A mix of fungi and bacteria added to the soil makes agriculture more productive–and helps stop climate change.

On thousands of acres of orange groves in Florida, farmers are adding beneficial fungi and bacteria to the soil, which makes the oranges grow bigger and sweeter–and makes the soil suck up enough extra CO2 so that each acre offsets the emissions from a passenger car. Call it probiotics for soil.

“Agricultural soils are one of the world’s largest carbon sinks,” says Paul Zorner, CEO of Locus Agricultural Solutions, the startup that makes the particular combination of probiotics in use on the farms. “If they’re treated right, you’re going to absorb a lot of carbon dioxide out of the atmosphere.”

Unlike the ocean, which has absorbed the brunt of human emissions so far–becoming more acidic and hotter and threatening marine life as that happens–soil can benefit from extra carbon. “Soil is the exact opposite,” Zorner says.