The Works and Days of a Missouri Farmer : FARM: A Year in the Life of an American Farmer, <i> by Richard Rhodes (Simon & Schuster: $19.95; 288 pp.) </i>

There was a time when a city-dweller’s model of the farmer was a hard-working but contented man pulling a plow with a tractor, feeding his hogs and mending fence. A dozen years ago, it was a prosperous businessman driving a $100,000 combine, reading the Wall Street Journal and plowing through as many acres of paper work as cornfield. Most recently, it was the same man, broke and brokenhearted, watching his farm machinery auctioned off.

All of these images form and reform in Richard Rhodes’ rich and sinewy portrait of Tom

Bauer, a Missouri corn, hog and soybean farmer who works 1,000 acres--a third of them his--and who has lived through good times without letting them sucker him, and bad times without letting them crush him.

Rhodes’ previous book, “The Making of the Atomic Bomb,” showed men at work

splitting the atom and launching the second half of the history of the world. “Farm” shows a man at work burning a dirt-frozen nut off a piece of damaged machinery, belly-bumping calves onto a truck, steam-cleaning corn bins, organizing supplies and parts for seven or eight different jobs in a day, and trying to guess the weather, the world grain market and just which bit of equipment will need shoring up against a hog’s insatiable curiosity.

It is not history’s second half; it is the salvaging of a part of the first half important to the second half’s survival. Rhodes’ book, a judicious and well-chosen “Works and Days,” has soberly dramatic undertones.

Tom Bauer, in his capacity for crushing and continually altering work, in the passion of an easy-natured man for making his farm survive and improve, in his canny give-and-tug upon a network of trust and assistance with his neighbors and suppliers, almost seems like a relic. But Rhodes manages to suggest, without pushing any distance, that the ability of this relic to survive means a lot more than his own fate. The world’s work, if it is to get done, would astound most of us.

Rhodes writes, essentially, of a year’s cycle in Tom’s life; and his command of detail and detail’s implications shows the large amount of time he spent with his subject. The year runs from late summer of 1986 through the summer of 1987; a brief epilogue sums up the following year down to around last Christmas.

“Farm,” therefore, begins with the preparations for harvest and not, as we might expect, with planting. The adjustment of that expectation makes one of the author’s large points about the meaning of farming today.

The American farmer has to be many things: field-worker, stockman, mechanic, electrician, blacksmith, planner, economist, negotiator, truck driver and, of course, a shrewd purchaser of equipment, supplies and services. Tom, for example--and it is one of the essentials to his survival--rarely buys any major piece of equipment new.

His flagship--a red Case combine as big as a double-decker London bus--would have cost $80,000 new; he got it, used, for $18,000 plus a trade-in. When hard times came, therefore, his debt load was much smaller than that of thousands of farmers who went on a spending spree during the boom grain prices of the 1970s, and then went under.

The farmer, to repeat, has to be many things; each involving some choice, some freedom, some combination of intelligence and hard work. The one thing he cannot freely be is a harvester and a seller. Harvesting is finally determined for him by the weather. Selling is finally determined by the grain markets around the world. The farmer whose existence centers on grain--the bulk of America’s commercial farmers--can only wager at each.

Thus, the choice of when to start the book. Fall’s wagers are the climax of the farm year. We see Tom negotiating storage space with a local grain-elevator company, trying to get as much harvesting done as possible before the rains and, most difficult of all, making daily decisions once the rain starts as to whether to cut wet corn and beans--the price drops--or hope for a dry spell, or risk losing more, or everything.

It is a complex fabric that Rhodes weaves around Tom’s testing season. In fact, 240 of the book’s 280 pages are spent just getting us from late August to New Year’s. By then, the wagers have been made and the results are in--not as good as hoped for, not as bad as feared, but, in any case, survival. The winter and spring work of repairs, plowing, fertilizing and planting are almost carefree by contrast.

Rhodes’ portrait of Tom is a vivid one, but it is admirably restrained as well. He comes to know him and his wife, Sally, intimately--more intimately, we believe, than he is saying. There is some sharpness in their marriage--it was more a friendship and a partnership than a love match--but Rhodes tells us just enough to give us a sense of both devotion and asperity, and moves on.

He is not, in fact, portraying Tom and Sally Bauer. He is portraying farmer Tom Bauer and farmer’s wife Sally Bauer. (The author has used a pseudonym; one that means farmer in German.) And this does not blur the image. Tom’s sweetness of temper, his forbearance, his conviction that fair-dealing with others is the foundation of rural life, all go to depict the farmer as much as the man.

So does his toughness; his close-eyed appraisal of what suppliers, bankers, elevator companies are up to. In the case of the latter two--a break in the forbearance--nothing very good. Confronting a rare mean neighbor, a man who steals property by moving fences, Tom tells him:

“We don’t work that way out here any more. Any more, the name of the game is cooperation.”

Similarly, Tom’s love for his two sons--sometimes it is tough love--is not just a portrait of a father. The older son has impaired vision; the younger joins the Air Force and may or may not come back. Tom bursts into tears a day or two after he leaves; they are the tears of a farmer-father who longs for a successor.

What we normally think of as farm work is Tom’s delight. When he is driving his combine, seeing the corn stalks bow comically like amputated scarecrows, hearing the cobs clatter into the bin, it is almost a state of altered consciousness.

Working the land, in fact, is what he lives for. The interminable errands, hauling, planning, repairing and trips to town take up most of his time; but they are all for the sake of planting and harvesting. A bumper crop is still fulfillment, even if it means lower prices.

As we follow the daily jobs and decisions that Tom and Sally make--she has a job off the farm but shares his work and worries--we see that money is not the ultimate motive. Tom agonizes, schemes and bargains to reduce costs and increase profits. At the year’s end, the after-tax net will be a decent but not lavish $19,000 (bearing in mind that many living expenses are taken care of). But we see the priorities.

Tom thinks of himself, more or less, as a man who farms to make money. Rhodes’ portrait is of a man for whom making money means that he can go on farming.