Erin Alladin

Back in December 2021 I came across the 2016 thread on this subject and went looking for research on dynamic accumulators. That happened to be the month Unadilla Community Farm released their report from the field trial they'd conducted on five presumed dynamic accumulators in conjunction with Cornell University. They tested redroot amaranth (Amaranthus retroflexus), lambsquarters (Chenopodium album), dandelion (Taraxacum officinale), red clover (Trifolium pratense), common nettle (Urtica dioica), and Russian comfrey (Symphytum peregrinum). The plants were chosen because they were popular permaculture plants and, with the exception of comfrey, had lots of data already available in "Dr. Duke's Phytochemical and Ethnobotanical Databases."

To run the trial they had to decide what the parameters of a dynamic accumulator ARE, exactly, and this is what they settled on:

- That the plants were accumulating beneficial nutrients in their tissues
- That they were doing so at concentration levels higher than those found in the surrounding soil
- That they were drawing significant amounts of the nutrients from the subsoil rather than competing with with other plants for them at shallower depths.

In the particular conditions of this trial, common nettle distinguished itself as a definite dynamic accumulator by that definition, and comfrey and lambsquarters met the required thresholds for certain minerals. However, there's a lot that's still unknown. Could the other plants  have performed better in different soil conditions? (And if that's the case, what does that say for using dynamic accumulators to improve poor soil?) How soon are the accumulated nutrients bio-available to other plants? Could plants with a reputation for scavenging one mineral actually be better at scavenging another one?

I wrote a blog post at the time summarizing the trial and giving as full a timeline as I could for the dynamic accumulator conversation in permaculture.

r ranson wrote:

First attempt at thumnails.
Anything show promise?

I think maybe something simple this year and I do more planning for next year's painting.

I like the portrait-orientation ones with the spray of lilacs curving over.

Nancy Reading wrote:My memory for some reason has them barricading the revolution outside the barricades, but that might be Vimes using smoke and mirrors to keep people safe.

Vimes sets out to keep one little corner of the city safe. But while he was away, Fred Colon oversaw the rest of the revolution pushing the barricades to contain more and more streets, reasoning that they wouldn't be rebelling against the city if they WERE the city.

“It was a beguiling theory that had arisen in the minds of Wiglet, and Waddy, and, yes, even in the not-overly-exercised mind of Fred Colon, and as far as Vimes could understand it, it went like this.
Colon: Supposing the area behind the barricades was bigger than the area in front of the barricades, right?
Colon: Like, sort of, it had more people in it and more of the city, if you follow me.
Colon: Then, correct me if I’m wrong, Sarge, but that’d mean in a manner of speaking we are now in front of the barricades, am I right?
Colon: Then, as it were, it’s not like we’re rebellin’, is it? ’Cos there’s more of us, so the majority can’t rebel, it stands to reason.
Colon: So that makes us the good guys. Obviously we’ve been the good guys all along, but now it’d be kind of official, right? Like, mathematical?
Colon: So, we thought we’d push on to Short Street and then we could nip down into Dimwell and up the other side of the river…
Colon: Are we going to get into trouble for this, Sarge?
Colon: You’re looking at me in a funny way, Sarge.
Colon: Sorry, Sarge.

r ranson wrote:a thimble?

Even better, a darning mushroom.

I'm so grateful that you did this research! I have been researching to write a blog post on the subject of dynamic accumulators, and for a long time the only discussions I could find were five years old. I had almost given up when I found your report. I'm very happily going through it now!

I shouldn't attempt a formal review because I read the book several years ago from the library and can't refresh my memory now, but I want to add my two cents. It was exactly the kind of book I was looking for after reading The Soil Will Save Us by Kristin Ohlson and Cows Save the Planet by Judith D. Schwartz. It took the ideas I formed from those books about how farming and ranching can sequester soil carbon, and expanded my understanding to include other food systems...other ecosystems. I found it deeply exciting to learn about both traditional whole-systems approaches that have existed for centuries and new ones that are being developed today. I'd love to read it again.

I suspect you'll see better results in coming years no matter what. I live on very hard clay and raspberries are one of the wild plants that thrive like nobody's business here.

Few things make me happier than having so many nasturtiums that I can eat all I want and not leave them visibly depleted. Here's to all self-seeding (desirable) flowers!

Good question. I'm personally very tolerant of wayward living mulches, but I did find others in my communal permaculture garden were a bit more bothered by plants going out of the bounds we planned for them. Borage was one for the same reason you described. Strawberries were another. I guess the important thing is to know before you start what you and other stakeholders are comfortable with in terms of plants that seed or spread freely.

Did you end up growing your pumpkins on the piles, Phil? My landlord (and, I think, the previous owner) left a big mess of piled-up logs that I've been mining for a hugelkultur mound, and it occurred to me the other day that it would be so much easier just to transplant some squash right into the log pile. I'm still finishing my non-lazy mound because I want it as a windbreak, but I am increasingly eyeing my too-abundant squash seedlings and the pockets of soil in the log pile...