fall his yield was more than 1,000 bushels an acre. Officials at the Fruit Research Laboratory of Virginia Polytechnic Institute say that is almost twice the yield of the average Northern Virginia commercial orchard at its prime.

Thomson sells his apples by mail order, at prices ranging from 81 to 97 cents per pound. It has been a good living. "All I can say is, I put four boys through college on 35 acres." A. P. Thomson III, 31, works in a greenhouse in Oregon; Paul, 28, is a lawyer in Winchester; John, 22, is working on a master's degree in environmental science at the University of Virginia; and James, 19, is a sophomore at Virginia Commonwealth.

His customers are devoted to him. He has 1,300 steady mail order accounts, and regularly receives letters from fans who rhapsodize about "apples that taste like I remember as a kid." Thomson believes his apples' sharp, distinctive flavor comes from their abundant minerals. Thomson says a 1968 study by Clemson University revealed his fruit had 8 percent more calcium, 70 percent more iron and 100 percent more zinc than commercial apples tested (Dr. Taze Senn, former head of the horticulture department at Clemson, says he cannot recall that particular test, "but we were testing apples at that time, and those figures are certainly possible." Senn is quick to add that "whether organic is always (nutritionally) better than the chemical product is still very much undecided."

Thomson says he is especially pleased by letters he gets from about 100 customers who are sensitive to herbicide and pesticide contamination. A woman from Mobile, Ala., wrote: "This is the first apple I have been able to eat in 22 years. I'm so allergic to commercial apples that I break out and almost go into a coma."

THE EVENING breeze is sliding down the foothills, and rays slant through the lead-glass windows and across the pine flooring to where Thomson sits in his living room, holding his thumb and forefinger one inch apart.

"There are as many living organisms in a single cubic inch of healthy soil as there are human beings on planet Earth," he says, gazing at the imaginary population between his fingers. "It's an integrated, pulsating, living, breathing system."

Thomson feels that a lack of respect for this complex world beneath our feet is chemical farming's greatest sin. The average apple orchard in Northern Virginia sprays about 15 times per season: there are sprays to kill insects, weeds, fungus, to force the blossoms open, to thin the blossoms, to thin the fruit, to enlarge the apples, to keep apples from falling, to make them all ripen simultaneously.

All of this percolates through the soil, and all of it bothers Thomson -- especially the herbicides. "They are just the worst thing imaginable. The visible weeds are killed, but so is this vast ecosystem beneath our feet, it is just burnt and destroyed, it loses its integrity, its erosion resistance."

Thomson also suspects dire long-term consequences for a society fed with fruits and vegetables that are grown with herbicides, pesticides, hormones, gassed with ethylene to promote ripeness, sprayed with coal-tar dyes for appealing color, and, if pending legislation passes, zapped with radiation to retard spoilage. "There is a time- delay effect with many of these things," he says. "I believe we are eventually going to see a massive breakout of birth defects, little children born without fingers and noses, cancer, just horrible things. I think we are walking on a minefield."

But Thomson is far from despairing. He is convinced that, sooner or later, the conversion will happen. "I'll tell you what will do it. We've had cheap food in this country for a long time, but that time is going to come to an end real soon." Thomson says though American agriculture remains highly productive, "I go out to the Midwest and talk with those boys, and they tell me topsoil that was three feet deep on their places is down to six inches. It can't go on much longer. We are talking about desertification."

In Thomson's mind, the question is whether Americans will have the foresight to make the transition easy, or whether they will wait until "the supermarket shelves are empty." He says several changes are needed:

*The tax system must encourage investment in soil improvement. A heavy dose of minerals can cost more than $2,000 per acre. Thomson says "once those minerals are in the soil, they last for years." But the average farmer, head over heels in debt, generally can only afford to squeeze out a yearly dose of quick- acting, short-life chemicals, with each year's harvest barely financing the next year's application.

*The public must be alerted about herbicides and pesticides. Like the smoking controversy, this is a public health debate that promises to drag on for years. But consumer wariness is growing -- a 1984 Harris poll of 1,008 shoppers showed 77 percent considered herbicide and pesticide residues a serious health hazard.

*The farmer must have access to information. Several periodicals, notably "Acres U.S.A. -- A Voice for Eco-Agriculture," "New Farm," and "Biological Farming News" have already sprung up, as have groups such as the Regenerative Agriculture Association and the Natural Organic Farmers Association. *Food grading standards must change. "The modern shopper is programmed to expect perfection in appearance and ask no questions about nutritional quality," says Thomson. "People will need to understand that biologically grown foods may not be as pretty."

This is a crucial point. One Virginia agriculture official, who asked not to be named, said, "I'd venture a guess that Mr. Thomson has more scab, more insect and disease damage than other commercial growers. That's fine for him, because he markets by mail order. But all growers can't sell that way." The official said as long as the USDA's commercial grading system requires cosmetically perfect fruit, "it's unrealistic to expect other growers to operate the way he does."

THOMSON OFTEN blames the federal government for protecting the current system, but Peter C. Myers, assistant USDA secretary for natural resources and environment, says, "It isn't correct to paint us as against organic farming. At some times, in some places, it is perfectly appropriate.

"But you're not going to feed the world that way. You've got to have some chemicals, especially nitrogen, or you won't get the yield." And Myers says organic farming has its own pollution problems: "Some of these all-manure operations are contaminating the groundwater."

Erosion, he says, is a "productivity problem." New USDA figures show that more than 3 billion tons of soil -- more than seven tons per acre -- are lost annually from American cropland. USDA models show erosion results in production losses of slightly less than $1 billion per year, a tiny $2 per acre.

But such estimates evoke a collective roar from organic farmers: "Sheer idiocy," rumbles Wes Jackson of the Land Institute, a nonprofit regenerative farming research group in Salina, Kan. "Define the problem with such narrow constraints, and of course it doesn't look serious." Jackson says we should consider "what we would do if the soil were gone -- what would it cost to replace it? The USDA models don't take it out that far."

Klaus Flach, special assistant for science and technology of the USDA's Soil Conservation Service, says the USDA is exploring farming methods that limit chemicals. "Mostly, it is because the stuff has gotten so expensive. We are working closer with some of the organic farmers who have backed off from that extreme viewpoint of no pesticides and are willing to look at ways of just minimizing their use." He says the USDA also keeps one man at the Rodale organic farming laboratories to collect data.

"We don't accept the basic premise of these farmers, that natural is better, that the fruit is better for you," he says. "But we feel that we can learn from these people."

THE BREEZES are cooling the orchard and Thomson is out walking again. He strolls past the chicken coop and stops in the family vegetable garden, kneeling to twist off several rhubarb stalks as thick as a man's wrist. "I love it out here. I don't even like to leave," he says.

"You've got to be that way. Farming is a way of life, and embedded in that is a philosophy, and if you don't have that, you are making a terrible mistake trying to get into it. There is a lot of hard work, and you don't get rich. But there is a deep satisfaction in it."

Thomson feels that although he can make a good, solid, sensible case for his style of farming, ultimately he is counting on "what is in the farmer's heart."

He uses this example: last February, he says, 500 farmers turned out for a natural farming conference in Pennsylvania. "There were farmers there from all over. The talks were going along for awhile, and then one man from the Eastern Shore of Maryland gets up and says, 'I have 1,200 acres, and I have killed all the wildlife, polluted and poisoned all the groundwater, and my place looks like a desert. I am here to learn how to get off the chemical train.' Well, that started it. One by one, these old farmers got up there, tired, their hands all callused, and they said, 'We just want to learn.'

"There is a spiritual bond between man and the soil, and these old fellows felt it had been broken. They just wanted to regain it."

Thomson is also encouraged by the movement of city people to the country. "I think these people are looking to restore that connection." He looks forward to a new generation of children who grow up close to the land.

"I remember when I was a boy, my mother would take me out into the garden. She would pick up that soil and say this is where our food comes from, this is what keeps us alive. So I had it in my heart very early.

"I think that potential exists in everyone, it just has to be awakened," he says. "You just have to give the child a chance to put its feet on the ground."