Remineralization Pioneer David Yarrow on Transforming Soils to Transform Ourselves
There’s no doubt that the industrialization of agriculture has changed the world we live in. With the advent of chemical fertilizers and pesticides, ‘agribusiness’ is a commercial enterprise seeking to do what most businesses do — maximize profit. But soil isn’t a static input, a sterile medium, or an endless reservoir from which crops will always sprout. In fact, treating soil in this way is a fast-track to depleting it. Continuing down this path is not sustainable, and it’s becoming clearer that we must rethink the way this system works, and move forward in a regenerative, holistic way.
One of the pioneers of this alternative approach is David Yarrow, an Earth advocate, remineralization trailblazer, soil whisperer, and life-long learner, who, for decades, has been pointing to the soil under our feet as the solution to humankind’s biggest threats.
Yarrow believes that to heal the soil and return it to its natural innate state of fertility, the chemical, biological, and physical nature of soil must all be addressed and remedied. When the soil is healed through this holistic approach, we will be on the path to healing ourselves through more nutritious fuel for our bodies and a deeper connection with the land. By facilitating healthier, more functional soils, we will also set on the path to remedying climate change by drawing down atmospheric carbon concentrations.
“A nation that regenerates its soil, regenerates itself.”David Yarrow, 2013
To understand how to elevate natural systems, agriculture, and humans to a higher state, Yarrow has looked closely at the complex, dynamic, and living world of soil. Yarrow, through design and evaluation of field experiments, prowess of ecological science, and human connection, has helped to bring degraded soils back to life and teaches others how to do the same.
Remineralizing soils and improving agriculture through SeaAgri
A 1976 graph of the projected exponential rise of carbon dioxide levels in the atmosphere instilled a deep concern in Yarrow when he saw it. He wondered how, in spite of unpredictable weather events and large-scale climatic shifts, we would be able to enrich soil fertility to grow food that feeds our communities without the use of high-energy fossil fuel derived fertilizers. Yarrow found a part of the answer to this question in the research of Dr. Maynard Murray.
Murray, (1910–1983) a physician, physiologist, and researcher, observed that while Americans might be well-fed in terms of calories, nutritionally they are starved. In a quest to address this problem, Murray realized that the 90+ minerals naturally present in sea water showed great success in reinvigorating depleted soils and improving plant health and nutrition. And consequently, these mineral amendments had the potential to address degenerative diseases in humans spurred from nutritionally poor diets. In his book, Sea Energy Agriculture, Murray explains that as soils are eroded away and soil nutrients are depleted with each subsequent harvest, they no longer produce foods which contain the complete chemistry that our bodies need. Through numerous experiments and case studies, Murray found that animals fed with food from soil fertilized with sea solids and plants grown in sea solid fertilized soils were able to resist disease when compared with control groups. Thus, Murray discovered that by recycling sea minerals back to the land, there was great potential to produce an adequate supply of nutrient rich foods that addressed nutrient deficiencies plaguing Americans.
“For man to continue to live on earth, he must make fundamental changes. He must look to oceans as a source of needed elements. These elements must be returned to soil so better quality, more healthful foods can be produced.”Dr. Maynard Murray, 1976 in Sea Energy Agriculture
At the time, Murray’s message was not widely received, until pioneers of the modern remineralization movement, including David Yarrow, unearthed his findings and continued his work. Yarrow helped Bob Cain in forming SeaAgri, with the goal of making these sea minerals available to farmers. In 2002, Cain and Yarrow (despite having a broken back and damaged, paralyzed hands) shipped more than 100 bags of sea minerals from a 22-ton semi-load to farms all over North America. Their flagstone sea mineral product, SEA-90, comes from the same remote North American marine deposit that Dr. Murray had discovered was a rich source of the pure sea mineral solids.
Since SeaAgri’s inception, various case studies and customer testimonies have shown how sea energy in the form of mineral solids can transform agriculture. While academic research using SEA-90 has been limited, a 2012 Rutger’s University study found that tomato plants fertilized with 550 pounds of SEA-90 per acre had increased yields for both fresh market and processing tomatoes (although results were not statistically significant). Authors also noticed differences in factors related to tomato quality such as total and titratable acidity, which suggests that SEA-90 can influence aspects of tomato quality, but these responses vary depending on variety. Another research report showed an increase in corn yields during drought conditions with the use of SEA-90 fertilizer compared to traditional urea (nitrogen) fertilizer. However, Yarrow stresses that sea minerals are more than just fertilizer; their addition also helps to restore the total health of the soil. Indeed, soils are more than just their mineral constituents— their physical structure and microbial populations are also highly important in soil functionality.
“Feeding these minerals to animals, or to plants, or to soil causes very subtle but very dramatic changes in how those systems function…I’m very happy to be able to share this and promote this idea to farmers because it’s not just going to make farmers more profitable, it’s going to produce food which is stronger and healthier for human beings to eat and it’s going to produce soils which are able to fully function.”David Yarrow, 2011 in an interview by tributaries radio
Impressively, SEA-90 has also shown the ability to enrich animal products. Jim Gardiner, a New York dairy farmer, told Yarrow that after supplementing the diet of his cows with sea minerals, the protein and butterfat contents in their milk rose and somatic cell counts dropped (eliminating the need for antibiotics). Another dairy farmer, Nate Harkness, told Yarrow of how his cows would eat soil on the first day after being let out into the pasture following winter. After Nate started feeding them 6 oz per day of sea minerals while confined in a barn over winter, they no longer ate mud on the first day outside, indicating that, nutritionally, they had everything they needed.
Remineralization for human health and connecting with our roots
Yarrow sees food as a tool to help support the body in healing itself and returning the body to health and wellness. He explains that we are intrinsically connected to the foods we eat because as our cells divide and multiply, the nutrients in our body obtained by us through food supply the building blocks of our new cells. Thus, the quality of the food we eat directly impacts the condition of our bodies.
As Yarrow said in our interview, “Food is the mechanism of evolution. By eating, we adapt and we change ourselves as a species.”
Unfortunately, the connection between humans and their food, Yarrow believes, has become detached. Food is no longer honored as a life-giving and health-maintaining tool, and American diets are saturated with over-processed and nutrient poor foods. Indeed, poor diets continue to be a leading cause of death around the globe, compelling an extensive intervention in food systems, starting with how it’s grown.
Yarrow’s response to this recognition was on the ground action to organize sustainable food systems that produce nutritive food. When Yarrow was walking around Syracuse NY in 1972, he spotted an abandoned, overgrown area that used to be a nursery. He envisioned people growing food in the plot of land, and set out to make that vision come true. After 2 years of coordinating efforts, gathering forces and asking the Parks Department for permission to use the space, Yarrow had started his first community garden, welcoming 55 families to begin cultivating the space. The various approaches, strategies, and philosophies that he saw people use made Yarrow realize there was great confusion when it came to working the soil and growing food. When the Parks Department later asked Yarrow to help convert empty lots to gardens, he saw it as an opportunity to get people involved in growing their own food. He also experienced first-hand the immense challenges associated with urban agriculture: how to create fertile, food-producing soil when starting from scratch.
These experiences helped to lay the foundation of Yarrow’s mission to transform others’ understanding of their health, the soil, and the way forward. Yarrow holds that our bodies have an innate biological intelligence to heal ourselves, and we can collaborate with our biology to get back into “working order.” Since we are a product of evolution, we are a product of the world around us. If the world around us is healthy and we contribute in a positive way to the natural world, we can restore our bodies. The soil our food is grown in will affect the nature of that food. Soil minerality and chemical makeup is therefore of utmost importance.
“We can improve the quality of soil so we can grow superior quality crops that can regenerate ourselves as human beings.” Yarrow added.
Soils which contain trace minerals can grow nutrient dense foods that help promote immune health. Yarrow points out that one reason for the excellent health and wellbeing of the Hunza people, who live in Hunza Valley, Pakistan, is their mineral-enriched water. The water flowing down the Hunza Valley comes from the Ultar glacier and is high in colloidal trace minerals produced by fine-ground sand and rock dust. Conversely, diets devoid of trace minerals can lead to deleterious effects on the human body. For instance, there is a relationship between chromium deficiencies and impaired glucose tolerance and type-2 diabetes.
Indeed, the optimal quantity of trace minerals in the body is crucial for maintaining healthy physiological functioning. Technological advances paired with increasing research in this realm is revealing the importance of trace minerals for human health and the dangers of nutrient deficiency. As stated in this review article on trace elements, “Little is known about the essentiality of some of the probably essential elements such as vanadium, boron, and nickel in advanced organisms and humans’ physiology and possibly treatment of diseases.” Yarrow demonstrates this point by pointing to more recent knowledge about ultratrace elements such as germanium, which has demonstrated therapeutic effects for treating cancer.
Yarrow recognizes the role that food plays in maintaining our bodies, and he believes that we must not only learn to use food as a medicine, but also respect it as the gift that it is for creating and sustaining life on earth.
Biochar and remineralization for total soil health
While remineralization is key for bolstering soil fertility by the addition of vital micronutrients, the chemical composition of soil is just one aspect to overall soil health. The physical composition of the soil (its structure) is also crucial for healthy soil functionality. When soil particles are arranged in aggregates, oxygen, water, and roots are able to move freely through the soil. If you’ve ever noticed a cookie-crumb like structure underlying grass, you’ve seen a granular structure, characteristic of organic matter enriched surface horizons. When soil structure is destroyed, as is done with tillage or plowing, soil aggregates are broken apart and soil can become dense, no longer allowing vital gases and water to seep into the soil. A part of the solution to amending soil whose structure has been destroyed is with the use of biochar, which as Yarrow puts it, is “a substrate to create structure.”
Biochar is a carbon rich charcoal-like substance created from burning organic material in high temperature low oxygen environments in a process called pyrolysis. When material is pyrolyzed, a porous mineral and carbon structure with a high surface area and large number of active surface sites is created. Small micropores, “nature’s nanotechnology” as Yarrow calls them, provide habitat for microorganisms, improve aeration, increase water holding capacity, hold onto important anionic nutrients in the soil, and sequester carbon. Where raw plant residues have a quick turnover rate, decomposing naturally in the soil when exposed to atmospheric conditions, biochar is a highly stable, microbially resistant form of carbon which can persist in the soil for thousands of years. To drought-proof soils, Yarrow notes, carbon must be added back, and biochar is a stable form to deliver that carbon.
Yarrow stresses that biochar alone is not a 1-shot solution or a full-proof antidote to remedying soil heath. It is likewise not a fertilizer or nutrient but rather a delivery system. He has found that often left out of the conversation is a discussion about the most important step of how to incorporate biochar in conjunction with other ingredients to promote living soil. Raw biochar alone is empty, so for it to be a functional soil amendment, it must be charged with mineral amendments and brought alive with microorganisms.
“The idea [is] teaching farmers not just to get this one-shot solution to problems they have but to begin to treat soil as a living community and address the needs of that community in a much more holistic and broad minded approach. This is going to need a bigger paradigm shift than even embracing climate change. It requires us to become stewards of the living community of soil.”David Yarrow in 2023 interview with the author
Yarrow suggests drenching fresh biochar in sea mineral enriched water to extinguish the charcoal fire and create a stream which fractures the biochar and creates more reaction surfaces. By mineralizing the biochar in this way, the major plant nutrients nitrogen and phosphorus are provided and stabilized by the biochar. Together with micronutrients from the seawater solution, microbes have everything they need to colonize the biochar and proliferate, and plant roots have the nutrients they need to grow healthy plants. Yarrow emphasizes that these amendments should be incorporated in the root zone of soil to be the most effective, because this is the most biologically active zone.
The improvements in soil health brought about by mineralized biochar amendments, Yarrow points out, sequester even more carbon by stimulating biomass growth — a positive and beneficial feedback loop. Indeed, higher organic matter and carbon contents in soil improve physical and biological properties including aeration, water retention, microbial biomass, and nutrient availability, which all serve to make the soil more productive.
Yarrow has seen the abundance that this approach can bring about. He tells of a man named Rod Brethower from Ozark Missouri, who used biochar, rock dust, and other biological amendments to grow okra in a poor stony soil in his garden. When it came time to harvest the okra, Rod needed a step-ladder to reach the plant which had grown over 10 feet tall.
For biochar to be a truly sustainable soil amendment and increase the net negativity of this approach, local and small-scale biochar suppliers will be needed. These efforts are already being undertaken in Minneapolis, where Jim Doten advocated for his city to invest in biochar production. Minneapolis was one of seven cities to receive a $400,000 Bloomberg Philanthropies grant to start a biochar plant, which will turn pest-decimated trees into the carbon negative soil amendment. The plant will eventually be able to sell carbon credits to companies looking to offset their own emissions. Similar endeavors are also being undertaken in Stockholm, where the city collects garden and park waste and turns it into biochar which residents can then pick up for use in their own gardens. Local suppliers and regionally tailored plans are important in curtailing emissions associated with transporting biochar from plants to different cities. People can even make their own biochar from waste they already have.
Many signs of the future show that we will have to produce more with less. Less square footage, less topsoil, less energy-intensive inputs. Bringing fertility back to the soil can help overcome this challenge by making soils more adept at what they naturally want to do, which is support vegetation. A whole-systems approach based on an integrated understanding of the soil as a dynamic, complex, and living body, like that adopted by Yarrow, is vital to achieve soil health. This approach can help solve the threat of “not enough” by supporting soil in providing abundance.
Soil as a carbon sink
Most people have heard the words ‘carbon sink’ by now. This term refers to natural reservoirs which are capable of capturing and stabilizing atmospheric carbon. Carbon stocks in the soil change depending upon the difference between carbon inputs from plant assimilation of CO2 and losses from microbial decomposition and respiration. The amount of carbon stored in the soil can be increased by practices which increase soil organic matter (and consequently, soil organic carbon).
Soils represent the largest carbon pool, holding 2,400 gigatons of carbon in the top 2 meters. This reservoir is larger than the combined amount of carbon stored in terrestrial plants and the atmosphere. Many studies have suggested that with widespread implementation of proven and well-known best management practices such as crop rotations, cover cropping, compost additions, and improved management of grazing land, soils can store between 4-5 gigatons (GT) of CO2 per year (billions of metric tons of carbon dioxide per year). Additional “frontier technologies” that are still being scaled up and researched, including biochar, could raise that number to an impressive 8 GT of CO2 per year, as described in this study. For context, the global greenhouse gas emissions for 2022 was 58 GT, the highest recorded level in history. To stay within the agreed 1.5°C/year warming established by the Paris Agreement and avoid the most catastrophic consequences of climate change, reducing emissions alone will not be enough. An estimated 10 GT of CO2/year carbon dioxide will have to be actively pulled (sequestered) from the atmosphere.
While altering traditional agricultural practices to meet this goal is important, Yarrow cautions against thinking about soil as a constant ‘pool’ to be dumped into, and stresses the dynamic nature of soil. He likens it to an engine, a “soil carbon engine,” which is fueled by plants. Within this machine, many complex interactions take place. Plants, for instance, supply carbohydrates and organic acids to microbes via root exudates. In turn, microorganisms in the rhizosphere help to make major plant nutrients such as nitrogen, phosphorus, and sulfur, bioavailable to plants. Mycorrhizal fungi extend the plant’s roots, helping to improve mineral delivery. So, soil is not only a place to sink carbon, but it functions intricately and perpetually as a soil carbon engine.
“[The] purpose isn’t to dump carbon, but to regenerate soil to initiate carbon cascades that multiply our initial effort.”David Yarrow, 2019 in his white paper, “Strategy to Remove Greenhouse Gases The Soil Carbon Sink”
Yarrow also stresses that merely putting our carbon away without a realization of the disturbance humans caused by putting it there in the first place, will not lead to lasting change. He believes it is deeply important that we have recognized our responsibility in causing climate change and its associated consequences to change our behavior moving forward. After this recognition and commitment to do better, people will feel empowered to become citizen scientists, working to sequester carbon in their own communities, and embrace soil stewardship.
Yarrow identifies some good places to enhance this soil carbon engine and become a soil carbon sink. This includes the Washington State capital, which would show a non-politicalized agreement of and commitment towards climate action. Golf courses and high schools are other places which can work to cut emissions, making traditionally consumptive and emitting landscapes sinks, and showing the next generation how to treat soil and natural resources.
“In this century, the next generations must store carbon in soil to assure fertility, food, sweetness, abundance and a habitable planet,” Yarrow explained in 2022 in his presentation “Soil Carbon Sink Demonstration Project”.
Practicing what he preaches and embodying this philosophy, Yarrow, managing a team of citizen scientist volunteers, helped to establish soil carbon sink test plots at Columbia Agriculture Park in Missouri in 2020. Three plots were designated to display 1) accelerated rise of soil organic carbon (SOC) percentage, 2) gradual incremental rises of SOC percentage, and 3) agroforestry plot using regenerative techniques. In the first plot, Yarrow worked with Columbia Center for Urban Agriculture farm manager Tony Minnick, Jack Meinzenbach from the Sierra Club, and a suite of volunteers to transform the plots from infertile, compacted, and biologically devoid soil into a productive and balanced plot of land.
Only a year after the plots were established, 1,200 pounds of nutrient dense sweet potatoes were harvested from the plots, and over 2 years plot 1 saw SOC increase from under 1% to over 5%, demonstrating the emerging fertility. Through this project, Yarrow was able to teach young volunteers how to restore soil so it can sequester carbon and how to make dramatic sustainable changes. Furthermore, Yarrow sees this project as a contribution towards the international “4 per 1000” Initiative which aims to increase soil carbon stocks by 0.4% annually by improving soil management.
“In 40 years, I built soil many times in many challenging situations. Assessing what I was seeing now, I became confident these quality ingredients at the generous rates we laid down will grow into a remarkable, strong soil ecosystem. Next year, the suffocated clay will have far greater structure, texture, aeration & fertility, with microbe multitudes to nurse plant roots into optimum growth.”David Yarrow, 2021 referencing the Columbia Agriculture Park plots in “Soil Carbon Sink”
While Yarrow stresses that he is all about the soil itself, and not any one ingredient, creating a soil carbon sink can be facilitated with the help of a combination of amendments including organic matter, microbial inoculants, compost, shell meal, biochar, rock dust, and sea minerals. Layering these additions in what Yarrow calls ‘lasagna beds’ provides the necessary conditions for the soil food web to flourish and vegetative growth to thrive. To create bed layers that are conducive to restoring soil health, Yarrow suggests following these steps:
- Gather plant biomass, including crop debris as the basis of the bed to encourage fungal growth
- Spray on a solution of microbial inoculants and minerals to reinvigorate the biological communities
- Cover the freshly sprayed biomass with saw-dust sized biochar to help create structure and protect new biological communities
- Mix in rock dusts, sea minerals and other mineral sources to add important nutrients and increase reactive sites in the soil
- Add compost to protect the fungal and microbial communities and facilitate their digestion of the biomass and mineral amendments
- Water the bed to activate the amendments and move them throughout the bed
- Mulch to provide shade, lower the temperature and retain moisture in the bed
Beyond the life-giving and ecologically transformative benefits that come from improving our soil, monetary incentives through carbon crediting programs are another (more modern) advantage of fixing carbon in the soil. Trying to fix a number value on carbon is challenging, with many different approaches and valuation schemes being tested across the globe. Yarrow sees the potential for transforming soil carbon sinks into financial instruments to create soil carbon banks. Monetizing carbon in this way can help to convey its ecological importance and get people to pay attention to carbon. To adapt tax law to account for the monetary inclusion of soil carbon, Yarrow believes that creative locally adapted approaches will be needed. He sees investing in carbon sinks as a way to alter the conversation with growers, and shift the mindset from “expenses,” like for seed and fertilizer, to an “investment” in long-term fertility. Likewise, the positive cascade of benefits, including increased productivity, from increasing soil carbon can be likened to “dividends.” In this mindset, soil becomes a stable protected reserve which one uses and returns to, similar to money in a bank.
Yarrow predicts that we have a few more years of the turbulent and frenzied rush to the market that we are currently seeing before financial and legal realities are made more clear, and certain companies come out at the forefront. Indeed, it’s still being sorted out which technologies and methods are workable and how they can move us forward. But, progress is continually being made on this front and efforts to establish a green economy are in full-force.
As David Yarrow put it in his 2019 white paper “Strategy to Remove Greenhouse Gases: The Soil Carbon Sink”, “If soil carbon is valued as a land characteristic, this boosts its priority in decisions.”
A legacy as a healer
Yarrow doesn’t claim to know the future, but he does believe that the next few years will be challenging— from the battle to finally depoliticize climate change to the physical strain brought about by extreme heat and weather events. However, in contrast to the nihilistic mindset that the earth would be better off without humans, Yarrow believes that humans have a functional purpose on the earth and beckons us all to live as part of the community of life.
“In the process of putting carbon in soil, we will change ourselves. And if we do this right, we will create a community of living organisms in soil and a community of life among ourselves again too. I truly believe that by doing one, we will also achieve the other.”David Yarrow, 2023
Yarrow strongly maintains that uniting science and spirituality is absolutely essential to overcoming our biggest issues. In his view, it is paramount that we stop treating the earth as a dead, inanimate object from which we can just extract resources. Instead, we must recognize and respect the living communities that existed before humans. We must also re-establish our connection to the foods that we eat. To create high quality foods that heal our bodies, we need high quality living soil. Yarrow believes that food should be grown with people in mind. Focusing agriculture on the communities of people who are created and sustained by what they consume, can help unite us, peacefully, towards a new more sustainable way forward. Yarrow sees future generations as a mechanism to foster this shift in mentality and believes that they can be more easily imprinted with new ideas, modes of behavior, and cultural norms.
“If I was to choose one word for the agriculture of the future, it’s not organic, or biological, or even regenerative agriculture. The one word I would pin on it is, the future is community agriculture— growing food to feed human beings and to create health, and wealth, again.”DavidYarrow, 2023
Yarrow is encouraged by progress within the USDA as they provide funding and support to farmers through their Partnerships for Climate-Smart Commodities program. The pilot projects from this program will help provide technical assistance and monetary resources to under-served producers to help get them up to speed in a market where consumers are demanding more from their products. This governmental assistance, Yarrow believes, is right on target with how to drive change forward in American agriculture.
Yarrow hopes he can create community centered agriculture which reestablishes the relationship between farmers and those they feed, show people that food is a life-giving force, and leave behind a legacy of helping to advance nutrient dense food. From his decades of learning about soils through experimentation, science, and intuition, Yarrow has helped inspire others to treat their soil as alive. He has challenged traditional mindsets around problem solving, emphasized a holistic mindset to soil management, and sought to reconnect humans to their food. David Yarrow is a true pioneer in redefining the ways humans interact with the earth, and thanks to his work, insights, and reimagined way of life, he certainly won’t be the last.
“Ultimately I am a healer who is trying to restore balance, health, and wholeness to human beings and to the earth…to nature. And they’re one in the same process.”David Yarrow, 2023
Dyani Frye is an environmental scientist passionate about communicating science so that it can be accessible to all audiences. She graduated from California Polytechnic State University (2022) with a Master’s degree in Environmental Science and Management. Her thesis project investigated the use of an emergent spectroscopic technology, portable X-ray fluorescence, to predict physical and chemical properties of California soils. This research showed the viability of these predictive models across a broad geographic range. She believes that to preserve our most precious shared natural resources and achieve true sustainability, science must be paired with inclusive social initiatives and economic incentives. Through her writing at RTE, she hopes to use her science distillation skills to give others a better understanding of earth systems and how we can all positively impact the environment. In her free time, Dyani loves to identify flora and fungi during strolls through the woods, play chess, and read fantasy novels.