Th e review by Spokas et al. (2012) presents a compelling
introduction to the environmental impacts of biochar. Th e
authors provide insight into the pyrolysis process and the
resultant biochars based on chosen feedstock; they go on
to present a summary of the types of biochars that provide
positive yield responses and the economics of biochar creation,
transportation, and utilization, following a whole-systems
approach. Th eir examination of 44 previously published biochar
research articles showed that approximately half observed yield
increases whereas the other half showed no or even negative yield
responses. Th is led Spokas et al. (2012) to conclude that not all
biochars are created equal and that biochars should be designed
with special characteristics for use in specific environmental or
agronomic settings (Novak and Busscher, 2012). Spokas et al.
(2012) also conclude that although current economics may not
be favorable for large-scale production agriculture utilization of
biochar, the potential exists for biochar to provide environmental
quality benefits and to improve nonproductive or degraded soils.