Kade Wilbourne pulls a lever and several tons of volcanic rock shoot behind us in a fan of blue-gray dust. We are sitting in the cockpit of a tractor on the Wilbourne farm in the county of Mecklenburg, Virginia. Normally, the yields of soy and corn are the metrics that count most here. But today, what matters is carbon.
The soil in farms like this is already a large carbon reservoir, contained in organic form in the body of microbes …
