Soil quality is a growing focus in the sustainability space, and for good reason: Fertile soil naturally stabilizes the climate and ensures resilient supply chains. But a third of the planet’s land is severely degraded, and fertile soil is being lost at the rate of 24 billion tons a year, according to a 2017 United Nations-backed study. So, a small but growing group of companies — some directly in agriculture or ranching, others indirectly via sourcing — are investing in healthy soil initiatives. Soil, no matter how healthy, may not be the spiciest climate solution. It’s not a giant machine that can suck carbon directly from the air — or is it?In fact, Earth’s soils contain more than three times more carbon than is stored in the atmosphere, and four times more than the amount in all living plants and animals. Biologically speaking, the microbes and minerals in soil systems serve critical, beneficial roles in land stewardship: They regulate water, cycle nutrients, filter pollutants, physically support plants and sequester greenhouse gases (GHGs). Soil is, indeed, a buried treasure.