Biochar – fact or fiction ?

Biochar is being touted as the latest silver bullet in both the agricultural realm and that of environmental stability. There is some evidence that the substance can improve productivity in poor soils, and as another (of many) temporary sequesterers of carbon.Biochar can act as a reservoir of exchange sites, water storage, and in some cases decays more slowly than more natural carbon structures (ie plant residues). It, however is a product that needs some manufacturing to exist, either backyard in scale or industrial. Good agricultural or permaculture practices allow for organic matter systems that negate the need for this remediation. Furthermore, the raw materials for biochar are the carbon containing residues so important to a living soil system, be that natural forest systems or crop residues. Therefore, the biochar approach has more appropriate merit for highly weathered and humus poor regions like the tropics, where apparently biochar was rediscovered. Environmentally ethical sources, also, would be those waste products of industry, not of living systems. It is similar to the idea of harvesting forest debris from the lumber industry for biofuel…it leaves nothing behind to support the forest ecosystem. For those farmers or gardeners with well drained or sandy soils and low organic matter, it is likely to aid plant growth and health. Adding any organic matter, charred or not, will do this. The living soil fauna require carbon (along with other nutrients) to survive. These creatures are of paramount importance. This requires the matter to be consumed, so although a slow decay process has merit, a carbon source that takes eons to decay (mixed evidence for biochar on this front), is not necessarily useful, especially in slow decay soils in cooler, acid climates. The purpose of this post is not to write off the merits of a new approach like biochar, but to allow folks to be more informed and to move slowly and think carefully when presented with a magic bullet, particularly when it is surrounded by a plethora of products for sale.

We came across the following article by Rachel Smolker in the Earth Island Journal. It is well written and sobering for those looking for a cure all. Rachel is codirector of Biofuelwatch and a climate justice activist. She has a Ph.D. in biology from the University of Michigan, and worked previously as a field zoologist.

Biochar Article PDF