Activated Charcoal, Hardwood Charcoal?

[neoguy]

I stumbled across a couple of threads at GW about using charcoal as a soil amendment. It led me to the following link. Very interesting stuff.

http://forums.hypography.com/terra-p...arted-all.html

Anyone using this as a soil amendment? Any thoughts?

[dcarch]

Originally Posted by neoguy

I stumbled across a couple of threads at GW about using charcoal as a soil amendment. It led me to the following link. Very interesting stuff.
http://forums.hypography.com/terra-p...arted-all.html
Anyone using this as a soil amendment? Any thoughts?

I have not read the whole thing yet, but to start:

1. charcoal is not the same as activated charcoal in molecular structure, but they both are mostly cabon (So is diamond).

2. Carbon is one of the most inert elements, in other words, carbon does not give up anything. When a substance is not giving up anything, I wonder what nutritional value it has?

3. I am not sure activated charcoal can hold much more moisture than organic (compost) material, which is more than 95% water.

4. Activated charcoal doesn't stay "active" for very long.

dcarch

[neoguy]

This is a quote from the last paragraph of the attached link.

"Recent efforts stimulated by Terra Preta research included the investigation of bio-char (biomass-derived black carbon or charcoal) as a soil amendment to enhance nutrient availability and retention."

http://www.css.cornell.edu/faculty/l...aPretahome.htm

[Worth1]

I have posted about terra preta before.
There is not much interest in it judging from the response.

I think it is a good deal for poor soil.

Worth

[neoguy]

Worth,

You're right about the lack of interest.

[dice]

Burning off everything on a piece of land ("slash and burn")
and leaving it in place or digging it in before planting
is a traditional subsistence farming practice in 3rd world
countries, especially Africa. But they don't do it for the
charcoal, particularly, it is probably the released potassium
that adds fertility to the soil. (The charcoal in the ash may
improve drainage a little.)

Soil like that may be great the first year or two, but it
gets "tired" fast, and the farmers that practice that kind
of agriculture need to move to a new field and do it all
over again every couple of years to maintain productivity,
allowing weeds to take over the old field until they get
back to it again years later.

I've dug into soil where someone had cleaned
out a fireplace a few times and dumped the ashes
there. It did not seem to be popular with the local
earthworms. Mix it into a compost pile instead,
and it does not seem to bother the worms at all.

If I were adding charcoal, I would add it just for
the drainage improvement in a heavy clay soil,
and I would mix it with compost or manure first.

Figure that it adds carbon to the soil, so it may induce
bacteria trying to digest it to consume more nitrogen
from the soil than they would have without it.

[Worth1]

We are not talking about ashes this is about charcoal.
http://www.championtrees.org/topsoil/TerraPreta.htm
Worth

[tessa]

worth...i saw a show on terra preta and it certainly grabbed my attention.
i tried making my own with the charcoal produced by my slow combustion heater.
i planted a roma tomato plant in it.
the plant looked healthy but somewhat stunted and never produced a single fruit. when i finally took it out of it's pot...it had the tightest root mass of any plant i've ever seen.

[neoguy]

Worth, thanks for the link, interesting stuff.

I may try using some lump hardwood charcoal in a small area of my fall garlic bed.

[dice]

Fireplace ash in particular usually has some charcoal
in it, and the slash-and-burn fields that I have seen
in television documentaries, etc, usually included
some small trees and woody shrubs (some of that
stuff grows pretty fast in the tropics).

I wonder how close the composition of burnt dry plant
material in general is to wood ash and charcoal.
(Probably depends on how much cellulose
it has; dry grass, for example, has lots of cellulose.)

I would expect that, like wood ash, hardwood charcoal
would be fairly rich in potassium with some phosphorus,
a few trace elements, and negligible nitrogen. It probably
breaks down more slowly than ash (the nutrients in wood
ash are available quickly and change soil pH fast).

Would charcoal have more bound carbon than ash?
That would tend to reduce available nitrogen in the
soil, as bacteria consume nitrogen trying to digest
high-carbon materials.

I took a quick glance at the Terra Preta sight.
I doubt whether the carbon in that soil is a big
help to growing plants (although bacteria and
fungi may find it useful). Add any high-carbon
material to soil without adding more high-nitrogen
material at the same time, and you will see just
what Tessa saw: stunted plants. I would expect
to see actual symptoms of nitrogen deficiency
in the leaves on fast growing plants, unless the
soil already had a lot more nitrogen than the
plants needed (in which case what is consumed
by bacteria digesting the high-carbon materials
would not make much of a dent from the plant's
point of view).

It seems likely that the ancient, artificial soils
described by Terra Preta were healthy but
nitrogen-poor soils, and the nitrogen that plants
growing in them consume is all coming from
the top few inches of humus (that in the tropics
is renewed constantly as plants die, drop leaves,
etc).

The ancient peoples that developed those soils
may also have had other strategies for compensating
for the high carbon content: adding high-nitrogen
manures of plant or animal origin, growing
companion cover crops that fix nitrogen on their
roots, adding urine to the plots, etc.

They would not have known why these strategies
helped. Some wise person would simply have
noticed that "this helps plants grow bigger" and
got the chief or witch doctor to incorporate it
into an official practice.

Just having an ancient agricultural soil in a lab
is not enough to understand the process that
the farmers that developed it used. One needs
to see a working example to have all of the
inputs to the soil that are/were used in practice.

[Worth1]

These folks aren’t for sure what the deal is, that is why we as gardeners need to study it and see what happens.
I for one have plenty of the same red soil that is like the stuff they have in the jungles of South America.
And do plan on experimenting with some this type of agriculture.
It may help me and others with poor soil.
Further more the cost of my research will be far less than what a government funded project would be.
With all of the waste involved.

I just like to think outside the box.

Love and Kiss’s

Worth

[Gimme3]

I aint even read the links proposed, i suggest anyone...to start with...understand...what exactly...activated charcoal really IS.....research will tell you....how..in the 1700's...a doctor serving a certain King, demonstrated his ability to take a well-known lethal dose of a certain substance,(strychnine) and then..by swallowing ...."activated charcoal"....surviving the incident.


Once u understand...exactly what makes charcoal ..." activated"....its very easy to contemplate it's natural, amazing attributes as a filter. Aside from bein a natural carbon...to soil...there is a whole lot of Learning...still goin on...as to how...it is a Refuge, a Home...to many precious soil microbial life forms that are beneficial towards breaking down an providing soluble nutrients to plants. Its a great question of worth...an somethin that really is enjoyable to learn about. The Maya's and the Inca's....left behind...evidence of how important charcoal was...to them.


i think the finest thing yet to be fully understood....about charcoals....is the natural shelter and attraction it offers to beneficial soil inhabitants that would otherwise not be present, or be present in plentiful numbers....but this is the on-going....secret....being sought to understand.

[dice]

I've read that wood ash (and probably charcoal, too) improves
drainage in heavy clay soils, probably by binding some
of the fine clay particles into larger structures. The earthworms
will tell you, however, that a little ash goes a long way in
a heavy clay soil (radically changes the pH). Less-soluble charcoal may have less drastic effects on pH while still
providing improved drainage.

I don't know enough about soil microbes to have an opinion
about how charcoal would be used by them, other than
to note the possible carbon-nitrogen issue.

[Worth1]

Gimme Old friend, thanks for your support.

I have been interested in the Incan, Mayan and Aztec way of agriculture for years.
This is where I got my idea for terracing my place, ‘The Incans.
For those of you that don’t know, just look up Incan terracing, it is amazing how these folks farmed the sides of mountains.

The Aztecs had floating gardens that supported whole communities.

I think we need to look back on our past and see what worked and not make the same mistakes that our ancestors did.

The flue killed off all of these people, ‘NOT poor farming practices.
As far as slash and burn I don’t believe that is what the Mayans did.

This is a practice of desperation and greed, pretty much the same as what we did to bring on the dust bowl.

A lot of land in the eastern states was used up before the middle of the 19th century.
We had so much we just moved on to better soil, we don’t have that option now.

I highly suggest if a person is going to get into this discussion that they not just skim over the subject matter.
Do some research, ‘as Gimme and others have.

We need to develop better ways of soil conservation today, so as we don’t starve to death tomorrow.


More on this later.

[dice]

"I think we need to look back on our past and see what worked
and not make the same mistakes that our ancestors did."

Fair enough. Where did the nitrogen come from to balance
the carbon? With the Aztec gardens, we can ask the
farmers that still grow flowers on them. Did we find
instructions carved in stone by the Incas or Mayans?

That would be my question to Terra Preta.

Edit:

Maybe some Spanish or Portuguese explorer or missionary
described the whole process in his notes?