Owen

Could other organic materials be used, say dried sewage waste?  Since
it gets burned, doesn't that mean that it no longer has the volatile
organic compounds in it anymore?

Very interesting article Owen, thanks.

best -

2-Burning anything is toxic.  Benzo-pyrene is a nasty chemical which
actually CAUSES cancer.  Anytime we burn organic matter at normal low
temperatures (charcoal, bonfires, open flames, etc.) we create
benzo-pyrene exhaust.  Smoking, barbecuing, campfire smoke, candle
smoke, etc. all create poisonous carcinogenic benzo-pyrene.

Burning organic corn may or may not create "organic" charcoal, but
organic or not, it will be poisonous.

Burning is bad.  Sorry.

We have other technology available which is not poisonous such as
focused sunlight, solar electric, wind electric, etc., etc.

Dave

I had heard that the char on meat was carcinogenic.

Based on how I read the original article that starts this thread, I
don't think the burning of the corn to create charcoal is going to be
used as a fuel source.  I believe the charred corn will be used as a
soil ameliorate.

Are focused sunlight, solar electric, wind electric going to be used to
make better soil?

Much of the natural gas used in this country is used to make
fertilizer.  And if we make charcoal without releasing tons of carbon
in the air, and then sequester it in the soil, that will pull a lot of
carbon out of the atmosphere, reducing global warming.

Finally, what I am not clear on is whether if we put charcoal into the
ground, whether it will in fact pass along those carcinogenic
properties to the food grown out of that ground?  I have no opinion on
it, I don't know - I would love to hear what people think on that.
Obviously from the original article, the author thinks that it is safe.

best -

I must admit that I don't know much about soils and fertilizers, so
forgive me my ignorant questions, but here goes:

1-Why burn the corn, as oposed to composting it, or feeding it to pigs,
etc.?

2-How is the natural gas used to make fertilizer?  Is it the energy of
natural gas that is needed, or some compounds in the natural gas that
are harvested to make the fertilizer?

Dave

There is a long discussion of Terra preta here
http://forums.hypography.com/earth-science/3451-terra-preta.html
There are lots of links to other sites, articles, research and blogs.

  and a shorter discussion of Terra preta at The Permaculture Forum.

  There will be a discussion group starting next week

One of the ingreadients in Terra preta gardening is charcoal. Produced
preferably at low temperatures of 400-500C
The systems I have seen such at that of "Best Energies" is self
contained and recycles gasses to run the plant and produce
electricity.I don't think Benzo-pyrene is a worry as the system is
self-contained, but I will ask
Isn't Benzo-pyrene produced when natural gas is burnt?

Charcoal tablets are often given to patients who have ingested poisons,
and activated charcoal  is used to filter and purify water, so I don't
think it can be too toxic

The role of charcoal in the soil is still being studied, but as far as
this group is concerned it lessens dependence on any fertiliser, other
than organic matter and manures.
It promote the microbial and fungal life of the soil in ways we don't
fully understand.
It improves soil CEC.enormously
  The Natives of the Amazon basin claim Terra preta soil "grows".
Certainly is is the most fertile soil seen in the tropics and is man
made.
The charcoal has been ground into a very fine powder. Soils can be
metres deep.

Other important ingredients of Terra preta soils seem to be fish waste,
organic matter, manures and pottery shards. There may be a special
"suite" of bacteria and fungi that make the  Terra preta of the Amazon
special. However I have seen good results using charcoal in potting
mixes. The Japanese have been using it for years and it is a major
ingredient in Bonsai Potting mixes.

Many people who are not gardeners or farmers are excited about Terra
preta's ability to safely and almost permanently sequester CO2 and thus
help reduce our Global Warming crisis

The main source of cancerous  Benzo-pyrene is cigarette smoke

To put it in perspective however, see the following chart (an extract
follows)
http://www-envirinfo.llnl.gov/1Radiationandyou_doc.pdf
(Page 2)
Riisky Busiiness?
Each of the following activities
increases your risk of death by one chance in one million
Activity                                                      Cause of
Death
10 millirem of radiation (typical chest X-ray)  Cancer
About 20 days of breathing
(radon "daughters" in air)
                                                                  Lung
cancer
Smoking 1 cigarette                                     Cancer, heart
disease
Drinking 1/2 liter of wine                               Cirrhosis of
the liver
Living 2 months with a cigarette smoker        Cancer, heart disease
Eating 40 teaspoons of peanut butter            Cancer caused by
alfatoxin B
Drinking Miami drinking water for 1 year        Cancer caused by
chloroform
Drinking 30 cans of diet soda                       Cancer caused by
saccharin
Eating 100 charcoal-broiled steaks               Cancer caused by
benzopyrene

Last week in Oz we had a lady die from drinking too much water!
 So even drinking pure fresh water can be deadly!