Waiting on amber: a note on regenerative agriculture and carbon farming

This post offers some further notes on the issue of carbon farming and regenerative agriculture, arising out of the discussion in this recent post of mine, particularly via the comments of Don Stewart. Don set me some onerous homework – a lengthy presentation by Elizabeth and Paul Kaiser of Singing Frogs farm in California, another lengthy presentation by David Johnson of New Mexico State University, and an interview with Australian soil scientist Christine Jones. Diligent student that I am, not only have I now completed these tasks but I’ve also read various other scientific papers and online resources bearing on the issue and am duly turning in my assignment. I hope it’ll provide some interest and a few points for discussion.

I started out with considerable sympathy towards carbon farming and regenerative agriculture, but with a degree of scepticism about some of the loftier claims made on its behalf by regenerative agriculture proponents (henceforth RAPs). And in fact that’s pretty much where I’ve ended up too, but with a somewhat clearer sense of where my grounds for scepticism lie. I hope we’ll see a shift towards more regenerative agriculture in the future. But if that’s going to happen, the RAPs will have to persuade a lot of people more inclined to scepticism than me about the virtues of their proposals – and if they’re going to do that, I think they’ll need to tighten up their arguments considerably. Anyway, in what follows I define what I understand regen-ag to be and then critically examine some of the claims about it.

Defining regenerative agriculture and carbon farming

Doubtless there are numerous possible emphases, but the fundamental idea revolves around restoring or maintaining the biological life of the soil, in particular the fungal component. Working as symbionts to plants and other soil organisms, fungi are able to deliver nutrients to plants that are otherwise unavailable, and also to sequester carbon by absorbing carbon dioxide from the air and turning it into stable organic carbon compounds in the soil. In order to achieve this, it’s essential to avoid tillage, since this destroys the fungal hyphae in the soil, and to keep the soil covered with living plants at all times so that there’s a healthy rhizosphere (root zone) interacting with the soil food web. It can also be necessary to inoculate the soil with the right kinds of fungi – apparently, not just any fungi will do1.

So the three key characteristics of this kind of agriculture are zero tillage, continuous cover cropping and fungal inoculation. David Johnson states that a one-off ‘dusting’ of 400-500lbs of inoculant per acre (that’s 450-560kg per hectare for those of us still hanging on in there in Project Europe) is all that’s necessary to create the right initial conditions in the soil for many years to come.

Proponents of this kind of regenerative agriculture have variously claimed that it can:

  • Protect soil from erosion and depletion, and indeed actively build soil
  • Provide adequate crop nutrients with minimal external inputs
  • Produce high yields
  • Produce healthy crops that are weed and pest-free
  • Sequester human greenhouse gas emissions – possibly all of them
  • Earn greater financial returns for farmers
  • Improve human health

If all that turns out to be true, then this is fantastic news. But these are powerful claims, and it’s surely reasonable for them to be examined closely before we collectively hitch our wagon to regen-ag. So here, in each case I try to highlight things that seem to be more or less well established beyond reasonable doubt, and things that don’t seem so well established, at least to me. I’m not an agronomist or a soil scientist, so doubtless there are things that aren’t obvious to me which are obvious to others, though I have a sneaking feeling that a few of the non-obvious things are brushed aside a little too quickly in the Regen-Ag movement, perhaps because they don’t quite fit the narrative. And then there are one or two things I’d like to highlight that seem not well established at all. So we have green-amber-red: Small Farm Future’s traffic light guide to Regen-Ag.

  1. Regen-Ag protects and builds soil

I think it’s reasonably well established that no till, continuous cover-cropping protects soil from physical erosion better than tillage farming2, so we can start with a green light. It’s not an all or nothing thing, however. There are places with strongly erosive conditions where it’s a really, really bad idea to practice tillage agriculture from a soil protection point of view, and others with less erosive conditions where perhaps it’s only a slightly bad idea. Sensitivity to local context, and other pressures, is in order before deciding how much to censure tillage practices. Nevertheless, I think it can be agreed that tillage is best avoided whenever possible. Of course, the mainstream ‘no till’ approach involves using copious quantities of glyphosate, synthetic fertiliser and heavy, compacting machinery of the kind that the late, lamented Gene Logsdon subjected to gentle ridicule in various articles3. It’s tempting to say that’s a whole different ball game from Regen-Ag, but actually it isn’t entirely. Many farmers lauded for their Regen-Ag credentials like Gabe Brown and Gail Fuller routinely use glyphosate or other herbicides, even if at a lesser rate than conventional farmers4. I’m not inclined to criticise them for it, but it falls some way short of the desiderata for a healthy soil food web generally emphasised by the RAPs, without apparently receiving much discussion.

In terms of actually building soil, RAPs like Christine Jones and Elaine Ingham commonly critique the widespread notion that soil formation is a slow process, arguing that topsoil formation can be ‘breathtakingly rapid’5. But it’s rarely stated how rapid. Many no till, regen systems I’ve seen involve importing compost in bulk. But that’s not soil building – it’s soil importing. So my question is, allowing for an initial ‘dusting’ of inoculate à la David Johnson, how quickly do soils under a regen-ag regimen typically ‘build’ with no subsequent imports or amendments, with crops being removed from them for human consumption all the while? Until that question is satisfactorily answered, I think the ‘building’ claim stays on amber.

The Kaiser’s Singing Frogs farm seems to involve importing quite a lot of compost, even if it’s used only as a soil amendment that helps stimulate the soil food web. In addition to the compost applied to their growing beds, they raise most of their plants initially as transplants in the greenhouse, which presumably also involves importing a lot of substrate. This is how most small market gardens operate, including mine (we import woodchip and some substrate). In our present economy, flush with fertility and fossil fuels, it’s a rational thing to do. But you do have to pay close attention to where the compost or substrate comes from, and how feasible it would be to scale its supply up across the farm sector as a whole, before concluding that soil-building of this sort has global replicability. Historically, in low energy situations the choice was essentially between tillage farming or diligent and extremely labour-intensive cycling of nutrients locally. As we confront the possibility of a lower energy future, it seems unlikely that farming systems based on importing compost in bulk will figure heavily.

  1. Regen-Ag provides adequate crop nutrients

There seem to be two ideas here. First, that once the soil food web is in good heart, there are enough nitrogen-fixing bacteria in the soil to give the crops all the nitrogen they need in better forms than synthetic fertiliser, which ultimately has a destructive effect on the soil food web and on the ability of plants to take up nutrients5. And second, that the overall metabolism of the soil food web makes the other nutrients needed by the crop more available than in soils compromised by conventional practices.

The first point seems plausible to me, but not definitively established. I think more quantitative evidence is required, which I didn’t find in my various readings of the RAPs. Much as I share the dislike of the RAPs for synthetic fertiliser (and I’ve never used it myself), about 40% of the current global food supply is based on the application of synthetic nitrogen compounds – this was a major limiting factor in 19th and early 20th century agriculture, and it seems doubtful that human populations would have reached their current level without the invention of the Haber-Bosch process6. Undoubtedly, there are downsides to synthetic fertiliser. The RAPs may be right that ultimately it’s destructive of soil health. And we may be able to do without it – either by careful cycling of organic nutrients, or by the kind of soil food web route advocated by the RAPs. Various people – including me – have asked whether it’s possible to feed the world through organic farming alone, and answered with a tentative yes. It certainly makes sense to start weaning ourselves off synthetic fertiliser whenever we can, but from a global food security viewpoint our current tentative yeses don’t seem quite enough for us to blithely ditch the synthetics quite yet. Generalised or anecdotal claims that crops will do better without synthetic fertiliser are all very well, but I think such claims have to stay on amber until more quantitative data is forthcoming.

In relation to other nutrients, I get that a thriving soil biota can pull in carbon, nitrogen and oxygen from the atmosphere, but all the other nutrients have to come from the soil. David Johnson talks about the “increase in the availability” of such nutrients in his version of Regen-Ag, which he calls “Biologically enhanced agricultural management” (BEAM)7. It’s plausible to me that a healthy soil biota makes these nutrients more available to crops than they’d otherwise be, but (unlike C, N and O) it can’t conjure them out of thin air. So if crops are being taken off, then it seems to me that ultimately these nutrients are being mined from the soil, unless they’re somehow getting put back too8. But since Dr Johnson also enthuses about retaining his modern lifestyle and jetting off to distant conferences, it doesn’t seem that he’s thinking of a smallholder-style world of careful nutrient cycling. So I wonder where these nutrients are coming from. Maybe the RAPs would argue that there are effectively limitless quantities of them in the soil if only they can be made more available by the soil biota – I’ve heard Elaine Ingham imply as much9. But again, I’d like to see more quantification of this point. By my calculations, for example, the 65 million of us in the UK need to consume about 24,000 tonnes of phosphorus annually, which would minimally involve stripping the phosphorus in its entirety out of about 24 million tonnes of soil every year, and that at an improbable 100% extraction rate. So for the moment I consider this another amber, at best.

  1. Regen-Ag produces high yields

Yet again, I’m struggling to find much quantification here. In Christine Jones’s article, various farmers practising regen-ag are mentioned who are “getting fantastic yields”10. Well, how fantastic? Wheat yields in the USA, for example, have averaged 46.7 bushels per acre nationally over the last five years11. How do the wheat yields of regen-ag farmers compare? I’m not seeing too many hard and fast figures in the literature.

Let me unpack this point a little under these four heads:

  • Biomass and harvest index
  • Necessary yield
  • Competition and agronomic variation
  • Cropland-grassland balance

Biomass and harvest index: David Johnson presents figures for the most productive natural ecosystems which suggest they produce up to four times more biomass than agroecosystems despite all the fertilisation and irrigation lavished on the latter. From this he infers that “We’re doing something wrong”12. But the main purpose of agroecosystems isn’t to maximise the production of biomass, it’s to produce digestible human food – carbohydrates, proteins etc. Human crop breeding efforts have actively tried to reduce the amount of inedible biomass relative to the edible portion of the crop (ie. increase the harvest index). In this sense, Johnson’s comparison presents little useful information. Further, the high productivity natural ecosystems he identifies are all from hot and/or humid places (swamps, rainforests…even kelp beds). It’s not clear that the same is true of his agroecosystem figure, so I’m not sure he’s comparing like with like. Then Johnson presents data showing that his BEAM system produces way more biomass than even the natural ecosystems. He doesn’t always make it clear exactly what these high biomass BEAM plants are, but they generally seem to be cover crops which, by definition, are plants that are unusually good at quickly producing copious leafy biomass in the short-term. So it’s not necessarily surprising that they outperform the range of plants found in natural ecosystems and agroecosystems. High biomass production can be one important agricultural goal, but what’s ultimately of greatest interest is the yield of the edible portion of the crop. The table that Johnson really needs to present here is the yield of edible biomass or of metabolisable human nutrients in the various different regimens. It’s impossible to know if we’re ‘doing something wrong’ in crop yield terms until he does.

Necessary yield. Of course, yield isn’t everything. A lot of crops are fed inefficiently to livestock, or exported, or end up as food waste. Undoubtedly there’s some slack in the system, so it doesn’t necessarily matter if regen-ag yields are lower than conventionally-grown crops if they bring other benefits. As with enthusiasts for perennial grain crops, the RAPs seem to feel the need to claim that crop yields are as good or better than conventional crops, when this may not be necessary for their case, and potentially draws us into needlessly oppositional arguments. But ultimately it’s necessary for any agricultural system to yield enough to feed the people relying on it. What counts as enough isn’t an exactly quantifiable number, but it should be roughly quantifiable, and I’d like to see the RAPs roughly quantify it.

Competition and agronomic variation: at one point in his presentation, David Johnson likens our major crop plants to weeds and says “we’re good at growing weeds”. That’s exactly right. The basic characteristic of most of our major crop plants is that, like most weeds, they’re pioneer, short-lived (usually annual or biennial, sometimes short-lived perennial) plants that usually fare best in disturbed (ie. ploughed), highly fertile ground. As argued above, disturbed ground isn’t ideal for other reasons, so if we’re going to grow our standard crops in regen-ag systems, then essentially we’re going to have to ‘trick’ them into growing in circumstances they don’t particularly favour. In particular, we’re probably going to have to grow them through cover crops that may compete with them for water, light and some nutrients, even if they may donate other nutrients (like nitrogen). Therefore we might expect them to yield less. Generally, the way farmers bicrop cash crops with cover crops if they don’t use herbicide (which in fact most of them do) is to use some kind of inherent seasonal check to the latter (eg. flooding, extreme heat/drought, or extreme cold) or else by damaging them mechanically by some method that falls short of full tillage. But that’s not possible everywhere – for example, in the moist temperate zone where I live, cover crops can happily grow more or less year round and I’m not sure there are obvious ways that, for example, a cereal crop could be established directly into them with uniform success and good yields. This article about Kansas regen-ag farmer Gail Fuller says “Instead of trying to figure out the best way to terminate a cover crop or pasture, Fuller is looking for ways to knock it back for a few days to allow the cash crop to compete as a companion crop”. Where I live, I don’t think ‘knocking back’ a cover crop for a few days would be anything like enough to establish a successful cereal crop into it – which is why cover-cropping farmers here continue to use glyphosate routinely. My feeling is that further experimentation with cover cropping may eventually mitigate this problem, probably at the cost of some yield loss. But it doesn’t seem to me that humanity has really cracked this one yet. I think the RAPs need to discuss this issue more clearly, perhaps with an acknowledgment that – as with their ideal cover crop – it’s not yet cut and dried.

Cropland-grassland balance: many of these cash crop-cover crop trade-offs disappear when the focus shifts to farming ruminants on grass, because – notwithstanding many farmers’ taste for temporary perennial ryegrass – the cash crop in this instance is essentially a long-term cover crop, which therefore fits easily into the logic of regen-ag. Perhaps it’s no coincidence that the farmers who get star billing as regen-ag pioneers are often ranchers on extensive, semi-arid grassland who are restoring soil and vegetation in the aftermath of ill-advised intensive grazing or tillage. All credit to them, but in terms of global food production it would be stretching a point even to call this a sideshow. The problem with grass as a crop is that humans have to jump a trophic level in order to be able to consume it as beef, lamb etc. and – as the likes of George Monbiot tirelessly, and correctly, remind us – this is pretty inefficient energetically. The contribution of rangeland beef to global food intake is minimal. On this note, Gabe Brown is frequently cited as a regen-ag pioneer. I haven’t yet established exactly what Brown’s system is and what his yields are, though it seems he has long fallows in his grazing rotations. Makes sense…but then he has a lot of (presumably cheap) acres to play with. Maybe his yields stand up even so. If so, it hardly fits into a Boserup model of agricultural intensification. Gail Fuller says “with low grain prices my bottom line is better grazing cover crops and pastures than growing corn…Right now, I make more money grazing”13. Of course, that’s absolutely fine at the individual farm level (though maybe it raises a question mark or two about those ‘fantastic’ regen-ag yields). But at the global food system level, it probably wouldn’t be fine, and we need to address that too.

In summary, I’m open to the idea that regen-ag methods produce ‘fantastic’ yields, but I’d like to know what they are. If no-till, cover-cropping methods can match or surpass tillage plus added-fertility methods for crop yield (rather than biomass yield) then that indeed would be fantastic – but it would run counter to what we’ve learned historically about agricultural development. Even if they can’t match them, it may not matter if they can yield enough. But some good, global quantification is necessary. For the moment, there are many ambers here.

  1. Regen Ag produces healthy crops that are weed and pest free

It seems plausible that a healthy soil biota, with fungal networks optimising nutrient transfer, will produce healthy crops – perhaps healthier than ones propped up by an agri-chem plus tillage approach. At the same time, as mentioned above, most of our crops are based on weedy, pioneer species that like to hoover up nutrients in disturbed soil, and they’ve been further bred to amplify these characteristics. So the idea that they’re happier in undisturbed fungal soils arguably requires demonstrating, rather than being assumed. I’d judge this assertion to be hovering on amber.

No doubt it’s true that healthy plants are more resistant to weeds and pests. This has long been the refrain of the organic movement, and I think it’s defensible so long as you don’t overplay the argument. Our crops, remember, are basically weeds, and the kind of soils they like to grow in will generally be to the liking of other weeds that humans don’t want. At Singing Frogs Farm, the Kaisers emphasise the use of mature transplants as a strategy to prevent weed ingress. That makes sense in the context of a small market garden, but it speaks of weed management, not a weed-free agronomy. It’s also labour and compost-intensive. It’s not necessarily applicable to broadscale farming – unless the argument is that we should minimise the latter and emphasise small-scale, labour-intensive farming. That, I think, is precisely what we should be doing. But we won’t have banished weeds, and we’ll have to scratch our heads to find the necessary inputs.

The pest issue mirrors the weed one. Different kinds of pests adapt to different kind of cropping regimens in different ways, and again it’s a matter of management rather than banishment. The Kaisers discuss the bird and insect problems they have and the crop covers they use to minimise these – so clearly they have pest problems. I find implausible the notion of a farm so tuned in to the natural world that none of its crop ends up in the stomachs of wild critters. Indeed, a farm tuned in to the natural world probably ought to be one in which some of its crop does end up in the stomachs of wild critters.

For me, it’s a red light on this claim.

  1. Regen ag sequesters human greenhouse gas emissions – possibly all of them.

It’s generally agreed that soils can act as a sink for carbon, and that soils containing a healthy food web are better at sequestering it – for example, through the fungal creation of chitin which holds it in a relatively immobile form. So I think we can probably award a green light to the basic claim that regenerative agriculture can sequester carbon. I say ‘probably’ because there are studies that contest the idea of carbon sequestration through no-till regimens14 – it seems to be the case that the ‘regimen’ can be more important than the ‘no till’. Still, I think it would be fair to say that the balance of the literature suggests sequestration is at least a possibility.

Even so, I’d like to make four caveats.

First, I’d hope we can all agree that the best form of carbon sequestration is the one where humanity leaves the world’s hydrocarbons in their well sequestered present locations deep down in the earth. Carbon sequestered shallowly in soils by living organisms is always going to be more potentially mobile. You could argue that, in practice, humanity just isn’t going to leave all that energetically useful carbon where it currently lies in the rock, and that we therefore need to think about other mitigation strategies. Fair enough. But David Johnson’s insouciance about continuing to live our present high energy, fossil-fuelled lifestyle while mitigating its effects through shallow sequestration in living soils doesn’t inspire me with a great deal of confidence.

Second, no till farming doesn’t have it all its own way in terms of greenhouse gas emissions, because it’s typically associated with greater nitrous oxide emissions – and in some situations these outweigh the carbon sequestration gains: “increased N2O losses may result in a negative greenhouse gas balance for many poorly-drained fine-textured agricultural soils under no-till located in regions with a humid climate”15. That sounds like an apt summary of many of the soils where I live. Proof again, if it were needed, that in agriculture as in many other things there are no one-size-fits-all solutions.

Third, there may be a limit on soil sequestration potential. Regen-ag heroes like Gabe Brown are lauded for taking on farms degraded by over-tillage and soil carbon loss and then building up the soil carbon stocks. But it seems to be the case that you can only build up the soil carbon for so long16 – we’re talking years, or decades at most – before it reaches an equilibrium where there’s no agricultural benefit to increasing carbon (as the Kaisers have already found) and it gets harder to do so anyway. So there may be a fairly short time-frame in which the carbon sequestration benefits of regen-ag are operative. Experiments like David Johnson’s have also been undertaken under short time-frames so far. Some caution about how much we can extrapolate these findings long into the future is probably in order.

Fourth and finally, we come to the vexed question of how much of the carbon that humanity is adding to the atmosphere can be sequestered in soil. The scientific consensus seems to be something in the region between 7-16% of current emissions17 – a useful amount, certainly, but not decisive enough to keep the climate change wolf from the door. RAPs like Christine Jones and David Johnson think that the potential is much greater, but frankly I’m doubtful of their claims. Jones appears to have something of a track record of questionable over-estimations of soil carbon sequestration potential of such proportions that it’s prompted even luminaries of the alternative farming movement such as Simon Fairlie and Rafter Sass Ferguson to distance themselves from her claims18.

Meanwhile, Johnson argues that since fossil fuel combustion is only responsible for about 3% of the carbon in the global carbon cycle, it’s better to focus mitigation efforts on the biotic side of the cycle. This strikes me as specious. True, there are large natural sources, sinks and fluxes of carbon which dwarf the anthropogenic ones, but these are well-established patterns that aren’t significantly responsible for the radiative forcing we’re now seeing as a result of adding new carbon to the cycle. And if I understand this right, this new carbon, this 3% (I think it’s possibly more than 3% if you consider all anthropogenic causes of radiative forcing), is being added every year. However we tend the soil, can we really expect the existing carbon cycle, its soils and vegetation, to take care of an additional 3% on top of its relatively stable totals on our behalf in each and every year for the foreseeable future so that we can continue flying around the world to go to soil carbon conferences? That’s a very large demand to place on Mother Nature. I suspect she has other plans. If the claim is that on the basis of a few short-term, small-scale, local experiments like Johnson’s we can be sure beyond reasonable doubt that all anthropogenic carbon emissions can be stably sequestered long-term in agricultural soils, then I fear I’m looking at amber turning to red.

This isn’t the first time it’s been claimed we can adopt agricultural practices that will sequester all anthropogenic carbon and banish our climate change woes. Those earlier claims were shown to be spurious19. The same outcome seems likely this time around.

  1. Regen-Ag earns greater rewards for farmers

I think the basis for this claim is that regen-ag farmers spend less on agri-chemical inputs, presumably without a concomitant decline in outputs. So it’s plausible that the current handful of regen-ag pioneers are making a bit more money just at the moment. But unfortunately markets don’t fix food commodity prices at levels determined by outmoded technical inputs – in fact, they barely fix food commodity prices at levels determined by inputs at all. If they did, I’d be a rich man. So if regen-ag proves itself and spreads, then absenting major structural change in the global political economy, no farmer is going to get wealthy from it, because commodity prices will adjust. In other words, it’ll play out the same way as every other technical innovation that’s enabled farmers to increase yields or reduce inputs without for the most part becoming notably better off. Even David Johnson concedes that farmers will need to be paid in order to adopt his BEAM approach. He says that we shouldn’t expect farmers to bear the brunt of society’s environmentally-damaging behaviours. I agree, though historically they generally have done. Of course, in the long run it’s not sound business sense for Homo sapiens Inc. to erode away all its agricultural soils, so at some level it must ultimately be true that it ‘pays’ to adopt regenerative practices. But in the short-run, while I’m sure some farmers have improved their incomes as a result of adopting regen-ag approaches, I’m not seeing a persuasive argument for how regen-ag will in itself improve farmer income. Another red light.

  1. Regen-Ag can improve human health

The main idea here – one debated under my earlier post – is that without a healthy soil biota to transport nutrients readily around, our crop plants are unable to access the range of nutrients (particularly the micro-nutrients) that they need for their full health, with negative consequences in turn for human health. I find this idea intuitively quite plausible, but intuition only takes one so far. Proponents of mainstream agriculture are fond of saying things like “nitrogen is nitrogen”, and to be honest I’ve not seen much evidence to refute them. Evidence of harm to human health from the proliferation of nitrates and other agro-chemicals in the environment is clear, so there are grounds for shifting away from it on that basis alone. But evidence of harm to human health from impaired soil food webs is more elusive. It seems to be the case that the nutrient density of our food is in decline, but it’s possible that this results from eating high-yielding modern crop varieties with poorer micro-nutrient uptake and from a poorer overall diet20, not because of the non-availability of micro-nutrients in the soil.

Christine Jones has this to say about the link between current agricultural practices and cancer:

“Not that long ago the cancer rate was around one in 100. Now we’re pretty close to one in two people being diagnosed with cancer. At the current rate of increase, it won’t be long before nearly every person will contract cancer during their lifetimes. Cancer is also the number one killer in dogs. Isn’t that telling us something about toxins in the food chain? We’re not only killing everything in the soil, we’re also killing ourselves — and our companion animals”21

Let’s unpack these statements a little. In the UK22 the current cancer ‘rate’ in the sense of new cases of malignant cancer occurring each year across the whole population is 1 in 182, but that translates into the expectation that indeed around one in two people will be diagnosed with cancer in the course of their lives23. If by a cancer ‘rate’ of 1 in 100 Jones means that ‘not that long ago’ only 1 in 100 people got cancer at any point in their lives (compared to the 1 in 2 today) I’d like to know how long ago that was. It would certainly be much longer ago than the 20th century, and the problem is that when you go back that far there are lots of other causes of morbidity – infectious disease and accidents, for example – that confound the attempt to make inferences about cancer aetiologies from rate changes. The fact that cancer incidence in pre-modern populations was low doesn’t necessarily mean that carcinogenicity in those times was concomitantly low (though that might be the case).

The difficulties of inferring changing carcinogenicity from historic incidence rates are compounded by changing age structures. The population now has a larger proportion of older people than before, and since the incidence of cancer is strongly associated with age, a good deal of the increase in cancer rates is purely an artefact of the ageing population. Meanwhile, cancer incidence is currently reducing in many ‘developed’ countries24 – though as a result of complex, multifactorial influences that push in different directions. So the straightforward answer to Jones’s question – isn’t the secular increase in cancer rates telling us something about toxins in the food chain? – is no, you just can’t infer that. That doesn’t mean she’s necessarily wrong. For all I know, it could be true that there’s a declining intake of micronutrients (or an increase in toxins – Jones seems a bit unclear on this point) with a positive effect on cancer incidence. Though if the finger of suspicion is pointing specifically at the decline of soil food webs, I’d observe that tillage agriculture has been the norm in many places for a long time, so the link between increased cancer incidence today and the destruction of soil food webs seems questionable. In any case, what’s clear is that the evidence Jones cites in support of her ‘toxins in the food chain’ view doesn’t in fact support it. There does seem to be evidence linking high dietary intakes of heavily processed food with raised cancer incidence25. Given current dietary patterns, adopting a diverse diet of fresh, unprocessed food may yield more health dividends than a switch to a regen-ag diet.

I’ve dwelt at some length on this rather abstruse cancer issue partly because I think it’s bad intellectual practice to justify an assertion in relation to evidence that doesn’t actually support it, and also because I think sloppiness of this order will easily torpedo the RAPs’ claims about the evidential base for regenerative agriculture more generally as they try to build wider support for regen-ag – and that would be a shame.

I think the health claims for regen-ag currently have to get red light status – though that may change in the future. I find it plausible that numerous aspects of our present food system may be associated with increased cancer incidence. It’s just that I haven’t (yet) seen any plausible evidence linking regen-ag practices to reduced cancer incidence.


I won’t try to summarise what I’ve said above. All in all, my traffic light assessment of the RAPs’ claims suggests to me a few greens, rather more reds, and a lot of ambers. There are numerous reasons why moving towards a regen-ag approach and sequestering some carbon in soils probably makes sense, but there’s a distinct lack of convincing empirical evidence to support many of the stronger claims made by the RAPs. For now, I feel like I’m waiting on amber.

Note: My thanks to Don Stewart for prompting this line of enquiry and to Clem Weidenbenner for an informative discussion.

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  1. David Johnson
  2. Eg. http://www.pnas.org/content/104/33/13268.short
  3. Eg. https://thecontraryfarmer.wordpress.com/2010/06/16/no-till-is-a-big-white-lie/
  4. Eg. http://www.cornandsoybeandigest.com/conservation/take-soil-and-farm-beyond-conservation; for a discussion of this among British farmers, see https://anewnatureblog.wordpress.com/2017/10/30/thoughts-on-the-glyphosate-saga/ 
  5. https://www.ncat.org/wp-content/uploads/2015/08/Acres-story-for-web-posting-March15_Jones.pdf
  6. V. Smil. 2017. Energy and Civilization, MIT Press, p.308; V. Smil. 2001. Enriching the Earth. MIT Press.
  7. David Johnson
  8. Disclosure: I once vehemently and obtusely sought to deny this point in an online discussion with an Australian scientist whose name now escapes me. Sorry, sir – I was wrong.
  9. E. Ingham. 2015. Presentation at Canadian Organic Growers’ Conference, Toronto, Feb 2015.
  10. https://www.ncat.org/wp-content/uploads/2015/08/Acres-story-for-web-posting-March15_Jones.pdf
  11. https://www.ers.usda.gov/data-products/wheat-data/
  12. David Johnson
  13. Gail FullerJ. Baker et al. 2007. Tillage and soil carbon sequestration – what do we really know? Agriculture, Ecosystems & Environment. 118: 1-5; Z. Luo et al. 2010. Can no tillage stimulate carbon sequestration in agricultural soils? Agriculture, Ecosystems & Environment. 139: 224-231.
  14. P. Rochette. 2008. No-till only increases N2O emissions in poorly-aerated soils. Soil & Tillage Research. 101, 1-2: 97-100.
  15. S. Singh. 2009. Climate Change and Crops; DEFRA (2007). The effects of reduced tillage practices and organic material additions on the carbon content of arable soils.
  16. IPCC; CGIAR; Singh, Ibid.
  17. S. Fairlie. 2010. Meat. Permanent Publications; Rafter Sass Ferguson.
  18. George Monbiot; D. Briske et al.
  19. M. Fan et al. 2008. Evidence of decreasing mineral density in wheat grain over the last 160 years. Journal of Trace Elements in Medicine and Biology. 22, 4: 315-24; F. Denison. 2010. Darwinian Agriculture. Princeton UP.
  20. https://www.ncat.org/wp-content/uploads/2015/08/Acres-story-for-web-posting-March15_Jones.pdfI’m not sure which country’s rates Jones is referring to. I’m most familiar with UK data, so I’ve used that – I doubt the conclusions I draw here would be radically different if data were used from other ‘developed’ countries.
  21. https://www.cancerdata.nhs.uk
  22. A. Jemal et al
  23. https://www.theguardian.com/science/2018/feb/14/ultra-processed-foods-may-be-linked-to-cancer-says-study

97 thoughts on “Waiting on amber: a note on regenerative agriculture and carbon farming

  1. I would love it you would give Holistic Grazing the same treatment. My parents land is sandy and dry, so I am curious what realistic results would be.

  2. Chris, you beat me to this. I’ve been working on a review of regenerative ag for a while, and more actively last week. You’ve hit many of the points I was going to make, and since our respective audiences probably do not overlap, I plan to finish my essay on this.

    I start near the place you ended. The goals and some proven practices are fine, it’s the claims that make me roll my eyes; extraordinary claims require extraordinary evidence, and far from extraordinary, the evidence is weak.

  3. Chris, I think you raised most of the pertinent point of skepticism, and I think I stand very close to your views. I do think that the renag movement brings in a lot of nice perspectives, just as the permaculture movement, in particular I like the attention to soil microbiota and root zone activity as well as the renag grazing ideas.

    While I totally agree with you on the danger of overstating the possibility to sequester carbon in soils, I would not agree with the notion that carbon sequestration necessarily will stop when reaching a new “equilibrium”. I have looked quite a lot into loads of studies on carbon in soils and very few of them would have the quality and scope to allow us any such conclusions. Most “carbon” studies were actually not carbon studies but measuring soil organic matter as an indicator of soil fertility. But those are quite different stories – also the renag proponents go into this trap.
    SOM measurements are mostly in 0-30 cm top layer or sometimes even in 0-10 cm top. It is quite obvious btw that if you let all organic matter on the top instead of plowing down you will bet more organic matter in 0-10cm btw. But what matters for long term carbon sequestration is carbon deeper down, which is a lot more stable.

    In addition the meaurement of carbon in a certain layer disregards the fact that soild also grow “higher” and “deeper”. It grows “higher” through the accumulation of new material on top, dust that blows in and organic material that accumulates. And it grows deeper by the roots of plants You can very well have a constant 5% SOM content of your 0-30 cm top soil while you accumulate large quantities of carbon by making the whole soil layer thicker.

    After all, those very fertile deep soils we all want to farm have had loads of carbon all way down to the bedrock,and they all started out as gravel or rock. In Sweden we have organogenic soils which can be several meters thick. And what happens when you grow on them is that top 0-30 cm continues to be very high in carbon, but the soil gradually shrinks, so that many such soils loose 1 cm per year, not through wind or water erosion but through oxidation of carbon. Our peat bogs are growing and growing to many meters thickness, while they will have the same carbon content in the upper layer all the time.

    So it is certainly both theoretically and empirically to have “eternal” carbon sequestration, to have it on tilled land is of course quite another story.

    Finally, there is actually yet one more way carbon can be sequestered in soils, or rather “through” soils. That is by becoming disolved organic carbon, which may end up in lakes or the ocean and is a major carbon pool. Just an example of research on that:

  4. Synthetic fertilizers have been tremendously important for the developmen of industrial farming, but I would not agree with the Smilish assertion that they have fed a certain proportion of the world’s population. All things equal it might be correct, if you take the existing system and just pull them out, yields drop etc, we all know it.
    But in dynamic systems you can never change one thing only (as Hardin stated) The introduction of synthertic fertilizers have shaped the current food system by disintegrating livestock and crop farming, by allowing us to flush human effluents into the seas and in general waste nitrogen – with precarious results. But a food system without them would have looked different, would have less chicken and pigs, more ruminants, less waste and proper nutrient cycles.

  5. Thanks for the comments.

    Ruben – the references under note 19 are a starting point on holistic grazing. And Simon Fairlie in the latest issue of The Land magazine. Maybe I’ll try to write something about it some time. I gave up on it with my sheep. Too much faff.

    Andy – thanks for that, I hope you’ll send me a link to your piece when you finish it. I’d be interested in any further thoughts you have – in particular on Gunnar’s points about soil carbon, and on the point about soil micronutrients.

    Gunnar – thanks for that. I lack the expertise to comment on your point about the possibility of eternal sequestration. It sounds plausible, though even if it is it doesn’t necessarily negate my wider point about the problems of assuming that the natural carbon cycle can absorb all the anthropogenic carbon, no? I agree with your remarks about fertiliser and the shape of the food system, which are nicely put. I guess I’d just say that currently we are where we are, and I’m not yet convinced by the strong regen-ag argument that plant growth is worse with synthetic fertiliser. Like you, I’d like to see us moving away from synthetic fertilisers and towards as fully organic an agronomy as possible…but I’d still be a bit cautious about dismissing synthetic fertiliser altogether at present until we’re a bit more up to speed on the alternatives.

  6. Sure, I am as critical as you are to the statements that we can go on with BAU and just suck up that carbon in the soils (which is even stronger expressed by the proponents of Holistic Management). I gives dangerous excuses for not curbing emissions and continued combustion of fossils. First step is of course the stop the continued loss of carbon from farming….

    Another interesting point is C-N relationships. This recent study in Nature supposedly shows that C sequestration will be offset by N20 emissions. But it is all modelling and I don’t assign much value to models as they are just proving the assumptions made to begin with. https://www.nature.com/articles/s41558-018-0087-z Similarly, conventional ag proponents claim that N-fertilisers help build carbon in soils, but in my view they seem to help carbon to be oxidised instead. Overall I think we still have a lot to learn…..and keep an open, but skeptical, mind.

  7. Chris, a few more remarks.

    I think you are right in bringing up the eventual equilibrium of soil organic matter/C in soils. Equilibrium levels exist and once you get there, it is very hard to store more C in SOM. As far as deep C and dissolved C, I think the story is still murky. If they are stable, and natural processes have been building them up for millennia, they could also be saturated (at an equilibrium level). Also, both deep and dissolved C may store additional C (how much compared to surface SOM is not clear to me) this is very different from regenerating soil. Gunnar’s peat soils are only formed in specific conditions, and cannot be generalized.

    Then there are the nutrient requirements of increasing soil organic matter which are substantial. I will cover this aspect in my review of regen. ag.

  8. Of course soils can be saturated and of course there can be equilibrium levels for each situation. And it is true that peat soils can’t be generalized, no soils are the same, they are formed by the conditions where they are. By giving peat soils as an example I just proved the point that it is not inevitable that there is saturation or new equilibrium, at least on the time scales we are interested in, that is thousand years or so. Similarly my understanding is that many of the most fertile soils have been building up for ages, becoming deeper and deeper as time goes. That also seems to be a “perpetual” carbon sequestration. Finally, research show that deep down the carbon can be thousands years old.

    So there is indeed a big difference between SOM as normally discussed and long-term sequesterd carbon (terra preta is of course another case in point, but I will not go there now). I think that difference also is very important when discussing the nutrient requirements. It is not apparent that they are the same for long term carbon sequestration as for building what we normally call SOM. My understanding is that the C/N ratio of stable humus is a lot lower than for the younger organic matter, and in addition that by adding N you can actually contribute to the break down of organic matter as much as the build up of new matter.

  9. Dear Chris
    David Johnson, Christine Jones, Gabe Brown, and the Kaisers (and everyone else exploring these general subjects) have different ideas, experiences, and agendas. In addition, all of them suffer from lack of funding. For example, David Johnson started out just trying to find some way to use heavily polluted dairy manure. That project morphed into trying to figure out a way to make money with carbon farming. Which morphed into his current effort which involves both making money with regular farming as well as carbon farming as well as ecological concerns.

    First point. None of the people I listed are ‘certified organic’. David Johnson presents statistics which show that ‘organic’ farming as currently practiced generates lower yields and marginally (at best) better results in terms of soil health. (Lack of pesticides in food and lack of pesticides poisoning insects and animals are a different subject.)

    David Johnson is not no-till. He uses disking between crops. But he keeps surface litter to preserve fungal life and to provide nutrient breakdown for the next crop. Gabe Brown claims that one advantage of farming in North Dakota is that the winters reliably kill cover crops…which is not true in North Carolina. David Johnson has read the same soil science reports that Elaine Ingham has read in terms of the potential nutrients available in soil (as opposed to the soluble nutrients available for immediate use). The fungi are the mechanism to turn potential into available. David has been cropping and removing everything from his ‘desert plot’ now for 7 years and yields have continued to increase. So for 7 years, there is no sign of nutrient depletion.

    But let’s step back for a moment to question whether this whole enterprise, regardless of the specific mechanisms in use in New Mexico or North Dakota or Australia, makes any sense biologically. Antonio Damasio, an honored scientist at Southern California University, has just published The Strange Order of Things: Life, Feeling, and the Making of Cultures. His argument is that homeostasis is the principle which has guided life from single celled critters up to human cultures. On page 51 he says:

    “I have greater sympathy for another term, ‘homeodynamics’ coined by Miguel Aon and David Lloyd. Homeodynamic systems, as is certainly the case with living systems, self-organize their operations when they lose stability. At those bifurcation points, they exhibit complex behaviors with emergent characteristics such as bistable switches, thresholds, waves, gradients, and dynamic molecular rearrangements.”

    What Johnson seems to have discovered, perhaps unwittingly, is that as the fungi available for symbiotic relationship increase, the plants exhibit the homeodynamic reactions that Aon and Lloyd were examining. For example, the dynamic apportionment of energy into exudates and plant biomass and fruits changes dramatically. The plant is exhibiting homeostasis (or homeodynamics, if you prefer that word). I suspect that Johnson could not get his paper published because one of the reviewers does not believe plants have the ability to act homeodynamically.

    Johnson is building on a long history of agriculture in terms of the amount of water he supplies, the technology of killing a crop or weeds, and so forth But the long history of agriculture has mostly not known or cared about fungi. When Johnson takes care of the fungi, then the plant becomes much more homeodynamically adept and lots of things work better. This should not surprise us as plants and fungi moved onto the land together and co-evolved.

    Christine Jones was asked whether she agreed that inoculating with fungi was a necessary step. She replied that she did not think so…a cover crop and appropriate farming practices were enough. She added that ‘tillage is not as damaging as we once thought, provided the tillage doesn’t destroy the fungi’. (Whether Johnson’s ‘desert sand’ plot needs inoculation is a different question.)

    One of Christine’s case studies is a wheat farm in arid western Australia. The conventional wisdom was that the land needed to be bare to conserve water for the wheat. One family began to let literal weeds grow between wheat crops. They were shunned by the neighbors and the Ag School predicted disaster. Instead, they are harvesting excellent crops by volume and the BRIX score is in the mid-20s in a region where BRIX scores of 2 or 3 are common. The weight of the wheat is such that they have to reduce the volume hauled in trucks to stay within load limits on the highway.

    Last week I heard a report from a young corn and animal farmer in North Carolina. He uses minimum soil disturbance with cover crops. He has stopped using glyphosate (because he doesn’t want to die young). He had the best yields for non-irrigated corn in the United States last year (only 2 bushels less than the irrigated champion), and his BRIX scores are in the 20s. There were lots of jokes in the meeting about the scores of ‘California Organics’ with BRIX scores of 4 or 5.

    David Johnson, operating on a financial shoestring and having a hard time getting funding, has demonstrated that he can grow cotton and peppers (both cash crops in New Mexico) on irrigated land with just an initial inoculation of spores….even in desert sand. He has graphically shown the difference in soil quality in his plot as compared to neighboring plots of Ag School land. He has demonstrated that, for a few months, growing a non-mycorrhizal plant does not fatally damage the fungal network in the soil.

    Christine Jones has lots of evidence that carbon rich soils many feet deep can be grown in Australia while producing grains and animals.

    The young North Carolina farmer has shown that he can cut the cost of inputs drastically and still produce high volume and high BRIX crops.

    The connection between BRIX and pests and weeds hasn’t gotten a lot of attention, so far as I know. However, the farmers who do pay attention to BRIX seem to agree that chewing insects can’t deal with the complex sugars, and go elsewhere. The rate of complex sugar formation is such that the vulnerable stage in the plant is very short. My experience is also that weeds have a harder time germinating in rich soils. It takes rich soils to produce high BRIX.

    Brown, Jones, and Johnson are all mostly interested in broad-acre crops grown on medium sized to huge farms and ranches. (Although Johnson will brag on his fungally nourished tomatoes.) The Kaiser’s are in a very different business and they are farming different plants….mostly non-mycorrhizal. What they are doing is the Parisian market gardeners or the Asian ‘Farmers of 40 Centuries’ updated. If fossil fuels go away, the Kaisers and similarly situated farmers will doubtless be required to move backward in time to the Parisians or perhaps the Asians. These crops are low calorie and mostly quite perishable. They are not at all like 5000 acres of wheat.

    As for the ultimate potential of carbon sequestration. David Johnson contrasts the ‘official’ statistics for carbon sequestration potential with his observed results. Yet when the New York Times writes articles, they ignore the outliers and only quote the official numbers…none of which used fungal friendly methods. In his talk at Chico, CA, David said ‘there is probably a limit to how much carbon we can store in an acre, but there is a practically unlimited supply of degraded acres’. We do have evidence from 150 years ago that soil organic matter content in Australia and the Canadian prairies was regularly in the 20s. I suspect that a concerted effort to take emissions and store them in the soil would work. However, the oceans and the atmosphere are a dynamic system, and dissolved carbon might come back out of the oceans…something I do not believe David considered. The legacy emissions may not be a trivial matter.

    Don Stewart

  10. Chris
    I would like to respond separately to the chronic disease and nutrient density argument.

    The health of the plant and the health of the human are related by very fundamental processes. My previous quotation from Damasio, and the bulk of Damasio’s book make this plain. So a fundamental assumption that I, an amateur, would make is that the factors which give a plant health (as measured, perhaps, by BRIX) are also likely to make the plant a healthy food source for humans and other animals.

    Now, figuring out just exactly what factors have led to the explosion of chronic diseases around the globe reminds me of a British whodunnit. There is a drawing room in a manor house, stuffed with people, every single one of whom had the motive and the means for committing the murder. The detective, using all his wits, finally reduces the number of suspects to one.

    We certainly know that there are multiple suspects. We know that stress is a fundamental factor in chronic disease, and we know that the stress can result from toxins in the air and water and food, or from mental and social stress, or from overwork, or from malnutrition resulting from a diet poor in nutrients. (We also know from the detailed study of metabolic pathways that micronutrients can play an outsized role in terms of turning food into nutrients.)

    The internet abounds with people who have recovered from desperate straights, each of whom typically has identified one of the suspects and the antidote as the source of their healing. Christine Jones experienced cancer and an autoimmune disease, she recovered, and she credits nutrient dense food. Who am I to say she is wrong?

    Don Stewart

  11. Thanks for your comments, Don. I’m quite prepared to accept that my ambers may at some point turn to green, but your comments don’t suggest to me that I got anything fundamentally wrong in my essay above.

    The kind of thing that’ll convince me the RAPs are right is quantified, long-term yield data along with other good input-output and agronomic data. So your examples from Western Australia and South Carolina are a start, but I’d rather know the yield in tonnes per hectare than learn that they have to reduce the volume hauled in trucks to stay within load limits on the highway.

    The kind of thing that probably won’t convince me is arguments from the general to the particular, as in invoking Damasio on homeodynamics and inferring that this is a generic property of life at all organisational levels. Even if that’s true (and here I think I’m more with Denison than Damasio) and plants apportion energy ‘homeodynamically’ in different ways across their structures in symbiosis with fungi (though I’m not really sure why homeodynamism is a necessary concept there), presumably nobody’s arguing that new matter or energy is being created. So while it may be true that there was no sign of nutrient depletion in Johnson’s desert plot for 7 years, that doesn’t mean that there’s no nutrient depletion – indeed if he’s taking crops off, I find it hard to imagine things could be otherwise (except with C, N and O), though the rate of depletion of course will depend on the crop. Maybe someone else can arbitrate on this one?

    On pests and weeds, doubtless it’s true that quick-growing plants are less vulnerable – but most people (the Kaisers, for example) still seem to find a need to invest in crop protection – the kind of plants we grow are inherently quite vulnerable. My experience of weeds is the opposite to yours – rich soils are a favourite, which is kind of what you’d expect from plant ecology.

    On health, I’m happy to go with your manor house whodunit analogy – all I’d add is first check that it IS a manor house and not an old people’s home, as you may find a mortality rate that’s suspicious in the former is less surprising in the latter. And second, feel free to harbour whatever theories you like, but if you publicly name a suspect on the basis of evidence that doesn’t actually incriminate them, then expect criticism. A problem with both Jones and Johnson is that some of their inferences are very slapdash, which diminishes their credibility. So, as I said above, there’s a danger here of the regen-ag movement undermining itself and its claims, some of which may be entirely valid.

    My ‘nitrogen is nitrogen’ remark was referring to human health, not plant uptake, but thanks for that interesting phosphate paper. I’m sure it’s true that plant and human health are related. I suspect proponents of conventional agriculture might argue that plant health is less compromised under their favoured regimens than is often supposed – I have no particular skin in that game, but I’m not sure that there’s strong evidence as yet to refute them. My hunch is that we’ll start seeing more evidence of pesticide problems and micronutrient deficiencies in human health – soil food web deficiencies, I’m not so sure.

  12. Chris
    *All the ‘RAPs’ are not alike, so trying to criticize them as a group doesn’t make much sense for a farmer who thinks it is going to be a struggle to survive. We should be looking for clues where we can find them.
    *There is sound scientific evidence that there is a great deal of potential plant nutrients in virtually all the soils in the world. Both Elaine Ingham and David Johnson refer to that science.
    *Ingham has not, in the past, been very clear about how the potential gets activated. Johnson is pretty clear that it happens when the ancient symbiosis between plants and fungi is reactivated. It makes ecological sense, it can be demonstrated.
    *As for nitrogen, Johnson seemed somewhat shocked about all the nitrogen his plants could access, in the absence of ‘nitrogen fixing’ plants. But Rick Haney with the USDA in Texas has long had a soil test which measures the amount of nitrogen fixed by bacteria associated with ‘non- nitrogen fixing plants’. The North Carolina farmer uses the Haney test, and finds that he needs to add much less nitrogen than the Ag School test.

    The North Carolina farmer, who is making money when most of his neighbors are not, advises people to ‘experiment…plant a test strip’. Your advice, as I understand it, is ‘do nothing until someone else proves it beyond a shadow of a doubt’.

    Don Stewart

  13. >Your advice, as I understand it, is ‘do nothing until someone else proves it beyond a shadow of a doubt’.

    Nope, my advice (if anyone asked for it) would likewise be to experiment. But it would also be not to make extravagant claims about the superiority of your approach until you have solid evidence to back it up – and to be aware of the trade-offs it involves

    On the differences among the RAPs, well no doubt – though there are substantial similarities in approach of the people I mention above, and they often cross-refer. Similarly, organic farmers are not all alike, but share commonalities – enough to be the butt of jokes and disdain in your comment above?

    Actually, both these points touch on the question of farming as a ‘system’, which I plan to look at in my next post.

  14. Chris
    Responding separately again on the health issue.

    I suggest that the cutting edge of age related medicine is currently on view in this video:

    The interviewer states (as I said in my previous note) that inflammation is at the base of virtually all chronic disease. Valter Longo disputes that and says that he believes the causation is the reverse. Aging and deteriorating organs are the cause of the inflammation. So inflammation is a marker and not a cause.

    So….what can we do to repair damaged organs? Longo says that periodic starvation is the key treatment. The average westerner can live for 60 days without food. The body, faced with a shortage of food, begins to kill off cells. The liver, for example, literally shrinks. Then, during the refeeding process, new organ cells are created rapidly. In effect, we have subtracted years from our age. Longo has a particular ‘fast mimicking diet’ which he is triaiing, to make the idea of starvation less daunting for the public. You can find lots of references to this on the internet.

    Now, let me pose a question. Suppose during the refeeding process, a person eats
    *junk food from fast food outlets
    or *nutrient poor whole foods from the local conventional farm
    or *nutrient poor whole foods from the local organic farm
    or *nutrient dense whole foods from a farm which is able to generate very high BRIX scores

    Given that the scientific tests have not yet been done, how would you place your bets?

    You will also, perhaps, be interested in Longo’s explanation for why fasting in conjunction with chemotherapy works so well. I’ll paraphrase. Fasting generates a lot of tough little slum kids, who are not phased by the chemo…they’ve seen worse. But the pampered rich kids, the cancer cells stuffed with sugar, are unaccustomed to challenges and quickly die. The body then repopulates from the tough slum kids, who don’t have the cancer.

    There is a new test for cancer which can detect cancerous cells before there is a tumor. I’m not an expert on this, so take the following with a grain of salt. The test detects cancer in about 40 percent of westerners of middle age. But the same test, when applied to a tribe of hunters and gatherers detects virtually no cancer. Is the difference because the hunters and gatherers eat more natural foods and get more exercise, or because the hunters and gatherers inevitably go through days of starvation, or both?

    Don Stewart

    • Have been preoccupied elsewhere so I may have missed it Don, but could I trouble you for some background on the BRIX measurement you are referring to?

      • Clem
        BRIX is a measure of the sugars in a liquid. Technically, a BRIX meter is a refractometer. For example, if you are making wine from grapes, you need to know that the sugar concentration in the grapes is sufficient to generate the alcohol required to convert to wine. In terms of leafy greens, a high BRIX implies that metabolism is firing on all cylinders and complete proteins are being made efficiently. A low BRIX implies the opposite.

        There is in the United States an organization dedicated to promoting high nutrient foods, as opposed to corporately defined ‘organically certified’ foods. They are supposedly going to come out with a smart phone app which the consumer can point at produce in the supermarket and get a reading. I don’t know any details, but I haven’t received any straight answers about whether it will be better than a BRIX reading. But a BRIX reading requires you to squeeze a drop of juice, which I guess the smart phone app would not.

        An analog meter can be had for about 25 US dollars, while a digital readout meter will cost a little over a hundred dollars.

        Don Stewart

        • Bionutrient Food Association, in conjunction with the Real Food Campaign, states that they are making a hand held bionutrient meter available to consumers. Info on product through BFA. Discussion and forums available, (as was this thread) through the Real Food Campaign. I don’t find the promotion of arguments for skepticism and the method of “amber lighting” to be helpful at this stage. I’m leaving this computer and taking out my compost. My garden, worms, SOM, and the microbiota are calling me. “Green light, GO!”

          • Fair enough, the world isn’t short of people who seem sure that they know exactly what the microbiota are calling to them. For my part, this certainty seems suspect and I think some of them will turn out to be wrong. But I’m all in favor of people getting on with whatever they think they should be getting on with. It’s the way we learn. Still, IMO there’s always something to be said for a bit of humility about the claims we make for our preferred approaches.

    • Thanks. That’s quite interesting. Cancer aetiologies are something that perhaps I’ll examine another time. My main focus in this post was really just the issues that arise with careless use of population health data.

  15. Hi Chris, great article! I’d like to say say, as a small scale veg and seed farmer, that I have wrestled with the no-till dilemma for years.

    There is no doubt for me that, for the most part, no-till is better for the soil, though it’s not necessarily the best way to grow all crops in my area (Pacific Northwest).

    The problem with no-till is that anything beyond a garden scale requires such vast amounts of mulching matierial— compost, leaves, whatever— to be trucked in that any carbon sequestration in the soil from no-tilling must surely be negated by tailgate emissions and also from the industrial composting facilities that use large excavators to mix, turn, and load the compost. Or the compost is made by large composters powered by the grid.

    I’m not aware of any study that measures this, but Micheal Pollan in his book, “Omnivores Dilemma” talks about this issue in large scale organic gardening.

    Finally, places like Singing Frogs Farm, which exist at an extreme end of a till— notill spectrum, have no more of a future than conventional ag as they are completely dependent on fossil fuels for their survival.

    • Hi Sal, thanks for commenting. Yes, I’d go along with all of that. The only really plausible way I see of generalising no till cropping is by generalising farming – hence the title of this blog! Most horticultural no tillers seem to go down the ‘French intensive’ route, which in the modern economy is a fossil fuel intensive one. The alternative is the ‘farmer’s of 40 centuries’ route – but in that scenario, I doubt they’d find themselves growing a lot of salads and selling them off for big bucks.

  16. Chris
    By ‘fertile soil’ I mean well hydrated, high fungal to bacterial ratio, lots of organic matter. I did NOT mean ‘lots of free nitrogen’.

    Free nitrogen definitely promotes weeds. If we accept Rick Haney’s measurements of the nitrogen required by a crop of corn, and as compared to the nitrogen required by Ag School measurements, we can see that farmers are purchasing lots of excess nitrogen in order to promote weeds. Which have to be killed with herbicides, or hoed by hand, And which washes down the rivers anyway. Creating dead zones.

    Don Stewart

    • OK, so I guess the agricultural situation we’re talking about here would be an established no till system. My feeling is that these systems have fewer weed problems mostly because they’re not constantly unearthing dormant weed seeds (and because on horticultural scales they mostly use clean, industrial compost), but it seems to me that new weeds seed in just as well as on other bare ground – hence, perhaps, the meticulousness of the Kaisers in their cover-cropping regimen to prevent weed ingress.

      Agreed, over-nitrifying the ground isn’t a good idea, and there are big problems with eutrophication caused by agriculture. Presumably a thoughtful conventional farmer might argue that if they get the amount and timing of the fertilisation right the problem can be minimised. But agreed, agriculture in general doesn’t seem to be doing a good job.

      I’d welcome any other views on these issues.

      • It’s interesting to note that many of the more loftily worded theories floating around are based on the work of William Albrecht.
        Who had very precise ideas about chemical elements that need to be present in certain quantities and ratios, to be replaced by man if need be.
        And who regarded a naturally ocurring monoculture not as an abnormality, but as a sign of optimal nutrition.

        • But monocultures are only really seen when conditions are so extreme that only one specialist species can grow there. In all other cases those optimal conditions tend not to persist long enough for one species to outcompete all others.

          • …or in Grime’s terms, when conditions are highly productive and a competitor organism gets to the scene first and is able to dominate it…but usually not for all that long?

          • Definition of monoculture would be important here. Is a conifer forest in northern latitudes with stands of single tree species a monoculture? Would you include coniferous northern latitude forests in the extreme conditions category? And you get callitris stands in some parts of Australia that don’t have any other tree species. I’m not sure if low-rainfall areas near Wilpena Pound north of Adelaide qualify as extreme conditions. Although to you soft folks from the soggy northern hemisphere they might look a bit that way 🙂

          • Addendum:
            Chris, do you remember than figure I cited of 9 heating calories to 1 eating calorie?
            If we assume that you can’t effectively use every bit of a woody plant for heating, there’ll always be smaller, compostable debris anyway.
            If we expand on this, we’d need a calculation of what that ratio would look like if we allowed for the carbon demands of both heating and intensive vegetable production to be covered by what’s produced on a piece of land. (Of course, planting more fruit trees and shrubs will provide a measure of food as well.)
            You’d end up with the largest part devoted to wood fuel and thereby tree crops, too. Pasture underneath would automatically profit from the agroecological synergies, though fuel production would take precedence.
            And then a percentage of that carbon would be used for vegetable production.
            Once you need to balance all these factors locally, it’ll be a pretty precise ratio for each place on earth.

          • Thanks for that Michael – interesting looking paper, which seems to push in a different direction to the origins of cereal agroecosystems approach I took in my perennial grains paper. I’ll have to read it properly and think about it.

            Heating vs eating (plus composting) calories is an interesting perspective. I’ll have to go back to Wessex analysis and take another look at it. Though I think the outcome would be quite sobering in terms of ‘carrying capacity’. Could we retain a post fossil fuel rock wool industry? Or sheep wool? Hmmm…

          • It would certainly put the ‘Whole’ back into ‘Whole Farm Planning’.

            On my own property, I’ve been planning – and thanks for making me spell this out properly – for all C and N to be fixed on-site, by design.
            That would be part of my Holistic Context, and I’ve only finished that energy flow puzzle recently.

            C and N alone will structure a landscape, which I think is a good thing. I still remember the first time I looked at the Somerset countryside from a landing plane and simply couldn’t believe the intricacy and beauty of it.

            The one thing the Wessex people will have to do better than most who came before them (in this part of the world) is to find an worthy analouge of all the myths, songs and tales that have managed to enscribe ‘carrying capacity’ into the collective memory.

    • Thanks for the link Don.

      I’ve dealt with Brix before – measuring light diffraction in a liquid (most often water)… even have a refractometer in the lab, so was wondering if your use was pointing to the same thing. Appears it might be. But the wheels started coming off when I saw the refractive index chart at the link you provided. It was originally developed by Carey Reams. Carey was special:

      Carey Reams is known for his alternative biophysical notions and concomitant alternative health advice. He claimed to have six doctorates, including some sort of medical degree from someplace in England, but he claimed he was not a medical doctor. He also denied that he posed as one, yet in 1976 he was arrested and convicted of practicing medicine without a license in the state of Georgia. He considered most medical drugs, all radiation, and most surgery harmful to health, preferring instead treatments such as Norwegian fjord kelp for brain tumors and cataracts.
      In 1931 during a period of prayer and fasting, Reams received a divine revelation of the biochemistry numbers for perfect human health: 1.5, 6.4, 6.4, 7, 1, 3, 3.

      From the link:

      Not going to suggest that everything at the Bionutrient Food Association is suspect – haven’t dug into other aspects yet. But the Brix discussion has some explaining to do.

      • There’s a whole industry based around BRIX, various versions of Albrecht’s ideas, potions etc for farmers. I’ve sat through various presentations at field days folks selling expensive products of this nature. Usually with some kind of gloss using terms from soil science and/or in touch with energies outside the ken of the common ruck. My experience is that when asked for data from independent control trials or well-run vernacular case studies these folks go into bluster mode/avoid the questions/disparage reductionist science/state the soil is so damaged from conventional agriculture that the treatment hasn’t worked yet etc

        Having said that, innoculants are useful in situations such as introducing clover to land that hasn’t seen clover for a while or planting trees with nitrogen fixing nodules like black locust (Robinia pseudoacia) in land that hasn’t seen this species. And FWIW I think there is something to the stance taken by permies regarding reductionist science as against a more systems approach. I’ve spent my working life building systems, designing systems, testing systems, using systems and so on. While going reductionist is essential at times, achieving a quality outcome is usually facilitated in my experience through broader consideration. I like the systems approach Dominique Hes is developing:


  17. “fungi are able […] to sequester carbon by absorbing carbon dioxide from the air”
    No they’re not. They are heterotrophs. I think this matters because it means they are subject to trophic losses just as agricultural animals are. Net land primary production is about 50 Pg C/y, and typically about 10% gets transferred up each trophic level. So even if fungi were to process 100% of primary production (which implies no other heterotrophs, including ourselves) then they would still be unable to keep up with current anthropogenic carbon emissions of 10 Pg C/y.

    • Dammit, you’re right! I knew they were heterotrophs…honest! That’s the second embarrassing blunder you’ve picked me up on in about a year…but luckily only committed quietly here on this insignificant blog. Well now, you’ve prompted me to spend a while reading abstracts of research papers on soil C sequestration, but without nailing the issue of trophic loss as emphatically as you do in your comment. Any other views on this? It seems hard to fault your logic, assuming your starting figures are correct and that fungi follow the same trophic rule. Can you cite a handy source for your figures on C sources? I’m feeling quite a way away from my disciplinary comfort zone on this one…

  18. Chris
    I think you are characterizing a group of people as ‘no till’, when in fact that word does not apply to all of them. As I said before, David Johnson is NOT no till.

    David’s basic point is to raise the F:B ratio from its current abysmal state in most agricultural land in at least the United States. So the farmer does whatever combination of ingredients gets him to a higher F:B ratio. That MIGHT include no till, but not necessarily. It probably CANNOT include repeated turning of the soil. But ‘light’ tillage, perhaps the disking that Johnson uses, does not destroy the fungi.

    In order to keep fungal numbers up, one may choose among several options:
    *Inoculate soil or planting furrow with spores (perhaps grown in Johnson’s BioDigester)
    *Inoculate seeds with spores when they are planted. (Johnson uses a mixture of milk and molasses to adhere the spores to the seeds)
    *Use litter containing fungi from the previous crop laying on the ground for up to a few weeks
    *Use a legacy fungal network which has had mycorrhizal friendly plants growing with no more than, perhaps, a 3 month gap

    So long as the roots can make contact with mycorrhizae within a short period of time, the fungi will act as a multiplier of the root system by perhaps a factor of 10 in terms of scavenging nutrients. Fungi can make acids which can retrieve nutrients that the plant itself could not retrieve.

    The point of the article I pointed you to reflects the fact that the photosynthesizing plant makes carbon which it trades to the fungi in return for the scavenged nutrients. Fungi cannot make carbon using photosynthesis. So there is a symbiotic ecological economy operating. The plants can direct the fungi to collect certain nutrients that they have in short supply. When a farmer applies phosphate directly to the field, the plant tends not to feed the fungi, since it does not detect a shortage of phosphorus. Besides costing money for something which would have been supplied for free, other things go wrong due to lack of fungi.

    Don Stewart

  19. Two more ways to get fungi started:
    *If you are starting transplants in a greenhouse, inoculate the potting medium
    *If you have even a few mycorrhizal fungi in the soil, or viable spores, then using cover crops and good horticultural practice may build up from the existing fungi. This is the method that Christine Jones recommends as a first choice.

    Don Stewart

  20. I doubt that any kind of agriculture can remediate more than a relatively small fraction of the excess CO2 released into the atmosphere by the burning of fossil fuels. Agriculture, indeed any form of land surface vegetation or soil carbon formed in aerobic conditions is part of the fast carbon cycle. Fossil fuels are part of the slow carbon cycle, more akin to limestone or weathered silicates than plant or fungal life above or below the land surface.

    In pre-agricultural times, the fast carbon cycle was little affected by humans. At the beginning of the Holocene the biomass on land and in the oceans had reached an equilibrium that was unchanged by human activity. I think it would be accurate to say that the earth’s surface was ‘saturated’ with fast cycle carbon. The diminishment of the ice sheets after the last ice age allowed the beginning of the slow carbon sequestration cycle by exposing more rock to atmospheric CO2.

    Deforestation and agriculture have reduced the amount of carbon below that pre-agriculture saturated level and each practice has contributed to excess CO2 levels in the atmosphere, but together they comprise only about 20-22% of excess emissions. The remainder is almost all fossil fuels and concrete production. If ‘CO2 equivalent’ emissions are considered (fugitive methane, refrigerants, etc.), deforestation and agriculture would be an even smaller percentage of the total.

    Thus, returning the surface of the earth (and the oceans) to conditions of the pre-agriculture era could reduce atmospheric concentrations of CO2 somewhat but it wouldn’t be nearly enough to solve the problem as a whole. There also wouldn’t be enough land to grow food for our current population.

    Although it might be possible for agriculture to chip in a little in reducing atmospheric CO2, what is really needed is a hybrid carbon cycle, fast sequestration and very slow release. On land bio-char might do the job, but at the expense of land area for food production. Ocean fertilization might also work, but at tremendous risk of other environmental upsets.

    • Joe, excuse again my ignorance… If charcoal/bio-char is dug in deeply enough, why can’t the same land still be used for food production? And what kind or condition of wood is optimum for conversion to bio-char, ie is a photosynthesising branch better than a pyrolysed one when it comes to carbon sequestration?

      • The use of bio-char in soil is either a neutral or positive enhancement of the ability of soil to grow food. We could bury giga-tons of it with no soil problem. It does tend to raise soil pH a little, so it would do best in overly acid soils.

        The reason bio-char would affect food supplies is that the vast acreage needed for planting carboniferous crops (trees) would reduce the land available for planting food crops.

        Any kind of woody material can be used to make bio-char. I purchase and use bio-char made from macadamia nut shells. There are pyrolysis temperature effects on the porosity of the resulting char, which can affect its biologic properties in the soil, but for sequestration of carbon it makes no difference.

        It also makes no difference whether the carbon removed from the atmosphere by photosynthesis is left in a living branch or separated by pyrolysis and buried, but we could do far more of the latter by growing trees on the same acreage over and over. Using nitrogen fixing trees would minimize the need for fertilizer application in such a project.

        One caveat; as far as I know, the only evidence for the longevity of bio-char in soil (it’s reported to last for thousands of years) is the existence of terra preta soils in the Amazon, which contain bio-char that is centuries old. I have not seen any recent studies on the matter of soil longevity, although some may have been done.

        Here’s a good summary of the issue. http://blogs.nicholas.duke.edu/citizenscientist/biochar-reality-check/

  21. For those having a hard time visualizing what the relationship between plants and mycorrhizal fungi looks like. Please see the cover photo on the book Mycorrhizal Planet:

    As you can see, the relationship is symbiotic…not a trophic level relationship. It is more like the mitochondria and the cell proper than a cow to grass.

    Now, the ‘symbiotic’ relationship is characterized by ‘infection sites’, which you can see in the photograph. The fungi literally enter the plants cell and feed nutrients directly into it. The plant suspends its immunity response for a time. But, after a couple of weeks or so, the plant begins to repel the invader. The fungal probe dies back, and the fungus grows somewhere else. The dead material is eaten by soil food web critters, which supplies them with carbon and other nutrients.

    This is why Christine Jones called it the Liquid Carbon Pathway almost 2 decades ago. To Christine, the Liquid Carbon Pathway is the vastly preferred way to get carbon into the soil. Turning under cover crops definitely IS part of the fast carbon cycle, and will add soil carbon only very slowly. The Liquid Carbon Pathway has the ability to add longer lived carbon very rapidly (by photosynthetic standards). It is limited by the photosynthetic productivity of the plants (which is why David Johnson measures total biomass) and the presence of plenty of mycorrhizal fungi and the absence of human applied phosphate rock and the need for soil hydration and the presence of soil aggregates (which have a limited oxygen interior) which are not destroyed by deep tillage.

    The ‘official’ projections of soil carbon sequestration from agriculture measure the carbon sequestered by things such as turning in cover crops or simply stopping the tillage. They do not measure the results of a healthy and vigorous Liquid Carbon Pathway. Perhaps without knowing exactly what he had gotten himself into, David Johnson has presented quantitative evidence of what the Liquid Carbon Pathway can do in degraded agricultural land.

    Don Stewart

    • As you can see, the relationship is symbiotic…not a trophic level relationship. It is more like the mitochondria and the cell proper than a cow to grass.

      I dunno Don. My quibbling whiskers are twitching on that one. I don’t see many mitochondria pulling off and walking away from their ‘host’. The trophic level piece might be causing the consternation – but ‘trophic level’ is a hominid classification meme that might get in the way. Chloroplasts and mitochondria would once have been considered at a lower trophic level than a higher plant (and where does “higher” come from in plant parlance??) back when they were independent critters. Cows eating grass is not a one way road… and cows choose which plants they’ll eat when given a choice. Plants benefit from cow waste products and grow more rapidly (fix more CO2) when clipped or grazed. Urine and feces are not the only waste products yielded by cows either (or more correctly – herbivores on a grassland). Cows calving on open pasture will leave plenty behind, and herbivores dying feed scavengers who in turn return nutrients. The circular nature of it makes more sense than a trophic level structure.

      Now, substitute bipedal hominids for cows or other omnivorous critters on the landscape (and push aside notions of Homo hubris and ‘top of trophic cascade’ nonsense) and keep the circle notion in mind. True, we do eat cows, drink their milk… but we also feed them, and protect them from predators. Still not a one way path.

  22. Don, the ‘no till’ epithet is of less import to me than it seems to you, but if you prefer I’m happy to call regen-ag a no till or min till regimen. On horticultural scales you get people like the Kaisers practicing no till via imported compost – it makes sense in the here and now, but it’s heavily dependent on a high energy, fossil fuel economy. On agricultural scales you have to get into cover cropping, and this is where the difficulties start if you’re trying to get a staple crop off. Maybe for some crops in some biomes it’s possible to do that using no more than a light disking, but I’d suggest that this generally isn’t the case in terms of staple cereals worldwide. And as for root crops…

    Your points about phosphate don’t seem to acknowledge that it’s a limited resource in the soil. If you’re continually growing major food crops and selling them offsite, then your fungal networks are just helping you mine phosphates and other nutrients more rapidly – ultimately this will become a limiting factor unless you put nutrients back…which, as we all know, fungi won’t do. Unless there’s some other nutrient pathway you’re suggesting?

    Inasmuch as fungi are relying on plants for C or anything else, then the relationship is surely trophic? Saying that it’s limited by the photosynthetic capability of the plant is just another way of saying the same thing, as per Erik’s comment. The issue I have with David Johnson’s biomass measures is the inferences he makes about dissimilar ecosystems on the basis of comparing their biomass production, not in terms of C sequestration. But again, since we all seem to be agreed that soil C sequestration is limited by photosynthetic capacity, then does it matter which pathway is involved? Surely what matters is the absolute potential, which as Erik, Joe, the IPCC and others suggest, is not that great? Consulting my copy of Begon’s ‘Ecology’ suggests about 50% of NPP ends up as refractory detritus in grasslands (probably the closest of the wild ecosystems they discuss to a regen-ag situation, though I suspect the figure in the latter case would be less). I don’t think that greatly changes Erik’s conclusion.

    Begon makes the interesting point that mycorrhizae don’t necessarily increase plant P uptake – it depends on the plant’s root architecture. But the plants that are best able to forage for P are also most susceptible to attack from fungal pathogens, and the AM symbiosis helps prevent this. From which I infer that it’s complex down there, and I’m not sure that anybody really knows what they’re doing. Preventing soil erosion and promoting some soil life seems like a good basic goal, however. I’m with Joe on the need to look elsewhere to deal with climate change. Johnson really seems to miss the point on this in his presentation.

    The idea of the plants directing the fungi to gather limiting nutrients is an interesting one. Do you have some references for that?

  23. Chris
    *Why not dispense with the ‘no till’/ ‘minimum till’ label altogether and call it ‘restoration of the ancient symbiotic relationship between plants and fungi’. Everything else is a detail. Details are important, but by singling out a detail, one limits the imagination of anyone serious about changing farming for the better.
    *As for the Kaisers. I believe I originally mentioned them as taking a quite different approach than David Johnson or the Brown ranch or the people Christine Jones has worked with in Australia. It is a fact that market gardeners raise a lot of non-mycorrhizal plants such as brassica and the beet and spinach families. Those plants will greatly benefit from a soil which has recently had a high F:B ratio…think of a clearing which has been created by a windstorm or fire in a forest. So we call them disturbance plants. How to integrate disturbance plants with mycorrhizal friendly plants is a challenging job for a gardener. I know…I’m doing it. It’s a matter of figuring it out…or using imported wind-row compost as long as it is available…or maybe worm castings as Helmut Schimmel’s recently translated book Compost Revolution suggests. Johnson laid a small foundation when he included some brassica in his successful rotation. The decades long trials in Jena, Germany which demonstrated the superiority of polycultures may also be worth studying. In short…opportunities.
    *The alleged limitation of phosphorus is sort of true, but may not be a big issue for now. There is so much artificial phosphorus in a lot of agricultural land that its efficient mining by fungi will take us a very long time to accomplish. Johnson’s ‘desert plot’ is the only test plot I know about which is aimed directly at trying to figure out how the abundance measured by the mass spectrometer soil science plays with the issue of removal. We can all agree that recycling is the best option. But it is worthwhile to reread Farmers of Forty Centuries every so often to understand just how hard the Orientals from a hundred years ago were working to make that happen.
    *Trophic. Plants direct roughly 30 percent of the carbon they make into exudates. Many of those exudates go to feed the fungi, which scavenge nutrients that the plant would otherwise have to make a much more elaborate root structure to get to (in the natural world, barring industrial fertilizers). Trying to call it trophic is like trying to figure out some sort of trophic relationship between the mitochondria and the cell proper. I won’t say it can’t be done, but it sound nonsensical to try.

    Over a period of years, in a stable soil economy, the mass of the fungi stays the same. Therefore, the carbon in the fungi stays the same. But the plants are making way more carbon, cumulatively, than the fungi contain. The rest of that carbon is either in the other soil food critters, or in non-labile carbon, or in labile carbon rapidly on its way back to the atmosphere, or else has already been lost to the atmosphere. What Johnson is measuring is ‘how fast can we grow non-labile carbon?’ Surely not a trivial question.
    *Absolute potential for photosynthesis. What Johnson has shown is that, in Las Cruces, it is entirely possible, without spending very much in the way of resources, to generate more biomass from photosynthesis than the Amazon rain forest generates, and way more than the average agricultural land generates. Now there are two caveats:
    First, Las Cruces is blessed with more sunshine than the Amazon (and it also has irrigation water)
    Second, Johnson is not producing ONLY directly human edible biomass. But then, neither is the Amazon.

    Do we need to do more study on this issue? Of course. Johnson, for example, is using the slash from a previous cover crop to generate nitrogen for the succeeding cash crop. Growing two cash crops in succession won’t work because there is likely to be a shortage of nitrogen. But the North Carolina farmer I have cited has learned that leaving his winter cover crop in the ground longer and planting his cash crop later is a more productive and profitable path. Being the first to get your cash crop in the ground is nothing to brag about. So…all farmers everywhere need to figure out how to balance all the competing and synergistic factors. Liberty Hyde Bailey, who was the head of the agriculture program for a long time at Cornell, said:

    Tell a farmer WHY, and he will figure out HOW.

    *Plants and fungi and limiting nutrients. I refer you to Mycorrhizal Planet…or somebody smarter than me. I also recommend that you reconsider your hostility to general principles and Antonio Damasio in particular. If a principle has been conserved by evolution for a few billion years, over orders of magnitude changes, then it probably applies on your farm. Just as I suspect that E equals M * C squared applies on your farm. Look carefully at Johnson’s graphs of the changing apportionment of carbon and nitrogen as the F:B ratio changes.
    *The higher the F:B ratio, the more carbon goes into the soil. Carbon feeding the fungi, and then the other critters, is just a way for the plant to insure that it gets the nutrients it needs so that photosynthesis can be maximized. And Damasio’s principle of homeostasis (or homeodynamics) implemented in the real world.

    I do not adamantly claim that a ‘natural’ agriculture can feed an unlimited number of people. I definitely do not claim that, in the absence of fossil fuels, handling the transportation involved in food will be easy. I do not adamantly claim that we can store enough carbon in the soil to offset all current emissions. (But I do object when the Officials fail to take note of those farmers who have been successful adding carbon to the soil.) I do think that the assumption that lack of industrial nitrogen and phosphate rock will necessarily lead to starvation for billions is not a necessarily true assumption. Studies are needed, and Johnson and others need funding. And most of all, farmers everywhere need to ‘plant a strip’.

    • Don, thanks for that interesting summary. I can’t respond now, but will post some more thoughts in a day or two. Meanwhile, I’m interested in any other responses…

      • Let me just put a word in from the tropics. No-till can kinda work, but only if other drastic measures are used. When I was working in Fiji, the first thing anyone did before planting a crop was burn off all the existing vegetation, classic slash and burn horticulture. Field crops required tilling, even those flooded crops, like rice and taro, which use water to suppress weeds. Sugar is raised on tilled land and plenty of herbicides are used also.

        Here in Hawaii, rain-fed agriculture requires tilling, even after herbicide application, especially for any root crop like taro or sweet potato. The Rodale method of beating down a cover crop doesn’t work here. The cover crop will just come right back.

        No-till only works for grazing and orchards, but even orchards and pastures require a lot of maintenance to keep out invasive tree species like yellow guava, eucalyptus and ironwoods.

        In the tropics, if there is rain and the land isn’t grazed, sprayed, paved or tilled, it will be jungle of some sort in a few years. Permaculturalists suggest planting a food forest as jungle. That might work, but the harvest labor would be so intensive that the people fed by it would have to live in it or nearby. A tropical food forest turns users into gatherers (probably hunters too, to keep out the foraging birds, pigs and any other animal that likes to eat).

        My neighbors’ sons have an organic farm nearby. They produce 19,000 head of lettuce a week in an area that is dry enough to require constant irrigation (sprinklers in this case). They till a lot to combat weeds and prepare the lettuce beds for transplant. I’ll ask them if they have ever tried no-till and, if so, what their problems with it were.

        • I can concur. I would put it even stronger. No-till is BS. You gotta get oxygen into the soil somehow. Soil disturbance is one of the maxims of Christine Johnson.

          Regen ag: “Protect soil from erosion and depletion, and indeed actively build soil”

          If this is all it did, it would be enough, no? Does it do that? Yes, in my own experience it does. How much does it build the soil, I don’t know, and last I checked, it was hard to measure. We won’t know for a while, but IMO that’s no reason not to go whole hog for regen ag. Fungi? The sandy and nutrient poor soil I was regenerating in Colorado did not really take off, despite my lasagna efforts with horse and llama manure, until I imported some forest soil with the fungi, as well as local medics. No innoculants, all local materials that came free. The soil took off, and finally, it had that wonderful sticky feeling that signals lots of stable carbon/soil glues.

          (And terra preta suggests that once you have it going, you can use it as innoculant elsewhere. Btw, the folks who sell terra preta in Brasil to other gardeners do not have any doubts about it growing fast. They treat is as a steadily increasing monetizable resource).

          If I had waited for proof that a certain “unproven” cancer treatment worked, I’d be dead today. The proofs won’t come until a lot of people adopt these methods partially on faith, partially on a hunch, and partially on reason. I say, let’s go for it!

  24. This may be an insulting post. I don’t mean it that way.

    Damasio reminds us that:
    “Because feelings mentally represent a currently salient state of homeostasis and because of the upheaval they can generate, feelings operate as motives for engaging the creative intellect, the latter being the link in the chain that is responsible for the actual costruction of the cultural practice or instrument.”

    Please watch this very short video made by David Johnson:

    I submit that if one is moderately well educated, and has some inkling of what the video demonstrates about chemical agriculture, one cannot avoid a feeling of revulsion.

    The question is: What sort of reaction to the revulsion will one express? Most people, in my experience, won’t even watch the video, and if they do watch it, they look for evasion of responsibility. For example: ‘Let’s set up a straw man consisting of Kumbaya people who preach no-till and then bash them’. Or ‘Let’s keep this in mind as we observe the slow evolution of the scientific literature over the next few decades.’

    David Johnson actually did engage his ‘creative intellect’ and produced a far superior result, as measured by homeostasis. Will his response work on your farm? Not necessarily…your farm needs to experience your own creative intellect at work.

    Don Stewart

  25. Some summary notes on where I’m at with this discussion, mostly in relation to Don’s comments but also generally:

    TILLAGE & REGEN AG. Heavy inversion tillage has been an extremely successful method in many agricultures for achieving the two key goals of adding fertility to the soil and reducing weed competition in order to achieve high yields of edible matter, but in the longer term it causes problems and is unsustainable – in some places more than others. Increasing the fungal activity in agricultural soils is a good idea for various reasons, but it’s incompatible with heavy inversion tillage. I’d be happy to describe regen-ag in terms of fungal activity without mentioning tillage and leaving farmers to figure out what works for them, provided it’s clear that the heavy inversion tillage (and its variants) that’s widely practiced isn’t one of the things that’s going to work. This is important because I think there’s too much magical thinking in the alternative agriculture movement that avoids facing hard ecological trade-offs of this sort. ‘You can have perennial grain crops that are just as productive as annuals, but without the downsides’ or ‘you can develop forms of regen-ag that sequester all anthropogenic carbon while producing high yields and building soils, without any of the downsides of tillage agriculture’ etc. We need to confront the trade-offs more squarely. In this sense, I’d suggest that the question of tillage is more than a ‘detail’. Definitionally, I wouldn’t call light disking ‘tillage’.

    TROPHIC LEVELS & CARBON PATHWAYS: whether or not we choose to call the plant/fungi relationship ‘trophic’, there’s surely a parallel when we come to talk about C sequestration inasmuch as there’s a limit to how much C plants can absorb from the atmosphere, and this establishes a limit (a much lower one) to how much C can be stably sequestered in the soil. I need to look into this some more, but it seems fairly clear from the discussion above that these limits are such that agricultural soil C sequestration is inadequate to cope with anthropogenic C. The talk of liquid carbon pathways and their neglected importance seems somewhat obfuscatory to me in this context. And David Johnson’s enthusiasm for flying in aeroplanes while expecting his soils to clean up after him seems positively complacent.

    PHOSPHATES & LABOUR: I’m glad to have wrung a confession, however grudging, that cropping off a regen-ag system involves mining phosphates and other nutrients, and is ultimately parasitic upon the unsustainable agricultures that are widely derided in the regen-ag movement for their inappropriate addition of nutrients. Don says that the efficient mining of these nutrients will take a very long time to accomplish – I guess I’m in need of a definition of a ‘very long time’ before I feel able to judge how relaxed I am about this limitation of regen-ag. Don also mentions King’s ‘Farmers of Forty Centuries’ as a kind of caution about the immense human labour that goes into a truly sustainable agricultural system. To which I can only say “Yes indeed”. Though I might add (1) It’s also worth bearing in mind the immense wealth and luxury enjoyed by the few that accrued on the basis of those immense labours, and (2) It’s certainly worth trying to figure out ways to steer between the Scylla of unsustainable modern mechanised farming and the Charybdis of a body-sapping low tech sustainable agriculture, but let us not fall prey to magical thinking that the trade-offs are easily overcome.

    YIELD TRADE-OFFS: Don writes that David Johnson has shown he can generate more biomass from photosynthesis than the Amazon rain forest generates, and way more than the average agricultural land generates. He caveats it by saying that Johnson is not producing ONLY directly human edible biomass, but adds that neither is the Amazon. However, the critical comparison here isn’t the Amazon but agricultural land, which pretty much IS producing only directly human edible biomass. Johnson’s failure to address this point is a big discredit in his analysis.

    SCIENCE & EVIDENCE: Various comments above try to position me as resistant to experimentation, unreasonable in my demands for proof etc etc. Frankly, I think this exemplifies what David describes above as “going into bluster mode/avoiding the questions” etc. There’s some shoddy science in Johnson and Jones’s presentations and there are some very lofty claims made by the regen-ag movement which are not well evidenced. If regen-ag proponents want to convince the wider world of their claims – and there are certainly good reasons why some of these claims should be taken seriously – I think they need to look at themselves a bit more self-critically, rather than turning their guns on folks who question the evidence. Questioning evidence is how good science gets done. I’m not going to debate Damasio, homeostasis etc as I think this is another iteration of the diversionary tactics identified by David. Suffice to say that I’m not hostile to general scientific principles, which I concede do operate even on my farm (despite the elaborate rituals I undertake daily to obviate it, which regrettably have borne no fruit so far ). But I am hostile to using scientific concepts in questionably rhetorical ways.

    EXPERIMENTATION: I’m very much in favour of people experimenting with growing methods in their gardens and farms, and ‘planting a strip’. I don’t think there’s anything in my essay above that suggests otherwise. I’ll say some more about this in my next post…when I get a chance to write it.

    Apologies if the tone above sounds overly critical or irascible. I’ve found this a useful discussion, and I’ve genuinely learned things from everyone who’s contributed – so thank you.

    • Hold up a second…
      However, the critical comparison here isn’t the Amazon but agricultural land, which pretty much IS producing only directly human edible biomass

      Perhaps if one limits a definition of ‘agricultural land’ to something like a turnip patch where roots and shoots both are human edible biomass… OR if one anticipates that animal fodder grown on agricultural land is human edible biomass once converted to meat by the capable assistance of a critter. But where I’m having some present concern in this debate is why it seems necessary to draw this particular line. I think Chris’ comparison is perhaps a degree closer for argument’s sake – but the whole of the biosphere needn’t be carved up into little boxes. Atmospheric carbon freely flows to and through all the ecosystems, whether we eat directly from them or not.

      The overarching nod to the existence of trade-offs is where I find the most value in Chris’ position here. And as a life long experimenter I suppose I should stand in favor of doing experiments – but simply “doing” an experiment doesn’t entitle one to project onto the whole of the planet some personal interpretation of an experiment’s results.

      I do want to offer some thanks that Don and Chris have brought this particular aspect of agricultural management before us. My own feelings on the broader issues here (which I find myself less studied upon than I like to admit) is that regeneration is possible – at least for more degraded patches. Regeneration is not free, and the benefits are not immediate. That said, benefits are demonstrable, and life cycle assessments seem positive. Land tenure issues may become increasingly significant as we look forward to more regenerative management strategies because benefits of these strategies accumulate to a wider audience and present economic mechanisms (political situations) don’t seem to reward the efforts as we currently know them.

      • For me, the context here is Johnson showing a slide comparing biomass production in (1) agroecosystems (2) a handful of the world’s most productive wild ecosystems and (3) his BEAM system – (1) being much the least productive and (3) being much the most. What can we conclude from this? Basically, nothing. Certainly not what Johnson concludes from it, that ‘we’re doing something wrong’ in agriculture. That would only be true if the aim of agriculture was to produce more biomass than any other kind of ecosystem. True, not all the biomass in agroecosystems is edible…and for sure we’re doing plenty wrong in agriculture. But the whole historic drift of it has been to increase the edible proportion of the ecosystem (within whatever wider parameters – cereal cropping, pasture etc.) and until that slide is re-presented in terms of edible matter within those parameters, I don’t think it tells us anything of value. In no way am I trying to suggest that there’s no virtue in regen-ag practices. But I think we could do with less hyperbolic claims about what it can achieve. That said, I agree with Don that it’s worth thinking about the importance of fungi in agricultural soils, which has been neglected in the past, or at least is more apparent now, and presents new challenges and opportunities.

  26. Flogging a Dead Horse
    I previously referred people to a Valter Longo You Tube interview on the subject of aging and disease. His book The Longevity Diet has subsequently arrived. I want to draw certain parallels with Johnson’s pots of pepper plants and Longo’s trials and tribulations with his ‘regeneration theory’.

    The overwhelming weight of scientific opinion has focused around ‘healthy habits’ such as eating a lot of antioxidants or taking magic antioxidant pills to avoid disease and prolong life. Longo emigrated from Italy to the US intending to become a rock star. However, he noticed that his Italian relatives in Chicago were eating a diet very different from poor Italians, and were developing diseases virtually unknown in Calabria. He enrolled in college in Texas, intending to become a musician. He was introduced to perhaps the worst food in the world, Tex-Mex. Somehow, he became more concerned about longevity and disease, and switched majors…against his counselors advice. Then it was on to graduate school at UCLA, where he observed the efforts of the head of the Department to starve himself into health using calorie restriction.

    From his musical background, he knew that ‘adding more cellos to a Mozart symphony’ didn’t make the symphony better, and he would agree with Damasio that starving oneself is not consistent with the evolutionarily conserved principle of homeostasis. Longo asked the fundamental question: ‘How can two adults with age-damaged genes give birth to a perfect child?’ And he knew that, somewhere, the body had a mechanism, which we knew nothing about, which was able to engage in regeneration of sperm and egg. Rather than trying to stop the freight train of oxidative stress, Longo decided to pursue ‘triggering the regenerative process’.

    After two fruitless years in the longevity program as it existed at that time, he switched to biochemistry. The overwhelming scientific opinion at the time was that humans were very unique and nothing much could be learned by studying the simplest organisms. (Damasio would laugh.) So he decided to study yeast…cheap and easy. ‘In a short period of time…I had identified not only the first gene regulating the aging process but also the entire signaling pathway, all thanks to a very simple organism. The system was so simple and so new that the scientific community was in disbelief and struggled to understand, let alone accept, the chronological aging system and the discovery of the pro-aging sugar pathway. Leading science journals refused to publish the findings my mentors and I found so extraordinary.

    It wasn’t until 1996 that Tom Johnson, who was trying to identify an unknown gene that made worms live longer, invited me to present my data on the ‘sugar pathway’ at a conference. When my presentation ended, the room was absolutely silent. The stars of the aging field…stared at me as if I had grown horns–no one had ever heard of the system I was working with, nor of the genes I had identified, and anyway, very few believed that similar genes and strategies could be affecting aging in such different organisms.

    It would take another 6 years for our data on genes activated by sugars to get published, along with the discovery of pro-aging genes activated by amino acids and proteins. 8 more years passed before different laboratories would confirm these data experimentally in mice, and another 10 years before my own lab provided initial evidence that similar genes and pathways may protect humans against age-related diseases.

    Back to me. The current state of the art is that Longo has published his book describing a basic Longevity Diet and a program of periodic fasting to reset the aging genes. He is proceeding methodically through the major degenerative diseases to adapt the basic program to each of them individually. His cancer protocol has been approved by the FDA, and can be used, for example, in conjunction with chemo. When paired with chemo, the results are much better than either treatment standing alone. We can expect a steady stream of disease specific recommendations, along with incremental improvements in the specific recommendations.

    It all traces back to the yeast. The sugar pathway in humans involves exactly the same genes. The amino acid and protein pathway doesn’t apply to the yeast (so far as I know), but finding it involved the same principles.

    Here is my point. Anyone who grows plants should look at the pictures of David Johnson’s pepper plants in pots, differing only in the F:B ratio, and start asking some very fundamental questions. We can choose to wait until the old-timers have changed their minds, or we can test it out for ourselves by ‘planting a strip’.

    And those who think about saving the world, should NOT assume that the future necessarily consists of fat and sick old people, or of degraded and unproductive agricultural soils.

    Don Stewart

  27. Mass Spectrometry and P

    I’m neither capable nor willing to become the expert on measuring Phosphorus in the soil. But I can read conclusions. And those who are smarter than I am think there is a lot of phosphorus in the soil for the fungi to mine. Not an infinite amount, but a lot. In addition, there is the breakdown of bedrock, which fungi can accomplish.

    Don Stewart

  28. IF depleted nitrogen and phosphorus and tenuous supplies of industrially mined and manufactured replacements are not the primary issue, what are the primary issues?

    I promise not to write volumes on the subject. Just sketch two recent examples. The first is from the Rio Grande Valley in Texas. The valley is subtropical (Zones 10 and 11), which allows for continuous cropping year round. It is semi-arid, punctuated by the occasional hurricane with torrential rains. A good bit of organic vegetables are grown and exported to markets to the north. The land is quite degraded, with poor infiltration of the rain that does fall, and soil organic matter around half of one percent. The microscope count of mycorrhizal fungi is very low. The weed pressure, as noted by David Johnson, is high.

    The intervention was to persuade the university farm and a couple of other farms to try some cover cropping with attention to mycorhizal relationships. The trial demonstrated that, as Christine Jones would predict, the number of fungi multiplied impressively. However, the team is also growing fungi in tubs with some grasses, to use as inoculants.

    Second example is from The Nature Conservancy, which just issued a magazine honoring the 25th anniversary of the Legacy Club. This magazine focuses mostly on growing food in ‘nature friendly’ ways. The Conservancy has hired a soil scientist, who says just about everything I have said on this thread. She previously worked in Africa. While it is easy to demonstrate the good effects of cover crops and interplanting, the people are very poor and cannot imagine planting something which is not used immediately for human consumption. They even gather dry grass to use as a fuel. The climate is tropical with a distinct wet season and a dry season.

    So….what are the real problem that have to be overcome or worked around in Texas and East Africa? If the answers were as easy as the nitrogen and phosphorus issues, the respective farmers would already be doing it. But they are not, and the soils are degraded and the produce is very likely not highly nutritious.

    Don Stewart

  29. Thanks for the reference to Miles King’s blog, interesting stuff. I’m just barely getting literate on comparative agricultural policy and he has a lively point of view in what can be a not very lively subject.
    As for regenerative agriculture, it seems a reasonable set of starting principles. Certainly lots more to be asked and learned. It’s not going to save industrial civilization from itself though and why should it?

    • “a reasonable set of starting principles. Certainly lots more to be asked and learned. It’s not going to save industrial civilization from itself though and why should it?”

      An admirably succinct summation of my own position. You could have saved me a lot of words, Michelle! I might just add “It’s not going to save industrial civilization from itself though and why should it – so let’s not claim otherwise”

  30. Here are 3 Slovak scientists who have a plan to save the world through restoration of the water cycle. I find what they have to say quite provocative.

    As a side note. I was instrumental in introducing a local conservation group to the notion that restoration farming might be something to get involved in. An elderly couple gave them a couple of hundred acre farm. I paid for a staff member to attend a restoration agriculture conference, where he had the chance to meet and mingle with the leading lights of the movement in the US and many farmers who are doing it.

    Then I went with two of the staff members to look at the farm they had just inherited. I used a penetrometer (which measures how much soil exists before a compaction layer (called a ‘plow pan’) prevents the downward growth of roots. I also used a soil corer, which lets you take a look visually at the composition of the top foot of soil.

    They were shocked at what they saw. The old corn and tobacco field had about 3 inches of topsoil with any carbon in it. The plow pan was down about 6 inches. Below that was yellow, compacted clay. The horse pasture, on the other hand, had about 6 inches of good topsoil with moderate carbon content, with the plow pan down about a foot. On a hillside, the slope of the hill had very thin soils with the plowman just below the surface. But at the bottom of the slope, I could push the penetrometer down 2 feet easily. The corer revealed wonderful black soil down to the 12 inch depth that my corer can sample. A wooded area revealed less soil than you might imagine for a wooded area. Apparently just letting trees grow does not automatically yield deep, carbon rich soils.

    The most amazing thing, to them, was when they walked across to a neighboring farm field. That field had standing water, a sure sign of compaction and lack of infiltration. They could not get the penetrometer into the soil more than a couple of inches. It is clear that the neighboring field has to be plowed and pulverized in order to grow anything. Which, of course, keeps the quality at rock bottom.

    Now back to the question of water, which the 3 Slovaks are talking about. They had put together a low-tech plan for slowing down water and letting it sink into the soil. They used unemployed or underemployed village people with no technical training to build the simple retaining structures. The results were good and relatively cheap. But a new government defunded the effort. So, having failed to save Slovakia, they are now aiming at Saving the World.

    If the slope on the farm we were touring had used methods to slow down water and let it sink on that barren slope, then it would have had deep, rich soils similar to those at the bottom of the slope. Carbon would be stored and productivity improved.

    I have spoken of the young North Carolina farmer who has become a master of sorts in a very few years. In a drought year, his crops looked a lot better than his neighbors crops. The neighbor needed something to complain about, so he focused on some trees between the young farmer’s field and his own field. The neighbor decided that the trees were ‘blocking the rain clouds’ and went to, believe it or not, the County Commission to demand that the trees be cut down so he could get his share of the rain.

    If you listen to the 3 Slovaks, they will convince you that trees really are a good explanation for a lot of the phenomena we observe in rainfall. So the idiot neighbor farmer was actually not entirely wrong, but, of course, his methods are completely missing scientific reality.

    Don Stewart

    Greetings Don,
    I hope your week is off to a great start. Staring
    out my window, I’m starting to see spring slowly taking effect
    with buds and flowers popping up everywhere (Though I know alot of you might still be buried in snow). However, we all notice weather extremes rising. Spring seems a rarity these days that sticks around for just a while before Summer heat arrives early on our doorstep.

    This week, we’re bringing three of the most incredible speakers we’ve had back on because they are going to share even more about how we can stabilize our weather and climate: Vlado Zaujec, Michal Kravcik, and Jan Pokorny. In their last presentation, they revealed a global plan for water restoration that could restore more stable patterns of rain and cool local temperatures. This time…they’re going even further, showing us how we could reverse sea level rise, and reverse drought in places like Capetown, Athens, and Cyprus. These lessons are vital for understanding a new way to restore our local ecosystems and climate in a rapid, holistic, inexpensive way. In invite you to come join us Thursday, because this will be something you won’t want to miss!

    Click Here to Register
    Just as a heads up, this is Part 6 of our series on Water Restoration. Eventually, we’ll be bundling them and re-releasing them, but you can find them all on De

  31. Have not been a steady reader lately, ( the 10-1/2 post opus bogged me down, and I STILL plan to read it all) so may not have seen all prior posts in this area, but I’m surprised to see no mention of the full transition to perennial agriculture as described by Mark Shepard’s work. I seem to recall Chris did some critique of Mark’s approach a while back. Others in the permaculture movement have described similar.

    Mark’s claims might be a bit hyperbolic, as are other proponents, but I think he is heading in the right direction. If nothing else, the permaculture approach fully engages with the fungal network, and offers very low or zero fossil inputs.

    Anyway, my view is that all the effort to optimize annual crops is still wide of the mark, it just won’t be as big a part of human nutrition after all the fossil fuels have gone below the EROEI threshold. By the same token, trying to pencil out an ag system that will provide for current populations is futile, and the carrying capacity of a food tree and perennial based agriculture system will be what it will be. I only hope we can chart a smooth course to a lower population, though it looks unlikely at this point.

    Additional: Regarding CO2 sequestration- woody crops can easily supplement long term CO2 storage simply through biomass, but then also through biochar production from prunings and coppicing. Not the complete solution, but one more arrow in the quiver.

    • I read Shepard’s book several years ago. I was enchanted by his concept right up until he got to the issue of harvesting. Apparently, a food forest can grow a lot of food, but getting it from the tree to the mouth is difficult. Shepard’s solution was to rely on “American ingenuity” to develop automated harvesting equipment that can harvest any tree crop efficiently. I think we are still waiting for it.

      I think a permaculture food forest makes sense as part of a self-sufficient small farm, particularly if there are plenty of on-site food gatherers available, but as a paradigm for replacing our existing cropping systems it seems implausible.

      Our typical monocrop field layout developed to allow machines to do most of the work, especially harvesting. No matter how we grow food for commercial sale, the growing is in many ways the easiest part. The harvesting, product prep and distribution to the end user is much, if not most of the work.

  32. Have not been a steady reader lately, ( the 10-1/2 post opus bogged me down at a bad time, and I STILL plan to read it all) so may not have seen all prior posts in this area, but I’m surprised to see no mention of the full transition to perennial agriculture as described by Mark Shepard’s work. I seem to recall Chris did some critique of Mark’s approach a while back. Others in the permaculture movement have described similar.

    Mark’s claims might be a bit hyperbolic, as are other proponents, but I think he is heading in the right direction. If nothing else, the permaculture approach fully engages with the fungal network, and offers very low or zero fossil inputs.

    Anyway, my view is that all the effort to optimize annual crops is still wide of the mark, it just won’t be as big a part of human nutrition after all the fossil fuels have gone below the EROEI threshold. By the same token, trying to pencil out an ag system that will provide for current populations is futile, and the carrying capacity of a food tree and perennial based agriculture system will be what it will be. I only hope we can chart a smooth course to a lower population, though it looks unlikely at this point.

    Additional: Regarding CO2 sequestration- woody crops can easily supplement long term CO2 storage simply through biomass, but then also through biochar production from prunings and coppicing. Not the complete solution, but one more arrow in the quiver.

  33. Thanks for the further comments. I only have time for a few brief responses.

    Thanks Steve for still reading! I agree that a shift in emphasis more to perennial crops would be a good idea, but I don’t think it would be sufficient…nor am I convinced that there’s no role for annuals in sustainable farming. However, I agree that certain kinds of annual optimisation effort are probably wide of the mark.

    My main problem with Shepard is that, like many in the alternative ag movement, he’s determined to prove that his approach is just as productive of macronutrients as conventional arable systems on a per acre basis when it clearly isn’t. In relation to Joe’s point, I’d argue that monocrop field layouts long predated machine agriculture – there’s an intrinsic ecology to cereal crops here that people have long relied on, but whose logic we’ve recently pushed to dangerous levels of over-reliance, to the benefit of few. So yes, a move towards food forests would be welcome…and yes I agree with Joe that the prospects for mechanising them aren’t good, which I think is no bad thing. Is it worth pencilling out a more sustainable ag system that can feed current populations? Personally, I think so – the main difficulties being socio-political rather than ecological/biological. But even if current human population levels prove unsustainable, I don’t really see the point of pencilling out agricultural utopias that magic large swathes of humanity out of existence. For now, we could do worse than starting to think seriously about what a world with a lot more human labour devoted to agriculture might look like.

    Talking of saving the world, Don writes “those who think about saving the world, should NOT assume that the future necessarily consists of fat and sick old people, or of degraded and unproductive agricultural soils.”

    I agree…though for the time being high income countries will certainly consist of a lot of old people, and those who want to make inferences about cancer aetiology from changing rates of cancer incidence do need to take age structure into consideration.

    • Re mechanising various more complicated, small-scale agricultural tasks, there’s quite remarkable developments in agtech occurring currently. Lots of cheap computing power, open-source, developments in and vastly increased access to machine learning/AI/data science/complex systems analysis/discrete simulation solutions, various initiatives in the US military to assist troops taking large loads into difficult terrain, occupational health and safety concerns in dangerous occupations like forestry, how to provide food and fibre for a global population heading towards 9-10 billion, crappy investment returns in many traditional industries, assorted green/sustainability/energy resilience issues, much better batteries as measured by various metrics and various other drivers are coming together nicely to push this area forwards. These days it’s not so much a question of if it can be done but more at what price point.

      I met a guy who does cargo drones the other day. He’s already producing drones that can do 100kg – and just to increase the doom and gloomer howls of outrage he’s been using 3D printing for years to make cheaper components. He’s looking at scaling up to 1 tonne units but there’s regulatory constraints on this rather than technical. A 1 tonne autonomous drone at a good price point would have a heap of useful farm and forestry applications. We had a very interesting chat about autonomous slashers capable of working on slopes – a sphincter clenching occupation with conventional kit as I can attest – without damaging young trees. A current autonomous, self-reproducing and fueling solution for this use case – AKA sheep – has a regrettable tendency to eat the young trees as well as the grass. We also discussed what might be involved in an autonomous weeding system. Never to have to mattock a blackberry, ragwort or thistle again!

      There’s a default apocalypterati viewpoint that roboticised agtech solutions won’t work due to some combination of fossil energy supply restrictions/supply chain fragility/complex manufacturing system dependencies etc

      Personally I think this is bullshit but I guess we’ll see.

      What I find interesting is how to democratise and encourage open access to this technology as the pricepoint declines and how best to use it in sustainable, socially equitable, productive, cost-effective agrosystems.

      • There’s a default apocalypterati viewpoint that roboticised agtech solutions won’t work due to some combination of fossil energy supply restrictions/supply chain fragility/complex manufacturing system dependencies etc

        Roboticised/mechanized farming is working right now and it may be that Shepard’s dream of a mechanical fruit/nut/berry harvester that can outperform a human will be invented. But all those machines do depend on those factors you mention that “apocalypterati” like me believe are not sustainable over the long term.

        If you believe that a high-tech, high energy industrial civilization can continue indefinitely without running into resource or environmental limits, then there is nothing to worry about except how to make sure that everyone shares in our cornucopian abundance. While that is a significant problem in itself, I personally think that limiting our problems-to-be-solved to that one is bullshit, but I guess we’ll see.

      • David, Joe – thanks for keeping this long-running debate alive! I guess I plan to maintain my lofty vantage point from my perch up here on the fence when it comes to matters apocalyptic, but it does seem to me that our ongoing and deep reliance upon fossil fuels is problematic, as even the likes of Smil seem increasingly to recognise, as per my previous post. As you both say…I guess we’ll see. Or at least somebody will. Meanwhile, I’m open to emerging possibilities for useful small-farm mechanisation, with the caveats that I think you need to look at how that plays out globally in terms of labour and surplus value, and that many of the problems we face are not fundamentally technological ones and won’t be fundamentally solved by technological means.

  34. Chris
    ‘those who want to make inferences about cancer etiology from changing rates of cancer incidence do need to take age structure into consideration.’

    Doing that very thing is what Valter Longo is doing. Valter has demonstrated many things, but I will zero in on just a couple:
    *That a 5 day ‘fast’ with protein restriction and just about as much vegetables as a person can eat will reset many age dependent indicators. We have known for a long time that a water fast (no calories at all) will do the trick….e.g. diabetes can be cured in 3 weeks, and heart disease can be quickly reversed.) What Longo has succeeded in doing is showing that his 5 day ‘fast mimicking diet’ can do the trick as well.
    * If the patient then follows up with a much less restrictive maintenance diet, then the body continues in a state of health we might call ‘reduced calendar age’.

    Now the obstacles to widespread adoption of Longo’s protocols is not primarily about technical issues. It is true that our society would have to produce a lot more vegetables, but backyard gardens can help immensely with that chore. The obstacles are that there are enormous industries dependent on the fact that most people eat an industrial diet which makes them age more rapidly than they need to, and never suffer any significant periods of time with less food than they think they want to eat. (In the developed countries).) So a vast amount of disinformation and inertia and economic and political arrangements need to change. Which will all be painful.

    But I heard a doctor active in rescuing severely diseased people yesterday. He said that what drives people to him is ‘pain and fear of death’. If society begins to disintegrate and unlimited funds for medical treatment are not available, then people will be motivated to try what works. This is one of the feedback loops a futurologist needs to think about.

    Don Stewart

  35. Neo-Peasant Societies?
    Those interested in the potential of a Neo-Peasant society as a replacement for, or successor to, the current Neo-Liberal model might like to take a look at:
    Ramp Hollow: The Ordeal of Appalachia
    by Steven Stoll.

    Stoll is a Professor of History at Fordham University. While his focus is on the destruction of the peasant farmers in Aopalachia in the United States, he links their fate to the fate of peasant farmers from the victims of the British enclosure movement to current developments in Mali.

    Briefly, the mountaineers were heroes during the Revolution when they defeated the British. Then reviled. Then heroes again (in the Union) during the Civil War when they fought with the Union, then reviled again, and ultimately destroyed. So the history covers both the social, political, and economic factors which worked against them.

    I think it is fair to say that the moneyed interests on the East Coast despised the mountain people who were living largely without money. Taking their land away from them was ‘good for the economy’. You can still find statements like that whenever Jeffrey Sachs volunteers to ‘help’ a country from Russia to Tanzania.

    The book might help one think through likely transitions….depending on one’s assessment of what events will actually prompt the changes.

    Don Stewart

  36. Some notes from yesterdays video conference with the Slovaks working on saving the world by restoring the local water cycle.


    However, findings on the principal role of water and plants in the distribution of solar energy and temperature
    control of ecosystems are not emphasized in policy recommendations issued by the
    Intergovernmental Panel on Climate Change (IPCC, 2007).

    What is less often realised is the fact that the annual increase in humanly induced carbon in the atmosphere is an amount equivalent to only 0.6% of the
    carbon contained in vegetation and 0.2% of the carbon contained in soils. Studies by
    Beran (1994) and IPCC (2007) put the annual increment of carbon in the atmosphere from CO2 emissions at 3.5 GT. In soil, there is
    c. 2000 GT of naturally occurring carbon; in vegetation 610 GT and in the atmosphere 750 GT of carbon. These various sources
    exchange carbon in a functional relation to each other, a dynamic that is uncoupled when local water cycles are damaged. This lost
    functioning is observed on a global scale in the Millennium Environmental Assessment (2005), which notes that every year, some 60,000 km2
    of badly managed land is becoming desert. About 200,000 km
    of land loses agricultural productivity as people in development projects or farmers themselves cut
    down plants and drain soils. The drying out and loss of ecosystem function now affects 30–40% of the global landmass

    The group, having been defunded by their government, will launch a kickstarted in the near future. The goal is a global but decentralized effort to restore the local ager cycle and tame harmful weather fluctuations.. I would note that Christine Jones quotes a figure obtained from satellite data that (as I recall) half of crop land is bare, on average. I will also note that, from my amateurish reading, the mowed meadow isn’t all that much better than concrete.

    A little more speculation. David Johnson’s restoration of the fungal networks plus the attainment of a high fraction of soil coverage with vigorously growing plants, coupled with the cooling effect of photosynthesis, may be a key contributor to his high productivity. (He has plenty of irrigation water.) The young North Carolina farmer I have referenced doesn’t have irrigation water, but he follows some of the same principles as David, and his drought year productivity speaks for itself. If the soils and roots are deep and have mycorrhizal infections, then the photosynthetic process will continue to work and the field will be cooler. The neighbor, ignoring all that nonsense, loses his crop and blames the trees.

    Don Stewart

    • Crikey, there are so many carbon figures flying about in this whole discussion that it gets confusing. But it’s surely necessary to distinguish between pools and fluxes here. The carbon being added to the atmosphere by human activities as a proportion of the total carbon in plants, soils, oceans etc. indeed is tiny. But the carbon being added to the atmosphere by human activities as a proportion of net carbon fluxes is about 100%, which is why it’s human activities that are responsible for the radiative forcing we’re experiencing. What’s mainly been at issue in this discussion is the capacity of soils to act as pools for this net anthropogenic flux via plant and fungal intermediaries, while continuing to furnish us with sufficient food – and I don’t think I’ve seen a solid and convincing figure for this yet…but I’m not convinced that it’s 100%, or even close to it. However, I’ll happily stand corrected if anybody else would like to weigh in with a convincing alternative construal of the evidence.

    • This article from the IPCC explains how much atmospheric carbon dioxide can be removed from the atmosphere if historic “land-use change were completely reversed over the 21st century” (about 40 ppm).


      Since we are about 130 ppm over pre-industrial levels, it gives one an idea of the size of the problem and how much could be accomplished by reversing human impact on land vegetation; it’s a decent amount, but not nearly enough. And how likely is it that we could reverse all land use change anyway?

      • Joe Clarkson
        I believe I made a previous reference to a doctor who treats (and cures) people with late stage chronic diseases. His treatment revolves around fasting….just stop eating. When he is asked why so relatively few people are willing to resort to fasting, when it has been so clearly demonstrated as effective, he shrugs and says:
        ‘People come to me to avoid pain and because they are afraid of death.’

        David Montgomery, a geologists who got interested in soil carbon and plant productivity, toured widely in the US looking at successful farmers who are adding carbon to the soil. One of his conclusions is that Federal Crop Insurance is the biggest obstacle to widespread adoption. So long as the Feds will only insure a monocrop, farmers who plant polycultures are absorbing risks that their neighbors are insured against. It takes rebels like Gabe Brown, who wants nothing to do with the government, to take those risks.

        I belong to a small farmer group. One of their perennial goals is to get legislative action making the Crop Insurance program relevant to small, diversified farmers. If we believe the ‘last resort’ doctor and Gabe Brown, and David Montgomery, then probably the best solution is to eliminate the Crop Insurance program. Which, after a painful period of transition, would leave ONLY the well diversified, carbon sequestering, water sinking farmers left.

        I hate to be so pessimistic, but I am reading Ramp Hollow about the destruction of my ancestors, the peasant farms of the Appalachian Mountains, and the amount of pure evil (both visited upon them and stuff they thought up themselves) does not lead one to unicorns and fairies.

        Don Stewart

  37. One acre farmed by hand vs. technology

    First, the technology perspective:

    Albert is very enthusiastic that bioplastics (including biochar as an ingredient) can help save us. Bioplastics can be made in Albert’s yard in a workshop, but seem more like global technology to me.

    At the other extreme, we have the subsistence gardening notion, which is one of the centerpieces of Ramp Hollow. The Peasant Economy in Appalaciha was the target of the Whiskey Tax of Alexander Hamilton. Hamilton wanted to force the peasant farmers out of their subsistence system and into a monetary system which would integrate them into the United States. At the time, several observers thought that the Appalachian people would declare their independence from the new United States. It would have been a little embarrassing to suppress the peasants when the Declaration of Indpendence and Tom Paine’s The Rights of Man were hardly cold in their graves. So Hamilton came up with a tax far more onerous than anything King George had tried to impose, which had the effect of undermining the peasant economy in the Appalachians. A force of 5000 soldiers was eventually raised, and marched west under first George Washington and then Hamilton. The peasants, of course, fled to the hills. The army caught and tried a few farmers in kangaroo courts and executed a couple. It became known as The Whiskey Rebellion. When Thomas Jefferson became President, he abolished the tax.

    Using whiskey and a few other easily transported goods, the peasants were able to trade not only with the eastern seaboard, and therefore the world, but also down the Ohio and Mississippi river to the Spanish and French in New Orleans. So the peasants were largely self-sufficient but also connected to the wider world.

    BUT, the peasants did not NEED the wider world in order to live a reasonably good life. What they DID need was a good garden plus a forest which provided game animals and wild plants. A hundred years after the Whiskey Rebellion, when Eastern Money had stolen much of the land, and figured out that extraction industries such as coal were the path to wealth, they needed labor in the mines. At first, they hired the peasants, but found that the peasants were way to independent for the iron discipline required by industrial processes. If a peasant became dissatisfied, he just went back to his homestead and garden and didn’t have to put up with the nonsense. So the corporations stopped hiring people with gardens.

    I have oversimplified the narrative in the interests of brevity. If anyone is interested, I recommend Ramp Hollow by Steven Stoll.

    Stoll traces the notion of the garden and the home economy as the basis for a society back to Robert Owen, the English reformer. Owen makes the point that a peasant with an acre of land can do well. But it takes a lot of acres to feed horses. So the ‘Family Farm’ , which sells to urban markets, is far more energy intensive than the peasant farmer.

    Quoting from Stoll, page 69:
    The true product of the agrarian (peasant) household is the survival and reproduction of the household itself.

    And yet, there is another sense in which peasants can attain great efficiency. They produce more energy (in calories) than the energy they expend. In Mexico, with no draft animals, corn yields nearly 11 units of energy for every 1 unit expended. In the Philippines, with animal labor, it yields 5 to 1. Compare this to the United states, where combines and nitrogen fertilizer recently produced yields of 3 to 1. Cassava production in Nigeria attains an output-to-input ratio of 7 to 1. Wheat in Kenya, using only human power, reaches 3 to 1. Draft animals reduce the ratio because they require food and human attention. Still, Filipino wet-rice planters who use animal traction realize a ratio of around 3 to 1, while mechanized rice production in the United States does no better than 1.5 to 1.

    Then there is swidden, a term for the way people have used fire to burn off vegetation before planting in the rich ashes. It can deliver rice at an amazing 25 to1, allowing families to provision themselves by working just two hours per day.

    Back to me. There is so much to think about in these paragraphs that we could talk about it for hours. But underlying all of the degradation of the Appalachians was the hostility (and probably fear) of the moneyed classes to anyone who could use swidden and live well with independence. When the population increased and there was less of an ecological base per person, the farmers had to abandon swidden and resort to more labor intensive gardening. But later on the coal companies found that one of their enemies was the ability of the newly minted miners to revert back to their gardens. The coal companies also used gardens as a way to reduce wages below subsistence levels. They could calculate how much food the wife and children could grow, and deduct that from the money they agreed to pay the male miner.

    Much food for thought for those of us who think that some Neo-Peasant Future might be more attractive than the alternatives.

    Don Stewart

    PS The output to input ratios are calculated at the farm gate. If the wheat has to be transported to a mill which makes flour which is transported to a bakery which makes bread which is transported to a store which sells bread which is bought by someone driving a car to the store, and which may be refrigerated at home before it is eaten, the ratios all become heavily negative.

    • I had heard about the Whiskey Rebellion, but never knew much about it. I’ll check it out and thanks for the reference to Ramp Hollow.

      I think that not only will peasant agriculture be “more attractive” than other alternatives, it will be the only path to subsistence for everyone, except those few who can rely on hunting and gathering.

      There may eventually be enough surplus for other occupations, but for some unknown number of years after collapse I think everyone will be scrambling to grow food (unless there is established a well developed community of peasant farms and ancillary support services prior to collapse).

    • I had heard about the Whiskey Rebellion, but never knew much about it. I’ll check it out and thanks for the reference to Ramp Hollow.

      I think that not only will peasant agriculture be “more attractive” than other alternatives, it will be the only path to subsistence for everyone, except those few who can rely on hunting and gathering.

      There may eventually be enough surplus for other occupations, but for some unknown number of years after collapse I think everyone will be scrambling to grow food (unless there are established well developed communities of peasant farms and ancillary support services prior to collapse).

  38. Tying Together Some Loose Threads

    This won’t be scientifically quantified evidence. More anecdotal evidence that we don’t know everything about soil and carbon.

    Bill Gammage, a historian, wrote The Biggest Estate on Earth.
    In the book, he shows how the Aborigines created ‘the Estate’ through the use of fire. The pictures painted by the early Europeans, which illustrate the book, reveal a ‘garden continent’ very much unlike the Australia of today. Go to Amazon Books and search on the title. When the book comes up, click on the title. Look at the first two pictures (the third is a T shirt). The pictures don’t look like the Australia we know.

    Christine Jones makes the same point from descriptions of southern Australia during the dry season. The early Europeans describe fields of wildflowers…not desert. And Christine also tells of the Polish scientist who traveled extensively in Australia gathering soil samples, which were sent to England for analysis. The samples reveal soil organic matter from around 7 percent to the mid-20s. The scientist took good notes, but, unfortunately, he was handy with the ladies at the isolated farms, and included those notes in with his science, and destroyed the notes before his death. (Today, he would go on television to monetize his exploits.)

    For some reason, there was a lot more moisture in the soil during pre-colonial times. We know, as Gammage demonstrates, that the Aborigines managed their Estate with fire. If you will forgive my faulty memory, there is also good evidence that the Native Americans managed the forests of the southern Appalachians with fire. Early travelers reported having traveled 10 or 15 miles in a day…with the current tangle of ‘laurel hells’, they would have been lucky to have traveled 10 feet. The Nature Conservancy has promoted restoring fire as a management tool in the mountains. I believe one of the by-products that they mentioned was reduced flow of water in the streams, Which implies more water storage in the soils. (And you should not put this factoid in the bank, because of my faulty memory.)

    So…let’s assume that the Slovak Mafia is on to something about restoring weather and photosynthetic productivity by building structure which slows down water and lets it sink into the soil. And lets assume that using fire in forests may also have the effect of putting more water into soil in forested, generally steeply sloping, soil. In other words, human intervention CAN put more water into the soil than unaided nature.

    We also know that water vapor is a greater influence on global warming than carbon dioxide.

    Now let’s look at the limiting factors for photosynthesis. Water, obviously….and maybe we can do something about that. For example, planting trees or hedgerows in Agroforestry on contour. One of my early memories at about the age of 12 was driving around in a pickup truck with the local Extension Agent looking at beautifully contoured farms with fields surrounded by the windbreaks planted by the CCC during the depression. The net effect was water slowed down and sunk, water erosion virtually eliminated, the wind slowed down, wind erosion much reduced, and evaporation from desiccating winds much reduced.

    I think I have dealt with the issues of industrial nitrogen and phosphorus…they do not limit us if we farm or garden correctly (at least for the next couple of decades.)

    The next issue is fungi. If we don’t have vigorous fungal activity, we don’t have good soil structure with oxygen-reduced aggregates in which nitrogen fixing bacteria can do their thing, and we don’t have the plants apportioning a third or so of the carbon they make to the Liquid Carbon Pathway to feed the fungi who supply them with phosphorus and other nutrients they need. Fungi cannot survive long periods of fallow. If one plows a field and leaves it fallow for a year, then most all of the fungi will die, but spores will remain. When the farmer is ready to resume growing, the spores have to be awakened. In short, the best way to keep the fungi active is to keep a live root in the ground all the time. There are good farming practices, such as discing the slash, which will keep live fungi between closely spaced crops, such as a cash crop closely followed by a cover crop.

    If we have plenty of fungi and plenty of water, we may achieve the primary productivity that David Johnson attains….given that David has a virtually ideal situation in terms of irrigation water plus just about as much sunshine as anybody except the Sahara desert. Albeit that David had to create soil where the Ag School had grown brick.

    Is heat a problem? There are studies showing that a few more degrees of heat damage crop yields. But the Slovaks show that a field of bare dirt which generates a temperature of 95 F, will generate a temperature of 68 F if it is well-hydrated and covered with growing vegetation. Is this the reason why plants could thrive with much higher carbon dioxide levels and temperatures than today? Such as the petrified trees near Colorado Springs. Is the bare soil which is featured in most industrially farmed fields the problem?

    If there is enough vegetation generating maximum photosynthesis, then there will be a cooling effect. Will the cooling effect be strong enough to stop the melting of the glaciers and the ice caps and the rise of sea levels? Not being a scientist I can’t say with any confidence, but my guess is that the seas will rise…but life may flourish in the land which is not flooded.

    On the other hand, if humans do nothing about industrial agriculture, desertification may continue apace, and even accelerate. So we have the worst possible outcome: hot, dry, and flooded. And bricks to try to grow food in.

    Don Stewart

  39. Additional Loose Thread: Productive Life Span
    Suppose that, against all odds, a significant number of humans manage to build an excellent relationship with plants, and through them with animals. What can we expect in terms of injuries and chronic disease?

    I won’t get into injuries and infectious diseases. Let’s just assume that we could somehow maintain injury treatment at the level of, say, 1950.

    As for chronic disease, Valter Longo is the current leader (in my opinion) in terms of avoidance of chronic disease and the resulting increase in Health Span. Valter is a Professor in the Gerontology section at the University of Southern California. Valter promotes periodic Fasting Mimicking Diets. Which involves 5 days where only non-starchy vegetables and nuts are eaten. The dieter eats plenty of food by weight, but it is calibrated to trigger the metabolic effects of periodic starvation. The body begins to break down tissues, preferentially going after tissues which are damaged. Thus, the liver or the lungs or the heart lose tissues which are damaged first. (I’ll come to cancer later.) When, after the 5 day period, the regular diet is resumed, the body begins to rebuild the lost tissues with new tissues. There is an increase in circulating stem cells and a reduction in markers such as C Reactive Protein and blood pressure and cholesterol. The frequency of the 5 day fasting depends on the status of the dieter. A dieter in poor shape should do it 5 days out of each month for 3 months in succession. Someone in better shape can do it once a quarter. Someone in good shape can do it twice a year. According to the measured changes in metabolism, the 5 day diet is actually affecting aging, so that the dieter can expect to live not only longer, but considerably more healthy during the time they do live.

    For cancer patients, Longo has shown that the 5 day diet causes non-cancerous cells to become tougher, which means they resist chemotherapy better. But the tumor cells, which are children of abundant sugar, do not react, and are sitting ducks for the chemo. The combination of chemo plus the 5 day diet has been shown to kill tumor cells much more efficiently than either treatment, alone.

    Of course, if a person had followed Longo’s diet since childhood, they would have a much lower cancer risk to begin with.

    A little rabbit trail off to the side? Why do we need so many non-mycorrhizal plants in the garden? (Think…brassica). Well, one reason is that brassica are famous for their antioxidant effect. Eating brassica causes one’s body to make more glutathione…the master detox molecule. But, as Longo observes, no one has yet produced a convincing story that lack of dietary antioxidants shortens life. So maybe we could just grow leafy greens (e.g., lettuce) which DO form mycorrhizal associations. Such a conclusion would definitely make it easier to maintain mycorrhizal fungi in kitchen gardens.

    So there is at least the potential that future gardeners could live long, productive lives (think the Okinawans or other Blue Zone people) working in excellent soil maintained with the help of mycorrhizal fungi. And recycling the nutrients from the kitchen. And maybe even the composting toilet.

    Don Stewart

  40. Don, Joe – thanks for the further comments. Apologies, I’ve had my nose to the grindstone on the farm the past few days. Much interesting info there…and perhaps also a few points to quibble at. No time now, but I’ll pick up a few relevant themes in upcoming posts.

    • At this time of year, I wonder how you have any time at all for blogging? Glad you do, but please don’t feel obligated to educate or entertain in preference to actually growing food.

      Please do let us know your posting schedule, if possible, so we will know when to check in for another stimulating dose of SFF analysis.

      • Thanks Joe. Well luckily nowadays there are other folks who do most of the hard work around the farm, freeing me up to cultivate my social media presence instead, but I do still have to show some willing occasionally. Generally, I’m aiming to post once every 2 weeks (down from my erstwhile weekly output due to other pressures), usually towards the start of the week. And there’s another post coming right up…

  41. What an interesting discussion going on here! I won’t try to comment on all the different ideas that have been expressed, mostly because the topics covered are so broad. But I wanted to say something about my own experience making soil enriched with compost.
    I think it is very difficult to define/describe healthy soil, plants, or people because of the many variables and perceptions of what constitutes health. But I have found that I feel better and seem to suffer fewer illnesses eating fresh food grown in my compost enrich soil.
    In my business I have learned much about making and using compost to enrich soil. The richest looking soil I make is made from composted mixed yard waste (branches, grass clippings, weedy stalks, and leaves) blended into natural soil. The small wood pieces that result from grinding woody debris seem to make a tilthier soil than using composted manure or biosolids. I am beginning to think it might be the fungi that comes with the decomposed woodchips. In my own gardens I’ve noticed a large influx of worms, arthropods, and beneficial insects.

    When I make soil I buy local topsoil for blending. I use a vigorous mixing process that is harsher than tilling. Once amended the soil is piled up until sold, sometimes for several years. I have noticed several things about these piles. They are softer and more friable, which is expected from the increase in organic matter (OM content is around 6-8%). Plants growing on the piles are much larger than nearby field weeds. Their root mass is considerably larger, also expected since the soil density is less.
    But what I find really interesting is the blended soil’s ability to decompose fresh organic matter. I used to hire labor to remove the weeds growing on the pile to prevent them from going to seed. Then I learned from experience that if I roll piles burying the surface weeds into the piles they are rapidly decomposed. I have seen lambs quarter five feet tall with stalks almost half an inch in diameter decomposed in as little as three months. If I did the same in a soil that is not amended the weed “carcasses” would still remain in the pile even after a year. I now think of this process of rolling weeds into the pile as “feeding” my piles. I’ve also learned that my finished compost piles also like a shot of fresh food.
    My point is that once the microbial/fungal population is rejuvenated in soil it becomes very dynamic! How we measure and describe this process, how it relates to plant health, their food quality, and our health seems a vast topic for future research.
    I recall reading a soil science research paper from the 1950’s that described a test where they buried natural cotton pads in pots of soil. They periodically removed and cleaned the pads to check their weight loss. I can’t imagine any scientist trying this now because few if any farm soils would have a population of the microbes that could digest natural cotton fast enough to make it worth trying to measure. Since cotton is mostly cellulose I’m thinking it was fungi that “ate” the cotton.

    Walking in the woods around my home I am struck by the amount of polypore fungi present. This land has never been farmed because it sits on the edge of steep ravines; many old growth trees hundreds of years old still standing. I’ve still a lot to learn about how forest ecosystems thrive. I’ve been reading “Mycelium Running” and I’m beginning to understand better and rethink the value of mycelium in soil. This spring and fall we will be inoculating logs and woodchips with edible mushroom spores. I think there are many opportunities to get know the land around our homes and find ways to harvest food from it without impairing it’s ability to regenerate itself. This is how I think of “regenerative agriculture”.

  42. Dear Chris

    Much of the quantifiable evidence you seek is presented by Gabe Brown in his presentation “Treating the farm as an ecosystem”


    Which is also an excellent description of his amazing farming innovations, with which you admit lacking familiarity. There you will find plenty of numbers regarding yields per acre, volume of soil created over time, etc.

    It is also a serious shortcoming in your analysis that you fail to recognise the importance of holistic animal husbandry in regenerative agriculture — not for the animal products it yeilds, but for the positive role of animal impact when well integrated with agriculture. Gabe Brown and Gail Fuller, for example, are only practising the reverse of what Colin Seis and Bruce Maynard do in Australia with pasture cropping and no kill cropping, respectively.

    Their presentations at the permaculture voices conference are eye opening, inspiring and well worth checking out



    • Thanks for your comment. I’m aiming to write a follow up to this soon… Meanwhile, I’ll try to take a look at your links. Could you further specify what the shortcoming you’re identifying vis-a-vis livestock husbandry is?

      • Some more hard numbers from independent sources

        “Here, we evaluate the relative effects of regenerative and conventional corn production systems on pest management services, soil conservation, and farmer profitability and productivity throughout the Northern Plains of the United States. Regenerative farming systems provided greater ecosystem services and profitability for farmers than an input-intensive model of corn production. Pests were 10-fold more abundant in insecticide-treated corn fields than on insecticide-free regenerative farms, indicating that farmers who proactively design pest-resilient food systems outperform farmers that react to pests chemically. Regenerative fields had 29% lower grain production but 78% higher profits over traditional corn production systems. Profit was positively correlated with the particulate organic matter of the soil, not yield. These results provide the basis for dialogue on ecologically based farming systems that could be used to simultaneously produce food while conserving our natural resource base: two factors that are pitted against one another in simplified food production systems. To attain this requires a systems-level shift on the farm; simply applying individual regenerative practices within the current production model will not likely produce the documented results.”


        • Thanks for that link. I’ll take a look at it – some of the findings sound, shall we say, intriguing. I hope to write some more on this topic soon. Though I’m not sure how much the hard numbers you cite undermine much of what I say above.

  43. Hi there Chris. Very much appreciate your writings here on this blog, which I only recently discovered. I run a very small nursery today with plans to some time be able to run a small farm too.

    This is a very old thread, so if you will excuse me for bumping it. My question is very simple: Where did you learn that Gabe Brown uses glyphosate? On his website he says they do not use it. This seems to be your major concern with how effective and ecological his methods are and yours is the only critique of his approach to regenerative agriculture I have come across. His operation is 2000 hectares, so if it is true that he in fact does not use glyphosate, it should be a very strong argument for regenerative practices for other farmers to take the step and transition.

    • Hi Malte, thanks for commenting and apologies for my slowness to reply. I’m a bit too stretched to pick up on this debate in detail right now but in brief I’d say my main issue isn’t the glyphosate – it’s levels of carbon sequestration, yields per hectare and the associated socio-agricultural systems. I’m not opposed to regenerative agriculture, just skeptical of some of the stronger claims made on its behalf.

  44. We are family based in North London and looking for produce grown in accord with the principles of regenerative farming you describe in this article. Is there an umbrella organisation that facilitates connecting such farmers directly to consumers? What are the best ways to source produce from regenerative farms?
    Thank you.

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