14. All states shall support improvements of soil health for resilient food production and carbon sequestration

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Rapporteur: Joanna Santa Barbara

This plank is directed at two of the six items on the Platform for Global Survival — Global Warming and Famine. It is also relevant to another major threat to human survival — the biodiversity crisis.


Soil health

A widely used definition is that of the US Department of Agriculture: the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans.

Soil is composed of inorganic matter (ground up rock), organic matter (living and dead plants, animals, bacteria, protozoans, actinomycetes and fungi), air and water. Soil health depends on complex interactions between these components. These determine the physical structure of the soil, its chemical composition and its nutrient levels, all of which affect the capacity of the soil to sustain life of plants, animals and humans. In general, the higher the organic component of a soil (generally about 5%), the more life it can sustain. This component is variously referred to as ‘soil organic matter (SOM)’ or ‘soil organic carbon (SOC)’, as it comprises carbon-rich compounds.

We need healthy soils to eradicate hunger, mitigate and adapt to the climate crisis, reduce poverty, provide clean water, restore biodiversity, reduce pollution, provide livelihoods and reduce the harm from extreme weather.

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This article discusses an interesting species of fern (Azolla) that has potential as a biofuel and major carbon sink. Of note is that “millions of years ago, this fern “sequestered so much carbon that it switched the globe out of ‘hothouse’ conditions into the relatively cooler conditions that we experience now.” See article information attached below.

Title: This Is the “Most Economically Important” Fern on Earth
Author: Sloat, Sarah
Publication(s): Pocket Inverse
Date: 14 July 2018
Link: https://getpocket.com/explore/item/azolla-the-tiny-fern-could-have-a-huge-impact-on-climate-change

Article Excerpt(s):

“Much like Frodo in The Lord of the Rings, the fern Azolla filiculoides proves that the small can certainly pack a punch. This minuscule water fern, which has leaves the size of a single gnat, was the focus of a 2018 study published in Nature Plants. Scientists say the bright green plant is complete with unique capabilities — and has the potential to help us mitigate the effects of climate change.

In the study, an international team of scientists announced they successfully sequenced the A. filiculoids genome as well as the genome of another floating fern known as Salvina cucullata. Co-author and University of California Berkeley integrative biology professor Carl Rothfels, Ph.D. tells Inverse that having these genomes brings scientists one step closer to “understanding some of the crazy biology of these particular species.”

Rothfels says that one of the most “extraordinary features” of this fern is its ability to have a symbiotic relationship with cyanobacteria, which in turn gives it the ability to “fix” nitrogen. Nitrogen fixation is the process by which plants use the chemical element as a fertilizer: Most plants typically can’t do this alone, but the blue-green cyanobacteria that live in the Azolla leaves allow for this process to happen. In turn, Azolla can sustain rapid growth in favorable conditions.

That’s important for multiple reasons, the first being that the fern shows “great promise as a biofuel,” says Rothfel. While it’s been used as a fertilizer for rice paddies in Asia for the past 1,000 years, he and his team are now curious to know whether it could be used as a sustainable fertilizer elsewhere. Its ability to help agricultural crops is compounded by its resistance to pests: Farmers have noticed for decades that bugs generally don’t like ferns, and now the sequencing of the Azolla genome reveals it carries certain genetic mutations that allow it to repel insects.

All of this has earned Azolla the nickname “green manure,” and co-author and Cornell University assistant professor Fay-Wei Li, Ph.D. says it is “perhaps the most economically important fern that has ever lived!”

But Li and Rothfel both note that the fern’s incredible ability to grow and thrive could help humans save themselves from climate change. In fact, it’s actually helped out the planet before.

“There was a massive Azolla bloom in the Arctic 50 million years ago so large that geologists believe it drove down a significant amount of C02 (carbon dioxide) and helped cool the Earth,” says Li.

That means that Azolla, one of the fastest-growing plants on the planet, has the potential to be a significant carbon sink today. A massive rise in modern-day atmospheric carbon dioxide levels are directly linked to the warming of the planet and overall climate change.

Millions of years ago, this fern “sequestered so much carbon that it switched the globe out of ‘hothouse’ conditions into the relatively cooler conditions that we experience now,” says Rothfel. If we grow a huge amount of this tiny plant, we might be able to make that happen again.”

Did you know that Canada has several native cacti species? These are all in the Opuntia family of cacti – commonly called prickly pears. Opuntia (prickly pears) are more commonly found in Latin America, Mexico, and the Southwestern USA – though grow throughout the Americas. Indigenous and Latin American peoples have used the species for centuries as sources of dyes, fibers, and food. One common cuisine produced from Opuntia (prickly pears) are Nopales – which are grilled cacti pad. Thornless varieties or cacti pads with the thorns (glochids) removed are preferred for culinary applications. Prior to colonization, cacti were only native to the Americas.

However – attention has been drawn to the species in recent years due to its drought resistance and its potential to become an essential crop in areas presently facing and/or at risk of droughts. The cactis are a source of minerals and additionally store significant quantities of water in arid and desert environments.

Here is a report from the Food and Agricultural Organization (FAO) of the United Nation around the benefits of Opuntia (prickly pears):

Title: Cactus pear deserves a place on the menu: Turning a useful food-of-last-resort into a managed and valuable crop
Author: Food and Agricultural Organization (FAO) of the United Nations
Date: 30 November 2017
News Agency: Food and Agricultural Organization (FAO) of the United Nations
Link: http://www.fao.org/fao-stories/article/en/c/1070166/

Article Excerpt:

“Climate change and the increasing risks of droughts are strong reasons to upgrade the humble cactus to the status of an essential crop in many areas,” said Hans Dreyer, director of FAO’s Plant Production and Protection Division.


Cactus pear cultivation is slowly catching on, boosted by growing need for resilience in the face of drought, degraded soils and higher temperatures. It has a long tradition in its native Mexico, where yearly per capita consumption of nopalitos – the tasty young pads, known as cladodes – is 6.4 kilograms. Opuntias are grown on small farms and harvested in the wild on more than 3 million hectares, and increasingly grown using drip irrigation techniques on smallholder farms as a primary or supplemental crop. Today, Brazil is home to more than 500,000 hectares of cactus plantations aimed to provide forage. The plant is also commonly grown on farms in North Africa and Ethiopia’s Tigray region has around 360,000 hectares of which half are managed.

The cactus pear’s ability to thrive in arid and dry climates makes it a key player in food security. Apart from providing food, cactus stores water in its pads, thus providing a botanical well that can provide up to 180 tonnes of water per hectare – enough to sustain five adult cows, a substantial increase over typical rangeland productivity. At times of drought, livestock survival rate has been far higher on farms with cactus plantations.

Projected pressure on water resources in the future make cactus “one of the most prominent crops for the 21st century,” says Ali Nefzaoui, a Tunis-based researcher for ICARDA, the International Center for Agricultural Research in the Dry Areas.

Here is a YouTube Video from the UNFAO on the benefits of Opuntia (prickly pears):

Title: Opuntia cactus: a useful asset for food security
Author: Food and Agriculture Organization of the United Nations
Date: 24 November 2017
News Agency: UNFAO (YouTube)
Link: https://www.youtube.com/watch?v=–0EdaCtR_4

For those of you interested in the Ontario context, here is an article and a website about the Opuntia (prickly pears) native to Ontario.

Title: Eastern prickly pear cactus
Author: Ministry of the Environment, Conservation and Parks
Date: 2009 / 2014
News Agency: Ministry of the Environment, Conservation and Parks
Link: https://www.ontario.ca/page/eastern-prickly-pear-cactus

Title: Prickly pear cactus at home anywhere
Author: Lee Reich
Date: 5 November 2008
News Agency: The Toronto Star
Link: https://www.thestar.com/life/homes/outdoor_living/2008/11/05/prickly_pear_cactus_at_home_anywhere.html

A Call for Climate-Focused Agriculture Policy
By Tara Ritter, Institute for Agriculture and Trade Policy


The current Administration has gone to great lengths to suppress climate change research, weaken key research institutions, and scrub mentions of climate change from government websites and documents. Despite these efforts, American farmers already know that the climate crisis is on our doorstep because they’ve been experiencing the negative impacts of it for years. Agriculture is among the hardest hit sectors by the climate crisis, and yet U.S. farm policy is largely devoid of climate considerations, and most climate change policy proposals insufficiently address agriculture.

As part of our efforts to arm farmers and ranchers with the tools they need to meet the challenges of climate change mitigation and adaptation head on, the National Sustainable Agriculture Coalition (NSAC) last week released a policy position paper: Agriculture and Climate Change: Policy Imperatives and Opportunities to Help Producers Meet the Challenge. This paper, which was co-authored by several members of NSAC’s Climate Change Subcommittee, reviews the latest science on climate change and agriculture and lays out policy recommendations to advance climate action that will help farmers meet the challenge and be part of the solution.

Impact of Climate Change on Farmers

Agriculture and Climate Change synthesizes the latest science on climate change to deliver concrete practice and policy recommendations to help farmers and rural communities lead the way on adaptation and mitigation solutions. There is no doubt that agriculture will face future challenges as a result of increasingly extreme fluctuations in average temperatures, rainfall patterns, and pest pressures.

In the American South, for example, farmers across the region have been experiencing record low temperatures that have led to extreme losses for South Carolina and Georgia peach farmers, Florida citrus growers, and Georgia’s Vidalia onion farmers. This increasing volatility will destabilize crop yields, contribute to livestock and farmworker stress, and increase economic uncertainty for farmers already facing the most challenging farm economy since the 1980s.

These disruptions, all of which farmers across the country are already grappling, will have disproportionately heavy impacts on low-income communities, farmers and farmworkers of color, and other historically underserved populations. Despite the disproportionate burden these communities bear, they have also historically been at the forefront of climate change advocacy and engagement – particularly our indigenous communities, farmers, and organizers.

Agriculture’s Impact on Climate

Agriculture is both impacted by climate change disruptions, and also contributes to them as a source of direct and indirect greenhouse gas (GHG) emissions. While agriculture is a relatively minor direct emitter of carbon dioxide, nitrous oxide (N2O) emissions are a bigger problem. According to the Environmental Protection Agency, agricultural soil management was the largest source of N2O emissions in the United States, accounting for nearly 74 percent of total U.S. N2O emissions in 2017. N2O is also released through fertilizer application and other practices that increase nitrogen availability in the soil.

Increases in total agricultural greenhouse emissions in the past 20 years can largely be attributed to the increasing use of liquid manure storage lagoons found on concentrated animal feeding operations (CAFOs). Manure lagoons emit substantial quantities of methane, and have a much larger GHG footprint than dry stacking, while aerobic composting or evenly distributed deposition on management intensive grazing pasture produce the lowest manure-related emissions. Agriculture also indirectly contributes to climate change as carbon stored in the soil is released. This happens when land is converted from forests, native prairie, and other grasslands to annual crop production with tillage and chemical inputs.

Where Does Ag Go From Here?

A fundamental rethinking of the structure of American agriculture – and the policies that created and sustain our current system – is needed if we hope to effectively address the climate crisis.

“U.S. agriculture has largely been designed to work with non-renewable fossil fuels, abundant freshwater reserves and a period of relative stability in the climate, all of which are now in question. The next generation of farmers and ranchers will need to switch to smarter agricultural systems…”
Agriculture and Climate Change: Policy Imperatives and Opportunities to Help Producers Meet the Challenge (2019)

Achieving an agricultural system that both adapts to and helps to mitigate climate change requires focusing on systems-based approaches to agricultural practices. While individual practices such as cover cropping or no-till can help keep carbon in the soil, integrated systems of practices based on agroecology have the greatest potential to mitigate agricultural GHG emissions and create a productive and resilient agriculture system.

Farmers’ management decisions aren’t just based on a single factor like GHG emissions, however. Farmers make planting and other production choices based on a complicated web of factors, influenced by intergenerational habits and community social norms. Corporate consolidation also factor into the choices that farmers make, primarily by restricting them – today, farmers are often confined to using certain seed varieties, chemicals, animal genetics, and management practices to meet the requirements of what the industry is selling and buying.

As the U.S. Department of Agriculture Secretary Sonny Perdue said in an October speech: “in America the big get bigger and the small go out.” This “get big or get out” sentiment is unfortunately built into current farm policy and has left many farmers struggling. The good news is that these attitudes and the policies that underpin them can be changed. We have a path forward if we are willing to follow it, and many concrete recommendations for how we can support farmers in implementing climate-smart practices are outlined in the NSAC report.

Federal Policy Climate Solutions

In Agriculture and Climate Change, NSAC takes a comprehensive look at the latest in agricultural and climate science, summarizing their analysis into 14 key research findings. Based on these findings, the paper puts forward eight policy priority areas that each include detailed recommendations, which NSAC hopes policymakers will utilize as they continue to develop and debate policies and programs to address the climate crisis.

NSAC’s overarching policy priorities on climate change are:

  • Support producers to make U.S. agriculture climate-neutral
  • Remove barriers and strengthen support for sustainable and organic production systems
  • Support climate-friendly nutrient management to reduce agricultural nitrous oxide emissions
  • Increase support for composting as a climate friendly alternative to landfill and manure lagoon disposal of organic “wastes”
  • Strengthen protection of carbon sequestration potential of sensitive and marginal lands
  • Support climate-friendly livestock production systems and end subsidies for Concentrated Animal Feeding Operations (CAFOs) with their massive GHG and water pollution impacts
  • Support on-farm energy conservation and low-carbon renewable energy production
  • Fund public plant and animal breeding for climate-resilient agriculture

NSAC will deliver their policy position paper to Congress as a blueprint for policy action, and as a challenge to the Administration’s false narrative that farmers neither want nor need strong climate action. The findings of the paper will also be used to inform recommendations to the House Select Committee on the Climate Crisis, which undertook its first hearing on climate change and agriculture just this fall.

Neil Havermale says:

November 18, 2019 at 11:01 am

This policy paper has merit. I would also ask for 2019/2020 Ag Policy Debate to include the role of the private market to provide a market mechanism that will allow a carbon conservation and sequestration policy bridge between corporate enterprise requirements to present carbon neutrality to their stock-holders?

One pathway to accelerate a national carbon sequestration policy would be to provide agricultural lands tenants and landlords special tax incentives as might regards income and long term capital gains benefits from certified soil carbon sequestration. Nationally upwards of 40 percent of harvested lands have some form of land lease upon it; some Garin Belt states this percentage may exceed 65 percent.

Offering bold conservation benefits via these land contracts might create immediate incentives to improve the investment in long-term sustainable soil health as well as to provide new farm-gate income to literally hundreds of million of acres .

soil in hands.jpg

Doug Gurian-Sherman replies:
I appreciate the article, and the points it makes, as well as several of the comments. However, there is an important technical error. The article says that methane, which is one of the most important ag GHGs, is mainly from increases in CAFO liquid manure. Although manure is a source of methane, it is actually much less than from ruminant digestion (“cow burps”). And the biggest source of methane from ruminant digestion is cows grazing on pasture. Less comes from CAFO grain feeding. This has important implications for GHG accounting in ag, so it is not a trivial issue. CAFOs are terrible for may reasons, good cow pasture management has many benefits over CAFOs, and when soil carbon sequestration is taken into account, may even be much better for the climate overall than CAFOs. But for a number of reasons, it is important to get the science right.

Hi Doug,

Your comment is partially right in that cow burps (enteric methane) are the major source of methane from agricultural systems – we address this issue in detail in the actual report, which we would encourage you to check out if you haven’t already. On page one, and in Figure 2 on page 8, we note that enteric methane from livestock at 32% is the number two contributor to GHGs behind only N20 from fertilized soil. GHG from manure storage facilities (which is both methane and N2O) ranks as third at 14%.

A cow fed to maturity on pasture usually does release more methane than a cow in a feedlot mainly because the cow in the feedlot gains weight more quickly and is slaughtered sooner. But the total GHG footprint, using life cycle assessment, of feedlot cattle is much higher than cattle on management intensive grazing (MIG). Furthermore the vast majority of cows (94 to 97%) mature on feedlots, not on pasture, so the totals (even if just from enteric methane) are much lower from pasture than from feedlots. Lastly, improving forage quality in MIG has shown a 30% reduction in enteric methane (see pages 25-26 and page 38 of the report).

We apologize for the unclear description in the blog, and will adjust the sentence in question to more specifically refer to *recent increases in methane production.

I keep coming across references to the usefulness of feeding seaweed to cows. How much does that reduce methane emissions?

Hi Metta,

The Yale Environmental Law Review published an article on this subject in July 2018. Here are the details:

Title: How Eating Seaweed Can Help Cows to Belch Less Methane
Author: Judith Lewis Mernit
Date: 2 July 2018
News Agency: Yale Environmental Law Review (Yale University)
Link: https://e360.yale.edu/features/how-eating-seaweed-can-help-cows-to-belch-less-methane


Unfortunately, it is only a specific species of seaweed that reduces methane emissions in cows. This seaweed species is called Asparagopsis taxiformis (a type of red algae) and is endemic to tropical waters. Traditional Hawaiian cuisine sometimes incorporates this type of seaweed into dishes. Apparently getting cattle to eat the stuff can be difficult at first – as some cattle are picky eaters – so researchers sometimes mix it with molasses. The article additionally notes some regions such as Ancient Greece. 18th century Iceland, and modern day Prince Edward Island (Canada) would graze cattle along beaches – so it is possible that cows additionally ate seaweeds in these environments – though whether it was the right type to reduce methane emissions has yet to be determined.

If this seaweed is to become a popular additive in cattle feed – it is important to consider how and where it will be grown and the environmental impacts of mass seaweed farming. Additionally – how will this seaweed – which grows in tropical waters – be shipped to regions around the world – which can be quite far from cattle? Does this seaweed have the same impacts on other large animals? How much seaweed is needed per kilogram of feed to generate this methane-reducing effect? The scientist noted in Mernit’s article mentioned methane emissions could be reduced 50-58% – but did not mention how much of this seaweed is required.

Scientists have tried other techniques to reduce cattle’s emissions as well – including selectively breeding less gassy cattle and the notion of vaccinating cows with a type of methanogenic vaccine – which would alter the cattle’s stomach microbiology and hopefully replace the methanogen bacteria which cause carbon and hydrogen to convert to methane in the stomachs. This vaccine (it technically is not a vaccine from the formal definition) would replace these bacteria with a type that produces less gas.

Here is a scientific study examining the link between Asparagopsis taxiformis consumption and methane emissions in cattle:

Title: Effect of the macroalgae Asparagopsis taxiformis on methane production and rumen microbiome assemblage
Author: Breanna Michell Roque et al.
Date: 12 February 2019
News Agency: Animal Microbiome (BMC / Springer Nature Journal)
Link: https://animalmicrobiome.biomedcentral.com/articles/10.1186/s42523-019-0004-4



A correction from my comment above: “a correction on the line: . “Additionally – how will this seaweed – which grows in tropical waters – be shipped to regions around the world – which can be quite far from cattle?  should read: “Additionally – how will this seaweed – which grows in tropical waters – be shipped to regions around the world where cattle are farmed- which can be quite far from areas where this seaweed grows?”  Sorry for this confusion.

One extremely important controversy about reducing global warming is whether to eat meat — and whether to raise livestock. The overwhelming preponderance of opinion holds that we should give up meat and convert land to vegetable crops and forests. But an alternative point of view is represented by the followers of Allan Savory, who insists that soil degradation can be reversed by the proper use of grazing techniques. I’d like to encourage an intelligent discussion of this issue on this website, since the evidence so far seems very mixed — and the answer is hugely important. Here is a post from a regenerative agriculturalist posted elsewhere.

I’m currently doing a course on Planned Regenerative Grazing in Australia.. This is what I have learned, as far as I understand it.

It’s not how long you graze a paddock that’s important, but how much rest it gets before you come back to it.

2. Move animals based on gut fill or before they start to eat down to the litter layer.
3. Don’t graze a paddock until the grass is at the stage where the lower leaves are decomposing and creating litter. You want to trample this litter onto the soil to build new soil. This is fundamental.
4. Use practice areas to establish how much time it takes for pasture to recover fully. Rest will allow perennial grasses to come back from the soil seed bank.
5. The idea is to have a high density of animals in a small area for a short period of time and then give paddock a long rest. In our area that’s going to be around 6 months rest. (brittle environment, 600 mm rainfall)
6. That means you need lots of paddocks. At least 30 is recommended. (I have 17) Then strip graze away from the water point in each paddock if you can.
7. Dung is a good indicator of animal health.
8. Creating a grazing plan by working out how many days you are going to graze each paddock based on its size and productivity and that will allow sufficient rest before you come back to it.
9. The hardest decision you make will be to sell stock when you realise you are overstocked. This must be done immediately. Or you have to make a decision to supplementary feed which is often not economical. Most conventional farms are overstocked.
10. Use Holistic management it integrate your planned grazing into the big picture of what you are trying to achieve.

I’m sure I’ve missed some things, but that’s the nuts and bolts of it off the top of my head. I’m just starting to implement this on our sheep property in Central Victoria.

Several staple crops such as cassava and sorghum naturally produce cyanide. The levels of cyanide in these crops increase with atmospheric Co2 levels and droughts. A case – several years ago – in the Philippines – saw 27 children die at a school after eating toxic cassava.

“Staples such as cassava become more toxic and produce much smaller yields in a world with higher carbon dioxide levels and more drought, say Australian scientists.

The team grew cassava and sorghum at three different levels of CO2; just below today’s current levels at 360 parts per million (ppm) in the atmosphere, at 550 ppm and double at 710 pm.

Current levels in the air are approximately 390 ppm, around the highest in at least 800,000 years and up by about a third since the start of the Industrial Revolution.

“What we found was the amount of cyanide relative to the amount of protein increases,” says Gleadow, referring to cassava.

At double current CO2 levels, the level of toxin was much higher while protein levels fell.”


Nitrogen fixing is a vital component of soil health. This can be done artificially or naturally. The tree species which are planted can have a significant role regarding this. I recently wrote to Urban Forestry at the City of Toronto regarding the increased prevalence of Kentucky Coffee Trees (Gymnocladus dioicus) being planted in the City of Toronto. These trees are apparently quite hardy, but they have another advantage: the trees are in the pea family and thus naturally fix nitrogen into the surrounding soil as they grow. This is quite the advantage in urban areas – as nitrogen is a vital nutrient for plant growth and thus ecological health. The trees are additionally quite unique – with the largest compound leaves in Eastern North America – and the seed pods likely date from the era of Woolly Mammoths – who may have chewed on them. First Nations folks used the pods as a laxative and stimulant – in something not dissimilar to coffee. (The trees are not related to traditional coffee trees). The importance of nitrogen fixing in soil health related discussion cannot be ignored.

Please explain earthworms. I had heard that they were very good for the soil — presumably all soil. But now I have learned that Canada never had earthworms until recently. They are an invasive species and biologists worry about them. Should we worry?

‘Environmental bastardry’: Looser grassland controls slammed
By Peter Hannam, August 5, 2019

The Sydney Morning Herald

A dispute is raging in Australia about managing grasslands in the state’s south just weeks after a scientific committee deemed them to be critically endangered, a move which has been blasted by environmental groups.

This is an excellent piece on soil degradation and the possibilities of reversal. It includes a very interesting section on perennial grain crops as developed by The Land Institute.


Terra Preta is a rich black soil in the Amazon that was created by Indians who lived there a thousand years ago. They created charcoal from their household waste and buried it. This removed carbon from the atmosphere and sequestered it permanently. We need to do the same. It’s the best possible soil for agriculture.

Mother Earth, our soil, can not only feed us but absorb the excess carbon we’ve poured into the atmosphere. But we have to respect it and treat it right.