We can debate whether human impact contributes to climate change, but we cannot deny that human agricultural practices harm range and farm lands. These practices can be changed in ways that will restore the land, its profitability and conceivably, help the climate as well.
NOTE: This post initially appeared on PermaCultureMag.org on September 18, 2017
“A lot of farmers are being educated about the capacity of soil to sequester carbon. It gets them excited to think that they can contribute to a reversal of climate change.”
– Kate Duesterberg, Farm Manager, Cedar Circle Farm, Vermont
A new and growing movement is inspiring farmers to produce food in a manner that can mitigate and even help reverse global warming. We call this “climate farming, the agriculture of hope.”
At the core of this movement is the understanding that soil health and climate stability are closely linked. The condition of one impacts the other. In the atmosphere, carbon exists as carbon dioxide (CO2), a greenhouse gas warming the planet. But in plants, carbon forms a sugary liquid (like maple sap) that is exuded through the roots and gobbled up by microscopic critters at the foundation of what soil scientist Dr. Elaine Ingham calls the “Soil Food Web.” This infusion of carbon and the microbial activity it supports gives structure to soil, improves the nutrient density of food, and, perhaps most importantly, increases soil’s capacity to hold water.
Working to put more carbon into the soil, the climate farmer is thereby enhancing the productivity of soil while contributing to the long- term welfare of the planet. Regenerative farmer Jesse McDougall, of Studio Hill Farm in Shaftsbury, Vermont, shares, “Carbon is the world’s best fertilizer. Our goal in farming is to pass on to the next generation land that is outrageously fertile.”
Photosynthesis is nature’s invention for pulling carbon out of the atmosphere and giving it to plants and soils. Respiration and decay then return the carbon to the air. In a natural state, this exchange is in balance. However, as soil is degraded through industrial farming practices, including plowing and the use of fossil fuel- intensive fertilizers, more carbon is released to the air than is absorbed in the soil. Fortunately, this process can be reversed. Soil can be a carbon sink. There are many methods to achieve soil carbon sequestration.
Courageous climate farmers are at the forefront of experimentation. Cover crops and no-till farming are recognized as core methodologies for improving soil health, and thus, improving carbon content. Organic farmer Kate Duesterberg states, “We have a pretty hard- and-fast rule to never allow bare soil after harvest. To the extent possible, we always have a cover crop. We are also experimenting with no-till farming.”
For grazing operations, mixed species, bunched herding, and well-timed animal movement are helpful approaches to aid in carbon sequestration. According to McDougall, “We chose to raise animals here for their amazing natural ability to revitalize the soil under their feet. The chickens, turkeys, and sheep that move through our rolling pastures every day are the central component of our regenerative farming practices. The animals, when allowed to act naturally in nature, restart the downward swing of the carbon cycle.” Improving the soil enables the grass to sequester more carbon, explains McDougall, who concludes, “It’s a food-producing, carbon-sequestering, positive- feedback loop.”
A difficult challenge of the climate farmer is weed control. In a grazing operation, weeds are less of a concern because animals graze on the weeds. In an organic, annual row crop operation, however, weeds can wreak havoc. As no toxic chemical applications are permitted with organic farming, tilling has been the standard approach. However, like pesticides, tilling degrades soil health in part by harming the soil biota. So, the staff at Cedar Circle Farm are experimenting with a solarizer – a thin sheet of clear plastic laid over the cover crop that heats the area underneath the plastic sufficiently to kill off the weeds, while not harming soil life under the matt of the flattened cover crops (typically rye). The solarizer is moved daily, depending on the weather, and weeds are killed with no chemicals and no tilling.
Nicholas Cook, research and development manager at Cedar Circle Farm, explains it this way: “We are trying to take a systematic approach to solving one challenge at a time. So, the first challenge that we decided to overcome with an organic, no-till system was making sure that we can have effective weed control for our cash crops.”
The Rodale Institute is promoting a new piece of machinery, a High Residue Cultivator, for managing weeds in a rotational, no-till system. It slices weeds both above and below ground without turning the soil or disturbing the desired crop or the fragile soil food web.
An increasing number of ranchers and traditional herders are turning to holistic planned grazing as a means to restore large areas of grazing lands. This methodology, developed by wildlife biologist Allan Savory from his work in Zimbabwe, uses livestock, typically cows, goats, and sheep, as proxies for the wild grazers with which grasslands co-evolved over millennia.
Animal impact is essential for plant growth and for the recycling of water and nutrients, particularly of carbon and nitrogen returned to the soil through dung and urine. Keeping animals closely together in herds assures adequate trampling of tall grass, while regular and well-timed movements prevents overgrazing.
Texas A&M research scientist, Dr. Richard Teague, has shown that well-managed grazing has many beneficial impacts on soil, including improvements to carbon content and water holding capacity. Teague and his co-authors, including esteemed soil scientist, Dr. Rattan Lal of Ohio State University, estimate that in North America alone, this approach to grazing could draw down 0.7 gigatons (700 million tons) of carbon per year from the atmosphere into the soil. This is a “net greenhouse gases scenario,” meaning that it accounts for methane emissions from cattle. Combined with improved cropping techniques, North American agricultural lands (grazing and cropping) could annually draw down approximately 1.2 gigatons of carbon dioxide, or about two- thirds of total U.S. emissions. Furthermore, according to the Natural Resource Defense Council, each 1% increase in soil organic matter enables retention of an additional 20,000 gallons of rainfall per acre.
Teague’s estimates are in line with those of other scientists. Dr. Lal estimates soils globally could sequester 1.8 to 4.4 gigatons of carbon each year for the next 50 to 100 years. Encouragingly, if combined with deep cuts in emissions, this could return greenhouse gases to safe levels within decades. But we must act promptly.
Hope on the Horizon
New services, protocols, and training programs are coming forth to help farmers implement restorative techniques and keep tabs on the carbon content of their soils. One example, spearheaded by Peter Donovan of Enterprise, Oregon, is the Soil Carbon Coalition, self-described as “a nonprofit organization working to advance the practice, and spread awareness of the opportunity of turning atmospheric carbon into water- holding, fertility-enhancing soil organic matter and humus.”
Donovan travels throughout North America showing land managers how to take soil samples, and has established an open-source database and app for recording results. Since 2010, he has established approximately 300 baseline carbon plots in the U.S., Mexico, and Canada to serve as starting points from which to measure progress. “As we start re-monitoring we now see results, not just baselines, which means we can track the actual changes in soil carbon and plant cover over time,” said Donovan.
Didi Pershouse, also of the Soil Carbon Coalition, has developed curriculum and learning resources for the USDA Climate Hubs, Future Farmers of America, high schools, and community groups to bring more participants into the Coalition’s citizen-science monitoring initiative. In fact, it was at Pershouse’s three-day “Land Listeners” training that Cook, the research and development manager at Cedar Circle Farm, learned how to take soil samples. The first batch, sent to a lab at the University of Vermont for testing, showed soil carbon between 0.1 and 3%, taken over a wide range of sites and depths. It will take several years to see a trend line. The Marin Carbon Project and other efforts are sprouting up across North America to aid in the important work of assessing which practices sequester the most carbon the fastest.
New programs at universities and extension services are also supporting farmers’ efforts to increase carbon in their soils. Jenn Colby, pasture program coordinator at the University of Vermont Center for Sustainable Agriculture states, “We are interested in helping Vermont farmers increase their soil carbon because soils with high organic matter are more resilient in times of flood and drought, cycle nutrients more effectively, and are more productive.”
And, finally, government itself is seeing the light and a slew of promising new legislation is evoking hope. In California, the Healthy Soils Initiative is a program of the California Department of Food and Agriculture to help offset the state’s greenhouse gas emissions by increasing carbon sequestration in soils. In Vermont, the Regenerative Soils Program, currently in committee, would create a certification program for land managers who demonstrate multiyear improvements in soil health, including such measures as carbon sequestration, water infiltration, and topsoil depth. The Center for Food Safety worked with Hawaiian lawmakers to create legislation establishing a Carbon Farming Taskforce, signed into law in June 2017. And, in Massachusetts, the “Act to Promote Healthy Soils,” would create a Massachusetts Healthy Soils Program and establish a fund for education and training for those engaged in regenerative agriculture.
Numerous citizen groups – including The Savory Institute, The Center for Food Safety’s Soil Solutions program, The Soil Carbon Coalition, Regeneration International, Kiss the Ground, The Carbon Underground, and our own, Soil4Climate, are working at all levels with practitioners, scientists, government representatives, and the media to help advance this important message of climate farming. Together, with like-minded organizations and permaculture practices, we can restore soil health and reverse global warming.
Here is the version of the article that was featured in Issue 06:
Seth Itzkan and Karl Thidemann are Co-founders and Co-directors of Soil4Climate. Steven Keleti is a member of the Soil4Climate Legislative Committee. Soil4Climate.org
Soil4Climate in a nonprofit educational organization with chapters around the world advocating for agriculture as a climate solution poised to reverse global warming. Soil4Climate educates through public lectures, white papers, legislation formation and testimony, online community, and even poetry and music.
Technical Potential Table (Above) :
Lal, R. 2010. “Beyond Copenhagen: mitigating climate change and achieving food security through soil carbon sequestration.” Food Security 2(2): 169-177. http://www.tinread.usarb.md:8888/ tinread/fulltext/lal/beyond.pdf