Review of the Effects of Biochar Amendment on Soil Properties and Carbon Sequestration

Biochar is one of a series of materials referred to as black carbon because it is produced by thermochemical transformation of the original biomass material under a variety of conditions. The objectives of this paper are to summarize the characteristics of biochar created from different feedstocks and identify the potential of biochar to maintain soil quality and sequester carbon. Biochar properties were analyzed in context to the biochar sources using indicators of their elemental compositions, pH, surface area, and cation exchange capacity. Application effects were also compared to evaluate the potential of biochar as a soil amendment and carbon capture agent on the basis of pot and field study results. Biochar performed well in terms of the improvement of soil pH and organic carbon, the stability of soil fertilizer generated from its large surface areas and cation exchange capacities. In general, the use of biochar proved to be an appropriate strategy for carbon neutralization resulting from carbon storage by itself and the decrease of total greenhouse gas emissions, including CO2, CH4, and N2O, although the effects of biochar on each gas differed significantly. Overall, biochar exhibits great potential for expanded use in environmental fields; however, additional long term field studies that would assess biochar application rates are recommended.