第1章
The Soil's Hidden Promise: A Climate Solution Beneath Our Feet
When I first encountered Kristin Ohlson's "The Soil Will Save Us," I was struck by its revolutionary premise-that the answer to our climate crisis might lie not in cutting-edge technology, but in the dirt beneath our feet. The book has become something of an underground sensation (pun intended) among environmentalists, regenerative farmers, and climate scientists alike. Even celebrities like Leonardo DiCaprio and Mark Ruffalo have championed its message in their climate activism. What makes this book particularly powerful is how it transforms our understanding of soil from inert "dirt" into a living, breathing ecosystem with the potential to reverse climate change. In a world obsessed with technological fixes, Ohlson invites us to consider that nature already designed the most efficient carbon capture system imaginable-and it's been operating for billions of years.
第2章
The Great Carbon Migration: From Soil to Sky
When I walk across my backyard, I'm stepping on what might be our planet's most misunderstood resource. The soil beneath our feet isn't just dirt-it's a vast carbon reservoir that we've been steadily depleting for centuries. Rattan Lal, a renowned soil scientist at Ohio State University, has dedicated his life to understanding this phenomenon. Walking through his experimental plots, he showed me how different agricultural practices affect soil structure and carbon content.
What makes Lal's work so compelling is the stark revelation about our carbon problem: much of the excess carbon dioxide in our atmosphere didn't originate from fossil fuels but from our mismanagement of soil. Until the 1950s, most excess atmospheric carbon dioxide came from how humans used land and forests. Through plowing, deforestation, and poor grazing management, we've released billions of tons of carbon from soil into the atmosphere.
The numbers are staggering. Ohio has lost 50% of its soil carbon in just 200 years of farming, while areas cultivated for millennia have lost up to 80%. Globally, soils have lost between 50-80 billion tons of carbon, and land misuse still accounts for about 30% of carbon emissions today. With atmospheric CO2 now at 400 parts per million-50 ppm beyond what many scientists consider safe for climate stability-we're in desperate need of solutions.
What makes Lal's perspective revolutionary is his insistence that this problem is reversible. "Soil carbon is like a cup of water," he explains. "We've drunk half, but we can refill it." When a ton of carbon enters soil, it removes over three tons of CO2 from the atmosphere. Lal estimates that 3 billion tons of carbon could be sequestered annually through better soil management, reducing atmospheric CO2 by 3 ppm yearly.
This potential has sparked what Ohlson calls an "agrarian renaissance." Small farm numbers in the US grew 4% between 2002-2007, with many new farmers discovering their sustainable practices create carbon-rich soil. Some have become citizen scientists "growing carbon" while exploring how to monetize this environmental service. Environmental organizations like Worldwatch Institute and National Wildlife Federation are embracing soil's climate-change potential, revolutionizing the environmental movement's approach to global warming solutions.
第3章
The Ancient Partnership: Plants and Soil Microbes
To understand soil's carbon-capturing potential, we need to recognize the remarkable partnership between plants and soil microorganisms that evolved over billions of years. This story begins with the first photosynthesizers-purple bacteria that appeared about 3.5 billion years ago, using light energy to power their metabolism. The real breakthrough came when cyanobacteria evolved to use water as their electron source during photosynthesis, releasing oxygen as a byproduct and gradually transforming Earth's atmosphere from a toxic soup to the breathable air we enjoy today.
Plants evolved when algae swallowed cyanobacteria and harnessed their photosynthetic abilities. Their leaves became Earth's first solar panels, capturing sunlight to split carbon dioxide molecules, releasing oxygen and using the carbon to create energy-rich sugars. These carbon compounds form the foundation of virtually all life on Earth-whether we eat vegetables or meat, we're consuming energy that originated from plants converting sunlight into carbon-based molecules.
But here's where the story gets fascinating: plants "leak" up to 40% of these carbon compounds through their roots. This isn't a design flaw but a deliberate strategy to feed soil microorganisms. A single teaspoon of healthy soil contains 1-7 billion organisms, including potentially 75,000 species of bacteria, 25,000 species of fungi, 1,000 species of protozoa, and 100 species of nematodes. There are more microorganisms in a cup of soil than all humans who have ever lived.
Plants and soil microorganisms have developed what Australian ecologist Christine Jones calls "the very first carbon-trading scheme." Plants provide carbon sugars to their roots, and microorganisms deliver minerals in return. The plant actively participates in this exchange, varying its carbon output to attract specific microorganisms carrying needed nutrients-like a homeowner summoning different service providers depending on what repairs are needed.
These partner microorganisms create soil structure by building tiny aggregates-bacterial colonies anchored to soil particles with carbon-rich glue, creating space for water and gases. Fungi then gather these bacterial aggregates to make larger structures. In healthy soils, trillions of these aggregates create a porous, dynamic structure similar to a living coral reef, allowing water infiltration, preventing erosion, and storing carbon in increasingly stable forms.
When fungi and bacteria consume carbon sugars from plants, that carbon becomes part of their bodies and waste. Through decomposition, soil organisms create increasingly complex carbon chains, eventually forming recalcitrant compounds like humin that can remain locked in soil for centuries. Though only a small percentage of carbon entering soil becomes permanently sequestered, this process could potentially help address our atmospheric carbon legacy if managed properly across large areas.
第4章
The Grazing Revolution: Learning from Wild Herds
In Zimbabwe's Africa Centre for Holistic Management, Allan Savory walks barefoot across the landscape, "reading the land" with his feet. Born in colonial Southern Rhodesia in 1936, Savory grew up passionate about wilderness and eventually became a research biologist and game warden. What he observed in the African bush contradicted conventional wisdom about land degradation.
Initially blaming cattle for desertification like most scientists, Savory noticed that even in areas without cattle, where only wild animals roamed, the land continued deteriorating. The conventional wisdom that rested land would heal itself proved false in African savannas, though it worked in northern Europe and eastern America.
Savory realized the critical difference was "brittleness"-whether vegetation routinely dried out completely. In dry regions with seasonal rainfall, bare land develops a hard surface that repels water, and dead vegetation oxidizes rather than decomposing, blocking sunlight from reaching new growth. Walking barefoot through various landscapes, he observed that areas with natural herding animal behavior maintained lush grass, while managed lands deteriorated.
The revelation came when Savory understood that wild herds' tight grouping (for predator protection) benefited soil by trampling vegetation into the ground rather than letting it oxidize, while their hooves broke up soil surfaces to admit seeds and moisture. Domestication had disrupted this natural pattern, spreading animals across landscapes instead of maintaining the tight herds that regenerated grasslands.
Savory developed holistic planned grazing as an approach that begins by asking farmers to describe the lives they want based on their deepest values and identify sustainable land practices. Drawing on Jan Smuts' philosophy that nature functions in wholes rather than as a mechanistic system, Savory rejected conventional tools like fire, technology, and rest for managing brittle landscapes. Instead, he proposed careful grazing with domestic animals moved through landscapes as proxies for ancient herds.
Despite growing recognition, Savory faces criticism from mainstream scientists who argue his methods lack rigorous scientific validation. Keith Weber, who conducted NASA-funded research, explains that true holistic management is difficult to study scientifically because it requires constant monitoring and adaptation rather than controlled variables. Scientific experiments typically run for only 3 years, while healing land with cattle takes 5 years or longer.
Nevertheless, about 10,000 known ranchers have adopted holistic management practices. Savory's Zimbabwe center demonstrates the method on 8,650 acres where cattle numbers have increased from 100 to 500, with plans to double that number to replicate the impact of ancient large herds. The results are visible: formerly bare, crusted ground now supports dense grass, and springs have returned to a river that had been dry for generations.
第5章
Rebuilding Soil in America's Heartland
In North Dakota, a group of farmers, ranchers and conservation officials tour fields where a revolutionary approach to agriculture is taking hold. Led by Jay Fuhrer, a USDA conservationist, they examine soil from Mike and Becky Small's cornfield, marveling at how it clings to plant roots due to natural glues and aggregates. The roots taste sweet from exudates that attract beneficial soil biology. In Burleigh County, 40 farmers and ranchers have achieved what many believe impossible: building carbon-rich soil while increasing yields and profits.
Conventional cropping devastates soil ecosystems far more severely than grazing. Plowing destroys mycorrhizal fungi networks and soil aggregates, leading to compaction that prevents water absorption. Nearly half of sea level rise comes from agricultural runoff, and 70% of America's freshwater usage goes to farming, much wasted due to poor soil structure. Chemical fertilizers provide only a narrow range of nutrients compared to the complex nutrient exchanges facilitated by healthy soil biology, and when fertilizers make nutrients readily available, plants stop providing carbon to soil microorganisms, breaking down the natural partnership.
American agriculture uses 32 billion pounds of chemical fertilizers annually, yet they're remarkably inefficient-up to 50% of nitrogen washes away, creating massive dead zones like the 6,000-square-mile one in the Gulf of Mexico. The rising cost of these inputs has farmers seeking alternatives, which is why Burleigh County's success is so compelling: their crops outperform chemical-dependent farms while saving thousands in input costs.
Gabe Brown's 5,400-acre farm outside Bismarck became ground zero for this soil health revolution after nature forced him to innovate. Unlike the neat geometry of conventional farms, Brown's land appears chaotically green with diverse plant species growing together and cattle concentrated in small, movable paddocks.
Brown started as a conventional farmer when he and his wife Shelly took over part of her parents' farm in 1991. By 1993, he questioned the logic of digging up soil only to complain later about dryness, so he sold his plowing equipment and bought a no-till drill. Then came four consecutive years of crop-destroying weather anomalies that nearly bankrupted him. Unable to afford fertilizer, Brown was forced to innovate, discovering that his earlier departures from conventional practices had improved his soil enough that he might not need chemical inputs.
In 2006, Brown and soil conservationist Jay Fuhrer learned about cover crop "cocktails"-diverse mixes of plants grown together. Different plants attract different soil microorganisms, creating a more resilient underground ecosystem. While monoculture test plots died during a severe drought with just an inch of rain over 70 days, the diverse cocktail fields thrived. Brown later added "mob grazing," concentrating up to a million pounds of cattle per acre for short periods, which multiplied the beneficial impacts of animals on the soil.
Brown's farm now employs this winning combination: no-till planting with diverse cover crop cocktails followed by mob grazing. His results are remarkable: 127 bushels of corn per acre (27 above county average) without fertilizers, pesticides or fungicides, at production costs of $1.00-$1.25 per bushel compared to the county average of $3.00-$3.50. His soil organic matter has increased from 1.7% to 5.3% in croplands and 7.3% in pastures.
Brown's farm has become a scientific playground for researchers. USDA entomologist Jonathan Lundgren was amazed by the insect diversity, noting that while conventional farmers view insects as enemies, only 3,000 insect species worldwide are agricultural pests, while each pest has approximately 3,000 beneficial insect predators. Brown hasn't used pesticides in 12 years because his diverse plant community naturally supports beneficial insects.
The most dramatic demonstration of Brown's soil health came when he pushed a 4-foot metal moisture probe effortlessly into his cornfield soil. This revealed soil so rich with microbial life that aggregates extended at least 4 feet deep, creating billions of tiny cups to hold water. "I don't worry about drought," Brown remarked.
第6章
Monetizing Ecosystem Services
In Western Australia, Bob Wilson has pioneered innovative soil-building practices similar to those in North Dakota. Wilson planted tagasaste (a legume shrub) in 1985 to feed cattle during dry months and prevent wind erosion, then took the radical step of introducing subtropical perennial grasses in 2003. Testing revealed significantly more carbon under perennial grasses and tagasaste hedges than under annual grasses.
When Wilson and agricultural extension officer Tim Wiley presented their findings to a 2008 Senate inquiry on climate change and agriculture, they stood out among nearly 20 groups. "Most of the other groups were talking about the problems that climate change was going to cause for agriculture and how they needed money for research," Wilson explained. "We were the only group who said we thought we could solve the problem."
Australia's Carbon Farming Initiative (CFI) offers farmers the chance to earn money from the country's carbon tax dollars by storing carbon or reducing greenhouse gas emissions. For carbon storage payments to work, several factors must align: carbon must be measurable, the practice must be "additional" (new to the farmer), it can't cause "leakage" (carbon loss elsewhere), and storage must have a meaningful lifetime-a concept called "permanence" that's problematic since agricultural lands frequently change hands.
Beyond carbon markets, the concept of "ecosystem services" recognizes that healthy, carbon-rich soil provides multiple benefits. Abe Collins, who I visited in Vermont, passionately argues that soil carbon is the most important life-supporting infrastructure on earth. Carbon-rich soil stores water, filters pollutants, prevents erosion, mitigates flooding and wildfires, cleans air by reducing particulates, and increases productivity.
By 2012, two hundred cities in 29 countries had invested in watershed restoration rather than building new water treatment plants-double the number from 2008. New York City famously saved $6 billion on a filtration plant by paying Catskill farmers to change land management practices that reduced runoff and pollution.
Accurately measuring soil carbon remains challenging. Traditional core sampling faces significant limitations due to landscape variability-carbon content can vary by up to 2 percentage points just 5 feet apart. Soil scientist Dan Rooney has developed technology combining proprietary sensors with software to accurately map soil properties across entire landscapes, primarily used with high-value crops and precision agriculture operations seeking to minimize irrigation and fertilizer use.
The Innisfree Village farm in Virginia's Blue Ridge Mountains serves adults with intellectual disabilities while conducting environmental research. In 2011, they established a sophisticated monitoring system to track how their management of cattle, sheep, and chickens changes the soil. Farm manager Peter Traverse deployed soil moisture probes, compaction meters, water quality gauges, and other technologies tied to GPS systems. "We're engaging the land in an active conversation," Traverse explains. "There are now ways to ask the land how it's feeling."
第7章
The Politics of Soil
At the 2010 Quivira Coalition conference, I witnessed remarkable presentations about soil health practices. Doug Weatherbee showed how compost tea helped poor Mexican farmers achieve lush corn yields during the worst drought in 60 years. Greg Judy demonstrated how "mob grazing" transformed depleted land into thriving pastures with abundant wildlife. Yet when I asked agricultural scientists about research in these areas, I was surprised to learn how little was being done. "The farmers and ranchers are way ahead of the scientists on this," explained one professor, while another noted that research funding is largely dictated by fertilizer and pesticide companies, not ecological approaches.
The current state of agricultural research traces back to Abraham Lincoln, who established institutions to improve farming. While initially revolutionary in bringing science to farming, these institutions have since evolved in directions that often prioritize industrial approaches over ecological ones. Behind agricultural innovation lurked a dangerous idea: humans should conquer nature. Fred Kirschenmann of the Leopold Center explains that the Enlightenment freed us from the Dark Ages but positioned humans as "masters and possessors of nature," viewing it as materials to manipulate rather than an interdependent living community.
The Dust Bowl sparked an agrarian renaissance led by figures like Louis Bromfield, a Pulitzer Prize-winning author who restored eroded Ohio farmland. J.I. Rodale, inspired by Sir Albert Howard's work in India, became the first to popularize organic farming in America through his magazine launched in 1942. After 30 years, the Farming Systems Trial results strongly favor organic methods: organic plots built soil carbon while conventional plots depleted it, yields matched conventional except during droughts when organic yielded 31% higher, and organic systems proved nearly three times more profitable.
The agricultural system Lincoln established to help individual farmers now primarily serves agribusiness interests. Ricardo Salvador notes that sustainable practices are framed as anti-progress because they resemble historical farming methods, though they actually represent sophisticated application of biological knowledge. Conventional farmers resist change partly because they've made massive investments in the current system, following Earl Butz's 1970s USDA advice to "plant fencerow to fencerow" and "get big or get out."
Through the farm bill, taxpayers reward soil-depleting agriculture at a cost of $95 billion annually. What began as Depression-era crop subsidies evolved by the 1990s into direct payments based on acreage, encouraging farmers to plant more crops regardless of market conditions. These programs disproportionately benefit the wealthiest farmers-three-quarters of subsidies go to the top 10% of recipients, while 62% of American farmers receive nothing.
Land-grant universities have been compromised by corporate funding as federal and state support has dwindled since the 1970s. By the early 1990s, industry funding surpassed USDA funding for agricultural research at these institutions. Nearly half of all land-grant agricultural scientists reported receiving private sector funds by 2005, creating a "funder effect" where industry-funded research tends to favor industry outcomes.
第8章
Finding Common Ground
As dusk fell on Davis, California, I arrived at the California Rangeland Conservation Coalition conference, where cowboy hats dominated the landscape. The organizers deliberately mixed the crowd, assigning seats to create dialogue between formerly opposed groups. This unlikely alliance reflected a broader shift in environmental attitudes. Since 1992, UN climate negotiators-primarily meteorologists and energy specialists-have focused on reducing fossil fuel emissions while dismissing land use strategies, despite land use accounting for 30% of emissions.
The conflict between environmentalists and agriculturalists runs deep in America's conservation history. Courtney White, an archaeologist and former Sierra Club activist, witnessed this bitter divide firsthand in the 1990s when "rivers of bad blood" flowed between ranchers and environmentalists. This prompted White to found the Quivira Coalition with a conservation-minded rancher, seeking the "radical middle" ground between these groups who both loved the land but for different reasons.
Environmental organizations are increasingly working with agriculturalists to build healthy, carbon-rich soils. The Nature Conservancy's work with nitrogen-fixing cover crops has convinced many California orchardists to adopt practices that improve soil and water retention. When rice farmers stopped burning stubble and began flooding fields after harvest, migrating birds along the Pacific Flyway found new habitat, and their droppings created more diverse microbial populations in the soil.
The California Rangeland Conservation Coalition exemplifies the new partnerships forming between environmental groups and agricultural producers. Founded in 2005, this unlikely alliance began when the Defenders of Wildlife sought to protect vernal pools from development. Research by scientist Jaymee Marty proved that grazing actually helped vernal pools thrive by controlling invasive plants. This science-backed finding enabled ranchers and environmentalists to find common ground, forming what they now call the "Boots and Birkenstocks Bunch."
Kansas rancher Bill Sproul represents a shift in thinking from commodity-focused to community conservation. Once viewing conservation purely in financial terms, he now sees himself as part of a larger ecological community: "Everything is part of the community. I'm part of it, you're part of it, the cattle are part of it. The air, the land, the ants, the lizards."
第9章
Becoming Heroes of the Underground
The people working to improve soil health share a striking quality: optimism. As soil carbon advocate Peter Donovan explains, "They're connected with the most powerful geologic force, which is life. Most of what we take to be the physical environment is, in fact, the creation of living organisms over time. That's a different paradigm than the idea that life is a fragile passenger on a dead planet."
We can all become heroes of the underground by caring for soil around us, supporting farmers who do the same, and monitoring policies affecting soil health globally. Organizations like the Union of Concerned Scientists and National Sustainable Agriculture Coalition help us understand food policy issues, particularly the farm bill which significantly impacts agriculture and the environment.
Groundbreaking research at New Mexico State University demonstrates soil's potential to reverse climate change. Molecular biologist David Johnson discovered that compost with balanced fungi and bacteria populations-not just nutrients-dramatically improved plant growth. In outdoor test plots using cover crops, soil organic matter increased 67% and water-holding capacity jumped 30% in just two years. Most remarkably, plants were transferring 72% of captured carbon to the soil, with carbon storage accelerating nonlinearly.
The researchers concluded that improving soil microorganisms on just 11% of world cropland could offset all anthropogenic CO2 emissions. While this doesn't absolve fossil fuel companies, it offers an immediate solution with multiple benefits: improved productivity, reduced water use, and decreased environmental impact.
Even in urban settings, we can contribute to soil health. Lawns are America's largest irrigated crop, taking up three times as much space as corn. With fewer chemicals, lawns become more diverse environments both above and below ground, supporting the partnership between plants and soil biology that sequesters carbon. Practices like maintaining grass at higher heights, using "lasagna" compost instead of herbicides, and creating biodiversity through dense plantings mirror what progressive farmers do to build soil health.
The key to addressing our climate crisis may not lie in complex geoengineering schemes but in working with nature's ancient partnership between plants and soil microorganisms. This approach doesn't just address climate change-it simultaneously improves food security, water quality, biodiversity, and human health. Perhaps the most revolutionary idea in Ohlson's book is that the solution to one of our most pressing problems has been literally under our feet all along, waiting for us to recognize and nurture it.
