Application of the charcoal to soils may be key to sustainability. Application of charcoal to soils is hypothesized to increase bioavailable water, build soil organic matter, enhance nutrient cycling, lower bulk density, act as a liming agent, and reduce leaching of pesticides and nutrients to surface and ground water. The half-life of C in soil charcoal is in excess of 1000 yr. Hence, soil-applied charcoal will make both a lasting contribution to soil quality and C in the charcoal will be removed from the atmosphere and sequestered for millennia.

The Godfather of Terra Preta, soil scientist Wim Sombroek (1934 - 2003) enjoyed a lifelong fascination with enhanced soil. The importance of plaggen soil in his native Netherlands impressed him at an early age, and early in the 1960's, he recognized in the Amazonian Dark Earths something familiar and precious. Before his passing, he assembled specific soil scientists challenged them to discover the process for making and sustaining a modern equivalent of the bio-char enhanced terra preta, what he termed terra preta nova. A great opportunity in answering Sombroek's challenge lies is surmounting the opacity of mutualistic rhizospheric species to traditional analytical approaches: only 1% of rhizospheric species are cultureable ala petri dish. We don't have a robust body of culture-independent studies against which to compare Terra Preta, so we are doubly challenged to reverse-engineer the phenomenon. Considering Wim Somboek's many noteworthy accomplishments, the perspective of his international leadership, and the late-in-life timing of his challenge, one senses he is pointing us to a mystery fundamental to understanding soil in new and exciting ways. This happens at a time when the soil science profession is in dynamic transition and sorely in need of a unifying vision. Wim Sombroek has given soil scientists a most welcome and worthy quest.

Peak Energy has a long post on Terra Preta that brings together what has been established on the subject. As of yet, there is no direct mention of the role of glomalin , just a minor mention of the mutualistic fungi that produce it. Glomalin is an unvalidated factor in Terra Preta formation that several of us sense will be demonstrated by soil research as fundamentally important. Spurred on by back40, I am fascinated with bio-char, Terra Preta's key soil amendment. Last summer I constructed a small charcoal retort out of a cracker tin. I used it to produce small pilot batches of low temperature charcoal. Hoping to transform my simple charcoal into a reasonably bio-char-like material, I am currently composting my bits.