Adding charcoal to soil through irrigation systems - ?

[InfiniteNow]

I had a thought today, and want to run it by the community to get some feedback on it. It's very much a "green" idea, in that I haven't even begun to think it through, but found it a concept which might make for a fun conversation.

Can charcoal be introduced to the soil via an irrigation system?

Let's say you have drip irrigation. Perhaps small lumps of charcoal could be added to the water source, carried down the hose, then onto the soil with every watering cycle.

• Would there be any benefit to continuous addition of charcoal to the soil?
• Would it sink into the soil quickly enough to have any real impact, or would it just remain on the surface doing nothing?
• Would pressure be an issue, and would the charcoal ever even make it to the plant?
• Is this a really and truly a useless idea, or have I just wasted a potential multi-million dollar patent concept by sharing it here?

[Michaelangelica]

My first thought is a company called Barmac in Australia sells activated carbon to green -keepers for about $150 for 3 liters/kilo? Very expensive in the scheme of things
but
They recommend using it as a slurry. So it would be very fine..

Second thought is that it depends a lot on your irrigation system. Overhead sprinklers seem to be on their way out here. Drip irrigation seems to be the latest fashion. Even though the 'Pick-up' activated charcoal is very fine it might block small drip irrigation 'holes". You would have to suck it and see. Many systems deliver water soluble fertiliser as well as water.

While I thought I read that activated charcoal had more adsobancy than normal charcoal; I am told I am wrong and there is no scientific evidence for that claim.

BTW it is called "pick-up" as it is used to mop up fertiliser and pesticide spills mainly on bowling greens.

So the answer is yes and no. No doubt you would get all the benefits of using char in the soil.But you would need to set up your watering system to cope with fine particles. I think they would perculate down though the soil if wet.

Mixing char with fertiliser first could be interesting as it would soak this up and let it out slowly. You would have to make your char very small

[Philip Small]

Originally Posted by InfiniteNow

would [charcoal] just remain on the surface

More work is needed in this area, but consider what happens to charcoal in nature for answers. Not surprising, a fair portion of existing soil organic matter can be charcoal. One grassland>wheat growing soil (Walla Walla soil series) studied had charcoal levels at 35% of total organic carbon (TOC). Five soils studied ranged from 10 to 35% Char:TOC (Pdf link)

A recent one-year study (pdf) found that:

Mice probably mixed charcoal particles lying on the forest floor with the uppermost part of the soil, and Fig. 2 shows that earthworms ingested charcoal particles <2mm and distributed them in the soil profile.

From: Biogeosciences Discussions: an open access publication hosted by copernicus.org

Depending on your earthworm population, it could end up getting into your soil fairly quickly. As Erich's discovery hints at, invasive earthworms in North America can have tremendous bioturbation impact, sufficient to alter ecosystems. I understand invasive earthworms are a recognized problem in Minnesota. I have the voracious little buggers in my compost (they came up from the ground soil), plus a fairly robust mix of tiny soil critters moving in the soil, plus freeze/thaw effects, so I am thinking surface application of charcoal (at the quantities have available) will work fine for me. For a soil on life support, surface applied char is probably going to stay right on top for a lot longer, especially if no freeze/thaw.

A mulch on top of surface applied charcoal would be good move for increasing the effect.

[Turtle]

Originally Posted by Michaelangelica

...
While I thought I read that activated charcoal had more adsobancy than normal charcoal; I am told I am wrong and there is no scientific evidence for that claim.

Who told you that!? Common sense is enough to see that 'activated charcoal' has more adsorbency than 'horticultural' charcoal. Activating is simply heating to a higher temp in the absence of oxygen and driving off allthe volatiles. The space said volatiles occupied is now empty, and free to adsorb.

From all my reading of these terra preta articles, none of the charcoal effective in soils is of the 'activated' variety. Activated charcoal is useful in filtering, but of dubious use as a soil additive. MTCW

[Michaelangelica]

Originally Posted by Turtle

Who told you that!? Common sense is enough to see that 'activated charcoal' has more adsorbency than 'horticultural' charcoal. Activating is simply heating to a higher temp in the absence of oxygen and driving off allthe volatiles. The space said volatiles occupied is now empty, and free to adsorb.

From all my reading of these terra preta articles, none of the charcoal effective in soils is of the 'activated' variety. Activated charcoal is useful in filtering, but of dubious use as a soil additive. MTCW

Yep, thats what I thought too. But the person should know ( can't tell you who-was at the IAI Conference) and just said there is "no scientific proof of that claim" although I thought I had read that activated char held more water than low temp char.
I see charcoal as corn kernels and activated charcoal as popcorn,( in structure) if you follow my simile.

[Turtle]

Originally Posted by Michaelangelica

Yep, thats what I thought too. But the person should know ( can't tell you who-was at the IAI Conference) and just said there is "no scientific proof of that claim" although I thought I had read that activated char held more water than low temp char.
I see charcoal as corn kernels and activated charcoal as popcorn,( in structure) if you follow my simile.

Aye...there's the rub. Obedience to authority. The 'person' used some means to convey their authority (title, clothing, etc.), and once that was established, that authority is blindly recognized (obeyed) even when it puts forward things you know to be wrong. Hold steady Micha! Challenge authority with reason. Be dogged in your application of the scientific method. Emulate Toto, and pull back the Wizzards' curtain.

[InfiniteNow]

The slurry idea seems promising. I tend to think of nuggets and blocks of char in the soil, and don't often consider smaller particles being distributed througout.

I'll have to do some 'sperimentin.'

[Turtle]

Originally Posted by InfiniteNow

The slurry idea seems promising. I tend to think of nuggets and blocks of char in the soil, and don't often consider smaller particles being distributed througout.

I'll have to do some 'sperimentin.'

If the particles are dust-size, they may fit through the drippers without clogging. On the other hand, they will float and may gather in the top of pipes and not reach the outlets.

[InfiniteNow]

Part of the intent behind the idea is to remove the sustaining manual labor issues. Most everything will require some degree of manual labor. However, if it is only required up front, then most people don't mind doing it for continued payoff.

Much like recycling would be done in much greater frequency if we had some sort of sensor on the waste hole... The individual simply puts all wastes, regardless of type, into a central repository... and the "system" sorts it and pushes it to the right place as recycle or refuse.

Here, you have your irrigation system setup (and I did fully intend drip irrigation, as spray is just a waste), and you add to the "hopper" once per quarter the charcoal dust.

Again, just thinking of ways to make it "easier," as most people won't tend to be standing outside with a wheelbarrow and brick smashing lump char. So, my thought was to use existing technology to implement this modernly ancient soil ammendment technique.


Aha!!


A rotory-tiller with charcoal bins attached on each side which drop chunk charcoal into the soil whilst tilling, hence also breaking it up and distributing it... See ghetto concept drawings below:

[InfiniteNow]

I'm beginning to feel a bit like the stinky kid in the lunch room. Were the ideas really that bad? It's okay... I've had some really bad ideas in my day, so it won't be anything new.