Curbing Climate Change Starts With Healthy Soil
Author: Bill Giebler | Published: December 1, 2016
It’s barely May, but Aspen Moon Farm is bustling with fall harvest-like activity. The inclusion of seedlings in its offerings makes today’s farmers market preparations hum. At least half a dozen helpers line the long dirt drive up to the house, where owner Jason Griffith breaks for a sandwich in his enclosed patio. At 45, Griffith has been farming this plot of land in Hygiene, Colorado, for just a few years—but long enough to expand to 10 acres and learn some critical lessons.
“When I first started farming I was gearing all of my production toward ‘how many crops can I get out of this bed or that bed and how intensely can I plant?'” he says. That approach—despite organic and biodynamic cultivation—resulted in soil degradation, evidenced by diminished plant health and increased pests. Griffith reassessed his multiple annual harvests.”We realized we were going to wear that field out quickly. It was interesting to see how fast it could happen.” Wearing out the field is not unique—modern agriculture relies on synthetic chemicals for fertility, too often viewing soil simply as an inert growing medium. What’s unique about Griffith—as with other small-scale organic farmers dependent on nutrient- rich soil—is he chose to do something about it.
For Griffith, the solution unfolded by reframing the farming effort. “It’s really just about changing the focus from the crop to the soil and what does the soil need so we don’t have to add a ton of fertility every year.” Reducing added fertilizers—natural or otherwise—meant giving scheduling priority to soil-building crops above revenue-producing ones. “Instead of setting up my schedule and saying, ‘I need to plant carrots, beets and all this stuff where I want, whenever I want,’” Griffith says, “I’m basically saying: ‘I need to have a cover crop in this field by this date.’” Then he determines what vegetables work in rotation. The result is a productive farm with a year-round focus on maintaining or improving soil fertility.
The dirty truth
It would be difficult to find a more passionate soil advocate than Tom Newmark. The former CEO of New Chapter supplement company, Newmark is cofounder and board chair of The Carbon Underground and co-owner of Finca Luna Nueva lodge and biodynamic farm in Costa Rica.
By phone, Newmark launches into a landslide of daunting truths. “Because of the worldwide destruction of between 50 and 70 percent of the fertile soil in which we grow our food … ” he says, also citing the FAO, “we have only 60 harvests [years] left before the world loses its ability to produce any food.”
Beyond dwindling food production, Newmark lists impending dangers, such as desertification—or drying up—of farm and range lands and a water cycle “so warped and distorted that much of the planet is whipsawed by either drought or flood.” If you’re concerned about the devastating weather extremes that have become far too common, he says, “You have to be concerned about soil.”
He explains how soil carbon correlates with soil organic matter: the rich, decomposing material and microbiology of the soil ecosystem. Acting as what he calls “the soil/water battery,” each percentage point of soil organic matter is able to hold between 20,000 and 70,000 gallons of water per acre. “When you don’t have the top soil, when you don’t have the organic matter in the soil, then the soil can’t store the rain, and plants can’t handle climate extremes because they don’t have water reserves in the soil,” Newmark says. The ripple effect of this includes local relative humidity, which distorts cloud formation and rain. “The destruction of the planet’s soil therefore has an immediate and direct effect on drought, crop failure and desertification.”
Possibly the biggest and most overlooked ecological service soil provides, however, is its role in climate change—via carbon sequestration. Global soils are, in fact, massive carbon storehouses—yes, that carbon: the temperature-raising, sea level-raising stuff of inconvenient headlines. The opportunity to lock this excess atmospheric carbon into the ground is at the root of a movement called regenerative agriculture. But with this comes awareness of the inverse impact: the vast release of carbon by agricultural means. “In fact,” Newmark says, “somewhere around 40 percent of the excess carbon dioxide in the atmosphere comes directly from the soil.” That’s astounding in a world where human solutions to human-caused climate change tend toward the cars we drive and the lights we turn off. Newmark’s 40 percent is difficult to substantiate.
A U.N. paper puts it closer to 30 percent. But, says Newmark, that doesn’t account for the soil organic matter oxidized due to tilling or nitrogen fertilization.
Regardless, in the broad view of climate change there’s a double win that comes from carbon-rich soil. In addition to slowing or even reversing atmospheric carbon, soils richer in carbon (read: sticky, quenched) are also more resilient to the impacts of climate change.
This is good news, and it sounds even better the astonishingly simple way Newmark puts it: The soil lost its carbon, it wants it back and it knows how to get it. “There’s actually technology that is time-tested, safe and available worldwide for free that will take all the carbon we have irresponsibly let loose in the environment and bring it back to earth. That technology is called photosynthesis.” There’s a third win, too: Getting that carbon into the soil is synonymous with the soil fertility Griffith is looking for.
“The bad news is, we’ve absolutely botched things up with agricultural malpractice in the last 50 years,” Newmark says. “The good news is we can put the carbon back in the soil, recreate fertility, recreate the soil/water battery, recreate food stability and reverse climate change by using agriculture that is in accordance with the laws of nature and not at war with the laws of nature.”
Fixing nitrogen
“The number-one thing we absolutely have to do is to stop using synthetic nitrogen fertilizer,” Newmark says. “It’s just that simple, and the research worldwide is clear: The use of synthetic nitrogen fertilizer corresponds with the destruction of soil organic matter and the release of CO2 into the atmosphere.”
We have long known the dangers of nitrogen fertilizer. Its rampant use has been linked to coastal dead zones, fish kills, groundwater pollution, air pollution and even “reduced crop, forest and grassland productivity,” according to the United Nations Environment Program (UNEP). What is newer to the dump on nitrogen is its direct correlation to carbon release and climate change. But, hold on: Nitrogen is a necessary plant nutrient, and the now 100-year-old ability to synthesize nitrogen from thin air is a key part of the agricultural “Green Revolution” that brought more food, more quickly, to more mouths in the mid-twentieth century. The need for nitrogen is what makes synthetic fertilizer so effective, and effectiveness is what makes its use so widespread.
What Newmark describes, though, is a distorted ecosystem, starting with an artificial growth factor—synthetic nitrogen—that stimulates a “rapid, wild cascade of growth of soil microbiome in an almost cancerous form.” Microbiological aliveness is a measure of soil health, but its unchecked growth creates an imbalance. It all comes
down to complex underground trade negotiations, Newmark explains. In order to uptake nitrogen naturally, plants undergo an elaborate exchange with soil bacteria. Although both carbon and nitrogen are amply available in the air, they are inaccessible depending on who’s asking for it. Plants can’t get at the nitrogen; bacteria can’t get the carbon. “But,” says Newmark, “the bacteria have the nitrogen and the plants have this carbohydrate [carbon in the form of plant sugars] so at the tip of the root of every plant there’s an exchange that can happen, where the plants can swap their carbon-rich sugars for the biologically available nitrogen that the bacteria have. Brilliant!” And natural.
Until the introduction of synthetic nitrogen fertilizer, that is. With it the plant has received biologically available nitrogen without having to put forth the effort of feeding the bacteria. A conditioned laziness ensues, closing a trade that includes not just nitrogen, but a host of micronutrients, too. “The whole underground economy shuts down,” says Newmark, “because we’ve been giving crack cocaine to the plants.”
What needs to happen, Newmark says unequivocally, is “all agricultural systems that rely on synthetic nitrogen fertilizers have to be abandoned, and they have to be abandoned quickly. We don’t have time to debate this issue.”
The second thing we have to do, Newmark says, is leave the carbon in the soil when it gets there. “If you have carbon that is in a relatively stable form in the soil, you have to leave it there, leave that structure undamaged.” But, he says, deep and repeated plowing, or tilling, breaks apart soil structure and releases CO2 back into the atmosphere. “We have to stop doing that,” says Newmark. “We have to stop ripping apart the thin layer of topsoil that covers much of our land surfaces on the planet.”