Biochar is a passion of mine, as is gardening and growing high quality food of course. Biochar is a soil amendment made from pyrolysis of any organic material. Pyrolysis is a fancy word for separation using fire. Heat biomass, separate out the gases, and burn them off. Biochar is the result if we restrict the air during the burning process to get heaps of char, and then extinguish the fire. There are various ways of doing this biochar and the good news is that it scales from using your wood stove at home, to outside in the garden, to industrial kiln machines. You can choose what fits your context. More information about this has been compiled by me on South Coast Environment Society’s website. It’s available to everyone for free.
What is is about Biochar that I am so passionate about? It’s the cascade of benefits it brings. Clean up waste from the garden and land (including household and livestock bones), add biochar to compost to super-charge it, or use it for a multitude of other things like in potting mix, animal bedding, for planting trees and in garden beds AND sequester carbon in the soil for thousands of years! Wow, okay, well, how does this work? The carbon skeleton of the biomass has millions of nanotubes (huge surface area) and these act like a sponge to hold both air and water, attract minerals, and house bacteria and fungi.
The carbon does not really decay through biological interactions and so it enhances the soil for a very very very long time. When biochar is added to compost it holds on to the nitrogen that tends to offgas, holds water and air, and is a habitat for the expanding biology populations. The addition of biochar has been proven to make compost faster and with better agronomic results than either adding compost only, biochar only, or compost and biochar together (so put biochar into your compost heap or worm farm).
If you don’t want to make your own biochar, the good news is that others are making it and selling it and/or selling equipment to make biochar. Wood vinegar is also available and is an excellent soil enhancer and plant growth stimulant. The Biochar New Zealand Network is a membership based national organisation who advocates for biochar around the country with close links to a similar organisation in Australia. BNNZ offers 3 tiers of membership: Ordinary $50pa, Professional $200pa, and Community $150pa with various member benefits. One of these is promoting suppliers of biochar and equipment, and listing events by Professionals and Community Groups to do with biochar. Have a look at their website and become a member if you like the sound of what biochar has to offer the world (and growing food and trees).
By Dylan Graves (part time employee and volunteer for both SCES and BNNZ) and member of Village Agarians
