Farmers, activist and scientists are reclaiming our shared soil as the site of regenerative possibilities, from multicultural agricultural fields, potential applications of biochar and hydrochar
Soil, as a carbon mitigation strategy
Later this year, the city of Glasgow will host the COP26. In anticipation of this yearly last hope event, world leaders from across the globe will express the underlying urgencies and possible outcomes surrounding it. Some have already started to express their concerns, such as Angela Merkel who hopes this summit will give new impetus to concrete measures. Others, such as Joe Biden, have set new greenhouse emission targets and expressed interest in look- ing at the soil as the next frontier for storing carbon. Soil, as a carbon mitigation strategy, will be a highlight of this year’s summit. Innovative climate policies exist and should be implemented in yet another effort to confront the complexities of our crisis as usual realities. Here, we bring forward how farmers, activists and scientists are reclaiming the soil as a medium of regenerative possibilities, from multicultural fields to biochar.
A third of the Earth’s topsoil – the upper level of the soil, containing the highest concentrations of organic matter, minerals and microorganisms – has been lost. The rapid degradation of global soils led the United Nations to warn, in 2014, that the world’s remaining topsoil would be gone in sixty years. That’s sixty harvests left, before the Earth can no longer feed the planet or support life. This threat is underlined by studies which demonstrate plummet- ing insect numbers and mass extinctions across the globe. Kiss the Ground is a documentary directed by Rebecca and Josh Tickell and narrated by Woody Harelson. This hour-and-a-half- long film brings forward issues relating to how the soil can be harnessed – and healed. It illustrates the way our soils have reached their current state of degradation and highlights the role played by agriculture. Centuries of damaging, industrialized farming practices have left the Earth scorched, nature depleted, and farmers struggling to make ends meet. Practices heralded for increased yields and optimization – such as constant tillage and the mass use of pesticides and fertilizers – have left much of the Earth’s soil lifeless, dry and unproductive.
Kiss the ground Netflix documentary
The documentary uncovers hopeful trajectories and tries to share them with the rest of the world. Finnian Makepeace – an activist, educator and co-founder of the Kiss the Ground organization – explains how his call to action occurred when he attended a lecture by Graeme Sait, a leading educator in sustainable agriculture, alongside a panel of scientists debating whether humans can sustain themselves on Earth. «Sait argued no, but if we start paying attention to the soil there’s this opportunity to rebuild the soil faster than we ever thought possible, sequestering carbon and building back all these functionalities of soil. If I – someone who thought they were educated on science, climate change, desertification – didn’t know, most people probably didn’t». He recalls this experience as the moment of realization that led him to found the Kiss the Ground organization.
One trajectory that has shown expansive results is regenerative agriculture. A growing num- ber of farmers are shifting the way they labor the Earth, abandoning modern farming methods and embracing a more responsible way forward. This shift returns to the essence of farming, of cultivating the land, of a time when yield was not king and small farms were not specialized in one type of crop. «We’re already too far degraded» – says Makepeace – «but regeneration is possible, faster than we ever thought». Where sustainability is about preserving what we have, regeneration is about rebuilding. Adding vitality to the land, rebuilding soil, landscapes and ecosystems, and regenerating community connections to farming and food. There are a number of elements to a regenerative farming system. It involves no ploughing or tilling, instead keeping the ground covered with crops all year round and growing a wide variety of plants rather than a monoculture. It also means using no chemicals, and in some cases, harnessing grazing livestock to increase soil fertility. Advocates claim this method of farming leads to huge increases in soil health, biodiversity and wildlife, as well as fewer floods and more resilient crops during droughts. The soil helps to support plants and provide food. It is also the most powerful form of carbon capture on the planet – better than any crop or forest. Eighty percent of the Earth’s carbon is stored in the soil. Healthy soil can absorb huge amounts of greenhouse gas emissions. Unhealthy soil – or soil that is tilled or managed inefficiently – releases it into the atmosphere.
Finnian Makepeace explains, «We have misconceptions about carbon. There is not more carbon now than there was a long time ago. It’s the same amount. The difference is we’ve put much more of it into the atmosphere». Makepeace explains that tackling the climate crisis is «two- fold». He continues, «we must both halt the trajectory of how much carbon we’re using, and build back the Earth’s carbon stores. How do we build up the storage sheds of carbon? Even though we’ve depleted our soils in the U.S., fifty to seventy percent of our carbon stocks are still in our soils. We still have more carbon in our soil than all the biomass and atmosphere combined. If we expanded the thickness of this soil carpet that envelops most of our nation, we could solve all of our emissions issues. And we know how to do that. By covering it with multi-species cover crops or getting into planned grazing operations that build soil carbon back». The health of the soil is also deeply connected to the weather and wider understanding of the climate we evolve in. «If we don’t have carbon rich soil, which creates the soil sponge, we’re dealing with a locked off surface when it rains. Water hits dead soil, it runs off and it carries with it even more soil and carbon. If we create a soil sponge, covered in plants, when rain hits the plants it slows down and trickles into that sponge».
Makepeace and the implications of our degraded soil
«It doesn’t matter if we halt all emissions tomorrow, we’re still vulnerable to any major changes in the climate, because we’ve degraded the very thing that makes life on Earth possible: the soil». It is soil degradation that has led to the widespread desertification of landscapes, currently taking place across the world. Desertification results from damaged soils: the intensive use of agricultural lands, poor irrigation practices, deforestation and overgrazing. These unsustainable practices place enormous pressure on the land, causing it to transform into desert over time. Two thirds of the Earth are currently turning into desert. According to some estimates, by 2050,1 billion people will be refugees of climate desertification. In this apocalyptic prediction, grazing animals can play a little-known role. The Kiss the Ground documentary challenges many misconceptions about the climate crisis, carbon dioxide and agriculture as a practice. One of these is the need for livestock in healthy land systems. It is not as simple as the synergy that grazing livestock causes greater carbon emissions. On the contrary, livestock have a vital role to play in a balanced soil ecosystem.
«They can be the worst or the best thing», says Makepeace. «It’s about how they’re moving throughout the land. You can have animals grazing, overgrazing, in a fenced area and causing very quick desertification and degradation of that land. And across the street, you can have animals being managed: moved to one paddock for half a day, another paddock for half a day, and then not coming back to those paddocks for months. When cows come into a paddock for half a day, trample a third of the grass, eat a third of the grass and leave a third standing with dung and urine on that grass, they’re doing the perfect thing for fertilization. Then they come back a year later, and they’ve created a regenerative system: with more biomass, more microbes in the soil, more abundance». Farmers are stewards of the land – and they are crucial to any hopes of healing the soil and combating climate change. In many countries, agriculture is the primary source of emissions. Globally, agriculture contributes thirty per- cent of greenhouse gas emissions. Farmers experience the impacts of climate change first: droughts, floods and other abrupt weather events ravage fields. Disruptions like Covid-19 hit farmers where they’re weakest. Within the crisis, there is the possibility to pivot farming from an environmental problem, to a crucial solution.
The documentary portrays a number of farmers in the U.S. who are actively embracing re- generative systems – and noticing significant results. «Farmers are essential in this. They’re the ones who are working with the land. With our farmer training, we help farmers and ranchers access the best education in regenerative agriculture or land management», says Makepeace. «It’s growing exponentially. We were surprised at the farmer community’s reception of the Kiss the Ground film. It was much more favorable than we anticipated». Alongside the documentary, which was created to raise awareness, the Kiss the Ground non-profit organization runs a plethora of programs and projects designed to move the conversation forward and encourage more people to take substantial action. «We’re moving away from just the awareness phase – which has to continue: we’re not even at critical mass yet. But now we’re saying, how do we create more valid action for people to take? So you’ve watched the movie. Now let’s train you to be a soil advocate, to bring this to your local, state, federal governments all over the world. We’ve trained 3,000 advocates in over thirty different countries. We’re giving people the empowerment tools so they can do what I do». The documentary offers hopeful and tangible trajectories, which all lie in the ground beneath our feet. «Humans are good at destroying things. But we’re also the only species right now who can help set up the rest of nature to enact this regeneration. A lot of organisms, aside from say beavers, can’t go and question, how are we going to manage this ecosystem so it jumps back to life in two years versus 100 to 150 years? We have that unique ability».
How regenerative agriculture methods can heal the soil
The Kiss the Ground documentary aimed to demonstrate how regenerative agriculture methods can heal the soil, revive ecosystems, increase farmer wellbeing and help balance the climate: awakening people to the possibilities of regeneration. The Kiss the Ground Impact Fund supports farmers, ranchers and land stewards from around the globe in their transition to regenerative practices. The Stewardship Program trains Soil Advocates to lead this movement in their communities. Scientists are working at different scales to ensure the continuity of methodologies and trajectories in better harvesting and taking care of the soil we all share. For the past twenty years, Dr. Johannes Lehmann has focused on «nano-scale investigations of soil organic matter, the biogeochemistry of pyrogenic carbon in soil and sustainable land use». Dr. Lehmann is a Professor of soil fertility management and soil biogeochemistry at Cornell University. Lehmann looks at the forms of organic carbon and nutrients, explain- ing biochar as «the product of heating biomass in the absence of or with limited air to above 250 degrees Celsius, a process called charring or pyrolysis also used for making charcoal. The material distinguishes itself from charcoal or other carbon (C) products in that it is intended for use as a soil application or for broader environmental management». Lehmann continues by highlighting that, in some instances, the material properties of biochar may overlap with those of charcoal as an energy carrier, but many types of biochar do not easily burn and char- coals are typically not made to address soil issues. Lehmann stressed a defining feature of biochars, similar to charcoal, is «a certain level of organic C forms, called fused aromatic ring structures». Biochar is a system, not just a material.
Dr. Lehmann introduces the early works of Dutch soil scientist, Wim Sombroek. «Sombroek mentioned using technology that produced Terra Preta in the 1960s», clarifies Lehmann. Today, the terms «Amazonian dark earth or Terra Preta de Índio» refer to «a dark soil most often found in limited zones in the lowland areas of Amazonia. These soils are, as a rule, concentrated near rivers and located on bluff zones above the floodplains. These soils are char- acterized by long-term fertility» (Klaus Hilbert and Jens Soentgen). This unique soil type has a «higher nutrient content, especially phosphorus and nitrogen, and a much higher pH value when compared to other Amazonian soils». The «large-scale production» of this very dark soil is «said to be an effective tool in efforts to mitigate global warming». According to Denevan and Woods, the Terra Preta sites cover «an area of 0.1–0.3 percent (6,000– 18,000 square kilometers) of the wooded Amazonian lowlands». Until 1992, this soil was studied within the context of ethnological, historical and archeological data. Sombroek’s «vision» was to study this soil «infused with climatic sciences and concerns». He did this through concentrating the scientific efforts to «manufacture Terra Preta Nova through the introduction of plant charcoal to nutrient-poor soils».
Almost thirty years later, the Terra Preta Nova, as a concept and as a physical substance, has now been seized up by commercial interests and is being offered on the home improvement/horticultural market right alongside the more widely known «enhanced home garden- ing soils» (Hilbert, Soentgen). Lehmann explains that Sombroek «did not know that Terra Preta contains biochar. It was then a few years later that the notion of biochar systems as a net carbon negative energy came in the mid-2000s through budding conversations between engineers, soil scientists and archaeologists». This anecdote about dark earth as «a climate savior» reveals the advancements of science in adopting multi-disciplinary approaches that bring the efforts of different fields and visions to better understand a layer of our shared world soil. This approach, perhaps not coincidentally, occurred at the same time as the U.N.’s Rio de Janeiro Earth Summit in June of 1992. Lehmann’s interest in studying biochar also intersects with this anecdote. He was working on improving degraded soils in the central Amazon from 1997 to 2000, when he became intrigued by the Terra Preta soils. He started adding biochar to soil in 1999 «to investigate its effects». Lehmann recalls it being «so intriguing that I continued to work on it».
The process of producing biochar and hydrochar
«It is always the same, but the conditions such as temperature, pressure materialize to pyrolyze may vary». Biochar is one way to manage soil organic carbon. He explains, «organic carbon contributes to many soil health functions. Soil organic matter is the central manageable property that controls soil health. Organic carbon in the form of biochar is always one to two orders of magnitudes more persistent than the organic matter it is made from. Some nutrients in residues become more, some nutrients less, available to plants when those residues are pyrolyzed».
The U.S. Director of the Ithaka Institute for Carbon Intelligence, «a non-profit research foundation and an open-source network for carbon strategies», explains that in Europe, the demand for biochar is «currently higher than supply which is not (yet) the case in the U.S. and other parts of the world. There are a growing number of small-to-medium-sized vendors, with many more coming online». Draper, for instance, introduced new realities in the making, highlighting the way biochar «can help decarbonize the fashion industry overall». She introduced a few projects, some «looking at converting post-consumer textile waste into biochar as an organics management process» and others «exploring the use of biochar in textiles: including in masks, to absorb dyes in wastewater, and on cotton fields that have been subjected to various chemicals for decades». While it is still quite unclear as to the precise price of biochar, Draper reinforces that it is «highly dependent on the quality and consistency of the biochar and what market you are selling into, as well as what products you are displacing. Some companies are selling for top dollar but only in small quantities to the horticulture market (price is likely to fall as production increases), whereas others are producing a low-grade biochar from heterogenous waste streams and having a hard time finding large scale off-take agreements».
The advancement of the research and implementation of biochar has opened up a multiplicity of new research and potential solutions, for instance hemp-based biochar is currently being studied. In an effort to reduce increased carbon emissions, more attention is also being given to the concept of a «circular bioeconomy», which focuses on the sustainable re-use and valorization of waste biomass to increase its useful «service» life. Nazih Kassem, a doctoral student at Cornell University who works on techno-economic and life cycle modeling of inte- grated bio-energy systems, is currently investigating the economics of using hydrochar as a soil amendment product versus an energy carrier. He explains that both biochar and hydro- char are produced from biomass. Unlike biochar, hydrochar is produced using hydrothermal processing in a water medium at high operating pressures and temperatures. This makes hydrothermal processing attractive for wet biomasses as it eliminates the need to dry the bio- mass feedstock before processing, which can be energy intensive. The different physiochem- ical characteristics of biochar and hydrochar imply different end uses for each. Hydrothermal processing research is relatively new, and hydrochar properties are still being investigated to understand its full potential. Kassem brings forward the potential of hydrochar. He reinforces that using lignocellulosic biomasses, such as woody biomasses and agricultural residues, to produce biochar is one such example where by-products of farming activities, which have limited to no economic value, can be processed into higher-value soil amendment products. Other biomass wastes, such as animal manures, food wastes and sewage sludge, which are characterized by high moisture content, can also be thermochemically processed to produce hydrochar. Kassem highlights that hydrochar is valued (and priced) differently for each end use. This has implications on the financial profitability of biorefinery systems processing waste biomass.
The concept and future prospects of soil health
In his recent co-authored paper, Dr. Lehmann and his colleagues highlight «the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and humans, and connects agricultural and soil science to policy, stakeholder needs and sustainable supply chain management». This is an integral starting point for many different fields, to better understand our relation to the microorganisms and species that share our world biome. Dr. Lehmann highlights that the «soil health approach is a clear expansion beyond humans». This is even more important when we think of the context in which we inhabit the Earth, our shared soil. Policy is needed to make meaningful and large-scale impact, so as the research practices and trials of scientists reach the discussion tables of decision makers at the Glasgow summit later this year, we can only hope that the implementation and research of regenerative agriculture and biochar will be reinforced post-COP26.