Image credit: Centre for Alternative Technology
The buzz around biochar is crazy these days, with some claiming that biochar could offer healthy soils and carbon sequestration, while others argue that the biochar business could be as dangerous as biofuels. The truth almost certainly lies somewhere in the middle. But how does one make biochar, and what are the benefits? The Centre for Alternative Technology (CAT) in Wales put together a great video on DIY Terra Preta that should interest the home hobbyist and the scientifically minded alike. CAT's approach to biochar is definitely on the low tech side - and looking at the smoke that is coming out of those kilns, that means air quality control is not quite what it could be. (No microwave biochar kilns here!) But the plus side is that almost anyone can build these kilns, creating a cooking stove and a charcoal kiln in one.
CAT's research is also looking at how biochar effects soil in a temperate climate - experimenting with plain soil, soil soaked in urine, soil mixed up with charcoal, and soil mixed up with charcoal that has been soaked in urine. (Apologies to those who find peeing in the shower gross!) The initial results seem to suggest that charcoal soaked in urine does indeed have a beneficial effect - retaining nutrients that would otherwise get washed away. It looks like it's early days, but the experiment is certainly worth watching.
It's also great to see CAT discussing land use issues, and the idea of biochar as a "get out of jail free card" - these guys are no breathless advocates pushing their chosen silver bullet at all costs. (The world has enough of those!) True to their heritage, CAT is continuing to explore what works and what doesn't, and broadcasting it to the world.