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  • From: Zachary Domike <zdomike@yahoo.com>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] Burning Issue of Biochar
  • Date: Wed, 11 Nov 2009 14:48:14 -0800 (PST)

Biochar is cutting edge investigation, so might be considered "Fringe:"

Frankly, I am disappointed at the way the Biochar discussion has played out.
Ken should know that there is an appropriate method to agricultural
techniques, or there is an inappropriate shortcut. Ken mistakenly describes
biochar as "burn up organic matter that the soil needs.?"

Proper charcoal production is a process that evaporates the vapor from the
carbon then shuts down the oxygen, so - when done properly - emits relatively
little carbon. The sad truth is that -worldwide- most agricultural smoke
comes from "burning waste" that could be profitably used as Biochar. The
hurdle is that biochar needs good technique, and a deep understanding of its
value in the soil to justify the expense to process those huge mounds of
"waste."

Organic matter takes a long delicate process to change into humus. Delicate
because it is so sensitive to oxygen and humidity and temperature and acidity
and the correct mix of micro-organisms, and it burns up (oxidizes) in direct
sun. (Turning the soil with a tiller exposes the organics to more damage,
which is an important, but separate, argument for no-dig.)

Soil science is new, as those who read Dr. Elaine Ingham know. But charcoal
has a long history as a filter, and works in a similar way on a microscopic
scale in soil. Distributed in the soil, charcoal holds all sorts of elements
and compounds which are then selectively available to roots.

The question was "Which would be better for the soil, biochar or chippings?"
If done properly, the BioChar is much better and longer lasting. How else
can we deal with the sticks and brush that even the goats won't eat?

I hope Marty's technique is clean and produces the most excellent soil
amendment! Let us know the results? Thanks to Bobby G. for his clear
description, so Marty knows what will be his benefits.

Sincerely,
Zack

Some selected recent responses to the question about Biochar:
"the pH of the bio-char be adjusted to slightly acidic to neutral ( 6.0 to
7.5 )"

From: Ken Hargesheimer <minifarms2@yahoo.com>
Subject: Biochar questions

Why burn up organic matter that the soil needs.? That is what nature would do
with it.
Ken
========================
It seems to me that if you chipped it you would have chips for
several years that slowly returned their carbon to the atmosphere as
CO2. Some would go into your soil and be returned as CO2 in a few
more years. If you made biochar and put some in your beds you could
see for yourself what effect it had on the soil. The carbon you put
in the ground as biochar is likely to be there for hundreds of years
and at least that bit of carbon will not be causing climate change.
Given our situation we need to find out if this option is helpful.

The process as i understand it is simple. I don't consider these
directions, just a description of the process as i understand it.

The designs for retorts are fairly simple, a barrel within a barrel,
the outside barrel having a lid with a stack in the middle. The inner
barrel is filled with dried plant material or even dung. It is turned
upside down in the outer barrel so it will lack oxygen and char
instead of burn. Put fuel around the inside barrel and light it from
the top. When the fire gets going good put the lid/stack on top which
will cause the gasses and smoke to ignite, cleaning up what is going
into the atmosphere. You have to quench it afterward so that the char
doesn't turn to ash and release its carbon to the atmosphere. Before
you put it on the soil you should mix it with compost to fill the
many bonding sites on the char so it doesn't pull minerals from your
soil.

There is a lot of information available if you search for it. In the
next couple of weeks i hope to have a simple unit up and running.

Marty Kraft
-----------------------------------
I have been clearing a 60 ft square section of scrub brush and small
trees where I plan to build a shop. The result is a huge pile of
branches that at first would make a good habitant but as the pile grew
that became impractical. I have been thinking of either burning it to
make biochar or passing it though a chipper.

Which would be better for the soil, biochar or chippings? There is so
much of this stuff that it would make a huge bonfire.

Don Bowen
--------------------------
Marty, my reading and understanding on this topic is about where you're at
with it. Biochar is not the same as "burning wood and throwing the ashes on
the ground." It's the result of a slow, oxygen-starved process that is
incomplete combustion.

Up-to-date processes for making the char involve using a retort, kind of a
slow-burn stove.

You can really take the process a whole lot further by capturing the
pyrolysis gases that come off the slow combustion. Most of the gases coming
off are hydrogen and other combustibles, not CO2, which is not combustible.

The reason the Europeans were able to run cars and trucks off pyrolysis gas
(or "producer gas" or "biogas") during World War II was because the burner
units produced these combustible gases, mostly hydrogen (though there are
other gases present, including some CO2). If the producer gas was mostly CO2,
no trucks would have run off the gas...

The modern retort leaves not ashes nor clinker, but mostly carbon (char) that
can be added to the soil. In the soil, it provides habitat for fungi,
bacteria, etc. and is very very slow to break down. It adds to the web of
life.

The pyrolysis gas driven off could be used on-farm to fuel power equipment,
heat buildings, heat houses, power vehicles or tractors, dry grain, whatever
uses combustible gases can be given.

I don't think anyone in biochar world is suggesting not to do composting, or
lasagna composting, or adding manure, or other processes to get organic
matter in the soil. The amount of carbon added isn't that big. And it's not
a "fertilizer" so much as a soil conditioner.

I think there's a lot more work to be done on this biochar question. I think
both the academics and the farmers in the field will play a part in it.

Bobby G.
Central Wisc. USA
-------------------------
Making biochar makes smoke; it releases CO2 immediately into the atmosphere.
Organic growing and putting organic matter directly into the soil does
sequester carbon, but chemical fertilizers and excessive tilling oxidize it.
Paul tradingpost

not think of any thing as destructive to the soil and organic matter as
biochar. Farmers did not come up with this hairbrain idea.? I studied
Brazilian jungle farming before the promoters got to college. Biochar
destroys the one thing the soil needs more than any other thing: organic
matter.? Burn it up and put the ashes on the soil.? Excuse me!
?
Ken Hargesheimer
------------------------
Marty Kraft <martyk@allspecies.org>
Subject: [Livingontheland] Biochar Questions
To: Healthy soil and sustainable growing
<livingontheland@lists.ibiblio.org>

I am getting interested in biochar or terra prita. I am interested in
hearing of anyone's applications to their soil. Did you buy it? Did
you make it? What was your burner or retort like?

I am working to collect the barrels to make it but might want to buy
some as well.

Thanks

Marty Kraft
Kansas City









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