Bio Char Bubble burst!

biocharWell it is time someone  came out and said it: “Bloody bio char !”  There , I said it.
Don’t like to quash enthusiasm, don’t like to offend friends who love the idea of bio char, but I don’t think much of bio char. It has never made sense to me to burn wood that could be chipped and made into wonderful water holding humus, and instead burnt  to make biochar for use as fertilizer. Particulate matter (smoke) and carbon emissions are put into the air  to manufacture bio char. Worse than wasting good fungi food like this, some are burning chook pooh  to make bio char! This is just using the blue skies of our planet as a dump for things too toxic to leave in a heap somewhere. Broiler hen manure from factory farms is implicated in cancer clusters in schools nearby in the U.S.. Someone in Serpentine had a mountain of  meat bird  poo they had to get rid of and  rang me, offering to transport it to our farm. I asked if their birds  ate GM food and said we could not take it if so. He hung up before any more curly questions could be asked.Bio char provides a ready way to greenwash the dumping of toxic waste mountains  into the air.

” From a NSW govt website :Slow pyrolysis utilises a kiln that is heatedexternally to achieve temperatures ofbetween 400 and 6000°C. The biomass isheld at these temperatures for over 30minutes. Slow pyrolysis yields two keyproducts, biochar and syn gas. The syn gasis a high energy mixture of methane,hydrogen and carbon monoxide which iscombusted to generate the heat required todry and pyrolyse the biomass, with surplusgas being available to generate renewableenergy, such as electricity.What can be used to make biochar?y Forestry and crop residuesy Poultry litter wastesy Animal feedlot wastes and some biosolids..”

Oh great! Burning not only the mountains of broiler bird manure that contains ARSENIC,  but human waste too ? ?!!
In 2014 I went to a lot of soil conferences and kept my ears out about biochar. Dr Maarten Stapper said the benefits you see last only 2 years and are due to the ash factor,  but once that’s gone there is no ongoing benefit. I understand this is  in contrast to compost which introduces beneficial microbes to the soil which can stay around performing their eco services for thousands of years.
Dr Christine Jones said into the microphone at Kojunup conference a year ago that the magical terra pretta was in fact magic because it was worm castings. She said there was a big trench at the back of the Mayan/ Inca villages and all the rubbish was thrown into it over centuries, and in the humid climate worms thrived amongst the weeds, branches, dead bodies, poo, wood ashes from the fire pits, rotten watermelon, broken pots, and more. Very stable humus resulted from raging earth worm populations. Their castings, as we all know (or maybe we don’t yet) give a lasting benefit to any plant . Dr Jones mentioned with disappointment the heaps of funding going towards bio char and said that in her opinion it is money wasted.
 At a later conference the wonderful Walter Jehne said that he himself had granted funding to a bio char project in Narrogin, (something like 7 million dollars) many years ago. They were going to generate electricity with syn gas by driving off the hydrocarbons under high heat and little oxygen and were last seen looking for a market for the medical grade charcoal ….unfortunately he didn’t describe the outcome of the project but was clearly disappointed  and was subsequently impatient with bio char enthusiasts statements veiled as questions . He didn’t encourage a questioner who was greatly excited about bio char. Dr Jehne responded that organic matter(OM), forerunner to humus, is a better option for farmers. Humus has more negatively charged micro sites for cation exchange, attracting positive ions like calcium, magnesium, zinc etc. He said O.M. is easy to get hold of with very little expense to the farmer and doesn’t add to that CO2 legacy load in the air causing all our climate and nutrition troubles. Bio char bloke  argued the point saying that a bio char experiment was going on in Manjimup with dairy cows eating it.  The dairy farmer was reporting that he had a fantastic population of dung beetles taking the bio char down in the ground all year, had stopped using vet chemicals and purchased fertilizers, was going great!

I piped up and said the same could be said of our organic farm: we have dung beetles burying every bit of pooh emanating from every rear end at our place and we have not purchased lime or fertilizers nor vet chemicals for a decade, but have wonderful pasture growth on little rain. ….but we don’t use bio char. These wonderful outcomes in the Manjimup trial may be due to other things which have changed on the farm as this farmer  gets educated……may be he has dropped artificial fertilizer?

Elaine Ingham is completely bored with bio char, says it is a lot of hype. Her team bought several bio chars and tested them and found them all completely ineffective at promoting plant growth. She points out that humus has enormous surface areas for bacteria and the rest to hide and feed in, far more than charcoal.
 Even though Elaine completes the hat trick of my favorite 3  teachers all putting the kyber and wet blanket on the fire ignited in many by bio char,  my friend Jeff N was using biochar and loving it.  So I did a little experiment: Several plants were potted up in soil in one pot and the same soil with bio char in another pot. I was disappointed to see no difference in the two, even 12 months later, and we had thoroughly mixed the charcoal in advance with urine as Jeff  recommended.
I do agree that charcoal has been used medically for centuries and a jar of it in the fridge or your compost toilet absorbs odours, but the good ol’ BBQ can easily supply all your ash and charcoal needs for those, and soap making needs, no worries. I think if anyone has wood waste a-plenty it  would be better for all of us if they were to  buy a HANSA chipper ( great machine!) than a pyrolysis machine. Chipping and composting  the wood in combination with manure from feed lots would make for far better rates of carbon sequestration and fertile soil regeneration.

Last time I spent a couple of days researching on google and you tube for the answer to the question “Does Bio char work”? the net conclusion was “NO” . As for scientific trials showing the efficacy of bio char, I can leave that to a team of experts who have reviewed all the literature on biochar and concluded that there is a small net benefit to using bio char of about 10 %. Is this over the results which would have been achieved by composting the starting ingredients? The jury is still out. The abstract of the meta analysis said this

“However, experimental results are variable and dependent on the experimental set-up, soil properties and conditions, while causative mechanisms are yet to be fully elucidated. A statistical meta-analysis was undertaken with the aim of evaluating the relationship between biochar and crop productivity (either yield or above-ground biomass). Results showed an overall small, but statistically significant, benefit of biochar application to soils on crop productivity, with a grand mean increase of 10%. However, the mean results for each analysis performed within the meta-analysis covered a wide range (from −28% to 39%). The greatest (positive) effects with regard to soil analyses were seen in acidic (14%) and neutral pH soils (13%), and in soils with a coarse (10%) or medium texture (13%). This suggests that two of the main mechanisms for yield increase may be a liming effect and an improved water holding capacity of the soil, along with improved crop nutrient availability. The greatest positive result was seen in biochar applications at a rate of 100 t ha−1 (39%). Of the biochar feedstocks considered and in relation to crop productivity, poultry litter showed the strongest (significant) positive effect (28%), in contrast to biosolids, which were the only feedstock showing a statistically significant negative effect (−28%). However, many auxiliary data sets (i.e. information concerning co-variables) are incomplete and the full range of relevant soil types, as well as environmental and management conditions are yet to be investigated. Furthermore, only short term studies limited to periods of 1 to 2 years are currently available. This paper highlights the need for a strategic research effort, to allow elucidation of mechanisms, differentiated by environmental and management factors and to include studies over longer time frames.”

You can delve right in to the review here.

 In the end you will make your own decision based on your research but realize there are  mountains of waste in this world whose owners are desperate to get rid of. Beware the green washing . I think the notion of burning perfectly good compost materials is dangerous to all creatures lungs and even harmful to  microbes. We know that the quality of compost is adversely affected by smoke. Probably the best use for abundant wood waste is to grow shitake mushrooms on it:  no effect on air quality, good nutrition, good soil, great.

I wish fungi would decompose wood , not fire which puts the carbon in the air. Viva la fun guy, not the match.


Image may contain: plant and outdoor


450 people reached



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s