Casaubon's Book

From the wonderful Agricultural Biodiversity Weblog (a favorite of mine) over at Research Blogging, is a fascinating summary of paper that describes the ways that most modern seed varieties, selected to be used under commercial conditions, don’t do as well under organic conditions, because we haven’t selected for the qualities that would enable success:

To perform well under organic conditions, varieties need to get a fast start, to outcompete weeds, and they need to be good at getting nitrogen from the soil early on in their growth. Organic farmers tend to use older varieties, in part because they possess those qualities. Concerted selection for the kinds of qualities that benefit plants under organic conditions, which tend to be much more variable from place to place and season to season, could improve the yileds from organic farms.

Read the whole thing, and the original paper – well worth a look.

It reminds me of a discussion I had with an older gentleman who in the 1980s had been breeding (for commercial production) a super-sweet non-hybrid corn with good cold soil emergence (translation, a really sweet sweet corn, much more than most old varieties, and one that can be planted early enough to produce well). He observed that the seed company that he’d been working with had been thrilled with the results of his nearly-stabilized breeding, which they felt was as good as most of the then-new super sweet corns developed through hybridization, and which handled wet years and organic cultivation better than most of the hybrids. But that company went out of business, and the gentleman went on growing this variety and eating it himself and giving it away to his neighbors and through Seed Savers Exchange, but never made a dime on it. What frustrated him was not the lack of profit, but that even the seed companies he tried to pass it on to (and by the end he was offering it up for free) in the 1980s and early 1990s didn’t see the value in a corn that responded better to conditions of organic production rather than conventional – it seemed like too small a niche market.

I’m an organic farmer (not certified), but I’m not an organic purist – that is, my claim is not that all agriculture must be organic all the time. But I think it is simple common sense that in a world of depleting resources and volatile price fluctuations for farm inputs, that more and more of our agriculture must operate with vastly fewer inputs. Figuring out how we’re going to do that well is essential.

Sharon

Comments

  1. #1 Ewan R
    April 28, 2010

    Perhaps the industrialization of the organic food system will lead to some good in that it will (or may already have become) be commercially viable to breed for increased yield under low input conditions rather than simply ramping up inputs – commercial breeders may be painted as evil in that they propagate an unsustainable system – but they do a damn fine job of it – which’d be awesome if applied to organic.

    Although I fear that the industrialized organic system is simply a case of switching man made fertilizers etc for those which meet the criteria for organic, although that should mean that modern cultivars perform equally well in “organic” and conventional settings, while underperforming in organic (dont have access to the paper to see what the organic techniques used were)

  2. #2 Sharon Astyk
    April 28, 2010

    Ewan, I agree with you completely about small O organic and industrial organic – both pluses and minuses – that’s why I only rarely talk about organic agriculture. Because so much of what is being produced by national organic standards simply shifts the fossil inputs around. Although I think what’s driving some of the new seed breeding going on is the growth in smaller scale producers – and an increasing concern about the Global South, where most agriculture is de facto low input by necessity.

    I think the difficulty of industrial anything is that it makes most of its admittedly fairly impressive gains at the cost of future productivity in a lower input world. Just as we extract resources faster now at the cost to our children and grandchildren, we do the same with agriculture.

    Sharon

  3. #3 Greenpa
    April 28, 2010

    Ewan: “commercial breeders may be painted as evil in that they propagate an unsustainable system – but they do a damn fine job of it – which’d be awesome if applied to organic.”

    I have reason to believe this is not actually so.

    If you listen to them touting their own accomplishments- they certainly are fantabulous. Try to get real outside quasi-objective confirmation of the performance of their genetic achievements, however- it’s nearly impossible; and anecdotal information from farmers often runs right up the middle (not counting the carefully filtered stuff.)

    The pressure to crank out “NEW! IMPROVED!” strains is very high indeed; meaning 99% of such new cultivars/strains are minimally tested; and for most of the test cycle, grown under “experiment station” conditions- ie. irrigated, 100% weed free, and 120% nutrient availability for the entire year. Seriously non-real world.

    An underlying assumption of their creed is “we know what we’re doing!”; and they actually believe that when they alter the genetics for Trait A, it has no real effect on Trait W. Which may in fact be true under their conditions- but is not true in, for example, a year with a dry spring, followed by a cool wet summer. Or something.

    I do some of this stuff myself; and am working on a paper which will basically say: in full cycle analysis, direct real-world, multi-decade field screening and breeding is faster and cheaper than lab-based “fast” breeding. When you measure actual success- at year 30.

  4. #4 Sarah E
    April 28, 2010

    Sharon,
    What is this sweet corn variety called? I will keep an eye out for it in the Seeds of Diversity (Canadian seed savers exchange) directory. It sounds really good. Thanks!

  5. #5 Ewan R
    April 28, 2010

    Greenpa – not quite sure what you’re going at, analysis of improved yield over the past 50 years shows that commercial breeders have certainly done a damn fine job in terms of breeding *for* the high input. I’m not sure whether you think I’m argueing for MAS, GM or whatever, but I was (or at least intended to be) merely commenting on ‘traditional’ breeding (ie success at year 30 – which at least in the handful of crops I am aquainted with would be hard to argue that breeding has not shown measurable success over the past 30 years)

    I’m all for also doing MAS and GM to improve low input ag of course, but that’s a completely different train of thought.

  6. #6 Jerry Grabarek
    April 28, 2010

    Sharon,

    You must realize that the big seed corn companies somehow engineer their varieties so that they produce very poor crops if they self pollinate in order to make farmers buy new seed every year. If by chance one does yield well Dow, Dupont, and Monsanto will be on your farm suing you for patent infringement.

    Jerry

  7. #7 Ewan R
    April 28, 2010

    Jerry – that is quite frankly absolutely insane!

    If it were the case why would farmers ever even contemplate saving seed? (as they do on occasion, albeit rather perilously)

    Poor (as compared to the hybrid) performance in the offspring of a hybrid is only to be expected because the Hybrid represents the bringing together of two distinct genomes into a high yielding variety (hybrid vigor) for a single generation (after which you’d expect pretty meh performance)

  8. #8 Don
    April 28, 2010

    I was going to ask what the name of this sweet corn is, too, but Sarah E already beat me to it.

  9. #9 Mike Cagle
    April 28, 2010

    What do you think of this fellow?
    http://blog.ted.com/2010/03/qa_with_chef_da.php

  10. #10 Greenpa
    April 28, 2010

    regarding Dan Barber- I like him a lot; he’s quite knowledgeable. I’d love to talk to him; I’m sure we’d both learn interesting stuff. :-)

    Ewan: “I’m not sure whether you think I’m argueing for MAS, GM or whatever,”

    not at all-

    “but I was (or at least intended to be) merely commenting on ‘traditional’ breeding (ie success at year 30 – which at least in the handful of crops I am aquainted with would be hard to argue that breeding has not shown measurable success over the past 30 years)-”

    I’m pretty sure we’re using different yardsticks. If you read the research reports from the Land Grant system, yup, their yields are up.

    To me, though, this is like announcing great success for the Mutual Fund you are running, based on only last quarter’s results. The real picture is way more complex, and includes, without question, things like aquifer drawdown, recharge and pollution; soil erosion and salinization, and health of farmers.

    Inputs required to make those higher yields are crazy destructive; and really should not be ignored on the balance sheet. An excellent example for us is China, where “modern” genetics, accompanied by fertilizer, pesticides, and much higher non-traditional irrigation practices in the last several decades have resulted in really tremendous losses to the land. The universities never put that in their ag yields reports, and I strongly contend it must be there.

    And in a different direction- sure, the ag guys are very proud of the fact that average maize yields were around 30 bu/acre before hybrid corn, and are now around 100 bu/acre- but- no one in the modern community has achieved anything like what the Native Americans did, transforming teosinte into maize, or domestic potatoes from wild roots, squash from wild cucurbits, and on and on. No modern breeder I’ve talked with even has such ideas on their horizon anywhere; they’re focused on incremental gains- and we need much bigger jumps.

    Gets to be a long conversation! :-)

  11. #11 Ewan R
    April 28, 2010

    Hmm, I’m more used to talking in terms of 150-300Bu/Ac corn.

    The issue was that breeders have made great increases within the high input system during the past 50 years. I don’t think you’d argue against this at all, with the caveat that the high input system itself is a problem (acknowledging but ignoring the destructive nature of the inputs)

    However – gains have been made here, and not elsewhere, because the focus has entirely been on selecting varieties which work in high input environments, leaving selection in low input environments largely untouched.

    now, given that there is significant variation within corn varieties for performance under limiting conditions (be that drought, nitrogen, cold, heat or any other stress – and I pick corn here onyl because it’s what I’m most familiar with, not because I’d advocate large scale adoption of corn as a good low input crop), and given that there is now a commercially viable reason to select for increased yield under these conditions my assumption is that traditional breeding should be able to increase yields under limiting conditions – unless of course the contention is that we’ve already reached the upper ceiling on yield under limiting conditions for various crop varieties (and given the variation within species I find this a little hard to believe)

  12. #12 Greenpa
    April 28, 2010

    “Hmm, I’m more used to talking in terms of 150-300Bu/Ac corn.”

    World wide? I think including all land, globally, in maize, my 100 is probably closer. No one I know gets 300 except the wackos entering yield contests, pulling all kinds of tricks. Do you know any commercial farmer who gets 300 year after year, and makes money? (Not saying you don’t- just that I don’t). :-)

    “The issue was that breeders have made great increases within the high input system during the past 50 years. I don’t think you’d argue against this at all, with the caveat that the high input system itself is a problem (acknowledging but ignoring the destructive nature of the inputs)”

    True. However; I’ve gotten to a place where I do not automatically ignore the destructive bits, in my own thinking. Can’t. It is only the whole that matters.

    However – gains have been made here, and not elsewhere, because the focus has entirely been on selecting varieties which work in high input environments, leaving selection in low input environments largely untouched.”

    True.

    “now, given that there is significant variation within corn varieties for performance under limiting conditions (be that drought, nitrogen, cold, heat or any other stress – and I pick corn here onyl because it’s what I’m most familiar with, not because I’d advocate large scale adoption of corn as a good low input crop), and given that there is now a commercially viable reason to select for increased yield under these conditions my assumption is that traditional breeding should be able to increase yields under limiting conditions – ”

    There is where we differ in a substantive way. A huge part of the “success” of modern crop breeding is based on measuring progress under the most uniform (ergo comparable) conditions possible. Eliminating variation in conditions is a big part of their philosophy, and the way they measure.

    My contention is that selecting for performance under limiting conditions will require substantively different procedures, due to trade-offs that occur in the physiology of the plants under one stress or another. The largest difficulties being pleiotropic gene effects and the inability to foresee what factor will be limiting this year, requiring planting of strains capable of dealing with multiple limits facultatively.

    That will have to require many more years of testing before performance can be assessed. The ability of models to project performance is not demonstrated. (Ask a salmon fisherman) :-)

    “unless of course the contention is that we’ve already reached the upper ceiling on yield under limiting conditions for various crop varieties (and given the variation within species I find this a little hard to believe)”

    No, I think the world maize gene pool is pretty good, though several other crops are better.

    It’s more like the apocryphal story of the Senator and the Nuclear Physicist. During the rush to build an atomic bomb, the Manhattan Project, the mythology says a Senator, pushing for faster progress, demanded of a project chief why the hell they didn’t just put more scientists to work and get this done. The scientist’s reply: “Senator- it takes 9 months for a man and a woman to make a baby. Now- if you put 9 men, and 9 women to work on the project… it will still take 9 months.”

  13. #13 Ewan R
    April 28, 2010

    No, not worldwide, but I’m also working on the assumption that commercial breeders have been far more active in the 150-300Bu/Ac markets than they have in the 20-50 Bu/Ac markets, which may be a drastically wrong approach to take, but there you have it!

    On ignoring the destructive bits – in this instance I was purely interested in increases in yield, while it remains true that these increases are based to a large extent on the destructive bits you decry whether or not the breeding programs have been succesful doesn’t have to include the destructive bits – it isn’t really helpful to include them when mitigation of the destructive aspects of ag wasn’t the goal of any of these breeding programs (perhaps it should have been)

    I don’t claim that selection for performance under limiting conditions would be easy – just that it would be possible – given that you see a year on year increase in performance in the paper under discussion under regular ag as compared to a total flatline in organic ag (and my take home here was that the main underlying difference was nutrient availability, rather than any severely limiting stress) I would expect that under selection in the organic conditions roles would perhaps be reversed (increased focus on season long nutrient uptake and uptake of more complex forms of N etc rather than a time specific concentration on sucking as hard as possible)

    My hope is that at least that one man and woman will be put on the project to make the baby, although ideally 9 men and women… because even if it takes time, it wont get done at all if we just flat out say it can’t be done. (and in the meantime lets get anotehr couple or six to work on finding the next big thing rather than fixing the last big thing)

  14. #14 Greenpa
    April 28, 2010

    I’d just like to say I’m enjoying our conversation. :-)

    ” while it remains true that these increases are based to a large extent on the destructive bits you decry whether or not the breeding programs have been succesful doesn’t have to include the destructive bits – it isn’t really helpful to include them when mitigation of the destructive aspects of ag wasn’t the goal of any of these breeding programs (perhaps it should have been)”

    I understand what you’re saying (I think :-) ) – but what I’m saying is that my own brain has moved to a place where I literally cannot conceive of calling what they’ve done “successful.” It’s like an airplane designed to carry more people- but they forgot the wings. Not a success. Though the engineers involved in producing the bigger body and adding more seats and more lavatories would quite possibly claim to have succeeded. I’m not saying that in any finger-pointing kind of way. Just from a different perspective. “Look, it carries more people!” “But it won’t fly.” “But look, we fulfilled our contract!” “Um. I guess. But it won’t fly.” Not successful.

    “I don’t claim that selection for performance under limiting conditions would be easy – just that it would be possible – ”

    Physically, it is possible, without question. I have serious qualms though about whether the current academic or corporate breeders would be able to do it- systemically. The grant cycle- the biggest engine driving research and careers- generally runs on a 3 year turnover. Show measurable progress in 3 years, or be terminated. Changing the grant cycle is a task that I can see no handles on; the barriers to changing it are located throughout all parts, top to bottom. It is almost impossible to conceive of a young researcher speaking this sentence; “Dean, I want to undertake a project- really important, but it will be 20 years until we know if it’s working, and 40, probably, until really significant progress.” The Dean’s jaw will drop.

    “My hope is that at least that one man and woman will be put on the project to make the baby, although ideally 9 men and women… because even if it takes time, it wont get done at all if we just flat out say it can’t be done. (and in the meantime lets get anotehr couple or six to work on finding the next big thing rather than fixing the last big thing)”

    I’m sure it CAN be done. But not, I fear, by anyone trained by, or working in, the current breeders’ paradigm. They just keep asking questions that do not lead to airplanes that can fly – and I don’t see any movement in the establishment to ask truly different questions.

    Ah- here’s the real world comparison I was looking for. The Cancer Research Industry.

    They’re in that position. Lots of “progress!” they point to; but from many perspectives, nothing like any reasonable return on the investment. In any competent industry- they’d have shut the whole thing down decades ago, and just looked for a completely different team to tackle it, from a completely different angle- ANY different angle. The fact that the established workers don’t see, or think there can be, a completely different angle- is exactly the problem. But we/they have nobody like a CEO/CFO at the top to just pull the plug.

  15. #15 Greenpa
    April 28, 2010

    oh, and just in case it isn’t obvious- my viewpoints on all this are not at all well received in the breeding/academic community. :-)

    Although I now have 5 universities, at last count, trying to duplicate my long term results.

  16. #16 Greenpa
    April 28, 2010

    I just realized where some of my attitude may have originated- with my father, a professional engineer turned engineering professor. He would periodically complain about his students’ complaints.

    They would sometimes come up to him and argue- “Look, I know I got the wrong numbers at the end of the problem; but if you look at my work, you can see that I really do understand the problem. I think I should get credit for that.”

    To which his response was “I don’t give a @%(&$_@@((!! whether you UNDERSTOOD the problem!! Your goddam building FELL DOWN. You failed.”

  17. #17 Mike
    April 28, 2010

    Greenpa: ” but what I’m saying is that my own brain has moved to a place where I literally cannot conceive of calling what they’ve done “successful.” It’s like an airplane designed to carry more people- but they forgot the wings. Not a success.”

    That is just dithering over semantics. When I talk to my students about the increase in milk production from a dairy cow due to genetics, nutrition, health, management, etc, I tell them that I consider this to be an amazing increase from a scientific standpoint. However, I remind the students that science is simply a method for examining the world and has no inherent ethics or morals or right or wrong.

    I think that you can acknoweldge the dramatic increase in crop yields is amazing from a scientific standpoint. The key concept is that as the price of energy increase, inputs will become more expensive. As this economic environment changes, breeders will take this into account and efficiency of using available nutrients in the soil will become more critical.

  18. #18 Greenpa
    April 29, 2010

    Mike- no, I really think it’s not semantics. I’m rather bemused by how I wound up here, myself. I talk with mainstream ag people at all levels, all the time, so I’m not unfamiliar, and I assure you I know the statistics on ag production; have published on it.

    It’s more, I think, a cultural thing. Something like the clash between European colonizers, and the many native peoples who had no concept whatsoever, including words, for the idea of private ownership of land. A basic disconnect.

    Which, if you permit me, you are illustrating at the moment. :-) You still want me to say modern ag’s “yield” increases demonstrate a success of some kind- and from my current, deeply held weltanschauung, there is no success there whatsoever.

    The stated purpose of agricultural science is to grow food- but there is also a primary assumption that is so buried and so universally believed as to never be examined. Farming is also supposed to be “healthy” – for all parties, and for succeeding generations. Just close your eyes and say “farm” – I guarantee you will see a sweet, productive, “good”, healthy, image.

    I think the current brouhaha over Goldamn Sacks may be a similar disconnect. Their defence is, “Our customers do not come to us for advice.” I think there’s a fair chance many of them actually believe that; they think, and always have, that the purpose of their business is to enrich themselves, period. All’s Fair. The outrage from Congress, real or otherwise, illustrates that the clients have always held a very different viewpoint- when they pay GS to set up deals for them, they have always expected GS to use GS expertise for the benefit of the client.

    I expect the clients may well say the GS defense is purely semantic, and cynically, knowingly, manipulatively mendacious. But based on the history of cultural disconnects, I have to think there is a good chance some of the GS people actually believe what they are saying.

  19. #19 clew
    April 30, 2010

    “no one in the modern community has achieved anything like what the Native Americans did, transforming teosinte into maize, or domestic potatoes from wild roots, squash from wild cucurbits, and on and on. No modern breeder I’ve talked with even has such ideas on their horizon anywhere; they’re focused on incremental gains- and we need much bigger jumps.”

    I’d call perennial grains a pretty big idea, and it has its champions:

    “Prospects for Developing
    Perennial Grain Crops”,
    THOMAS S. COX, JERRY D. GLOVER, DAVID L. VAN TASSEL, CINDY M. COX, AND LEE R. DEHAAN:

    Perennial plants,growing in mixtures,make up most of the world’s natural terrestrial biomes.In contrast, monocultures of annual crops are sown on more than two-thirds of global cropland.Grain and oilseed crops are the foundation of the human diet,but to date there are no perennial species
    that produce adequate grain harvests. Yet perennial plant communities store more carbon, maintain better soil and water quality, and manage nutrients more conservatively than do annual plant communities, and they have greater biomass and resource management capacity. These advantages provide a base from which to begin hybridization and selection for increased resource allocation to developing seeds,a decades-long process that must overcome or circumvent genetic complications.Breeding programs aimed at developing perennial grain crops have been initiated in wheat, sorghum,sunflower,intermediate wheatgrass, and other species.

    BioScience, Aug 2006 pg. 649ff. Don’t know if it’s public access:

    http://www.bioone.org/doi/pdf/10.1641/0006-3568%282006%2956%5B649:PFDPGC%5D2.0.CO%3B2

  20. #20 Greenpa
    April 30, 2010

    Clew: “I’d call perennial grains a pretty big idea, and it has its champions:”

    I’m intimately familiar. I agree it’s a lovely idea. The problem is- there is NO progress, after 30 years or so. Really none. If you check Wes Jackson’s writings and press from way back at the beginning of The Land Institute, his statement has been; every year, “look, this is a complex problem. In 20 years, we’ll know if it can work…” It’s still 20 years away, just to know if it can work.

    It’s just an idea; not an achievement, alas. And by far the great majority of ag researchers, mainstream and contrarians, do not think it can work- because of actual energy in-out measurements. The energy for annuals or forbs to both survive winter and produce crops of seed comparable to beans and corn- just isn’t there.

    Personally, I find this a better idea:

    http://www.badgersett.com/info/woodyag1.html

    And these guys have people growing their crops- now. And Rutgers, U Neb, U MN, U Wis, OR State – all announcing they’re picking it up; and they’ve got the Federal funding in their pockets.

  21. #21 Michelle
    May 2, 2010

    I received this information via email recently:

    The reason for non-labelling of GM oils, especially canola, has been that there is no detectable GM DNA present in the final foods. This new study shows the assumption to be wrong as DNA is detectable; which means that we have been deceived for over a decade.

    ‘GM DNA detected in refined GM oil – Public deceived – Farmers should be advised

    GM DNA has been detected in refined oil. This means that oils such as GM canola should be labelled ‘genetically modified’, under Australia ’s current labelling standards.’

    (Read the full media release and study details here….
    http://www.madge.org.au/Docs/MR-100415-GM-DNA-in-refined-oil.pdf

    And this:
    Bayer now joins Monsanto in admitting that GM contamination is out of control.

    EXTRACT: Bayer has admitted it has been unable to control the spread of its genetically-engineered organisms despite ‘the best practices [to stop contamination]‘(1). It shows that all outdoors field trials or commercial growing of GE crops must be stopped before our crops are irreversibly contaminated.

    Read the full article here…

    http://www.organicconsumers.org/articles/article_19777.cfm

  22. #22 Ewan R
    May 3, 2010

    Greenpa – on the woody Ag, what’s the general yield like? Definitely looks like something that could easily come in and be competitive with other commodity crops even given that nuts are high in oil.

    Also, what’s your general opinion on the concept of making c3 plants behave more like c4 plants (other than perhaps a feel that by the time you manage to make a C3 act like a C4 the competitive advantage will be completely removed due to high atmospheric CO2 levels…) – I’m guessing this is another ‘in 20 years we’ll know’ prospect – but hey – in 20 years we’ll know…. right?

  23. #23 Greenpa
    May 4, 2010

    Ewan- a bit of “full disclosure” – I know the people at Badgersett quite well, and work on some of this research with them. I shoulda said that in the first place.

    “on the woody Ag, what’s the general yield like? Definitely looks like something that could easily come in and be competitive with other commodity crops even given that nuts are high in oil.”

    in their Short Course this year, the information was approximately this: they have about 10 different hybrid hazel bushes which- IF and WHEN whole fields can be brought into bearing like theirs (based on years of bearing records), the yields of kernel would be more than 250% of average soybean yield. Hazels are approximately 10% protein, 65% oil- and the oil is literally chemically identical to olive oil.

    Basic reason- these are 5th/6th generation selections for heavy crops, very far beyond wild-type, and woody plants in general capture 200-300% more sunlight than an annual crop like maize.

    “Also, what’s your general opinion on the concept of making c3 plants behave more like c4 plants”

    It would be a mistake. (Opinion, you said. :-) ) C4 photosynthesis is kind of a red herring, I think. So far all C4s require fairly hot temperatures to work- over 80°F or so? I’m out of date there. But- in the temperate zones, where much “modern” agriculture is inflicted, the way this turns out is- average Growing Degree days with a base of 55°F; used for maize crop predictions; are about 1500 in the northern US “corn belt”.

    C3 plants, however- which a lot of agronomists now sneer as as less efficient- photosynthesize quite well at far cooler temperatures – actually even down to 34°F (pretty slow there- but…) Northern corn belt Growing Degree Days at base temperature 45°F = 3,210. The hazels are hard at work on any cool misty day May through October; and on the hot days too. C4′s are only really at work on hot days, June through August. Even with global climate change- there will be lots of cool days in the year; woodies can use them; C4′s can’t.

    Somehow, people who grow annual crops haven’t noticed. And foresters don’t think this way.

    Vastly- and I use the word carefully- more energy is available for tweaking in the woody system.

  24. #24 vertalio
    May 4, 2010

    Far more carbon absorbed, too, no? And if the hazels are coppiced, quite a lot of fine quality hardwood suitable for charcoal, for those who suspect technology will roll back to the need to smelt iron locally, without the grid. Or just to sequester carbon, for biochar.
    Also, of course, topsoils will stay put in woody ag.
    And for those who like to eat rodent…
    bonanza!

  25. #25 Greenpa
    May 4, 2010

    vertalio- carbon absorbed; yes. The hybrids are bushes, not trees (more productive, easier to handle) and are coppiced once every 10 years or so, instead of any annual pruning; lots of uses for the wood; it’s another crop. They come back very quickly. And the soils not only stay put- they actually build.

    You catch on quick! :-)

  26. #26 Sharon Astyk
    May 5, 2010

    Awesome conversation, folks. But Greenpa, you are a shameless flirt ;-).

    Sharon

  27. #27 Ewan R
    May 7, 2010

    Thanks Greenpa – given me a bit to think about, and to poke holes when anyone brings up C4s inherent superiority – good to get a different perspective on that one…

    Gotta go mutiliate a bunch of corn roots now – may return with some followups so watch this space! (or not)