When a farmer implements a new practice such as cover crops, a verifier comes in and calculates how much carbon is being captured. It then will certify that work and create a credit to sell on the market, most often to corporations looking to offset the carbon emissions they aren’t able to cut in their own process.
Farmers have previously been limited from participating in carbon markets, often due to high costs and poor measurement tools. Most land-related offset practices have focused on planting trees and how forests are managed.
Measuring soil carbon is directly tied to the efficacy of a carbon market. Sampling is accurate but expensive and narrowly focused, meaning farmers get compensated more fairly by the market. Modeling is broad and cheap, but too inaccurate to base market rates on. The answer lies somewhere in the middle.
There are different approaches on how to account for all these things and come up with a number: one relies on modeling and the other on sampling.
Sampling, on the other hand, is much more accurate. It also is much more expensive—as much as $2,000 to $3,000 each time—and difficult to do in a comprehensive way. Multiple samples need to be taken at multiple depths on each field, which would be hard to do for every farm, every year.
The sampling approach could lead to more credits per acre, but farmers likely wouldn’t see that return because of the additional cost to get that data, said IndigoAg’s Hernandez.
IndigoAg uses a hybrid approach. A subset of acres in their program is sampled, which helps “ground truth to the model and increases its accuracy,” Hernandez said, “but then lets us scale the model in a manageable way.”