Every week more & more peer reviewed literature on biochar is published and 2019 will see the debut of a peer reviewed journal dedicated solely to biochar research. On average there are at least a dozen new papers each week making it impossible to stay on top of all the news coming out about biochar. Nevertheless, I persist! I confess that scanning new titles a few times per week has become a bit of an addiction. Most of the research is still behind paywalls, but a growing number of papers are open-sourced so the full report is downloadable. [If you’d like a monthly bibliography and good synopsis of the new research, consider becoming a member of IBI and you will get Bob Gillett’s monthly listing which also tells you which ones are free or behind a pay wall.]
The majority of the research is still heavily focused on agricultural uses but other topics are beginning to show up with more regularity. Filtration is big, remediating metals and other toxins in soils is also a frequent topic. Unfortunately, it is still not common to read biochar papers on its use in livestock feed and building materials (good recent exception here). [HINT: sometimes if you search for ‘nano-charcoal’ or ‘biocarbon’ you may find a few more.]
This week my favorite freebie comes out of Appalachia where researchers are testing biochar to help regrow forests on former coal mining lands. This particular paper jumped out as I just wrote about Negative Emissions Technologies (NETs) and how biochar can be used synergistically with two of the other NETs: afforestation/reforestation and soil carbon sequestration. When it comes to climate change solutions, we need less siloed thinking and more NET gestalt (meaning an organized whole that is perceived as more than the sum of its parts). The Fields-Johnson et al (2018) paper highlights this very concept perfectly. Here is how…
Reforesting land that was stripped or blown apart in the careless crusade for fossil carbon is challenging both from a soil tilth and toxins perspective. Considering how much land has been pillaged for short term profit using surface mining, a whopping 1.2M hectares in Appalachia alone, being able to re-establish armies of CO2 sucking soldiers (aka trees) would be an absolute tour de force in our fight to rebalance carbon, not to mention a huge boost for biodiversity, flood control and economic development.
Researchers in West Virginia showed that biochar applied either in the root system or top dressed at varying rates for 2 different types of year-old sapling trees could potentially double above-ground biomass. Saplings grown in 100% biochar even doubled the below ground biomass as compared to mine soils.
Even though this was confined to pot trials using mine soil, this is really quite incredible when you consider the down stream implications. Getting fast growing native species to grow in contaminated soils could draw down an enormous amount of CO2. The rough math using 2,500 trees per ha and assuming 20 kg of CO2 absorbed per tree comes to 50 metric tons of CO2 per ha per year! Multiply that by 1.2M ha and Appalachia’s former mine lands could breathe in 60 Million metric tons of CO2. Now apply that to all the mine lands waiting to be resuscitated around the planet.
But wait there is more. Soil carbon sequestration should also be considered. The researchers applied biochar at three different rates: 2.3, 11.2 and 22.5 tons per hectare. The paper does not indicate the carbon content of the pine sawdust biochar but it is likely to be around 75% or more. At these rates the biochar could add 6.3, 30.8 and 61.9 tons of CO2e per hectare respectively. In Appalachia that would be 7.6M, 37M, or 74.3M tons of sequestered CO2e. The combination of photosynthesis and carbonization/sequestration could total more than 130M tons for the region!
Now imagine the Abandoned Mine funds set aside by coal companies being used to rebuild and rebalance carbon instead of adding insult to injury in the form of dumping fly ash or sewage sludge onto mine lands. Imagine carbon taxes on fossil fuel companies going towards rebuilding communities and eco-systems negatively impacted by drilling and desecrating landscapes. Combining reforestation, biochar & soil carbon sequestration to regenerate mine land is what I imagine an ideal NET gestalt looking like!