The benefits of biochar to soils for agricultural purposes are numerous. Biochar may be added to soils with the intention to improve the soil, displace an amount of conventional fossil fuel based fertilizers, and sequester carbon. However, the variable application rates, uncertain feedstock effects, and initial soil state provide a wide range of cost for marginally improved yield from biochar additions, which is often economically impracticable. The need for further clarity on optimizing biochar application to various crop yields is necessary if it is to gain widespread acceptance as a soil amendment.
Filiberto, D., & Gaunt, J. (2013). Practicality of Biochar Additions to Enhance Soil and Crop Productivity. Agriculture, 3(4), 715–725. https://doi.org/10.3390/agriculture3040715