Agrarians from various ancient cultures around the world discovered the soil fertility benefits of charred biomass over two thousand years ago.

Now known as ‘biochar’, this ancient soil management practice has been enjoying a renaissance of late for a number of reasons largely related to the need for more resilient and productive soils and biochar’s ability to sequester carbon in a safe and beneficial manner.

Biochar is made by baking organic material in an oxygen-limited environment, called pyrolysis. Benefits vary depending on the soil, crops and climate where biochar is used with poor soils benefiting the most. Providing long-lasting organic material, improving water and nutrient holding capacity, and improving overall soil tilth are all potential benefits.

Due to its porous nature and cation exchange capacity, biochar can also be used as a filtration medium to prevent nutrient run-off from farms into local water bodies. In Europe livestock farmers are adding small amounts of biochar to feed rations to improve feed conversion ratios and overall animal health. Biochar as carbon fodder has also shown promise as a way to reduce enteric methane emissions.

Biochar is increasingly available to purchase but farmers can also convert their on-farm waste biomass in to biochar.

Farm scale equipment for making biochar is evolving and shows promise not just as a waste conversion technology which produces a valuable soil amendment, but also as a means for farmers to generate renewable energy in the form of heat, and in some cases electricity.  For the Silo,  Kathleen Draper.

Kathleen Draper is the US Director of the Ithaka Institute for Carbon Intelligence, a non-profit focused on research, education and program services that promote climate positive solutions which enhance land management, urban design, and resource efficiency.