AS THE auto industry goes, so goes the American food supply.

At least according to the Cornucopia Project, a research effort led by organic gardening prophet Robert Rodale and released at a press conference Tuesday.

The United States food system, says Rodale, can be compared to the auto industry in the early '70s. Detroit finally learned that gas guzzlers were anachronistic, that they had no place in a society where energy, raw material and labor costs were skyrocketing.

The American food supply follows a similar trend. Great American farms were started and supported in an environment of endless fertile land; a favorable climate for agriculture; plentiful (cheap) energy from oil, coal and water; a profusion of labor, and advancing technology.

But there's trouble in the never-never land of America's bounty, says Cornucopia Project director Dr. Medard Gabel. America's resources now show very definite signs of limits. "The American food system is not sustainable," he says.

He outlines weaknesses in terms of short- and long-term threats to the food system. There are many.

The Cornucopia Project attempts to assemble them all in one place, to "look at the whole food supply system," according to Gabel. This comprehensive approach analyzes food production as an integrated system -- involving everyone from farmers to politicians. Rodale and his staff hope such an approach makes it easier to see problems and achieve solutions.

In the short term, organized labor threatens the food supply at any one of several levels. From production to retail sales, labor strikes could limit supply and increase prices.

Farmers, no less than consumers, have been badly hit by rising energy costs, which in turn increase food prices. Water, says the report, will soon become precious. Any embargo on food transports, such as the one prompted by the medfly infestation, might cause prices to rise. American farmers, it says, are already $160 billion in debt and hold little collateral but their land, which grows more valuable only as a reflection of inflation.

Long-term threats include extensive soil erosion, which results in low yields and even abandoned farm land. Limits on fossil fuels and mined minerals (phosphates, nitrogen used as fertilizer) may cause yet more dependence on foreign imports. Pesticides and chemical fertilizers deplete the soil, which traditionally has not been allowed to recover sufficiently from one year to the next.

The chronicle of threats, say the authors, may present a doomsday situation. "The situation could get critical before it even seems serious," says Gabel. And in the interim, the problem touches every facet of American life -- farmers, packagers, transporters, consumers, politicians, industry of every conceivable kind.

Consumers perpetuate many of the weaknesses. They implicitly support the top-heavy food system every time they go to the grocery and buy celery from Florida and apples from Washington State. And if they continue this support of traditional food production, the Cornucopia Project predicts, consumers will pay $7 for a loaf of bread by the year 2000 and $6 for three tomatoes.

The study estimates that food travels an average of 1,300 miles from producer to consumer, sometimes traveling for two weeks. And transportation is expensive.

It costs money; it costs flavor; it costs nutrients. For every $2 spent on growing food, $1 is spent to move it around. Last year consumers in the state of New York paid $6 billion to import 24,000 tons of broccoli, mostly from the West Coast, 2,700 miles away. Broccoli is just one of many vegetables that prefer cool weather and can be grown almost anywhere in the country. Thus, the typical Rochester consumer is left holding an old, relatively expensive stalk of broccoli that is most certainly less tasty and probably less nutritious than a locally grown vegetable would be.

In addition, the picture-perfect food demanded by the consumer often requires the use of pesticides or herbicides that don't necessarily affect the integrity of the food itself, but make the final product prettier. Using such chemicals interrupts the ecology of the land, diminishing natural attributes (favorable insects and extant nutrients), while drastically increasing the need for reapplication -- the more these chemicals are used, the more they are needed.

Consumers also pay for processing -- an extremely expensive phase of the food supply chain. The Cornucopia Project illustrates this point using potatoes as an example. People now eat 74 percent fewer fresh potatoes than they did in 1910, the writers note, but potato consumption has increased 71 percent.

This not only hurts their pocketbooks, it could preclude optimum health. A hundred grams of baked potato is about 90 calories; 100 grams of potato chips is almost 600. Processed food is typically lower in natural nutrients (as in the case of refined flour) and higher in sodium, fat, sugar and additives of dubious reputation.

Cornucopia offers solutions, however, as it deals with each segment of the food chain individually.

Farmers, for instance, are advised to diversify production (grow more than one cash crop to insulate against devastation), to stop soil erosion, to investigate alternatives to chemicals. Parallel suggestions are made for the food industry and city, state and federal governments.

And for consumers. By educating consumers, says Rodale, he hopes to "insulate" them against food's inevitable cost increases by making them more self-reliant. "I don't want to overstate what we're doing," he says, "but it could be a new approach to consumerism."

The recommendations suggested by the project range from the predicatable to the bizarre. First, consumers are encouraged to become more aware of where their food originates and what is done to it. They are advised to purchase locally grown food in the hopes of getting food at its peak and bolstering the local economy.

Food-buying groups, and on a larger scale food co-ops, are promoted, in order to reduce consumer expenses because bulk purchases are usually cheaper.

If possible, food should be bought in bulk and processed at home, eliminating the need for commercial processing and packaging, which add to expense. Consumers who process and preserve their own food, or that purchased from a local farmer, can control cooking times, processing techniques and additives, the writers point out.

Furthermore, they say, most consumers can afford to modify their diets, concentrating on foods high in complex carbohydrates (vegetables, fruits and whole grains) and low in fat, sugar and salt, as consistent with the U.S. Dietary Goals.

As might be expected, the Cornucopia Project encourages consumers to grow their own fruits and vegetables -- either in a cooperative venture with neighbors, in back yard gardens or even in solar cold frames that can sustain lettuce in the dead of winter.

The most impractical suggestion (but one that apparently has its share of enthusiastic followers), is to raise back yard animals such as rabbits, chickens and even fish.

Although each participant in the food chain is asked to make sacrifices, Gabel says the project does not necessarily ask consumers to sacrifice fresh raspberries and kiwi fruit. Some food must travel. Simply put, Cornucopia seeks to reduce the average distance that food travels from 1,300 miles to a more managable 500 or so.

Its authors hope that farmers, encouraged by food industry and consumers, will become interested in the long-term integrity of their land and the environment. They ask that government at all levels make it legally and economically practical and attractive for everyone to participate in creating a "sustainable" food supply.