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