Farms go out of business for many reasons, but few farms do merely because the soil has

failed. That is the miracle of farming. If you care for the soil, it will last — and yield — nearly forever. America is such a young country that we have barely tested that. For most of our history, there has been new land to farm, and we still farm as though there always will be.

Still, there are some very old farms out there. The oldest is the Tuttle farm, near Dover, N.H., which is also one of the oldest business enterprises in America. It made the news last week because its owner — a lineal descendant of John Tuttle, the original settler — has decided to go out of business. It was founded in 1632. I hear its sweet corn is legendary.

The year 1632 is unimaginably distant. In 1632, Galileo was still publishing, and John Locke was born. There were perhaps 10,000 colonists in all of America, only a few hundred of them in New Hampshire. The Tuttle acres, then, would have seemed almost as surrounded as they do in 2010, but by forest instead of highways and houses.

It was a precarious operation at the start — as all farming was in the new colonies—and it became precarious enough again in these past few years to peter out at last. The land is protected by a conservation easement so it can’t be developed, but no one knows whether the next owner will farm it.

In a letter on their Web site, the Tuttles cite “exhaustion of resources” as the reason to sell the farm. The exhausted resources they list include bodies, minds, hearts, imagination, equipment, machinery and finances. They do not mention soil, which has been renewed and redeemed repeatedly. It’s as though the parishioners of the First Parish Church in nearby Dover — erected nearly 200 years later, in 1829 — had rebuilt the structure on the same spot every few years.

It is too simple to say, as the Tuttles have, that the recession killed a farm that had survived for nearly 400 years. What killed it was the economic structure of food production. Each year it has become harder for family farms to compete with industrial scale agriculture — heavily subsidized by the government — underselling them at every turn. In a system committed to the health of farms and their integration with local communities, the result would have been different. In 1632, and for many years after, the Tuttle farm was a necessity. In 2010, it is suddenly superfluous, or so we like to pretend.