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Good morning all! I have a question that I'm hoping someone can help me with, please. Yesterday I dug out the Honeysuckle that I had growing in a half-whiskey barrel and decided to put a couple climbers in it instead. As I didn't have an actual trellis or anything, I decided to improvise, and "created" one, with rebar and gardening twine. DH mentioned to me that the rebar might be a bad idea for the soil, since it's made of steel. Could someone shed some light on this for me, please? Should I take it out and make something else? Any and all help would be appreciated.
Well, I know there there is such a thing as 'too much iron' in plants, and it can effect the roots and the uptake of other nutrients in the plants, but I have seen and heard of oooodles of other instances where people use rebar, un-covered by anything, as plant supports and have had no problem with this. But, I figured I'd ask in here, of people I trust to actually know stuff. =)
In any case, the stuff is in the barrel and working ok so far, so I'm gonna leave (no pun intended, heehee) it in there until I see bad things happening. Or until someone comes along and tells me I'm behaving badly by using it. ;)
But I think the iron from the rebar is going to be not enough to contaminate the whole pot. It just seems to me that with common fencing being steel, we'd hear something more about danger if there is . I have plenty of junk growing all over and under any kind of old fencing in my yard,.
Yeah Sally, that's what I was thinking too; with so much metal fencing and caging and other stuff, I didn't really think this would be too much of an issue either. Well, I know what to look for in regards to iron overload, so I'll just keep an extra eye opened for it. I'll be sure to check the roots really well next Fall when I give 'em a good root pruning, too. =)
I think that, to get too much iron, you would have to buy a bag of iron sulfate and sprinkle it deliberately. Like maybe 1/4 - 1 ounce per square foot?
Rebar can't rust fast enough to add more than grams per year per foot of rebar.
However, some mines leached out some product when bacteria metabolised something (iron ore? iron was involved) and vast amounts of it polluted soil downstream, They ahd to seal the mines so those areas went anaerobic, stoping the bacteria from exporting the pulloution.
Too busy last night to hunt! I bought a used M icrobiology text that is around 3 1/2" inches thick, so it takes some hunting.
Thedy were something like "chemo-auxotrophic" bacteria. Most things oxidise organic matter for energy. I t6hink these oxiudised one kind of iron into a more soluble form, that leached out and poisoned things until they figured out that they had to seal up that kind of abandonned mine.
Maybe some day they'll figure out a way to use bacteria to do the mining for us.
Or extract metals from land fill dumps!
Hmmmm, I did a bit of a google search using all the key words you provided (chemoautotrophic bacteria, leak, mine), but didn't find anything. Well, that's ok, you just take your time, I ain't goin' nowhere... Lord willin' and the Crick don't rise. =)
I found it last night and took some notes: my memeory was off.
"chemolithotropic bacteria". They oxidise things other than organics to get energy ("they eat rock").
And it was coal mines, not iron mines. In the Appalachian Mountains, leaching into the Ohio River.
Bacteria including Thiobacillus ferroxidans "eat" Iron Pyrite (FeS2) and oxidise it with oxygen, if the mine is not sealed tight. That releases lots of sulfuric acid, which is the main problem becuase it solubles the iron, and leaches other meatls also. And I guess people, fish and plants don't like drinking dilute, metal-laden sulfuric acid, given a choice.
FeS2 + O2 + H2O --> Fe+2 + H2SO4
Then, they also oxidise the Fe+2 (ferrous ion?) to Fe+3 (ferric ion?) using more oxygen, and CONSUMING a little of the acid they just produced. Therse little guys really like acid, but they mess up the neighborhood. I wonder if the immegrated here from Venus?
They get their carbon by reducing CO2, which I guess requires even more ferrous ion.
I think I got this mostly correct now. The ferrous / ferric loop was not very clear to me, bu it was clear that first they produce a lot of sulfuric acid, then consume some of the "H+" they just created.
They prevent most of the pollution by sealing old coal mines enoguh that they turn anearobic. That is one thing these chemolithotropic bugs can't deal with. In the environments they like, they really thrive, because they have NO competion. But they need oxygen to produce energy as they eat reduced forms of iron.
from "Microbiology", 4th edition, Prescott, Harley & Klein
I agree with Sally agreeing with Rick, that's why I'm leaving the rebar in there. I would tend to feel the same way about the fence posts as well. Heck, I've got a metal fence, posts and all, separating the neighbors and us, and my "driveway side" bed is RIGHT up against that fence. I have no qualms growing my babies in there, and they do very well. I just don't think it's enough to have that much of an effect.
I agree with Speedie agreeing with Sally agreeing with me!
>> rebar and metal fence posts are OK
Totally! Unless your soi is acid enough to burn your skin, iron or stell in contact with the soil will takes years or decades to rust enough to contribute any significant iron to the soil. Even then, that's just enriching the iron content.
Enough to HURT a plant? I think you would have to use a belt sander and collect enough iron dust to fill a jigger or 4 ounces, then rust it quickly with some acid, and then throw it all at once into a small amount of soil.
Even then, only the presence of excess acid would make iron soluble enough to bother a plant. At reasonable pH, iron is not very soluble. At reasonable pH, even a large excess of iron would at most interfere somewhat with uptake of something else (?? phosphate ??)
Rust from rebar could only help (by contributing iron if you happenh to be low on it).