In a state of nature, out on the grasslands, ruminants, such as bison, graze in tight and continually roaming herds. They eat down the grass and return it to the soil as fertilizer. They do not eat all the grass, but leave a generous stubble primed to regenerate. The action of their hooves aerates the soil. Flocks of birds follow the ruminants and pick the bugs and seeds from their manure. The birds return the seeds to the soil soaked in powerful fertilizer.
The herds graze with the greening of the grass, north in summer, southward in winter, and the birds follow on their hairy backs. This continual action–the snipping and fertilizing and aeration of soil–causes the grass to grow dense and thick and lush. This density of grass creates a living mulch over the soil to regulate moisture and soil temperature, and to protect the soil.
Every so often, lightning sparks the prairie, and all the grassland that needs a replenishment of minerals receives it through fire. When the grass is at optimum health, it does not catch fire. The lightning then serves to enrich the rain with nitrogen to further stimulate growth.
The prairie itself is not a monoculture of a single grass. It is a poly-culture of many types of grasses, weeds, and flowers that share the space in a companion partnership. The soil beneath the poly-culture is teeming with thousands of beneficial microbes and bacteria. These microbes are the very life of the soil.
This progression of ruminants and birds and grass and fire, over thousands of years, creates extremely healthy soil. This soil turned the Great Plains of America into the richest farmland in the world.
The Floor of the Jungle
In a state of nature, in the jungle, trees and brush grow thick and lush. Monkeys feed in the canopy of trees and drop their manure to the jungle floor. Down in the shadows, every manner of herbivore and carnivore cycle themselves through the intestines of one another, and are deposited as fertilizer among the detritus. The jungle floor is crawling with a decomposing compost of the refuse of animals, leaf litter, fallen trees, hot blood, and digested teeth and bones.
The moist soil beneath this composting mulch holds enormous energy. Every cubic inch of soil is filled with millions of microbes that transform the compost into food for the plants. The wet weight of green bears continually down and is swallowed by the living microbes and given back to the trees to be carried up to the monkeys to be dropped again.
This progression of plants and animals and compost and microbes, over thousands of years, creates soil so healthy, it nearly vibrates in your hands.
The Delicate Soil
It takes nature thousands of years to develop this soil, but man can destroy it in a very short time—a generation, even in a few years.
The ecosystem of the Great Plains formed over millennia. However, the southern edge of the Plains was devastated during the great cattle drives of the 1880’s. In less than 20 years, the overgrazing of the cattle herds stripped the grass from the soil, and it never recovered. The soil grew thin, dry, and weak, and the healthy bacteria and microbes in the soil vanished. The cattle coming up from Mexico brought their mesquite beans with them in their bellies, and this opportunistic invader, the mesquite tree, spread north along the cattle trails like an infection through an open wound.
Illustration Courtesy University of Austin
Within a generation, a giant swath of Texas became a desert of thorns that once had been thick grass and endless herds of bison. The old-time settlers of the day wrote about this with piercing sadness: how when they discovered the virgin country, they could ride for hundreds of miles through grass that grew to the withers of their horses, and now the whole landscape was covered in mesquite and cactus. In less than a generation, an ecosystem was transformed, not by machinery, but by an over-concentration of cows.
Photo Courtesy Kansas State Historical Society
Industrial farming equipment created another surge of soil destruction on the Great Plains in the 1920’s and 1930’s. This disaster is known as the Dust Bowl. The dust was actually soil, the unprotected soil of a thousand farms, that was picked up by the wind and carried away. The farmers had taken everything they could from the soil, and did not protect it, mulch it, cover crop it, or give anything back, and the soil quit them. Nearly 100 years later, the farmers are still trying to get this soil back.
I saw a forest in Africa that had been strip-mined. A thousand years of building that forest into an extraordinary ecosystem had been wiped away in a few short years by mining companies. In its place was a bare stony desert that held the heat of Africa like a white-hot fire, and everything that walked across it was burned.
The local African government, with help from the mining companies, had begun to restore the forest in 1970. Forty-one years later, with the heroic work of thousands of people, and millions of dollars, the jungle had only barely begun to return. At the tops of the trees, monkeys howled, and threw their fertilizer down to a thin forest floor covered with pine needles, but the forest floor was cool and dark. The soil was slowly regenerating.
From their view at the top of this tiny forest, the monkeys looked across a vast field of white-hot rock, active quarries, and industrial mining equipment. There was still much work to be done to return this forest to a state of nature.
Monkey in Haller Park, Kenya, being reclaimed to forest from mining quarry
Building the Soil in a Backyard Garden
I never thought very much about soil health, until I started a farm. I didn’t realize how hard it is to create soil, or the value of good soil, and how easy it is to destroy. Now, the focus of my daily work, one way or another, is building healthy soil.
My goal in the next several posts is to discover the ideal method of preparing the soil for a backyard garden. I will show how we build soil health on our farm and the principles of nature that dictate our process. My hope is to demonstrate to a new gardener not only the best method to build healthy soil, but also the reasons why.