On a sweltering summer afternoon in Minnesota, Paul Lightfoot clambered into a deep ditch to inspect the root structure of a plant called Kernza.

Mr. Lightfoot is the general manager of Patagonia Provisions, the nascent food business operated by Patagonia, the outdoor apparel retailer from Ventura, Calif. And he believes that Kernza, a type of wheatgrass that can be used for baking and brewing, has the potential to change the food system.

Standing at the bottom of a trench cut into a field of farmland, Mr. Lightfoot traced his fingers along the exposed roots, which stretched more than 10 feet down into the soil, much farther than traditional wheat.

Those roots are what makes Kernza so unusual, allowing it to absorb more carbon dioxide than many crops, and turning it into a theoretical ally in the fight against climate change. And because Kernza is a perennial grain and doesn’t need to be replanted each year, it requires less water and fertilizer than traditional wheat, making it a boon for cost-conscious farmers.

“It’s just a way better way of doing things,” Mr. Lightfoot said. “Humanity isn’t doomed to do things in a way that ruins everything.”

Current production of Kernza is minuscule, with fewer than 4,000 acres planted in the United States, compared with more than 47 million acres of wheat. Just a handful of other companies are making products with the grain. Hardly anyone knows about Kernza.