Just as we’re told about the vast ecosystem living in every handful of dirt, there’s a lot life and activity teeming beneath the deceptively simple surface of “The Real Dirt on Farmer John.” Not just a documentary about one eccentric farmer, who in one scene rides his tractor in a bee costume, “Farmer John” is a busy collage that fuses the soap opera of one man’s life, the intimacy of his relationship with his mother, the confounding economics of the farming industry, and the more spiritual nature of man’s relationship to the Earth — all orchestrated by director Taggart Siegel in a way that makes the tale accessible to just about anyone.

The film’s clear-cut agenda — to entice viewers to support local, independent organic farmers over the product of industrial farms — is unmistakable. But given the story that it has to work with, one can understand why the movie would come to the conclusions it does. Had we experienced and lived through life like farmer John Peterson has, no doubt we too would be compelled to grab the world by the arm and convince it that local and organic is the only way to go.

There seem to be four chapters here, all tentatively tied together and headlined by the demise of a family farm — a painful loss that’s narrated by Mr. Peterson himself. As he reminisces about his youth, recalling how he used to watch his dad and uncle work their sprawling farm in northern Illinois, he remembers fondly when dad was in the field, mom was running off to her second job teaching at a nearby school, and the world was limited to the green hills spreading in every direction.

But everything changed when Mr. Peterson’s father died at a relatively young age and left the farm to his son. Simultaneously farming and attending a nearby college, Mr. Peterson began inviting classmates out to the farm to smoke marijuana, build some bonfires, and try to work the land. Not surprisingly, the farm struggled in this period, and soon Mr. Peterson was one of many farmers facing a desperate situation in the 1980s — over-leveraged and under-funded, forced to sell off the majority of his land and equipment to avoid foreclosure.

But this is where the standard story of the struggling farm ends and the unusual tale of Mr. Peterson’s unexpected triumph begins. Feeling that he failed to preserve the family business, Mr. Peterson sank into a deep depression, abandoning the Midwest to travel south to Mexico, where he stayed for a year. When he returned to Illinois and made another go at farming, he began to find some unusual allies: environmentally minded Chicago residents interested in forging a one-to-one relationship with an area farmer.

Skeptical but desperate, he first partnered with a dozen Chicagoans, then a few hundred, and then more than 1,000 interested buyers, all committed to buying organic and buying local. In the span of just a few years, Mr. Peterson and his farm were back in the black, and he had forged friendships with an army of people who were interested in hearing about — and in some cases working on — the farm.

Looking at the big picture here, “Farmer John” is a movie about the death of the family farm, and then the unlikely revival made possible by the education and activism of the general public. While some may avoid the film, thinking it will be little more than the story of a hippie who got lucky, this last bit seems to spin that concept on its head, presenting a distinctly market-oriented solution to a market-based problem. Farmer John’s underlying philosophy is that modern American culture is more removed than ever from the Earth and the source of its food, but the key factor in resurrecting the farm is a combination of community activism, business savvy, and economies of scale made possible by keeping the scale small — only a two-hour drive between dirt and dinner table.

There’s something uniquely nostalgic and emotional about farming in our culture — about the way America grew on its sprawling farmlands, and then in the way those farms, in only a generation, unceremoniously become relics. Maybe that’s why the emotional roller coaster of Mr. Peterson’s life is a match for the larger issues at play. Much as Al Gore took a tedious scientific topic in global warming and gave it a dose of moral outrage in “An Inconvenient Truth,” so has Mr. Peterson taken the dry economics of food production and put a human face on them.

Late in the movie, when a number of those Chicago shareholders hear a pitch from Mr. Peterson and agree to join forces by buying a second lot of land adjacent to the farm so that he can expand his operation, something remarkable is afoot. Here we have a man who once teetered on the edge now being propped up by his consumers — and a simple film made by a few people in the Midwest that manages to send us away with new thoughts about the food we eat, the way we live, and what’s possible in our endless hunt for sustainability.