I am a regular maker and user of biochar. It helps my plants produce higher quality and more food. I know that it is helping the climate change problem to a degree, because the carbon is so stable in the soil. However, I don't know the most effective ways to make it happen. What are the most effective ways to use biochar for climate change?
Great question John. I need to dig though my notes to find the data, but off the top of my head I believe that mixed conifer biochar put down on forest floors have been shown to increase overall tree growth by 8% at 5 ton/acre lay down and 10% at 10 ton/acre lay down rates. I hope that I'm remembering that correctly. So not only does the biochar carbon remain fixed for 100s to 1000s of years, but the extra tree growth over that time will also store very significant additional carbon both in their bodies as well as in the soil they produce. To convert that to easier to use measurements 5 ton/acre is about 1/4 gallon (1 quart) of biochar per square foot and 10 ton/acre is about a 1/2 gallon of biochar per square foot. Therefore a cubic yard of biochar would be spread over roughly 800 square feet of forest land to produce 8% more growth per year.
To take advantage of this magnification of carbon fixing with trees I use my biochar in my forest garden as well as in forests, spreading it at lower rates to gain maximum benefit per pound of biochar I produce. I can always come back around and add more if I ever have more biochar than land, though I have a decent amount of forest land and it will take me a long time to cover it all (I need to step up my biochar production rate!).
I need to find data on growth increase rates at all the different stages of succession.
John Suavecito wrote:...What are the most effective ways to use biochar for climate change?
Hi John and Greg,
Following this with interest as I too am a strong advocate of biochar use. Since the time I first started learning about it (2007) I have kept coming back to the same thought:
It's important to determine the minimum amounts needed to unleash its benefits to the soil, but if it really has the ability to sequester massive amounts of CO2 and other climate gasses, shouldn't we also be asking how much can we possibly add before causing a problem? For instance Stockholm Sweden has started using a 'manufactured soil' (we've all done this to some extent or another since we started horticulture and farming) with a very high proportion of biochar. http://www.biochar.info/?p=en.biochar_urban_landscapes
Some of my questions were answered when I read Albert Bates and Kathleen Draper's newest book, "BURN: Using Fire to Cool the Earth" where they develop scenarios where we could be using far more biochar by developing 'carbon cascades' to design new carbon rich materials for manufacturing and engineering based on biochar. You might be interested in listening to an interview I did with Albert about that and related topics: https://rasa.ag/albert-bates-using-fire-to-cool-the-earth/
I'd also highly recommend getting a copy of his earlier book "The Biochar Solution" which is a thorough and accessible exploration of agricultural and permacultural applications.
"I live on Earth at present, and I don't know what I am.I know that I am not a category.I am not a thing—a noun.I seem to be a verb, an evolutionary process—an integral function of the universe."
Companion Planting Guide by World Permaculture Association