I've been collecting quite a collection of scale, and, being the hoarder I am, I wondered if anyone had horticultural uses for it. Would it give iron to my plants if I crush it up and sprinkle it in the garden?

Probably not; scale is mostly Fe₃O₄ (magnetite), and since the iron atoms are solidly bound to the oxygen atoms, they're not available to be taken up and used by the plants. Iron deficiency in plants is usually treated with iron sulfate or chelated iron, but addressing soil pH can also be effective in making the existing iron in the soil more bioavailable. 

However, magnetite is sometimes used as an iron ore by those who make bloomery iron, so you might see if there's anyone in your area who might want it for that.

Scale will rust to Fe2O3 if in a moist environment.  Finely divided should work.  I'll try some on the 'maters...

I was thinking that over time it could help- talking years, not months. I guess its worth a try, or to save... maybe there's a Potter that wants it for glazing around me?

I suspect that the strong bonding between the Fe and the O would still be a problem, but I've submitted this question on a (strictly evidence-based) soil science FB group I belong to; I'll keep you posted on any replies.

Jhcc- thank you! I suppose if no mineral transfer would occur, it could still help in the way that any additions to largely clay soil would help- to break up the soil and provide an additional substrate to allow water in. Purely hypothetical, though. 

Almost all natural iron in soil would be an oxide; that's how it's been since we got an Oxygen rich atmosphere!

The problem with adding material to clay soil (such as sand or whatever) is that you're basically making adobe. A much more effective way to improve clay soil is by encouraging the natural processes that build good soil in the first place: slow-decaying organic material added on top (wood chip or straw mulch), minimal disturbance of the soil (which tends to clump the clay particles together, so no double-digging and minimize tilling as much as possible), don't block moisture exchange (no cardboard or plastic mulch), and so on.

4 minutes ago, ThomasPowers said:

Almost all natural iron in soil would be an oxide

True, but iron is taken up by plants as ions, not as oxides.

The first response is in! This is from Linda Chalker-Scott, Associate Professor of Horticulture at Washington State University:

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Interesting question!

Plant roots and microbes do transform soil chemistry to acquire nutrients through acidification, chelation, and chemical reduction. After all, plants and microbes can transform bare rock into soil over many years. So theoretically this iron could be transformed into a plant available form.

That being said, I would not add it unless a soil test revealed a deficiency in iron.

 

Linda further comments on about whether iron sulfate or chelated iron are effective treatments:

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Yes, though it is a short term solution and I'm really not sure it would be needed given the ability of roots and mycorrhizae to acquire nutrients. It would require both a soil test and a leaf analysis to figure out if there was a soil deficiency and/or a foliar deficiency.

 

One thing I should say about Linda (having interacted with her for about ten years now) is that she is very much a hands-off person when it comes to soil amendments, fertilizers, etc. Her general rule is, "Unless a test shows a deficiency, don't add anything!" She also likes to point out that there's no such thing as anything that's universally "good for" plants -- even excesses of composted organic matter can be washed out of the soil, with that runoff contaminating waterways and causing unwanted algae growth.

Look what heavy rainfall has done to "jungle" soils in the Amazon.

On 6/11/2021 at 4:10 AM, Ridgeway Forge Studio said:

I've been collecting quite a collection of scale, and, being the hoarder I am, I wondered if anyone had horticultural uses for it. Would it give iron to my plants if I crush it up and sprinkle it in the garden?

I read a book some years ago which was based on the idea that plants grow better in paramagnetic soil. The author did extensive research and cited many examples to support his theory. 

Mixing scale in the soil might help in that regard. I'll look for the book to give you the title and author if you're interested. 

Please do. I’d like to hear what my friend Linda might have to say about that. 

My Grandmother drove 3-4 plain iron nails in the trunks of the peach trees when we moved into a new place. She said they needed the iron. 

I scattered scale off the shop floor round a few wild roses of MANY around here and those bushes still have much darker brighter flowers. Almost purple as opposed to violet. 

Frosty The Lucky.

On 6/26/2021 at 8:03 AM, JHCC said:

Please do. I’d like to hear what my friend Linda might have to say about that. 

The book is titled: "Paramagnetism: rediscovering nature's secret force of growth".

By Philip S Callahan PhD.

Thanks.

Well, while we wait for science, I suppose anecdotal testing may be in order- I'll sprinkle some around a few plants and see what we come up with!

Linda has responded; I'll compile her comments here, as we had a bit of back-and-forth Q&A.

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Run away from this book as quickly as possible. It is pseudoscience at its best.

 

To do a real analysis I would have to see the list of "research articles" to assess their credibility. Ask for those and then if you like you can [send them to me to look at].

 

I looked at this probably 15-20 years ago in some detail but I can't find my notes. I can tell you there were NO credible science-based references at that time (because I did an exhaustive search), so I have no idea what is promoted as such in the book.

The Callahan book was published in 1995 (the author died in 2017), so I'm pretty sure her earlier search results covered everything that was available at the time of its writing.

I also did a bit of looking at Callahan himself, and his CV and work published in peer-reviewed scientific journals don't appear to have anything to do with plant growth. Instead, his scientific work seems to have been almost entirely focused on insects, especially on the electromagnetic aspects of their pheromone-based communication.

It's worth noting that most chemical elements and some compounds are paramagnetic (affected by magnetic fields but not capable of retaining a magnetic field in the absence of an externally induced magnetic force). Since one of those compounds is iron oxide which occurs in most soils, I imagine that it would be hard to find a soil that was not paramagnetic to some degree.

I was just curious enough to do a search and see if I could find the book online. I found an excerpt and am unimpressed and really skeptical after the first few paragraphs. His basic premise seems to be that science has it all wrong, his is the only valid method. yada yada yada. 

http://www.rexresearch.com/callahan/callahan.htm

The little bio blurbs I saw said he's a brilliant philosopher and accomplished entomologist and sometimes ornithologist. Not a word about agriculture until you get to the link I posted.

In my vast studies I've concluded crop circles are plants controlling paramagnetism and line dancing to the music of the spheres.

Frosty The Lucky.

I thought a crop circle is what you get when your grazing animal is tethered to a stake!

I think we’re going off on another tangent. 

  Here, let me help...   Everybody knows crop circles and paramagnetism are caused by activity in the earths core.

I thought crop circles were made by cereal killers 

That's a common misunderstanding. Grazers and cereal killers make cropped circles. See what happens when you combine things?

Frosty The Lucky.

And tartan is worn by serial kilters. 

Possibly not if they are "off Kilter".