Soil Part 1: How Soil Impacts Our Health—and the Health of Our Planet – Nama


Soil Part 1: How Soil Impacts Our Health—and the Health of Our Planet

Healthy soil is fundamental to healthy food production, and ultimately healthy people. This mixture of sand, silt, and clay has a much bigger story to tell than you might imagine, and like many aspects of our environment today, it’s at risk. We’re diving deep on the topic of soil in this 3-part series to introduce some of the challenges, show you farmers who are working to nourish the soil, and give you tips for creating healthier soil in your own backyard and at home.

Walk into any grocery store today and you have access to almost any kind of food you want. Around the perimeter you’ll find the fresh foods—colorful fruits and vegetables, eggs, dairy, meat, and fish. In the middle aisles, you find the convenient foods—canned, packaged, and ready-to-eat.

We enjoy such easy access to this cornucopia of food thanks to a robust farming system.

Starting in the mid-20th century, industrial agriculture surpassed backyard and small, family farming to feed millions of Americans. We now have more than 900 million acres of farmland in the United States alone.1 Canada has more than 158 million acres.2

But only a tiny fraction of those acres, about 5 million, are certified organic, meaning less than 1 percent of total farmland uses organic practices.3

Conventional agriculture relies heavily on large-scale monoculture—when farmers grow or produce a single crop or livestock species in one field or farm at a time. While this kind of intensive farming can help maximize output, it also involves employing vast amounts of synthetic fertilizers and pesticides to keep weeds and pests at bay for higher yields.

The U.S. uses more than 1 billion pounds of pesticides each year, according to the U.S. Environmental Protection Agency4 and lags behind countries like Europe, China, and Brazil for banning these harmful chemicals.

About 85 pesticides used throughout the U.S. have been banned or are in the process of getting phased out by these other countries, mostly because of their harmful impact on human health or the environment, according to a 2019 study published in the journal Environmental Health.5

But it doesn’t have to be this way.

At the foundation of every farm growing food is the soil. Healthy soil is fundamental to healthy food production. This dark mixture of sand, silt, and clay has a much bigger story to tell than you might imagine, and like many aspects of our environment today, it’s at risk.

The composition of soil is quite malleable, depending on factors like the weather, the health of organisms that compose it, and the types of plants that grown in and on top of it.6

It’s prone to the same kinds of pollution found in our water and air, and industrial farming practices can have a huge impact on it.

In contrast, soil can also be amended and improved by adding nutrients back into it. When farmers work with the land and focus on building healthy soil, they can make crops stronger and less susceptible to pests and drought.

A Brief History of Why Dirt Matters

President Franklin D. Roosevelt once said, “A nation that destroys it soil destroys itself.”7 He should know. During his presidency, he dealt with the largest manmade environmental disaster in history: the Dust Bowl.

Intensive farming on fertile Midwestern grasslands triggered this event. As eager farmers tilled millions of acres of land, the soil became exposed and vulnerable when a long drought hit. Winds swept across the plains generating massive dust storms and turning hundreds of millions of cropland into barren wasteland.

Today, threats to our soil continue thanks to unsustainable farming practices, including overuse of chemical contaminants, over-plowing and tilling the land, and not utilizing crop cover.

According to research from the USDA, it takes 500 years to build an inch of topsoil and for crops to flourish, you need about six inches of soil.8

In the last 150 years, we have lost half of the topsoil on the planet.9 This destruction affects not just soil fertility, but the future of our farming system.

A Not-So-Hidden Realm

Kristin Ohlson, author of The Soil Will Save Us, describes soil as the hidden kingdom.10 It’s only in recent years that scientists have discovered just how many microorganisms reside in our soil and why they are so important to all life on the planet.

Researchers consider soil a living community.11 Billions of organisms exist in a single teaspoon of soil.12 It contains an entire universe of life—bacteria, fungi, and earthworms alike.

And farmers agree. Wesley Sleight, an organic grower in North Carolina, says his focus is fostering this massive colony of microbial activity underneath the soil surface.

“Our main goal is to feed these little creatures so that when we put the plants in the soil, they will treat our plants right. The richer the microbial activity, the more resistant they are to bacteria. The stronger the plants are, the less pests will attack them. So it’s just got such a myriad of benefits.”

It’s not hard to see the results of working with the land.

“One of my most gratifying things is when I’m working with the soil in the spring and I’m plowing pasture and the earthworms are just teaming out of there—a single handful of soil will have 50 earthworms,” he said. “It’s amazing! The soil is just so fluffy, it’s got tons of organic matter in it.”

Now consider the microbiome living inside of you. It’s a bustling network of bacteria, fungi, parasites, and viruses, all coexisting to help stimulate immune function, breakdown food compounds, synthesize vitamins and enzymes, and even protect the body from pathogenic organisms.13


This entire microbial village exists in your body, and many scientists consider it to be as important as any other organ.

The soil’s microbial population functions much in the same way. The strength of life that exists in the dirt also impacts the nutritional value of the food that grows in it.

Plants rely on the organic matter in the soil to grow and thrive. When soil is depleted of these essential nutrients, you can easily imagine that the nutritional value of the plant themselves deteriorate.

Scientists have studied it for decades. One investigation published in the Journal of the American College of Nutrition in 2004 examined 43 crops, comparing nutrient levels in 1950 to those in 1999 (using USDA information) and found that protein, calcium, iron, phosphorus, and vitamins B2 and C had all dropped significantly.14

USDA researcher Rick Haney says the use of fertilizers, herbicides, pesticides, and other chemicals is killing our precious soil and threatening our farms.15

He works with the USDA’s Agriculture Research Service (ARS) in Texas, teaching farmers throughout the country how to maintain healthy soil. The mission of the ARS is to find solutions to agricultural problems that affect Americans every day from field to table.16

“We know that over the past 50 years the levels of organic matter—it is kind of a standard test for soil in terms of its health and fertility—have been going way down,” he said in an interview.17 “That’s alarming. We see organic matter levels in some fields of 1 percent or less. Whereas you can go to a pasture sitting right next to it where organics levels are 5 percent or 6 percent. So that is how drastically we have altered these systems. We are destroying the organic matter in the soil, and we’ve got to bring that back to sustain life on this planet.”

He describes pesticides as similar to chemotherapy for cancer, as these chemicals kill the good bugs along with the bad bugs. When we spray soil with toxic chemicals, we are killing the microbes we need to stay healthy.

Thankfully, many are now working on ways to restore the soil and support land use that nourishes life.

Farmer Spotlight: Sleight Family Farm

Anna and Wesley Sleight, and their son Finley, grow organic fruits, vegetables, and microgreens on their 30-acre farm of lush fields and forest in Pleasant Gardens, North Carolina.

In the spirit of disclosure: I’m a big fan of their microgreens and potatoes, among many other beautiful veggies I’ve bought from them over the years at my local farmers’ market. When I spoke to Wesley about his farm practices, it really hit home how stewarding rich soils and working with the land, creates amazingly tasty and nutritious produce.

Wesley spent his summers and a few years after college at his family farm in upstate New York.

“My family has been farming since the 1600s,” he shared. “It was a beautiful property and I had been planning to taking it over since I was a little kid. It was my grandparents farm, where my dad grew up, but the soil is really rocky up there.”

When he and Anna moved to North Carolina, they found the perfect combination of elements. Their farm has beautiful southern exposure, and it was a former pasture that had been lightly grazed by some cows, horses, and sheep.

“It was perfect land to break in a farm,” Sleight said. “The soil was already in wonderful condition.”

The land had never been grown conventionally, it was undisturbed and grown without any synthetic input. In other words, it has always been organic.

“This particular farm is where the Catawba River used to flow right at the base of this hill where we have our fields situated,” Sleight said. “When the river would flood 3,000-4,000 years ago, it would wash this rich, beautiful silty loam on all our lower fields. The farm was actually listed on the North Carolina Department of Ag as a ‘soil of national importance.’”

The Catawba River has since changed its course and it’s about a quarter-mile away from its location a few thousand years ago.

“We have this rich soil, but there’s no fear of flooding into our fields,” he said. “It had all the deposits washing down from the foothills of Mountain Mitchell—all those nutrients coming down from the mountains have percolated into this sweet little river basin.”

He views his whole land as its own living entity, a fully symbiotic ecosystem.

“We are just orchestrating it like conductors but very gently,” he said. “I do minimal tillage just trying not to disturb the earthworm or microbial activity too much. I also supplement with humates, which is food that gets the microbial populations pumped up and strong.”

He lives by the concept of feeding the soil not the plants.

“I try to maintain a good balance of what nutrients I add to the soil, according to what plants I’ve had in there before, and what I’ve taken out from the soil through the harvest,” he said.

Photo by Markus Spiske / Unsplash

Final Thoughts

Think about the fresh, colorful foods on your plate—or in your cup. The source of this healthy food begins under your feet.

Even food giants like General Mills are starting to see the benefits and take more care of their soil. In 2019 the company announced its commitment to advance efforts to address soil health and biodiversity on one million acres of farmland by 2030.

“Investing in soil health and regenerating our soils has numerous benefits including water infiltration, reduced pest pressure, resilience to unpredictable weather, and reducing greenhouse gasses,” said Lauren Tucker, executive director of Kiss the Ground in a statement.18 “We have an opportunity to not just sustain our natural resources, but to restore them for generations to come. We can only advance the adoption of these practices that benefit people and the planet if we partner with and support our farmers.”

Even if you’re not a farmer, there are many ways you can support soil.

  1. Shop at your local farmers’ market. Bonus points if you make friends with your farmer and ask them to tell you about how they care for their soil.
  2. Start your own garden, even if it’s just a few herbs in a windowsill. As you foster these relationships with plants, notice how the soil impacts the health of them.
  3. Compost your kitchen and juice scraps at home. Food waste can help feed and amend the soil. Don’t have a backyard? Many farmers’ markets and cities will let you bring scraps to them to create more compost in your city. For inspiration, watch The Compost Story.

Stayed tuned for Part 2 of the soil series that will explore regenerative agriculture, a system of farming that goes beyond organic to help replenish our soil, which in turn, helps nourish us too.