What is Biochar?

November 16, 2009

For the past year and a half, I have been working with biochar for use as a soil amendment for sand-based turfgrass rootzones. Biochar has been gaining a lot of momentum in some agronomy circles as a cure-all soil amendment to improve the sustainability and productivity of our agricultural soils. A flurry of research has been funded and published related to biochar, but what really is this biochar stuff?

In a nutshell, biochar is the co-product of a biofuel production process called fast pyrolysis. Essentially, a biomass feedstock is pyrolyzed, or burnt, at a very high temperature and bio-oil is produced along with biochar. The oil can be used for consumer use after refinement similar to gasoline (see Figure 1). Originally, not much thought was put into using the biochar for any practical use, but agronomy researchers believe there is some potential for its use in agricultural settings.

I will be posting a series of threads relating to biochar in the coming weeks. If you have heard of biochar or have any firsthand experience with biochar or materials similar to it (ie. activated charcoal, fly ash, etc.) please post a reply explaining what your experience or use for these products has been. The reason I ask is because I received a question pertaining to whether biochar will deactivate herbicides, fungicides, ect…

*Illustration borrowered from Johannes Lehmann. Department of Crop and Soil Sciences, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853 (CL273@

cornell.edu) Front Ecol Environ 2007; 5(7): 381–387


Shane Brockhoff
Iowa State University