Reviewing Biochar Research and Introducing a Possible Classification System

Biochar is the product of burning biomass, such as hardwood, rice hulls, bamboo, or even chicken litter, in a low- to no-oxygen environment. The result is a black carbon skeletal-like structure of the original biomass. Research into biochar as a soil amendment has been influenced by the study of anthropogenic dark, richly fertile soils found in the Amazon rainforest where the native forest soil is acidic and low in fertility. Biochar research for amending agricultural soils is relatively new but there are strong indications that this practice can decrease the need for additional fertilizer and water inputs. Biochar products will vary in physical and chemical properties and therefore behave differently in the soil. A classification system has yet to be adopted to identify different biochar types. Consequently, there is no data base to search for a particular biochar type for a particular soil or climate. This limits the ability to effectively organize studies or to synthesize research results and clearly communicate to the general public that the results of any one study are not applicable to all biochars. This paper reviews the importance of soil health and the limitations encountered in biochar research which highlight the need for research design protocols and a classification system. A possible classification system is presented in Chapter 4