Roberto pokachinni wrote:
Well I just tried to access two articles on that google scholars link and found that I was expected to pay US$36 for the privilege. Not tonight, especially with the CAN $ exchange rate the way it is right now at 78c US.
Roberto pokachinni wrote:
In the comments below that article, a person wrote this: "Lawrence D Hills carried out extensive trials, at his Henry Doulbeday Research station and Trial grounds, at Brooking, Essex, UK. His experiments and analysis were though and scientifically rigid in their methodology and presentation. His results were presented in the Comfrey Report (published by the HDRA in 1975). There is also a good summery of these experiments in Hills book ‘Fertility Without Fertilisers,’ also published by the HDRA. All of the results were laboratory tested by the Michaelis Nutritional Research Laboratory. The HDRA later changed their name to Planet Organic."
So this is the other information I found that connects comfrey with some data on it's dynamic accumulator function, but I have not found the studies by Hills to read myself, so I can not tell you or anyone what information it contains.
There is definitely something to this Dynamic Accumulator theory.
The permies community could even develop a "crowd science" study, where a simple protocol could be debated and developed by the forum and implimented by anyone anywhere who wanted to take part. Results could be shared on this site.
one would need to either add amendments to each plot uniformly or not add any amendments to any plot for the duration of the experiment. Preferably the latter, if the goal is to determine what each DA contributes to soil fertility?
On the nitrogen fixer issue: I haven't grown comfrey before, but what I have read is that it requires added fertility (principally nitrogen) to thrive. "It does well in most soils but prefers a rich soil with a lot of nitrogen...It is best to dig in manure between the rows in the fall or spring. Raw manure will not burn it. Comfrey loves nitrogen. You will get a lot more yield."
This is certainly true. The issue is, I guess, whether it is the soil organic matter, particularly fungi (likely in my opinion), who are solely responsible for the release of the locked up nutrient into the available nutrient stream, or if this would happen all alone, given enough time, in poor soil conditions, with the plant just happening to be there?-does it get locked into mineral form and that's it, if the soil is poor? Which brings us to the crux of the problem, and to the next quote by Jim:
I am sure the soil organisms (which ones?) have ways to make this soluble again, otherwise you'd lock it all up over time.
Exactly, and under what conditions? The plant may hyper accumulate minerals, but are they available, and if they do become available, when, and with the help of whom?
What isn't clear is, once their residues are laying on the surface, which minerals are water-soluble, and how long does it take them to become soluble?
but is this accurate, when considering what Jim T astutely brings up here:
I was talking with a well recognized naturalist about this discussion today, and he said that when plants draw up minerals (like the calcium I talked about above) from the soil, they do so in a "soluble form" which makes it easy for future plants to use it AND easy for rain to wash it away.
I personally think the jury is still out. This is not cut and dry.
Google "calcium oxalate". True, the Ca must be water-soluble for the plant to uptake, but then it is bound to other materials, making it insoluble.
But this isn't how nature operates. Nature throws seeds out and some land in ideal circumstances and many do not. Some thrive anyway, in spite of these less than ideal conditions. Fukuoka advocates a different approach than is conventional or what is historically done in the organic movement where preparing the land extensively is quite normal. Many others who practice no till and those who broadcast seed, do so randomly to produce the strongest, most resilient seed or plant stock. Sepp Holzer, for instance, gathers seed from the strongest looking plant that thrives in the poorest conditions. Now, I'm not saying that we should do, or should not do, anything in particular, but I am thinking that if we are going to have controls, then we need to figure out for starters what we are trying to do? Are we trying to demonstrate what the plant can do, on it's own, regardless of circumstances. If this is the case then we need to just let people do as they will, so long as they are doing before an after tests and documenting as much as possible, what is present and what changes. I don't know. I'm just typing away here...
Conventional farmers would either till / plant / cultivate, or apply herbicide / plant. Organic growers would either till / cover crop / till / plant, or sheet mulch / plant.
and I get that, and appreciate John Polk furthering this
I haven't grown comfrey before, but what I have read is that it requires added fertility (principally nitrogen) to thrive. "It does well in most soils but prefers a rich soil with a lot of nitrogen...It is best to dig in manure between the rows in the fall or spring. Raw manure will not burn it. Comfrey loves nitrogen. You will get a lot more yield."
Indeed, comfrey is a nitrogen hog.
, but I've seen comfrey plants thriving jammed against a south facing concrete house foundation and an old and compacted driveway with very little visible soil organic matter, where it had self seeded at a place I was renting. The house was 90 years old, and so there was some advancement to the soil culture over time, for sure, but it certainly wasn't ideal circumstances. Sure, it will reach it's full potential as a plant if it's seeds land in more ideal circumstances, but i think that the testing should not necessarily be solely in ideal circumstances. The test is to see what the plant does, not necessarily what it does given perfect conditions. Those known perfect conditions can also be part of the equation of various plots, but I don't see why a selection that is less than ideal for a baseline, should be avoided.
Hills recommends planting it near the poultry house, or pig pens to assure a frequent supply of manures
For healthy growth, it needs the addition of Nitrogen, and Phosphorus. It seems to find enough potash (K) deep in the soil, but it does best with ample & frequent applications of fresh manure.
For example (I'm going to use comfrey as the example, since I actually am getting some in the ground this year for sure, but we should probably focus on some other plants since comfrey is already the one with the most study)
There are people studying, according to what I read-but none were named, except for Robert Kourik. I don't know if anybody on Permies is doing the science end of things. It would be great if there was an academic, who is also a permie, who could lead this discussion from this point on. Not that I am absolving myself of pushing this ahead, but I would certainly bow to those who's knowledge and experience would give us the most gains.
Has anyone looked into grants to actually start some solid science on these issues?
Noel Deering wrote:and matter and energy cannot be created or destroyed.
Noel, my concern, and the reason for posting, is not about whether the plants actually function to accumulate minerals, or whether those minerals will eventually be made useful to the surrounding plants, but the lack of data on when individual minerals are made available.
I was never concerned that the Accumulators hypothesis might not be true.
Nor am I, and I would never suggest that people stop using the plants known as Dynamic Accumulators.
While I look forward to a concise confirmation that will convince skeptics, I'm not waiting for it.
Before I comment I will post another two quotes:
Kitsteiner points out that plants accumulating elements is well documented, but then wonders whether the nutrients in a plant are going to be available to other plants after decomposition. This, frankly, seems silly to me.
Deep soils of Iowa exist not because Mammoths were fond of using Miracle Grow and superphosphate, they're here because living things break down soil particles and they use, and are composed of, nutrients and when they defecate and die those nutrients are returned to the soil from whence they came. That's all obvious.
The article in question, and the purpose of this post is not about the long term usefulness of said minerals accumulated; Certainly the soils of Iowa were developed and their minerals made available through a variety of processes, but the processes of glaciation, the resulting deposition of soils, the wetlands which preceded the prairies, the herding that followed the grasslands, and the many, many changes in the plant communities over thousands of years while all this was taking place will create a depth of living soils and a usability of the nutrient and mineral base that no gardener or single plant could match, but this is not at all what we are concerned with. Over time, I think that all the minerals accumulated in a plant will be made directly available (given a lack of leaching or erosion and the stability of the soil food web), but the question, as stated above in this post, as well as numerous times in this thread is how much time will be necessary before the minerals are available? I'm not sure how multi millennial primal soil ecosystems relate to this topic. Maybe I'm missing something.
It has to be there, and when it is, it is used. Same goes for all other nutrients.
I think that you are under some impression that there are people who have posted that are making this assumption. I can't remember anybody making this claim in any form. Individual elements and energy sources can not be made or destroyed, but they can be made insoluble and thus unavailable for plants to pick up on their own. Through the mediation of a volume of time, or though a symbiotic relationship with a fungal partner, or through some other dynamic in the synergistic soil food web, or through some combination thereof an individual accumulated mineral becomes available to other plants. While in some instances, the accumulated mineral might be available directly to subsequent plants in a soil made up partly of the decomposing hyper accumulating plants in a pretty much immediate fashion, the subject of this thread is figuring this out. In this way, or as a result, we as permaculture practitioners and teachers, can give good information, based on fact, rather than running on theory and unproven hypothesis of what we think is common sense.
and matter and energy cannot be created or destroyed.
Simplifying the questions may help. Instead of "Do DA's work?" Perhaps "How long until a certain mineral is water soluble from plant X?"
are perhaps the subject of other projects. Although they have merit, I think it might be even harder to study these then the soil around a plant over time.
Maybe we should forget the taproots and all that and focus on the fun-guys? Perhaps they're networking and storing minerals specifically to confuse us? Mayhaps intense UV rays alter these minerals at leaf fall?
We can study Comfrey in a lab all day under perfect conditions, but what does that tell us about what it will actually do in MY yard?
I guess the way that I'm thinking when I read your post is that with enough "crowd science" we will have a range of information on individual "My yard"s and from this, a range of data that can be averaged out, to show indeed whether the minerals are becoming available, and when, and under real world (non-lab) conditions in a variety of locations and climates. I think that is what you are getting at.
Makes me wonder if 'crowd science' is actually going to be *more* scientific on this issue - in the way of producing helpful and accurate information applicable outside of a lab.
The more knowledge we gain, the more we should realize this truth. The Universe is many times more complicated than we will ever know. There is a favorite quote that I will paraphrase here: "The Universe is not only stranger than we know, it is stranger than we can know." This is not to say that we should not seek to find answers or to make sense of things.
Sometimes Im just blindsided by the realization that.... we don't know much :p
Tyler Ludens wrote:Phytochemical Database http://www.ars-grin.gov/duke/
What, precisely, is the purpose of having "scientific" determination...
Ian Rule wrote:False information is pretty damning to Permaculture, and I think quantifiable information protects Permaculture from naysayers... in that regard.
The establishment has the money to throw around studies and science, we need to tread lightly.
We, as Permies, know these things work and to some degree 'how', but if I walk onto someones property as a Designer expecting money, They are going to expect answers beyond "It depends". While an accurate answer to most questions in this field; if I want to win any accolades from Jimmy Cattleman, Id better be able to tell him with relative accuracy why his stuff wont work, or he'll categorize me as a "stupid hippie" and go hire the local landscapers.
If I can tell him what he can do without a passionate plea for him to go study ecology - and it works and seems scientific - it will also seem legitimate, but without a big sciency degree that demands I go do ConAgs bidding.
I don't imagine we're going to solve our cultural fixation with 'experts and studies', but we can.... tiptoe around it?