The Secrets of Soil

By Matt Power | 4/19/2012

Abused, misunderstood, poisoned and taken for granted, soils deserve better. They’re essential to life, more complex than you can imagine, and in serious need of stewardship.


When soil expert Mark Fulford gives his talk, he likes to spend three days just getting through the basics. Soft spoken, with graying beard, baseball hat, a hint of a world-weary slouch, and a chemistry degree, he’s not the guy you’d select out of photo lineup as a radical who wants to drastically change how we live on Earth. But he’s that guy.

Some of the stuff Fulford talks about will blow your mind. Take trees.

“If you could put a radioactive isotope in the ground 100 feet from the trunk of a mature tree, so you could track its position, within 24 hours it would be inside of that tree trunk.”

In his dry, matter of fact way, Fulford doesn’t pull any punches about his views of how modern society—agriculture in particular—has gone seriously astray. But if his message is sometimes apocalyptic, it’s also restorative.

“If you soil organic carbon by 1% over 12 inches of depth, it can sequester 59 more tons of CO2 per square acre.

“So think of it this way,” he continues. “About 12% of the earth is arable. If we increased organic matter on all arable land by 1.6 percent, we could sequester enough carbon to get us back to the preindustrial level of 299 parts per million of CO2.”

The global warming tipping point is largely agreed to be about 400 parts per million. So in other words, soils have the potential to save us from ourselves. But we have to treat them a lot differently.

Raising the Dead

Before soils can do any heavy lifting, they may need re-animation. That’s because the model of industrial agriculture adopted following World War II, Fulford asserts, is one based on mining, not biology. In this model, crops aren’t really grown in soils, they’re grown in chemical soup.

“A lot of farmers put what is essentially mustard gas on their soils,” Fulford says. “In one swipe they kill the whole ecosystem. When you break up the soil fungi and add phosphorous, the fertilizer burns out the natural humus.”

The same concept of starting with a “clean slate” carries over into building site development. Bulldoze every living thing off the site. Compact the soil with heavy equipment. Build the house. Spread replacement soils and “turf” around, then spray it all down with petroleum based nitrogen, so that plants have the semblance of health.

“Why do we buy nitrogen and jam it into the soil,” Fulford asks, “when there columns of air containing hundred of pounds of nitrogen over every foot of soil? Nature knows how to draw carbon in and bank it in the soil.

“It’s not impossible for human beings to [restore soils],” he continues. “Some cultures have done it. We’re just now discovering how the Amazonian took soils unfit for agricultural land and turned it into great soil. It’s anthropomorphic soil. People manipulated it to increase the soil efficiency, to the point that at one point 10 or 15 million people lived there.

“We need to relearn how to do paleo-farming,” he explains. “We need to trade information with other cultures that know how to reinforce their natural systems, not destroy them. Most farms, even good ones, don’t achieve more than 15 to 20 percent of their potential.

Hidden Treasure

The living things below ground are often overlooked entirely as part of the biomass of an ecosystem. As Yvonne Baskin points out in “Under Ground,” a prairie grows more biomass below ground than the grasses above.

Soils are often misunderstood and underestimated, especially the thin layer of earth able to support life. He notes with irony that $820 million has been spent trying to probe the surface of Mars with the last two rovers, “vastly exceeding what has been spent exploring the soil beneath our feet.”

A single spade of healthy garden soil, he notes, “may harbor more species than the entire Amazon nurtures above ground. Two thirds of the Earth’s biological diversity lives in its terrestrial soils and underwater sediments.”

You could easily spend a college semester just learning the basics of how soils work. Scientists, Baskin says, have classified Earth’s soils into 11 major orders, “from the dark, fertile Mollisols of temperate grasslands to the highly weathered Oxisols of the humid tropics.”

The web of life in these soils is just beginning to be understood. For example, the role of fungus is extremely complex. They bring in oxygen, help plant roots absorb water and fight off pathogens.

Microbes also play a key role, converting airborne nitrogen into nitrates that plants can absorb. They too keep unwanted pathogens at bay.


The point: All of these symbiotic systems have a place in a healthy soil system. Treat the soil as inert “growing medium,” and you destroy its ability to support vibrant life.

Fulford uses GMO crops as an example of the perils in ignoring how plants and soils work.

“GMO grains have no immune system, because they’re incomplete plants, susceptible to molds, such as fusaria. The mycotoxins that grow on these grains are so toxic that they can kill a whole barn full of animals in one feeding.

“I’ve stood around with farmers watching a lot of animals die,” he notes. “The more we rely on GMO grains, the more exposed they will be to disease. We’re seeing fewer and fewer good grain crops brought in when we do analyses.”

Sickness or Health

Ben Falk of Whole Systems Design in Vermont points out, there are only 5 areas of the world where soils support significant levels of biomass, and the pace of desertification is increasing. It you’re a technotopian, you may feel this doesn’t matter—that farming technology is extracting more food from less land all the time. But this reading of what’s happening is based on extremely “brittle” system, as he puts it.

Because much of today’s farming is completely fossil fuel dependent, not a result of thriving soils, the actual nutritional value of our foods decreases each year. Plants, Fulford says, are getting only a small part of what they need from these sickly soils.

“The real healthcare system is nutrition, but we live in a country where the health care system profits from sickness,” he says. “In the U.S., only 2 percent of us are involved in growing food, whereas in most countries it’s 70 or 80 percent. By the time food gets to our dinner table, it’s poison. All the nutrition is lost. Try opening your refrigerator and tracing everything in it back to its origin. That’s a fearless moral inventory.”

One of the most common mistakes about soils, Fulford says, is the assumption that simply by measuring and ministering to Ph, you can “fix” the soil’s health. But soil acidity merely represents one aspect of the soil—like taking a person’s temperature. What’s more, Ph changes constantly. The same soil may vary by as much as 2 points over 24 hours.

End Game

“We’re living in the Roman Empire on steroids,” Fulford asserts. “Non-humic soil can’t support microbial life. It can’t hold the limestone you put on it for fertilization. But you can’t buy humate off the shelf. It takes time. Compost is a homegrown humus.

“Anytime you put chemistry on the ground,” he explains you have to also supply food for soil microbes, stuff like compost is the best but often it’s not included in the picture.

“Plants are feeding the soil, not just extracting from it,” he adds. “Keep in mind that 80 percent of their nutrition comes from the air. And the roots need air below ground to live. That’s often overlooked.

“We think of plants as being good enough at producing for us that we can feed them once a year,” he says. “Why would anyone believe that? Soil can undergo rapid changes within 1 ft. from an edge zone, and that host soil has a memory that can extend out 60 feet, from the edge, even when it’s been badly degraded. It may eventually remember what it was and come back, but only as long as there’s a point of reference.”

New research shows that soil life is far more sensitive to minor climate variations than previously known. In this “doom and boom” cycle, microbes can quickly “shut down” in times of stress, and remain dormant for decades, or explode with activity when conditions are right. What will happen as global climate changes? Will the life or death of soils save us or speed us toward new, unpleasant extremes? Scientists aren’t sure yet. The science is too complex, too new.

What we do know is that life on earth probably began with the tiny bacteria found in soils, and that they may account for half of the “living protoplasm” on the planet. As Baskin puts it, “the bacteria in an acre of soil can easily outweigh the cow or two grazing above them.”

Whatever humans do the Earth, chances are good that bacteria will survive to rebuild. The question is whether we will become partners and beneficiaries of the gift of soil, or, as Shakespeare’s Hamlet so succinctly put it, “food for worms.”



To view this article as presented in our March 2012 issue, with additional images and sidebars, please visit our Magazine Archive.




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