Biochar: Its Pluses and Minuses

In recent years, biochar has received a lot of attention: some positive, some negative. Biochar is a super-charged charcoal, created when organic matter — wood, grain stalks, grasses, peanut shells, etc. — is burned slowly with almost no oxygen in an enclosed chamber at nearly 1,000 degrees Fahrenheit or higher. The result is a stable crystalline substance rich in carbon that is resistant to decomposition. The pyrolysis (burning) creates small chambers capable of holding moisture, nutrients, and a diversity of microbes. 

As a soil regenerator, biochar works best when combined with compost or livestock manure, additions that provide microbes and nutrients. By itself, it is not a fertilizer. Biochar varies greatly depending on the organics or feedstock used. At its best, biochar increases agricultural productivity, improves soil health and resilience, transforms a waste product into a resource, and helps resolve the climate crisis by sequestering carbon. There has also been a lot of promising exploration and development of the use of biochar in industrial applications.

Because of the organic feedstock used in its production, biochar is sometimes considered the successor to biofuels. Such fuels have an uneven history, since sometimes they add to deforestation and greenhouse-gas emissions, and even at times deplete oxygen levels. Biochar raises alkalinity levels when applied to fields, making it critical that soils be tested and analyzed before deciding on its addition.