Mr. Leslie voiced a similar sentiment in “The New Horse-Powered Farm: Tools and Systems for the Small-Scale Sustainable Market Grower,” published last month by Chelsea Green. In it, he writes, “I envision a day when live horse power will be joined in tandem on farms with new and cleaner technologies that will include tractors and delivery vans that will run on alternatives to diesel such as recycled vegetable oil, locally and sustainably produced biofuels, and solar-powered batteries, just as the glory days of horse power in North America and Britain coupled advances in horse-drawn implements with stationary steam-powered engines.”

With their strong, arched necks and stiff, clipped manes — white with a black stripe down the middle — the Fjords look like proud warriors, their big heads bobbing in concert as they keep pace down the field of winter oats. These nimble-footed horses, which hark back to the Vikings and are still bred by royalty in Norway, plow and disk the fields here, spread manure and cultivate rows of vegetables, mow the hayfields in summer and pull logs out of the 30-acre forest in winter. On that recent day, they were plowing in a cover crop to feed the soil with nutrients and give it good tilth, as farmers say, referring to moist, well-aerated earth teeming with microbes.

Across the fields, the cluster of barns and hoop houses was part of the same working landscape, in which animals — sheep, milk cows, beef cattle — and constantly rotated crops aimed to achieve what sustainable farmers call a closed-loop system. Cover crops and manure from animals enriched the soil; solar-powered buildings reduced energy consumption; and hay, vegetables, milk and cheese, beef and lamb from the farm provided most of what the animals and humans consumed.

It is an idyllic life in many ways, but it isn’t for everyone.

“Not everybody is geared toward having the patience and sensitivity to work with animals,” Mr. Leslie said. But before the tractor, all farmers had to work with horses, he added, whether they liked them or not: “Back then that was what was available, even if you were an impatient and hard-driving person.”

Mr. Leslie, however, seems particularly well suited to this life, although his path was a circuitous one.

He studied painting and drawing at the School of the Museum of Fine Arts in Boston in the early 1980s, he said, “but I didn’t really see what I was making art for.”

Then his interest in Eastern and Native American spirituality led him to the writings of Thomas Merton, the Trappist monk and social activist, and he spent seven years at the Weston Priory in Vermont. He not only learned to garden there, but was also politicized by the monks’ trips to Mexico and Guatemala, where they helped indigenous communities set up health centers and farm collectives, and escape persecution.