Underground, soil is made of complex layers (Image source: National Geographic) 

If you’re like most people, you think about dirt only when you’re scrubbing stains out of your children’s clothes. Or maybe you’re one of the many who’s started “pandemic gardening,” and think soil comes in bags labeled Miracle-Gro. Even introductory biology courses in high school and college are dismissive in their dirt talk, reducing dirt to a nonliving resource for living things to take advantage of.

But soil is alive. More and more research tells us that soil is teeming with underground fungal networks. The fungal networks act as a telephone wire for plants, allowing them to alert one another of disease and attack by insects. These fungi also allow plants to take up more nutrients themselves, as well as share those resources with their neighbors. Even outside of fungi, soil is packed with life—one teaspoon of soil can hold a billion bacteria. Zooming out more, you’re likely familiar with the giants who call soil home, including earthworms and insects, through your own experience with soil. Your biology textbook wasn’t entirely wrong in its characterization of soil as abiotic. Soil structure is mosaic-like, with biotic and abiotic pieces coming together to make something beautiful.

Artistic Representation of Underground Fungal Networks (Image Source: BBC News)

Those abiotic bits of soil have huge consequences for living things that interact with them—including humans. The amount of minerals like zinc and iron in soil can have long-standing consequences on human health. And soil’s connections to human wellbeing don’t end there. Iodine deficiencies in soil can lead to life-long thyroid conditions.

Soil also affects health on an even larger timescale—it plays a fundamental role in mitigating human-caused climate change. Simply put, we’re past the point where climate change can be prevented. Finding ways to store excess carbon dioxide from the burning of fossil fuels is key to limiting its scope and scale. Soil, and especially well-managed soil, has the potential to act as a reservoir for that carbon, keeping it out of Earth’s atmosphere.

In looking at soil through the lenses of environmental health, public health, and climate change, I will make the case that if we care about the future of our planet and each other, we need to stop treating soil like dirt.