In the Oscar-winning science-fiction film Interstellar, our dystopian future is beset by incessant storms of filth and dust. “Well, of course my father was a farmer—like everyone else,” an elderly woman tells the camera in the film’s opening scenes, describing her childhood in this unimaginably grim setting. “We had acres of corn … but mostly, we had dust.”
With Oscar-winning special effects, fields of verdant corn swirl in winds of dirt. Farmers battle the constant hail of grit, arduously sweeping huge piles of filth off their balconies— just as one might shovel fresh snow from the sidewalk. In the distance, dark storms can be seen lurking over the horizon.
In this nightmarish future, there is no escape. Indoors, dirt covers every corner of even the tidiest homes. “When we set the table, we always had to set the plates upside down,” a man recalls, as images of dust-free circles are revealed on tabletops when crockery is removed.
This is the stuff of nightmares as well as blockbuster material.
But here’s the thing: it’s likely that only very few people in the cinema realized that those terrifying stories from the elderly veterans of this dystopian hellscape were not the stuff of science-fiction. Those were real interviews extracted from the award-winning 2012 documentary The Dust Bowl by Ken Burns, a four-part series recalling the worst ecological disaster in America’s history: a decade of soil loss, crop failures, and terrifying tempests of dirt.
No need for an imagined nightmare: one already existed from human history for inspiration.
Today it is estimated that in the 1930s more than 1.2 billion tons (1 billion tonnes) of soil were lost from the American plains, swept up in the region’s notoriously strong winds.
The American government had been granting free plots of land, and homesteaders flocked westward. But those who had staked everything on a new life in the Midwest suffered terrifying storms of soil that turned day into night and buried their homes. Farmers could do nothing to stop the fertility of the land they had optimistically come to sow from blowing away—leaving fields bare and skies filled with the very soil they had come to use.
“My mother had respiratory problems right up until the day she died,” recalls American-born Craig Sams, former chairman of the Soil Association in the UK, whose family lived through the nightmare of the Dust Bowl on their farm in Nebraska. “People kept going west when they had exhausted the soil in one location. And when that new soil was shot, they would again move further west, until eventually nobody wanted to go further because every move west got drier and drier.”
A series of droughts in the 1930s are typically blamed for the disaster, but the American Midwest had dealt with strong winds and dry spells for thousands of years without any such catastrophe.
The real cause, we now understand, was human error: our ignorant attempt to conform the landscape to our ways.
For thousands of years, native grasses had covered the plains. Naively, European settlers eagerly yanked these up to replace them with fields of corn and wheat—without realizing the original grasses had adapted over millions of years to the region’s notoriously extreme weather by evolving deep root systems that reached many meters down, and thus would not only hold soil in place during high winds, but also retain precious moisture in the drought-prone region.
To make matters worse, farmers ditched old single-blade horse-drawn plows for new tractors with multiple rotating blades. Increasing the amount of soil turned over and exposed to the elements dramatically amplified the amount of earth lost to the skies.
Planting trees as windbreaks, improved rainfall, and the adoption of nitrate fertilizers helped turn the situation around. Today, not many seem to remember the catastrophe. I am al-
ways amazed at how few people in Europe have even heard of the event. When I show friends images of those horrifying dark clouds, most presume they are screenshots from another dystopian science-fiction film.
How easily we forget. And as the adage goes, she who does not know her history is condemned to repeat it.
According to the Food and Agriculture Organization of the United Nations, over a third of the world’s soils are de- graded—and up to 90 percent will be degraded by 2050. An oft-repeated statistic from the U.N. from 2014 is its estimate that the world’s soils have fewer than 60 harvests left in them (which would mean we barely have 50 now). The crucial probem: it can take 1,000 years to produce a few centimeters of soil—but we can use it up in the blink of an eye.
Many have questioned how dire that estimate might be. But given the extent to which people questioned the severity (or even reality) of climate change, and that we are now seeing glaciers melt and forests burn far faster than almost any ecologist imagined, we have every reason to think the contemporary global soil crisis could be far worse than even those figures suggest.
“There are two kinds of soil degradation: soil loss, and a decline in the quality of that soil, and battling those two problems is a long-running story that has been repeated all over the world,” says David Montgomery, Professor of Earth and Space Sciences at the University of Washington in Seattle and the author of Dirt: The Erosion of Civilisations.
“The reason I wrote that book is that hardly anyone remembers The Dust Bowl.”
One reason few remember: modern farming relies on chemical fertilizers loaded with nitrogen, phosphorus, and potassium to nourish our crops. Food security is taken as a given, and it is accepted as an article of faith that only industrial agriculture can sustain the human population today, given past catastrophes.
“But why did chemical fertilizers take off in the 20th century? Because Europeans had degraded their soils so much that they needed them to maintain fertility,” says Montgomery.
“The idea that we need large-scale industrial monocultures that are chemically supplemented to feed the world is just not correct. We only need chemical fertilizers if we have degraded soil.”
Those chemicals have indeed produced impressive results: German chemist Fritz Haber received the Nobel Prize in 1918 for developing a process that would “fix” nitrogen from the atmosphere and convert it into usable products, including explosives, chemical weapons, and fertilizers. It is estimated that today, half the world’s population is alive thanks to his methods.
But the doubling of yields has not come without a price: up to 80 percent of the nutrients in our fertilizers simply wash away, polluting lakes, rivers, and bays, leading to eutrophication and creating enormous “dead zones”. These low-oxygen levels and high-nutrient volumes lead to explosions in toxic algae where little else can survive, such as the 6,000 square mile (15,500 square kilometer) zone in the Gulf of Mexico— fed by those very fertilizers applied to the Midwest farm belt to grow the corn and wheat that was little suited to the region in the first place.
“Scientists often create as many problems as we solve— every time we add new chemical solutions into the mix, we just dig the hole deeper as we try to bring the soil back to life again into a normal, functioning, biological entity,” says microbiologist Anne Biklé, Professor Montgomery’s co-author on The Hidden Half of Nature (2016) and Growing a Revolution (2018).
And this is the biggest issue: most of us don’t even realize what soil is.
Soil is so much more than just ground-up rock mixed with water. It is one of the most complex ecosystems on Earth, an incredibly assemblage of microbes, fungi, invertebrates, decaying plant matter, and much we have not even discovered. Half a millennium ago, Leonardo da Vinci remarked:
“We know more about the movement of celestial bodies than about the soil underfoot.” And this remains true today.
Like any living system, it needs to be actively regenerated—it cannot be magicked into existence in the lab, despite what we would like to believe with technophilic promises of vertical farming.
The problem is we have spent a century relying on chemistry instead of biology to maintain the world’s soils. Not only does this approach lead to other forms of pollution and un- intended consequences, it is not sustainable.
But if we learn to maintain the health of the soil by under- standing its natural functioning, just as we might the health of a river, or the health of our body, there would be no need to continually pour chemicals into the earth to boost productivity. Moreover, those microbes, fungi, and invertebrates are crucial for breaking down dead matter and feeding the nutrient cycle: they keep the earth alive.
“When I was doing my PhD decades ago, it was pervasively thought that I shouldn’t even bother researching the fungi and bacteria in the soil because everyone thought they don’t DO anything, they’re just ‘there’—and you still find people like this in agronomy, and in particular at the big chemical companies,” says Dr. Elaine Ingham, microbiologist and founder of the Soil Food Web. “Generation after generation came through these institutions [and] were taught the same thing, and then went on to teach the same thing: if you have any issue with your crops, just pour a little herbicide on here, or a little more fertilizer there.”
And those misconceptions just perpetuated themselves, she says, to our detriment.
“All organic fertilizers are salts that kill the organisms in the soil—and every pesticide has non-target effects. There was no incentive for chemical companies or universities to research the organisms in the soil, because they were so tied to the old way of doing things—and there was so much prejudice to new permaculture techniques, we were always accused of wanting to bring everyone back to the Dark Ages. It’s hard to make people understand that new techniques actually are more sophisticated, more scientifically minded, and just require new and sensitive ways of understanding soil diversity and ecology.”
One burgeoning area of interest for biologically minded researchers: the number and diversity of fungal species in the soil, which varies from location to location—and is crucial to understanding how to restore not just soil, but entire ecosystems.
Reforestation attempts, for example, will come to little if trees are not planted without the symbiotic mycorhizzal fungi they need to thrive.
“Mycorhizzal fungi wrap themselves around the roots of plants—they’re like conduits for nutrients,” explains David Satori, mycologist and founder of Rhizocore, a British NGO dedicated to enhancing forestry with fungi.
Biochar is another tool generating great excitement. Often dubbed “a climate savior”, it’s essentially charcoal—organic matter charred black. If buried in the soil, it not only boosts soil fertility, it also increases the soil’s ability to store carbon. Studies estimate that the amount of carbon soil can store is doubled when biochar is added, making it a win-win.
But the most surprising new ingredient in the menu of options to repair the world’s soils: cows.
Cattle-farming has ubiquitously become enemy number one for environmental activists: herds are es- timated to be the number one source for agricultural greenhouse gas emissions worldwide, with every cow producing up to 500 liters (110 gallons) of methane per day. Even the most devoted carnivore (such as myself) would not dispute that factory farming is irredeemable in every form: cruel, wasteful, and profoundly unnatural.
However, as every biologist knows: “Nothing in biology makes sense except in the light of evolution.”
Grass has a peculiar quality: it is loaded with silica (lay- man’s term: slivers of glass), and is extremely difficult to digest. You can’t digest it; your pets can’t digest it. Only one branch of life on Earth has evolved to break down grass: ruminants: animals with multi-chambered stomachs such as sheep, giraffes, deer, and cows.
“That’s why when massive herds of bison roamed across the North American plains, the topsoil was so healthy,” says Bobby Gill, Director of Development and Communications for the Savory Institute, a nonprofit devoted to “large-scale regeneration of the world’s grasslands”.
Their solution? Cows.
This may come as anathema to most eco-warriors, largely because “vegans have very successfully controlled the narrative,” says Gill. “But grazers are the only ones who can digest that form of cellulose in their fourth stomach—and therefore they’re the only ones who can upcycle nutrients and energy,” he says.
To break it down: cow manure is a far more efficient way to nourish the landscape than chemical fertilizers. What’s more, fertile soils store far more carbon than depleted soils.
“Converting the guts of cows from climate villains into climate saviors is pretty simple,” he says. “Introduce herds of cattle, appropriately timed to match the amount of foraging material they need, and then honor the recovery rates—you will find that in pastures given the opportunity to regrow and fully recover, that is where the magic happens.”
It may sound like hippy hyperbole, but given that chemical fertilizers and pesticides are largely made from fossil fuels (thus, not sustainable), have been tied to a host of environmental and health woes in wildlife and humans, and cost money, non-industrial means of caring for the world’s soil don’t just make biological sense, they also make economic sense.
Eliminating chemical-based fertilizers and pesticides from a farming operation and adopting “holistic management” can dramatically increase productivity—leading to huge savings. Gill points to one study from Mexico, published in the journal Agricultural Systems in 2013, comparing 18 farms using conventional techniques with seven that had adopted holistic management. Overall, the net profitability of the holistically managed farms was 903 percent higher, a stagger- ing increase. The cherry on the top: dramatically increased carbon storage in the soil, around three tonnes (3.3 tons) of carbon per hectare, plus biodiversity boosts.
“You can carry more animals on the land, and you see an explosion in biodiversity with life fluttering all around,” says Gill, “There is that much untapped potential lying in our grasslands if we just manage them appropriately—and considering grasslands represent a third of the Earth’s landmass, around 12.5 billion hectares (30.8 billion acres), of which at least 30 percent are turning to desert because they’ve been mismanaged—there is so much opportunity there to turn things around.”