We recently visited Stoney Creek Farm, operated by Grant and Dawn Breitkreutz near Redwood Falls, MN. Grant and Dawn hosted a field day allowing the public to see, first-hand, how regenerative agricultural practices can quickly increase profits and repair soils. Their experience has been featured in numerous publications and most notably, the short documentary ‘Farmer’s Footprint’. Having attended several other field days, I had one burning question to get answered: “Is it possible for farmers to build new topsoil in their lifetime?“
The Status Quo
“It takes at least 100 years to build one inch of topsoil”. I have heard this discouraging narrative my entire life. The statement echoes from the Dust Bowl Era of the 1930’s when concern for topsoil first entered the nation’s consciousness. The preceding two decades, before the Dust Bowl, had spurred farmers to quickly expand plowing up native grasslands to supply wheat for World War I and to counter the Great Depression. A severe drought in 1931 left the Great Plains of the United States utterly exposed to the elements. The crops had failed and the roots of the native grasses had been tilled under. Nothing was left to hold the remaining loose, dry soil in place. As powerful winds swept across Texas, New Mexico, Colorado, Nebraska, Kansas, and Oklahoma, massive clouds of nutrient-rich topsoil were carried thousands of miles away and dumped into the Atlantic Ocean. By 1934, an estimated 35 million acres of cropland could no longer be farmed.1
Franklin D. Roosevelt’s administration responded in force, creating programs and agencies to work with farmers to establish windbreaks and get education. This is when the Soil Erosion Service was formed, today known as the Natural Resources Conservation Service (NRCS). Results were varied and the farmers, that hadn’t gone out of business, were slow to adapt. Had the rains not arrived in 1939, the nation would have been crippled and unable to respond to the rising Nazi threat in Europe. It is scary to think what the world would be like today had we continued loosing our country’s most precious asset.
The NRCS and Universities have done a wonderful job of stressing conservation and holding topsoil in place since the dust bowl. But they have been unable to solve the problem. Today we see the 1930’s windbreaks being removed from the landscape, dust clouds returning, and huge tracts of land washed out by heavy rains.2 A new study indicates that prior estimates of soil degradation have significantly underestimated topsoil loss. The study estimates that 35% of America’s cultivated land has lost its topsoil.3 As is all-to-often the case, the problem traces back to politics and money. The US Department of Agriculture’s (USDA) subsidy programs, legislated in The Farm Bill, now incentivize most farmers to grow only corn and soybeans while leaving the soil fallow (unplanted) for 7 months out of the year. Using lobbying groups and associations, behemoth food, seed, and chemical corporations have sunk deep roots into the back pockets of our government representatives.
The Old Narrative: Geology
The political and economic barriers farmers face today are symptoms of an even deeper issue though. Misguided propaganda continues to spread from the Dust Bowl Era. With a focus primarily on geology, our most trusted institutions portray topsoil and soil health as a finite resource that can never be replaced. Although well-intentioned, this narrative leaves growers with few options. Marry this with chemistry’s NPK mentality4, and farmers reason that once their topsoil is depleted, their only choice is to rely on a steady stream of synthetic inputs to keep their land productive. These expensive inputs have been decimating small family farms for decades. In 2019, the USDA estimated that between 58% to 81% of small farms have operating profit margins in the high-risk zone.5
As a farm kid picking rocks in the field, I saw the exposed subsoil beneath my boots. The hilltops lost topsoil first to wind and water erosion. The exposed dirt is a light-brown color. Plants growing here are short and struggle to produce seed while weeds thrive. Each season we were told to rely on the fertilizer company who would pour tons of synthetic nutrients onto that subsoil for us in order to make something grow at all. We can also pay them to knock back the weeds with expensive herbicides. As we lose topsoil and deplete what remains, we are told to continually increase these inputs. According to the USDA, US farmers applied 4.5 million tons of nitrogen fertilizers, in 1960. By 2015, that number had ballooned over 6 times to almost 28 million tons!6 The cost of inputs continue rising and topsoil continues to disappear. Basic arithmetic tells us this is not sustainable. Why would anyone sign up to run a business doomed to lose its only intrinsic resource and continually rely on government support?
Year-after-year, thousands of university students get agronomy degrees through courses about subsoils and managing nutrients through direct application. They are taught about the different chemicals to apply for weeds and pests. They study the various attributes of treated corn and soybean hybrids available for different conditions. These students are not being groomed to run farms. They’re training to become employees for the input providers who sell products and make recommendations to farmers. And farmers have been listening. US farm production expenditures were $358 billion in 2019, up from $290 billion in 2010.7 Agronomists and supplier reps have college degrees in this stuff, so they know what they know what’s best, right?
The field days I have been attending are held to educate growers on soil conservation and new research. At many of these events a 4 foot pit is dug into the field. Soil geology experts from a university hop down into the soil pit to measure and mark the distinct layers of subsoil. First thing they do is scrape away the “O-horizon”, which they deem insignificant because it’s mostly decaying plant material and living organisms. This is not an area where geologists specialize. With the O-horizon out of the way, the geologist can measure the depth of the “topsoil” and subsequent subsoil layers. Farmers gather around the pit as the geologists describe how these layers were formed over the eons. Part of the discussion is reserved for the topsoil layer, or the “A-horizon” in geological circles. This is where we’re told most of the plant’s nutrients exist and it can be significantly altered by the farmer’s management practices. If a field is regularly tilled and/or has a lot of equipment traffic, a dense compaction layer forms here. Water, worms, and plant roots have a difficult time penetrating a compacted A-horizon.
The pit provides farmers insight into how their practices affect plant growth. But for a growing number of farmers, we might as well call it “the pit of despair”. Take a minute and put yourself in the boots of a farmer standing at the edge of that pit. Imagine you have already lost a lot of topsoil in your fields. When you look over them you see only that light-brown dirt or grey silt remaining. Now you’re standing at the edge of the pit and a geologist standing at the bottom points to the A-horizon (“topsoil”). The geologist looks up at you and as if delivering a message straight from hell, says: “Topsoil can not be rebuilt in your lifetime. It takes at least 100 years to increase it by 1 inch“.
The message is meant to be one of conservation. The geologist is stressing the important principles of practicing no-till and keeping living roots in the soil. And for that we should all be grateful. But what message also comes across to you, the farmer who has already lost their topsoil? How do you interpret being told the nutrient-rich layer your plants rely on is gone, never to return? I think what a farmer hears is: “You – Are – Screwed”.
Luckily, a different story has emerged..
The New Narrative: Biology
Humans consistently underestimate the power of nature. There are forces at work that we are barely coming to comprehend. The earliest life forms of bacteria and fungi transformed this once desolate rock, we call Earth, into a flourishing utopia of plants, insects, and animals. What many geologists are missing, and what farmer’s aren’t being told, is the critical role biology plays. We have been working against the natural systems that were developed through millions of years of evolution. But, in the past few decades, farmers and ranchers have discovered something very important: We CAN rebuild topsoil rapidly, using regenerative practices.
“Without life, you might as well be farming on the moon.”Ray Archuleta, Certified Professional Soil Scientist
The claim that farmers could rebuild their topsoil flies in the face of the conventional narrative and stirs up a lot of debate, but its nothing new. Since the 1960’s, ecologist Allan Savory has been working to reclaim former grasslands lost to the deserts of Africa. His approach, coined “Holistic Management”, utilizes livestock to stimulate plant growth and replenish nutrients in the soil. Ranchers and farmers practicing Savory’s techniques have proven that in as few as 1 to 3 years, it is possible to significantly increase the depth of organic matter content and microbial activity in any topsoil. Regenerative agricultural practices are less about doing more, and more about doing less. Regenerative agriculture enables our natural ecosystems of animals, plants, worms, insects, fungi, and bacteria to do their jobs.
The debate surrounding rebuilding topsoil may be one of semantics. To a farmer, “topsoil” simply means the dark, rich soil on top of the field. Geologists argue though that “topsoil”, as they’ve defined it, may not actually be part of that dark, nutrient-laden material on top of the field. There’s another layer they’ve added to their graphical illustrations to define what might actually be on top, the “O-horizon”. Geologists submit that growers may be able to build an O-horizon in just a few years by adding organic matter or leaving crop residue to decay. But they argue that the A-horizon is actually what they call “topsoil” and that will remain unchanged for centuries. Geology defines topsoil by the minerals rising from the parent soils beneath it or deposits left behind by flooding and glaciers.
At the Stoney Creek Farm however, I learned regenerative farmers like Grant Breitkreutz, disagree with this rigid definition of topsoil. Instead, regenerative farmers like Grant propose that topsoil actually forms from a top-down process. These farmers have watched, before their very eyes, as decaying plant material gets broken down and pulled deep into their soils by water, plants, and billions of small organisms. Plant roots, worms, dung beetles, bacteria, and fungi thrive throughout the first 6 to 12 inches of soil and work tirelessly to recycle organic material, converting it into nutrients. Plants set deep roots and release exudates while feeding carbon to this biology. The O-horizons and A-horizons are not as mutually independent as the geological definitions suggest. Biology is at work, rapidly changing the constituent materials of the A-horizon. Making it darker, and thicker, as organic matter content increases. New topsoil is being born every day.
Why does geology give so little credit to biology’s role in topsoil formation? Could it be that geologists fear losing their status as the saviors of plant health and life on earth? Why was biology ever relegated to take a back seat in our studies of soil formation? I don’t know these answers, but its seems farmers have not been given the full story. Along with water and ozone, a farmer’s topsoil (O-horizon, A-horizon, or both. Whatever you want to call it.) is one of the most valuable assets on earth. Healthy topsoil sustains the plant, insect, and animal life we all rely on. My hope is that geology and biology will come together to promote the regeneration of our planet’s topsoil. Creating an opportunity for nature to get back to work undoing the damage and allowing it to rebuild flourishing ecosystems.
4 Greta Marchesi; Justus von Liebig Makes the World: Soil Properties and Social Change in the Nineteenth Century. Environmental Humanities 1 May 2020; 12 (1): 205–226. doi: https://doi.org/10.1215/22011919-8142308