Image credit: Woods End Laboratories
Despite claims that biochar could offset 12% of human carbon emissions, and boost agricultural production in the process, others are not so sure. Whether it's the author of the biochar solution saying it's not a solution (OK, not a complete solution), or George Monbiot's warnings on the large-scale production of biochar, there is no doubt that this much hyped technique for carbon sequestration is by no means a miracle cure. We've just come across a video that casts further doubt on some of the grandest claims being made for terra preta.Produced by Woods End Laboratories—who, it should be noted, are commercial producers of compost—the video asks whether we are better off producing active, living compost that interacts with the soil, or inert biochar that provides more stable carbon storage.
Looking at effects on soil PH, plant growth, and the relative energy intensity of biochar versus compost production, the video doesn't come to any firm conclusions—but it strongly hints that compost comes out on top. As I mention above, this comes from a lab that makes its money from compost, but nevertheless it is food for thought. Certainly the visual of plant roots grown with and without biochar is a pretty striking image.
More on Biochar and Terra Preta
Author of Biochar Solution Says it's Not a Solution
Biochar Alone Could Offset 12% of Human CO2 Emissions
Jason Aramburu on the Promise of Biochar
Haiti's Rebuild May Be Biochar's Big Breakthrough
DIY Biochar (Video)