Kimberly Gomes recently wrote an article on Biochar for the SF Chronicle exploring its’ potential to ameliorate the issue of nutrient loss in low carbon soil. Biochar is a substance we here at Lily Films have often mused about. In our short film, The Promise of Biochar we explore the substance (carbon made from burning biomass in low-oxygen situations through a process known as pyrolysis.)
It has been hailed as the perfect blend of indigenous wisdom and modern technology, and many claim it to be the silver bullet of climate change, soil exhaustion, and resource depletion. But can one substance really achieve all these goals without any externalities?
Picture by Harley Soltes
While we are curious about the application of this technology- and happy that scientists are paying attention to the importance of a soil component besides N,P,K- we are hesitant to whole heartedly endorse Biochar. First off, any technology that advocates the burning of biomass should be properly scrutinized. Yes, pyrolysis is different- the controlled low oxygen method of burning has very low emissions and in some cases has an added benefit of creating biogass. However, there are time tested methods of recycling organic matter back into the soil (aka Compost), which achieve the dual goals of simultaneously feeding micro organisms and creating a stable carbon base. As Gomes noted in the Chronicle Article- this base doesn’t last forever, which is why soil management is a continuous process. Biochar advocates seem attracted to the possibility of a one-stop-shopping experience of adding carbon to the soil. ‘It will last indefinitely!’- they have decreed.
We agree with one of the subjects of Symphony of the Soil, Vandana Shiva, as she was quoted in the Chronicle article. “She advises proponents to avoid a reductionist carbon mentality and keep in mind that plants, like humans, need all the essential micronutrients and trace elements.”
Reductionism in mind, we are curious to hear more evidence from Biochar advocates. How will they regulate where biochar is sourced from? Will they begin to regulate feedstocks to assure that the material is not polluted by industry? How does Biochar hold up over the long term? What are the numbers for nutrient retention in Biochar and how does it compare to compost?
All of these questions will have to be answered before we make a decision on the probabilities surrounding the actual promise of biochar.
– Jessy Beckett