Saturday, May 30, 2009

Easy bamboo biochar

The other day, my internet friend Patrick popped up on Skype to tell me about a simple method of making biochar. He'd been to a talk in Tokyo, and he knew from my blog that I'd be interested. How did we used to manage without the interweb, and how impoverished would we be if it was taken away?

The trouble with this method is, most metal cans are of standard sizes, and they haven't been designed with charcoal making in mind. However, being one who takes a keen interest in places where rubbish accumulates, I managed to find an eccentrically-sized can that just fits through the hole in the top of my incinerator.

Cutting the bamboo to the right size took much longer than I had bargained for. A frog in the bushes got rather excited by the sawing noise and felt stimulated to compete. Consequently, there was a general cacophony this morning in the garden. Fitting the slivers tightly in the can also took a while and involved some hammering.

It seemed a shame to waste the space between the bamboo, so I pressed some spare rice husks into service as filler. (Is there any purpose to which rice husk is not ideally suited?)

I put part of a thick rice bag over the top of the can to get it into the incinerator without all the bamboo and rice husk falling out.

There seemed to be a lot of scrap wood and bamboo around the garden to use for fuel, but I made two trips to the bamboo grove anyway, to scavenge dead culms. In the end, I used a lot of fuel.

Ignition! Off to a good start...

Oh shit! I hadn't expected quite such intense calorific output...

Fortunately, I'd prepared two buckets of water and a watering can too. The heat was phenomenal, and when embers spilled out from the holes in the bottom, the already dry grass around caught fire very easily. I had to resort to the watering can a number of times, and if I hadn't been paying attention, the fire brigade would have been out.

The instructions say that you can easily tell when the pyrolysis gas catches fire, but perhaps because I had such a jolly old conflagration going, I had no idea. Not that I wasn't paying close attention either -- I was most anxious not to burn everything on our property to charcoal.

The seemingly vast quantity of fuel burned down to very little ash

After more than an hour of cooling, the inner can was still very hot, but not so hot as to reignite.

Since I hadn't observed pyrolysis, I was concerned that I might still have a lot of brown bamboo. But all of it was gratifyingly black, except for the tips of a few bits in the middle. The quality of the charcoal seemed to be very high -- clean, glassy and brittle. I expect it will be very easy to crush and mix into soil.

Judging by the way the bamboo was all bent and twisted, I suppose it must have got rather hot in the little can.

In general, this seems to be a good way of making charcoal, but next time I'll use much less fuel. Bamboo burns very hot and fast, so I believe the same result can probably be achieved without the 4 ft flame.


Erich J. Knight said...

Biochar Soil Technology.....Husbandry of whole new orders of life

Biotic Carbon, the carbon transformed by life, should never be combusted, oxidized and destroyed. It deserves more respect, reverence even, and understanding to use it back to the soil where 2/3 of excess atmospheric carbon originally came from.

We all know we are carbon-centered life, we seldom think about the complex web of recycled bio-carbon which is the true center of life. A cradle to cradle, mutually co-evolved biosphere reaching into every crack and crevice on Earth.

It's hard for most to revere microbes and fungus, but from our toes to our gums (onward), their balanced ecology is our health. The greater earth and soils are just as dependent, at much longer time scales. Our farming for over 10,000 years has been responsible for 2/3rds of our excess greenhouse gases. This soil carbon, converted to carbon dioxide, Methane & Nitrous oxide began a slow stable warming that now accelerates with burning of fossil fuel.

Wise Land management; Organic farming and afforestation can build back our soil carbon,

Biochar allows the soil food web to build much more recalcitrant organic carbon, ( living biomass & Glomalins) in addition to the carbon in the biochar.

Biochar, the modern version of an ancient Amazonian agricultural practice called Terra Preta (black earth, TP), is gaining widespread credibility as a way to address world hunger, climate change, rural poverty, deforestation, and energy shortages… SIMULTANEOUSLY!
Modern Pyrolysis of biomass is a process for Carbon Negative Bio fuels, massive Carbon sequestration,10X Lower Methane & N2O soil emissions, and 3X Fertility Too.
Every 1 ton of Biomass yields 1/3 ton Charcoal for soil Sequestration, Bio-Gas & Bio-oil fuels, so is a totally virtuous, carbon negative energy cycle.

Biochar viewed as soil Infrastructure; The old saw;
"Feed the Soil Not the Plants" becomes;
"Feed, Cloth and House the Soil, utilities included !".
Free Carbon Condominiums with carboxyl group fats in the pantry and hydroxyl alcohol in the mini bar.
Build it and the Wee-Beasties will come.
As one microbiologist said on the Biochar list; "Microbes like to sit down when they eat".
By setting this table we expand husbandry to whole new orders of life.

This is what I try to get across to Farmers, as to how I feel about the act of returning carbon to the soil. An act of pertinence and thankfulness for the civilization we have created. Farmers are the Soil Sink Bankers, once carbon has a price, they will be laughing all the way to it.

One aspect of Biochar systems are Cheap, clean biomass stoves that produce biochar and no respiratory disease. At scale, the health benefits are greater than ending Malaria.
A great example;
h t t p://

The biochar Fund is also doing amazing work in the developing world;
h t t p://

Also , I would like Rebut the BioFuelWatch folk's recent criticisms with the petition of 1500 Cameroon Farmers;
The Biochar Fund
h t t p://
and to explain their program;
h t t p://

The USDA-ARS have dozens of studies happening now to ferret out the reasons for char affinity with MYC fungi and microbes, but this synergy is solidly shown by the Japanese work, literally showing 1+1=3

Mann ("1491") in the Sept. National Geographic has a wonderful soils article which places Terra Preta / Biochar soils center stage.
h t t p ://

Biochar data base; TP-REPP
h t t p://

Rod said...

Thanks for commenting Erich.

I've been interested in Terra Preta since I read the book "1491: New Revelations of the Americas Before Columbus". I don't know whether it's actually feasible to achieve something similar in the Japanese climate and as an individual who only has the weekends to play with, but I intend to try.

Incidentally, simply burying rice husks without any treatment results in a lot of white fungus in the soil. How beneficial it is, I have no idea, but it doesn't seem to do any harm.

Patrick: said...

Rod, I am glad my link helped you have a fun for one afternoon. The charcoal looks really good! I wish I was out in inaka home to try it in our place.

I think to cover any major quantity of bamboo, one would need to resort to mechanised saws. Also its a shame to waste the heat, it would be great if you could use the heat, for heating water or cooking something.

One thing to watch out for is to test the coal in different concentrations on different patches of your field. Apparently "BioChar done wrong" can be toxic, or degrade a good soil...

Please keep a record of the results of using treated soil and untreated soil.

Erich J. Knight said...

since your blog blocks active links,
send me an email and I'll send the most important MYC fungi work with char. The work done in Japan over the last 15 years is the most advanced


Rod said...

I was thinking that an electric saw would make everything much more productive. Also a longer can would be good, but long, narrow cans are most uncommon.

The soil in my garden is pretty awful, so I don't think anything much could degrade it more. I have another post coming soon about how I'm burying the charcoal. (Please don't expect a rigorously scientific approach though...)

Rod said...

Erich, I've looked around for your email address, but I can't find it anywhere. I'm interested in getting that info though.


Anonymous said...

Damn I was going to buy a new Hummer in late 2012 and drive around the country for a vacation, Now I am going to have to shave my head and join the Hari.s, Muslims, Jews, Jehovah s, Mormons, Christians, and a few other wing nut groups just to cover all my bases.
]world schedule 2012
[/url] - some truth about 2012

Erich J. Knight said...


This is the finest explanation I have read on the process of biochar testing. Hugh lays it out like medical triage to extract the data most needed for soil carbon sequestration. A triage for all levels of competence, the Para-Medic Gardener to the Surgeon Chem-Engineer.

The Ozzie's for 5 years now in field studies
The future of biochar - Project Rainbow Bee Eater

The Japanese have been at it dacades:
Japan Biochar Association ;

UK Biochar Research Centre

Virginia Tech is in their 4 th year with the Carbon Char Group's "CharGrow" formulated bagged product. An idea whose time has come | Carbon Char Group
The 2008 trials at Virginia Tech showed a 46% increase in yield of tomato transplants grown with just 2 - 5 cups (2 - 5%) "CharGrow" per cubic foot of growing medium.

USDA in their 2 nd year; "Novak, Jeff" , & "david laird" ,
There are dozens soil researchers on the subject now at USDA-ARS.
and many studies at The ASA-CSSA-SSSA joint meeting;

Nikolaus has been at it 4 years. Nikolaus Foidl,
His current work with aspirin is Amazing in Maize, 250% yield gains, 15 cobs per plant;

My 09 field trials with the Rodale Institute & JMU ;
Alterna Biocarbon and Cowboy Charcoal Virginia field trials '09

Erich J. Knight said... email........
shengar at