Glory and misery of biochar

Biochar refers to carbon-based dusty residues obtained from biomass pyrolysis. This recently rediscovered traditional soil improver is currently being glorified for its wide portfolio of favorable environmental aspects. With its lifetime of several centuries, it is being widely accepted as a promising method of carbon sequestration. Moreover, it has been demonstrated that biochar can reduce bioavailability of some heavy metals and that it has a high adsorption capacity to persistent organic pollutants. These effects are explained by a complex of physical, chemical and biological mechanisms. Besides agriculture, it has been currently used in food and chemical industries, as well as in the building industry. Many other promising applications are under investigation. However, contrary to many enthusiastic proclamations, no revolution in agriculture or environmental management is taking place. Despite significant achievements in reduction of biochar production costs, high demand from the industry and energy sector keeps the biochar price still high, which prevents a return of the ancient farming practice on a commercial scale.