Homegardens are typically less designed on paper than the modern cold climate food forest. I think this reflects the thousands of years of tradition. Nonetheless one sees the same issues at play - spacing, shade impacts, polycultures, diverse yields, livestock integration. They are not perfect but extremely interesting. I think we should be studying them intensively. I like describing the cold climate food forest as a temperate homegarden. It gives credit to the true developers of the notion, and points to us in cold climates as the very very new kids on the block. For terminology, I'm partial these days to calling food forests just another type of multistrata agroforestry (Chapter , towards the more intensive small-scale end of that category.
Also interesting about the distinction between the food forest vs. productive management of wild ecosystems (covered in Chapter 9). There is no precise line between these. Books like Tending the Wild (California) and The Biggest Estate on Earth (Australia) provide a look at traditional land management, which is on a continuum with multistrata agroforestry systems like homegardens. These days I am very interested in the 1000 different points that live between "farming" and "nature" that incorporate a perennial element and some human management. My own highly planned food forest is now directing much of its own evolution, as polyculture partners find each other and fruits like persimmon, currant, grape, hazel, and pawpaw germinate spontaneously.
Hello everyone, great discussion so far. I'm hard at work doing further carbon farming research, but very happy to answer questions once people have read through a section. I can be reached at toensmeier [AT] gmail, and I'll come chime in. Just let me know what you need me to weigh in on. Thus far I can say that most of the questions and concerns that people have put forward are answered in the pages to come - including those related to Savory's claims, methane and livestock (juicy controversy!), the unsustainability of offsets, and the avoidance of silver bullet thinking. And I agree - "solution" is not a perfect title but it was the best out of about 50 titles we thought about. Eric
Well thanks everyone it's been really fun. I was telling Lorenzo the other day that I have been very impressed by the high caliber of everyone's questions and comments. I hope those of you that want a book enjoy it, and that the rest of you get a chance to read it whether you buy your own, borrow from a friend, or get it from the library. Climate change gives us a motivation to take what we've been learning and spread it and scale it up. And the science I've investigated in the book also challenges us on a few of our dearly–held beliefs, though mostly it reinforces what we've been saying all along.
I've been in terrible health and won't be on the road teaching much at all. I do plan to do some long form a webinar classes this year to offer people a chance to get some of what they might get in a five day course, from the comfort of their own home. By doing so we get a far better carbon footprint anyway And don't forget to check out all the free resources at carbonfarmingsolution.com.
Thanks again to everyone at permies for organizing this event and for your support and sponsorship of the three years it took me to write it.
In tillage agriculture humus burns up, both conventional and organic. Cover crops, crop rotations, and compost application can keep levels pretty decent though. No-till systems including mulching are far better in terms of carbon though difficult to operate organically at a mechanized scale.
Hi Neil, I do touch on this in the book. Albedo impacts are much stronger at higher latitudes and minimized in the tropics. As you get to higher latitudes (like Northern Canada, Scandinavia, Siberia, perhaps Tierra del Fuego) planting evergreen trees has a net warming impact because their albedo outweighs the carbon they sequester. This is because a dark green tree is so much darker than a white snowy field. In mid-latitudes, like temperate North America, evergreen trees lose something like 10 to 40% of their impact due to albedo. these impacts are much less for deciduous trees. Fortunately we have very few evergreen crop trees for temperate and boreal climates, pine nuts are really the only ones I can think of. But deciduous trees are still worse than grassland or annual cropland in these climates. Perennial grains, when developed, will be a really valuable strategy for high – latitude climates. This is true both in terms of their albedo and their cold hardiness. I think this is an area to think quite a bit more about, we're really lacking a lot of the data we would need in order to. Really understand and develop a platform for albedo – friendly agriculture at high latitudes. Nice to see you thinking about this though!
We have to look at the full lifecycle analysis of a practice, which includes in this case the energy required to chip the wood and transport the material. With that said, mulching is a great practice in the early years of rehabilitating a degraded sites. In the long term however we want to produce our own mulch materials right on-site. The best place I've ever seen doing this is Las Canadas in Mexico, where they grow giant biomass grasses and woody legumes to produce compost in their bio intensive areas, and for chop and drop in their food forest. Last fall I planted out a bunch of giant miscanthus grass in my garden to provide mulch for my annual beds. My perennial beds most themselves now that they are more mature, and if you annual crops like grains produce enough of their own mulch from their crop residues, the most annual crops require some mulch from somewhere else.
100% yes annuals have a place in carbon farming. There are a number of practices for annual crops alone that have a modest sequestration impact. These include organic practices, crop rotation, cover cropping, reduced tillage, system of rice intensification, and more. There are also many, many practices that incorporate annuals with perennials to provide a somewhat more substantial sequestration impact. These include multiple agroforestry practices as well as others that involve, for example, strips of perennial grasses on contour. Pasture cropping also fits into this category.
just to be clear: there are ways to raise livestock that have a net sequestration and net mitigation impact. AND most of us in the wealthy countries need to eat much less meat in order to have a better climate impact. My personal proposal is as follows. Stop feeding the annual grains to livestock (one third of all annual cropland goes to feed livestock and annual cropland is a huge part of the problem); produce livestock on the land not suited to annual agriculture (too steep, too rocky, too remote); convert pasture to silvopasture wherever there is sufficient water to allow this; manage the remaining grasslands with holistic raising and other managed grazing practices. Note that scientists do not yet remotely agree on whether or how this sort of manage grazing is possible and whether it is appropriate on all kinds of grasslands.
Probably the biggest thing we can do is get involved in the movement to keep fossil fuels in the ground. In terms of our personal lifestyle, my afraid I'm not the right person to ask. And most of the sites and resources that help you analyze your carbon footprint look at your admissions but not at your sequestration. One of the big things we can do in the wealthier countries is greatly reduce our levels of consumption, which I suspect most members of this site are already well on their way towards. Likewise reducing energy use, increasing energy efficiency, and so on. Some afraid I don't have a great answer for that but it is a question I get a lot and I' ll need to get a better response:)
I do think making improvements to allow better kinds of agriculture is a good use of remaining fossil fuel. Or even better of biodiesel or vegetable oil fuel. I can't speak to the particular soils and situations in your area, but a savanna is still a really wonderful thing, Including in terms of carbon.
This is a very interesting question indeed. up until now a lot of what we have focused on in permaculture has been our own farms and gardens. To address climate change really requires engaging in the climate movement, in policy advocacy, and then large – scale efforts to train farmers and land managers in new techniques. Because even 10 million awesome gardens or homesteads are not enough to do the job this case. We have to transform much of the world's farmland as well, And on a timescale of just a few decades. Some of the larger ecosystem impacts you mention like increasing rain clouds can only happen in a much larger scale as well.
Tyler you might take a look at Brett Chedzoy of Angus Glen Farm, he's done some very nice work on converting secondary forest to silvopasture. he says that you have two choices with the secondary forest ( relatively young regrowth of relatively low quality), first you could preserve your best trees for future timber use and manage the rest for firewood. The other option is to keep the good quality trees as in the first option, but thin out the rest and seed in shade – tolerant pasture species for conversion to silvopasture. quite interesting.
Afraid I don't have a lot to offer here is I haven't worked a lot in dry climates. The suggestions around burying, mulching, and biochar seem promising. Some Carmen is lost as they dry but some is also lost when would decompose is in the soil. I don't have a good understanding of the best way to conserve that material. Whatever the practices are in your region that end up building organic matter in the soil most effectively would be the ones to look at. Good luck and let us know what you learn!
Hi Xisca, it is a citrus farm in Uruguay. Looks like they are being intercropped with eucalyptus. We paid an aerial photograph artist for the right to use it. It's sort of it encapsulates the notion of a new kind of agriculture doesn't it?! Eric
Great minds think alike. I do have a whole chapter on this challenge in the book as I think it is the key limiting factor in farmer adoption, not that access to training seeds etc. is an important. The best thing I can do though in response to your question is to recommend a book by Elizabeth Ü, called Raising Dough, which provides an outstanding overview of the traditional and new alternative finance models for agriculture and food businesses. Your dream organization could also work closely with USDA NRCS, who offer cost – share programs for implementation for many carbon farming practices. You can learn more at the COMET-Planner website.
Hi Tyler good question. I do hear people talk about this. At a certain point when a tree slows growth its carbon sequestration also slows. If you want to really maximize carbon sequestration in your agroecosystem you could cut trees at that point and use them for building materials. If they then re-sprout or you plant another tree to replace them you can keep your system sequestering at a faster rate because it doesn't "saturate" and start to slow down. However there are certainly some loss when a tree is cut no matter what, and this can vary from almost negligible to quite serious depending on a number of management factors like how much the soil is disturbed during the harvest process. Bamboo is a classic example, managed bamboo forests actually sequester more carbon than wild bamboo forests both because of the stimulation of faster regrowth and the use of treated bamboo as a long – lived building material.
More great questions! I'm doing my best to reach both audiences with this book. On the one hand if conventional farmers with large acreage can shift their production model even slightly back and have a big impact, and sometimes we need to meet people where they are. On the other hand we need innovative farmers (like yourselves) to push as far as we can with the most carbon – friendly models available, and to develop new ones.
I look a bunch at issues around adoption of practices in the book and conclude that while education, access to the right seats and equipment, and so on are very important, the main factor limiting widescale implementation is money. Even just converting from conventional agriculture to organic is a transition that takes several years and involves reduced yields an income during that period. Converting to perennial crops and agroforestry systems is even more challenging. Many countries already have financing systems in place for carbon farming, places like Mexico, Australia, Brazil, and India. One of my goals with the book is to help to spur the creation of more of these financing mechanisms, including government, NGO, and traditional and alternative finance options. We do have a great opportunity with so many people and organizations divesting from fossil fuels, and we need to make it easy for them to invest that money in regenerative agriculture instead.
Believe it or not I have a chapter on this in the book! These species are known as dedicated biomass plants. There are three basic categories: bamboo, coppiced woody plants, and giant perennial grasses. In your region you could try fast – growing woody plants that Reese Prout after cutting like poplars, willows, and so on. Fast – growing giant grasses for your area would include phragmites, giant miscanthus, and arundo donax.
And I forgot to mention, yes that study is correct. Between 10 and 40% of the sugars formed from photosynthesis are exuded from plant roots within an hour of photosynthesis! These feed the soil organisms and are one of the mechanisms by which carbon stored in the soil.
I get this question a lot, about the role of various microbes and fungi and so forth in carbon sequestration. These organisms play critical role in converting dead plant biomass into soil organic matter, which is the primary repository of carbon in the soil. However the carbon itself is removed from the atmosphere by plants through photosynthesis. My focus in the book is looking at the practices that we can perform, that is the farm management systems that make this process happen, though of course much of the mechanism of transfer of that carbon happens through various non-plant organisms in the soil. But the question to me is what do we need to do to make that happen? Planting more trees on farms is one of the key steps we can take.
Good question. Most of the studies that were available for me to work with just look at the amount of carbon in the soil and or in aboveground biomass. Another way of doing this is life cycle analysis, which also looks at emissions from transportation, chemical fertilizers, integrated livestock, etc. Lifecycle analysis is a much more complex and much more useful for providing the kinds of comparison you're talking about. I haven't been able to find a whole lot of lifecycle analysis studies of carbon farming systems, though I hope more will be coming. That kind of study does permit a direct comparison between say conventional agriculture and an agroforestry system. Was clear even from the studies I do have is that it is possible to have much much better results than conventional agriculture, and to turn agriculture from a source of emissions to a net source of sequestration and mitigation.
Great question. I'm not aware of the distinction in the carbon sequestration rate of broadleaf versus conifer per se. Slower growing trees tend to be denser and sequester more in the long term, but faster growing trees sequester more in the first 10 years or so as a general global trend. It may be that what they're looking at is albedo, which refers to the reflectivity of the Earth's surface. A dark surface like asphalt absorbs heat from the sun and warms up, while a lighter surface heats up less. The same is true of a northern forest in winter. A bunch of evergreen trees are darker than a snow-covered field. Deciduous trees are somewhere in between. In high latitudes like much of Canada, the carbon sequestration impact of planting coniferous trees is offset or even worse by their albedo impact. This should be a good reason to plant deciduous trees at high latitudes.
Anything that increases the amount of organic matter in your soil or the amount of perennial biomass above ground is sequestering carbon. So compost, mulching, intercropping with perennials, and any number of strategies are all workable. The great thing about growing in the city is that you have access to the urban waste stream and all of the marvelous carbon it contains.
I'm not sure what scale you are producing at but an excellent strategy to try is the System of Rice Intensification. This is an intensive organic smallholder approach to rice production that is showing impressive impacts on yields (doubling or more in many cases). As it is not a flooded system, it does not result in methane emissions as regular paddy rice does. However it is a very labor – intensive practice. The international Rice research Institute has been looking a lot at rice production practices for methane reduction and has developed some interesting options for larger operations, most of which involve minimizing tillage and reducing or shortening the flooded period.
I don't have any specific strategies for that specific challenge, as it is a book for the entire planet and only 500 pages long. However a number of the strategies I include deal with regeneration of degraded lands, which sounds very much like your situation. All the strategies we know in permaculture for improved annual cropping like cover crops, compost, crop rotation, mulching, biointensive are all relevant. Adding perennial elements like coppiced nitrogen fixing trees can also be very helpful. Managed grazing, or even better manage grazing with trees Incorporated is another strategy. Finally edible reforestation with lots of support species, a strategy we like to call the food forest in our movement, is another one of my work.
All that sounds great. There's lots of work that's been done on reducing emissions from rice paddies as well as sequestering carbon in rice production systems. Emissions can be reduced by minimizing the flooding period. The International Rice Research Institute has been doing a lot of work on this. We are also very close to the commercial release of perennial rice, which will represent a carbon–sequestering practice. Finally I've gotten very excited about the system of rice intensification, a non-flooded intensive smallholder rice production model that sequesters carbon will greatly increasing yields. And as a non-flooded system it also greatly reduces methane emissions.
What's an RMH? Generally speaking woody perennials are best, with dense and long-lived species ideal. These are followed by herbaceous perennials, and finally by well – managed annuals, ideally in a minimum tillage or mulched situation with crop rotation and cover crops.
It's maybe not phase 1 in terms of most likely for rapid adoption but yes absolutely. Application of compost regardless of the raw materials used can increase carbon sequestration in croplands and grasslands. It would be interesting to look at the admissions from our current sewage treatment practices which I imagine are fairly high and contrast them with the potential of composted human manure applied to productive agroecosystems.
I'm afraid I don't have the perfect answer as to what works in the Northwest. I found essentially no scientific information on the carbon impacts of hugelkulture, so I will have to remain agnostic on that front. I do very much agree with some of the commenters about the potential dangers of land grabs and the industrial production of biochar. these are the same arguments that we use against industrial scale biofuels, and a range of other "carbon grabs" that use climate change as an excuse to further nefarious ends of greed in land acquisition. We always need to look to the social and ecological impacts beyond merely climate mitigation, or we can get into some dangerous waters very quickly. With that said the IPCC is enthusiastic about biochar and report a global average of a 15% increase in yields. I think the jury is still out on whether it is the right choice for any particular soil or climate. In Sandy soils and tropical sandy soils in particular it can make a big difference in improving cation exchange capacity and reducing nutrient leaching while sequestering carbon.
What an excellent thread. These are exactly the kinds of questions I set out to answer in my book. I do provide lots of data from individual studies, scientific reviews, and expert estimations, estimate the sequestration rates above and below ground of a variety of farming systems. They vary widely between and within practices as you might expect. I also look at the long term soil carbon storage potential which also varies widely between practices.
The general trend is that systems with trees sequester more than systems without, both above and below ground. This goes for annual crops vs. annual crop agroforestry, pasture vs. silvopasture, and annual crops vs. perennial crops. Multistrata perennial systems (including the permaculture "food forest") are in the highest category.
Estimating the carbon in aboveground biomass is fairly simple and well – understood, in that about half of the aboveground biomass is carbon on a dry weight basis, and there are well – established methods of measuring and or estimating aboveground biomass. It's when you want to measure or estimate carbon in the soil that things become a bit more challenging. Scientists have yet to agree on a standard method for doing so, one even finds that studies are measuring 10 cm or 30 cm or a full meter or even to full meters. This makes comparison very difficult. Lots of the key people working on this understand that it is a key issue holding back the wider implementation and financing of carbon farming, and they are hard at work on developing standardized systems that will be both accurate and cost – effective. As far as I know we're not there yet though.
Hi Maggie, good question. In short: most energy needs to come from clean source like solar wind and water, but some can come from biofuels, including biodiesel. I'm particularly interested in producing biodiesel from perennial crops to get the double impact of carbon sequestration and emissions reduction. I have a list in the book and on the website of perennial, inedible "industrial oil" crops that are strong candidates for biodiesel production, as well as for bioplastics, vehicular and industrial lubricants, and more. Eric
Until and unless I learned how to respond. I post, I'll just handle your thoughts and questions here.
Burra Maluca - Well gosh thank you! That's about as good a review as a writer ever hope for.
Feidhlim Hardy - I don't talk much about human manure in particular in the book though I agree it is a critical strategy. I do however talk quite a bit about the use of compost (from whatever raw materials) and its impact in improving carbon sequestration in cropland and grasslands.
To everyone excited to read the book: I'm excited for you to read it too. My editor encouraged me to "let the geek flow through me", so it is dense but there's some pretty cool stuff in there. Hope you enjoy it.
Todd Parr: Edible forest gardens are a subset of the category of multistrata agroforestry. Multistrata agroforestry itself is only one of about 40 strategies that I address in the book. So there really isn't a whole lot of overlap with any of my previous books. I'm looking much more at farm scale, looking globally, and looking at many more practices including those that incorporate livestock and annual crops. I also include six chapters on perennial staple crops to provide protein, carbohydrates, and fats, as well as six chapters on perennial industrial crops for materials, chemicals, and energy.
Thanks for spending the week with me. And thanks very much for the 10 out of 10 acorns review! I worked long and hard on this book, thanks to the support of my kickstarter backers who no doubt include many of you. In fact if you look closely, you'll notice that permies.com is mentioned in the dedication, because so many people from this community help to support me in writing.
A few words about my overall goal of the book. It is not particularly written for gardeners, though it has much to offer to gardeners. The primary audiences are farmers and farmer groups, policymakers, funders, and researchers. One of the goals that became apparent during the writing process was to pull together scientific evidence supporting regenerative agricultural practices, to help us to gain access to the hundreds of billions (yes that's billions with a "b") of dollars already being spent on climate change mitigation. Agriculture and land use are responsible for a quarter of all emissions but we receive about 2% of mitigation funding. One of the limitations to our getting access to that money, and to the scaling up of our practices that would enable, is a lack of awareness and understanding of the scientific evidence. Thus I've worked hard to present this in the book. Some great practices that I personally am a fan of, like keyline and holistic grazing, receive much less airtime in the book than I would like because scientific evidence is either largely absent (keyline) or a source of much controversy (holistic grazing). For the record, once again, I think both of these practices are great, but in the absence of robust scientific evidence in their favor I chose not to emphasize them strongly because my goal is to achieve legitimacy for the practices we know and love (and many that might be new to many of you, as some were to me), so that we can get ourselves in the center of the climate solutions platform and the funding that comes with it, and the increased funding that will be coming with it down the pike.
I'll also invite you to visit carbonfarmingsolution.com, where I've posted a lot of free material from the book as well as a number of really fantastic videos describing the range of practices covered in the book. I'm well aware that the book is a pricey one, though at one cent per page the price seems fairly reasonable to me, especially including all the beautiful color photographs that help bring the ideas to life. This is why I'm posting lots of information on my website and will continue to do so, to make it possible for people to get as much of the information as possible without owning a copy. As some have already mentioned in the comments, it's a great book to get your library to order.
As for the big vision of the book: it provides a toolkit of practices, species, and policies to enable the rapid expansion of carbon–friendly agriculture. In particular I am looking at practices that sequester carbon in soil and in above–ground biomass. While it is not the case that this can return us to "stone age levels of carbon", wide implementation of these practices could really save our bacon if implemented alongside drastic reductions in emissions and a substantial transformation of every aspect of civilization – a transformation that, let's face it, was really overdue for a long time regardless. In all I cover about 40 different practices, many of which are familiar in the permaculture lexicon already. One of the most striking things for me was learning the very large scale at which some of these things are already practiced, and that some of them have been practiced for thousands of years. It turns out that our permaculture movement, while very significant, is only one of many players in the carbon farming game, some have of whom have been at it for 10,000 years or more. Always nice to be humbled eh!