In an excerpt from his latest book, David Montgomery says we must leave the plow behind for a climate-friendly future.
In an excerpt from his latest book, David Montgomery says we must leave the plow behind for a climate-friendly future.
November 6, 2017
[Editor’s note: Today, the 23rd annual U.N. climate talks begin in Bonn, Germany, and this week Civil Eats continues to explore agriculture’s role in causing—and mitigating—climate change. This is an edited excerpt from David Montgomery’s new book, Growing a Revolution: Bringing Our Soil Back to Life. See also our Q&A with Montgomery about his climate optimism.]
I confess I never thought I’d write an optimistic book about the environment. For many years, I was a dark green ecopessimist convinced humanity was rushing headlong into self-inflicted disaster. While I still harbor some such fears, I’ve become far more positive about our long-term prospects. Over the past few years, I’ve traveled extensively, meeting visionary farmers who are restoring life and fertility to their land. These experiences convinced me that it’s possible not only to restore soil on a global scale, but to do so remarkably fast.
At least I hope it is, since we face the confluence of the end of cheap oil, continued population growth, and a changing climate over the coming century. How farming will adapt remains uncertain, as political, economic, and environmental interests push competing visions, policies, and agendas. No matter how all this plays out, it will shape the fate of nations and define the world we leave for generations to come.
My perspective on this issue started to change a decade ago, after I did something some colleagues might consider unpardonable—I wrote a book about soil and titled it Dirt. You see, soil scientists consider it blasphemous to call soil dirt. This is because there are very important differences between soil and dirt. For one, soil is full of life, dirt is not. So why would a geologist like me write an irreverently titled book about the importance of what covers up rocks? While my primary focus of study is how landscapes are shaped by natural processes and changed by people, over the course of examining the evolution of landscapes around the world, I came to see how soil erosion and degradation influenced human societies.
Some geologists argue that people, directly and indirectly, now move more earth around than nature herself. Earth scientists have even proposed a new epoch, the Anthropocene, or “Age of People.” Although we argue about when this epoch started, it is perfectly clear that of all our world-changing inventions, the plow was, and remains, one of the most destructive.
Yes, you read that correctly. The plow. That iconic symbol of our agricultural roots that helped launch civilization as we know it. The plow enabled few to feed many and set the table for the rise of commerce, city-states, and hierarchical societies with priests, princes, politicians, and all the rest of us who don’t farm. The problem, in a nutshell, is that the plow makes land vulnerable to erosion by wind and rain.
Through fieldwork spanning three decades and six continents, I realized that long-cultivated regions that had lost their topsoil remained impoverished as a result. Telltale signs are etched in ragged gullies and slopes with subsoil exposed at the surface. The poor fertility of the soil that remains on the land is harder to see.
However, it’s worth noticing—and reversing. For restoring the soil can help address the fundamental challenges of water, energy, and climate, as well as a number of important environmental and public health problems. Nitrogen pollution, born of our dependence on fertilizers, is affecting urban water supplies in the Midwest and creating a great dead zone in the Gulf of Mexico off the mouth of the Mississippi River. Algal blooms from excess phosphorus in agricultural runoff kill fish in the Great Lakes.
Direct exposure to insecticides and indirect effects of herbicides that kill their food source contribute to crashing populations of pollinators, like bees and Monarch butterflies, with dire implications for crop production and biodiversity. Wholesale reliance on agrochemicals directly affects human health, too, as increased risk of depression and certain cancers are associated with pesticide exposure. Restoring healthy, fertile soil would cast a broad net, helping to address all these problems. So how feasible is it?
After writing Dirt, I received invitations to speak about the history of soil loss and degradation at more farming conferences than I can remember. This gave me opportunities to travel to places I wouldn’t otherwise go (geologists usually gravitate toward mountains rather than to flat farmland), and the chance to meet innovative farmers I wouldn’t normally encounter. At first, I didn’t fully appreciate this opportunity. But after hearing one story after the next of how farmers revived degraded land, I started seeking out their opinions on this pressing issue. In doing so, I began to realize that I shared more common ground with farmers than I thought. Many of them saw the destructive effects of plowing as clearly as I did, if not more so.
In 2010, Guy Swanson invited me to speak at a farming conference in Colby, Kansas. His company sells an attachment to no-till planters that helps farmers reduce the amount of fertilizer they use. No-till farmers don’t plow, they use specialized planters that open a narrow slot in the soil about the width of a kernel of corn. Seeds drop down into the slot, disturbing much less of the surrounding soil than plowing it up would.
Swanson’s system injects a uniform amount of fertilizer adjacent to and below each just-planted seed, putting nutrients right where plants need them—and only there. This uses far less fertilizer than spraying it all over the field. The farmer saves money and fewer chemicals run off to pollute streams, lakes, and oceans. That sounds like a win-win, except of course to fertilizer companies. Swanson had seen me talk at a no-till farming conference and wanted me to come speak about the civilization-killing problem of soil erosion to potential customers contemplating a shift to no-till methods and precision fertilizer use.
As I ended my talk, I looked out on a sea of baseball hats. One elderly fellow in the middle stood up, stuffed his hands down into his pockets, and said he’d taken one look at me and didn’t think I could possibly say anything worth listening to. I braced myself for what was to come. But then he surprised me. He said the more I’d talked, the more sense I’d made. He’d seen what I was talking about on his farm. It no longer had the rich fertile topsoil his grandfather had plowed. Something needed to change if his own grandchildren were going to prosper working his land.
Time and again, at one farming conference after another, instead of walking out or lobbing verbal grenades at me, farmers readily acknowledged the possibility that plowing resulted in long-term damage to the soil. A surprising number said they knew this to be true from firsthand experience. Older farmers would share stories about how their soil quality had gone downhill over their lifetimes, too slowly to notice year to year, but plain as day in retrospect. One after another piped up to say that they’d noticed their soil decline under the now-conventional marriage of the plow and intensive fertilizer and agrochemical use.
In hindsight, I really shouldn’t have been surprised that farmers recognized the twin problems of soil loss and degradation. After all, who knows the land better than those who work it for a living?
After that talk in Colby, I started paying more attention to what individual farmers thought it would take to carry on farming well into the future. I asked them what they were doing—and how they were doing it. It didn’t take long to see common threads running through their answers.
I began to wonder what it would actually take to generate a resilient, productive, and permanent agriculture. I doubted there was a simple one-size-fits-all-farms answer. And I knew the answer wasn’t simply organic farming. Many, if not most, organic farmers plow to suppress weeds and prepare the ground. I realized that the basic question that society needs to focus on is how farmers of all stripes can forgo the plow and leave their soil better off after a crop is planted and harvested—over and over again.
A New Revolution
A look back at our agricultural past reveals a long series of innovations, and a few bona fide revolutions, that greatly reduced the amount of land it takes to feed a person. These changes led to a dramatic increase in how many people the land could support and a corresponding decrease in the proportion of people who farm. By my reckoning, we’ve already experienced four major revolutions in agriculture, albeit at different times in different regions.
The first was the initial idea of cultivation and the subsequent introduction of the plow and animal labor. This allowed sedentary villages to coalesce and grow into city-states and eventually sprawling empires. The second began at different points in history around the world, as farmers adopted soil husbandry to improve their land. Chiefly, this meant rotating crops, intercropping with legumes (plants that add nitrogen to soil), and adding manure to retain or enhance soil fertility. In Europe, this helped fuel changes in land tenure that pushed peasants into cities just in time to provide a ready supply of cheap urban labor to fuel the Industrial Revolution.
Agriculture’s third revolution—mechanization and industrialization—upended such practices and ushered in dependence on cheap fossil fuels and fertilizer-intensive methods. Chemical fertilizers replaced organic matter-rich mineral soil as the foundation of fertility. Although this increased crop yields from already degraded fields, it took more money and required more capital to farm. This, in turn, promoted the growth of larger farms and accelerated the exodus of families from rural to urban areas.
The fourth revolution saw the technological advances behind what came to be known as the Green Revolution and biotechnology breakthroughs that boosted yields and consolidated corporate control of the food system through proprietary seeds, agrochemical products, and commodity crop distribution—the foundation of conventional agriculture today.
What will the future hold as we burn through the supply of cheap oil and our population continues to rise alongside ongoing soil loss and climate change? A recent study authored by hundreds of scientists from around the world concluded that modern agricultural practices must change once again if society is to avoid calamitous food shortages later this century.
We need to ask what agriculture would look like if we relied on building fertile soil instead of depending on chemical substitutes. What would this new, fifth agricultural revolution look like?
Those at the vanguard invoke a variety of names—agroecology, conservation agriculture, regenerative agriculture, and the Brown Revolution. While proponents of these approaches include those who passionately disagree about the roles of organic practices and genetic engineering in the future of agriculture, I am more struck by the common ground they share in placing soil health at the heart of their practices.
When the United Nations declared 2015 the International Year of Soils, I received more invitations to speak at soil-themed conferences. I listened to farmers tell of how they changed the way they farmed, restoring life and fertility to their land. After a while, I started to think we might actually get it right this time. Maybe we could reverse the ancient pattern of farming ourselves out of business.
Seeking to understand what an agricultural revolution centered on soil health might look like, I set off on a trip across several continents to visit farmers who were restoring life to their land. What I learned shattered central myths of modern agriculture and pointed to simple, effective ways to help solve some of our most vexing problems.
Not all the farmers I met did things the same way. How could they? They grew different crops in different regions with different soil and different climates. Some integrated livestock into their operations. Others favored cover crops. A few, perched in the cabs of space-age prairie crawlers, worked fields stretching to the horizon. Others labored by hand in the tropics to coax sustenance from small plots to feed a single family.
As varied as their situations and practices were, they all viewed farming as working with, rather than against, nature. When I realized that they all operated according to a common set of principles, I knew that the foundation for a new agricultural revolution had already been laid.
The singular message that came through loud and clear from farmers I visited was that restoring the productive capacity of the soil could be done quickly and profitably. But it meant doing things differently, a willingness to walk away from conventional practices and to take a chance on the idea that building healthy soil was the best investment a farmer could make. Most of all, it seemed, it took the courage to try new things in the face of regulatory disincentives and skeptical corporate and academic crop advisors. These farmers were not being encouraged to change. They were deciding for themselves that they needed to practice a radically new form of agriculture.
Though already underway, the revolution still has a long way to go. Like all revolutions, it faces entrenched opposition from powerful interests and conventional thinking. Yet if it succeeds, it could solve one of humanity’s most pressing problems: how to keep feeding us all on this lonely rock in space.
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