The Brown Revolution is happening. If the last time you talked about soil was to call something as boring as dirt, heed what Leonardo da Vinci said: “We know more about the movement of celestial bodies than we know about the soil underfoot.” That was 500 years ago and soil experts agree that it’s still true today.
What we do know is that soil is complicated. One teaspoon of soil has more microorganisms than there are humans on earth, according to George Siemon, a founding farmer of the Organic Valley Cooperative. He spoke last week in Washington, D.C. at Save Our Soils, a celebration of organic farming’s healthy impact on soil. And soil deserves to be celebrated for its foundational role in creating the food—both crops and animals—that makes people healthy.
Healthy soil’s impact is wide-ranging but three big effects are: its ability to improve human health, its ability to halt soil erosion, and its potential to slow the effects of climate change.
First, improving soil health will improve human health through food. Cover crops—also known as Green Manure for the Brown Revolution—are crops planted by farmers (or home gardeners) to enrich soil when it’s not being used. For example, a farmer may decide to plant clover (a fast-growing cover crop) after a soybean harvest, rather than keep the land empty. Having a cover crop is better than leaving the land barren and unused, because cover crops interact with the soil, exchanging nutrients through the roots and building richer soils. It’s manure without the, well, manure. And fewer pesticides are needed to keep the land free of weeds. Even better, some cover crops are also delicious, like buckwheat (a top earth-friendly food).
Soil health ultimately determines how well crops grow and whether the planet can feed a population of 9 billion by 2050, a figure that looms large as we gear up to address hunger on World Food Day this Friday.
Additionally, for dairy farmers like Jon Bansen in Oregon, having almost 600 acres of pasture ensures that animals have ample grazing time. Grazing gives animals access to the outdoors, feeds them some of their diet of origin, and improves soil health by blanketing land with pasture that enhances, rather than depletes, nutrients in the soil.
“Soil health is important to animals as grazers, because of the interaction between the soil and the plants, and the plants and the animals, and the animals and our health,” Bansen says. “Soil is ultimately all about Medicare and Medicaid and obesity.”
Second, soil erosion is a healthy-soil issue. Healthy bacterial activity acts as a glue, helping soil clump together. Squish a ball of dirt in your hand. If it forms a ball, it’s likely got great bacterial activity and is healthy soil. Excessive pesticides and herbicides destroy soil’s complex and delicate bacterial activity and create soil that is loose and doesn’t hold together. When there is a soaking rainfall, rich soil can clump and hold onto the water, storing it for plants. Unhealthy soil gets washed away with the rain, bringing dirt and pesticides into the waterways and eroding the earth. Once a soil’s nutrients have been depleted, a vicious cycle of soil loss begins that takes a concerted, dedicated effort to stop.