On a visit to the University of California Santa Cruz's Farm and Garden a few years ago, I met an apprentice who was trying to grow an entire year's food supply in one small corner of the farm. He planted wheat, corn, beans, potatoes and a variety of salad crops.

Although it would be several months before the first harvest, he had already put himself on a diet consisting only of the food growing in his garden. He looked skinny, but not malnourished, on his diet of bread made from wheat he ground himself, dried beans and canned tomatoes.

"The only thing this diet lacks," he told me, "is a good source of vitamin B12. It's hard to get enough B12 from vegetables."

I pointed out that his diet was also deficient in chocolate, decaf lattes and fettuccine alfredo, three items I considered essential to my own health and well-being. He just laughed, shrugged his shoulders, and went back to sowing beans.

I didn't know it at the time, but this earnest young apprentice was a disciple of John Jeavons, organic gardening expert and author of "How to Grow More Vegetables Than You Ever Thought Possible On Less Land Than You Can Imagine."

For more than 30 years Jeavons has been preaching the benefits of small- scale, sustainable farming. Now, on a farm just outside Willits, Jeavons operates the nonprofit Ecology Action and teaches his methods to gardeners from as far away as Siberia, Africa and Latin America.

Sitting in his kitchen one afternoon, Jeavons shows me snapshots from those workshops.

The students stand in a circle around him while he demonstrates his soil preparation technique. He is a distinguished fellow of 60-something who manages, in his trademark tweed coat and cap, to make digging in the dirt look elegant.

In fact, he looks more like an Ivy League professor than an organic gardening visionary, and it is easy to see how he could be effective in both worlds: He recently presided over a worldwide food and soil conference at UC Davis in which farmers and scientists came together to address the looming food shortage that is the focus of Jeavon's work today.

Jeavons sets the photographs aside and recalls the question that led to the development of his farming techniques.

"In the early 1970s, I went to the San Joaquin Valley, where approximately 30 percent of the food in the United States was being grown at the time, and I asked farmers this question: "What is the smallest area you can grow all your food and income on?' And they said, "Well, we don't know, but if it's a good year, if you have a thousand acres of wheat, you'll be able to pay your bills. ' "

"I realized that if I wanted to know the answer to my question, it was 'tag- you're it.' "

By 1972, Jeavons had formed Ecology Action and was farming nearly four acres in Palo Alto. Alan Chadwick, pioneer of the French intensive/biodynamic method of farming, came up from Santa Cruz to teach classes. The first edition of "How to Grow More Vegetables" was published two years later. At last, Jeavons was finding answers to the question he'd been asking farmers for years.

"It takes about 15,000 to 30,000 square feet of land to feed one person the average U.S. diet," he says. "I've figured out how to get it down to 4,000 square feet. How? I focus on growing soil, not crops."

Jeavons took the best of Chadwick's intensive farming techniques, including double-digging, composting and closely-spaced planting, and added a few ideas of his own.

An organic farm should be a closed system, he reasoned. Off-the-farm inputs like manure, bagged compost, alfalfa meal and liquid kelp all require additional land, water and resources to produce. That, in Jeavon's view, is hardly sustainable agriculture.

"We have an opportunity to grow very high yields using a fraction of the resources. One of the ways we do this is by growing all the organic matter that we need in the garden, or on the farm, that's producing the food."

This closed-system concept is the hallmark of Jeavons's Grow Biointensive method, a term he registered as a trademark in 1999. It allows farmers to grow large quantities of food with few expenses beyond seeds and manual tools.

And Jeavon's method is about more than dirt-under-the-nails farming; he has 30 years' worth of data to back him up. Each edition of "How to Grow More Vegetables" contains more statistical data than the one before: In the latest edition, for instance, you can calculate the precise number of beet seeds you'll need to grow 30 pounds of beets, along with the protein and calorie content, space requirements, and the percentage of the harvest (i.e., trimmings and inedible portions) that can be returned to the soil as compost.

While this approach may be an interesting experiment for a university student, it could be a matter of survival for people all over the world.

Conventional farming practices, Jeavons explains, deplete the soil of nutrients and lead to wind and water erosion. In the face of increasing populations and a dwindling supply of farmable land, he sees his approach as a sustainable, soil-friendly way to feed the world.

"So we're talking not just about this fantastic technique for raising really tasty fresh food with only a fraction of the resources, but we're talking about rebuilding soil. With our methods, you can actually build up to 20 pounds of farmable soil for every pound of food eaten."

Jeavons gets up from his kitchen table and leads me outside, where we walk down a sunny slope to the mini-farm he and his apprentices tend.

He moved Ecology Action to this site outside Willits in 1982. The nonprofit's Common Ground Garden Supply store is still located in Palo Alto, but it is here, in Willits, where he teaches most of his workshops, conducts research, and oversees the day-to-day operations of the Bountiful Garden catalog business.

Farming conditions in Willits are far from perfect, but Jeavons sees a benefit to the difficult site. In the new edition of "How to Grow More Vegetables," he writes that the "heavy winter rains, prolonged summer droughts, short growing season, steep slopes, and depleted rocky soil are similar in many ways to those in countries where Ecology Action's work is having its most dramatic impact."

We stand on a rise above his terraced farm. Nestled in the center is a familiar sight: a large circular garden planted with all the crops that would be required to feed one person for one year.

I have begun to recognize the typical Jeavons garden: It is densely planted with carbon crops like corn, wheat and millet that are important food sources but also produce plenty of high-carbon scraps for the compost pile.

Over half of the garden is devoted to these seed and grain crops. Another third is given over to high-calorie root crops like potatoes, parsnips and turnips. These crops store well and produce a large amount of calories in a relatively small space.

That leaves only a few small beds for the vegetables that occupy most ordinary gardens: tomatoes, squash, cucumbers, peppers, lettuce and broccoli.

Still, Jeavons tells me, thanks to closely spaced plantings and compost- enriched, double-dug beds, these smaller beds produce enough vitamins and minerals to sustain a person for a year.

It's late in the afternoon. All this talk of food production has made me hungry. Back at his office, Jeavons has stacks of research papers and pages of statistics to give me. But for the moment, we are two gardeners in early spring, looking down on the beds of young fava beans, onions, lettuce and herbs. And like any other gardener, Jeavons is eager to show off his work.

"Come down to the garden," he says. "There's a few things here I want you to taste."

EIGHT STEPS TO GROW BIOINTENSIVE GARDENING

-- Double-dug, raised beds. Loosening the soil to a depth of 24 inches allows roots to penetrate more deeply and creates a raised bed effect. John Jeavons' video "Dig It" demonstrates an Aikido-style movement that makes double-digging almost effortless.

-- Composting. A healthy compost pile is key to replenishing the soil.

-- Intensive planting. "Ignore the spacing instructions that come with your seeds," Jeavons told me. Plant seedlings so close that when they are mature, the leaves touch. This keeps soil moist and prevents weeds from sprouting.

-- Companion planting. Green beans love strawberries, corn provides shade to cucumbers, and fast-maturing radishes grow well in between slower-growing carrots.

-- Carbon farming. Corn, millet and oats, along with other seed and grain crops, make up an important part of the diet and provide plenty of high-carbon additions to the compost pile.

-- Calorie farming. Growing a year's food supply means focusing on high- calorie, space-efficient foods like potatoes and parsnips.

-- Open-pollinated seeds. Special hybrids aren't needed in healthy soil, Jeavons says. Using open-pollinated seeds like the ones offered in his Bountiful Gardens Catalog helps preserve genetic diversity.

-- Use the whole method. Jeavons emphasizes that high yields come from using all Grow Biointensive components together. -- Amy Stewart

RESOURCES

-- Common Ground Garden Supply, 559 College Ave., Palo Alto; (650) 493-6072 www.commongroundinpaloalto.org. Ecology Action's nonprofit gardening store sells seeds, plants, tools and books. Classes (taught by John Jeavons and others) are offered regularly.

-- Bountiful Gardens,(707) 459-6410; www.bountifulgardens.org. Ecology Action's nonprofit catalog offers inexpensive seed packets, along with plants, books and tools.

BOOKS, VIDEOS, ETC.

-- "How to Grow More Vegetables Than You Ever Thought Possible on Less Land Than You Can Imagine" (Ten Speed Press, 2002).

-- "The Sustainable Vegetable Garden: A Backyard Guide to Healthy Soil and Higher Yields" (Ten Speed Press, 1995).

-- "Proceedings From the Soil, Food and People Conference: A Biointensive Model for the Next Century" (Ecology Action, 2001).

-- "Dig It!" double-digging video (Ecology Action, 1997).

-- Ecology Action booklets and research papers are available on a wide variety of topics. Some are published in Spanish, Arabic, French, German and Hindi. Check the Bountiful Gardens catalog for details.

WORKSHOPS, CLASSES, FARM TOURS

The Common Ground Garden Store in Palo Alto offers classes on a wide range of topics, from worm composting to drip irrigation. Upcoming classes include:

-- Introduction to Grow Biointensive and Double Digging, both with John Jeavons, April 20.

-- How to Start an Organic Garden with Jody Main, April 27.

-- Plants for Garden Pollinators with Kate Griffin, May 4.

-- Aromatherapy in the Garden with Jeanne Rose, May 11.

Events are held throughout the year at Jeavon's farm in Willits. Call (650) 459-0150 for more information. Upcoming events include:

-- Farm tours: May 25, June 8, June 22 and Aug. 3.

-- Workshop: Grow Biointensive one-day workshop Sept. 7; three-day workshop Nov. 1-3.