When it comes to removing carbon dioxide from the atmosphere, one of the first questions is often: What should we do with it? Making new things is an obvious answer, though it’s still an expensive proposition. Stashing it underground is another, cheaper option; it usually involves compressing and injecting the gas into underground rock formations, kind of like oil drilling in reverse.

But when it comes to storing carbon underground, there’s another choice that’s even more straightforward: agricultural soils. Farming and ranching has the potential to store from 2 billion to 4 billion metric tons of carbon dioxide every year for between $45 and $100 per metric ton, according to the Intergovernmental Panel on Climate Change (IPCC). As carbon-removal schemes go, that’s pretty cheap.

“Soil science, for the last 20 years, has been banging their drum to say there’s an enormous opportunity here,” Yard Stick CEO Chris Tolles told TechCrunch+.

But how much carbon is held by soils — and how much they capture over time — is not an easy thing to measure. Most soil sampling is done by hand-digging cores out of the ground and sending the samples to a lab. It’s labor- and time-intensive, which means it’s not cheap.

As a soil scientist, Yard Stick scientific adviser and research collaborator Cristine Morgan was intimately familiar with it all. For years, she researched how to use probes to characterize soils, reducing the entire process down to one step. By the time Tolles contacted her, the technology was pretty well developed. In the fall of 2020, she, Tolles and chief engineer Kevin Meissner founded Yard Stick to commercialize it.

It works something like this: The probe part sits near the tip of what’s essentially a foot-and-a-half-long drill bit. It uses spectroscopy to determine how much carbon is locked in the soil. That basically means it shines a light on the soil through a sapphire lens and measures what gets reflected. The device samples hundreds of spectral bands, from visible violet light all the way up to near-infrared. The smarts of the unit sit in a case atop the drill bit; it’s a little bit bigger than a rugby ball. The whole thing is then attached to an off-the-shelf cordless drill, and a sample takes less than a minute to complete.

Tolles said this version is just the first of many, a proof of concept that will be further refined. Next year, the company plans to build a version that can be attached to the back of a truck, allowing the operator to drive up to a sample site, press a button, and let the rig do the rest of the work.

The different versions will help the company characterize soils in a range of different environments, but for now, Yard Stick is focusing on farms and ranches.

The startup recently closed a $10.6 million Series A round, TechCrunch+ has exclusively learned. The round was led by Toyota Ventures with participation from the Microsoft Climate Innovation Fund, the Nature Conservancy, Lowercarbon Capital, Breakthrough Energy Ventures and Pillar VC.