I’ve posted before on Royal Society discussion on biochar (try a search on ‘royal society’). I missed this important report [linked here] when it was released last year. A search on ‘biochar’ in the report pulls some results. Here are some cuts and comments…
Page 140: “Figure 5.32 Possible technical and management options, and their stage of development, to reduce GHG emissions in the agriculture sector by either increasing efficiency /productivity or reducing emissions per animal”
Biochar gets listed but when you look at the table, biochar could have been discussed in 6 of the 7 table items.
Page 146: Box 5.4: Changes in soil carbon under grazed pastures
“…There is also interest in biochar to increase carbon stocks. Biochar is organic matter carbonised at high temperatures under controlled conditions that restrict oxygen from the process. There is good evidence that biochar represents a very stable form of carbon, so it could be applied to soils to store more carbon. Specific biochars could also possibly help reduce N2 O emissions, although the specific mechanisms are not yet clear. Other potential benefits for improving soil functions and reducing emissions from pastures are also being evaluated. However, the main challenge at present to any widespread use of biochar in a pastoral system remains its cost and the large area that would need to be covered, which makes this strategy not economically feasible to New Zealand farmers without a very high carbon price.
Given the relatively high existing soil carbon stock in New Zealand’s pastures and the scientific and technical difficulties in monitoring and verifying long-term systematic changes in soil carbon stocks, relying on increasing soil carbon would not appear to be a viable mitigation route for New Zealand in the near term. However, subject to substantial additional research and the development of cost effective farm-scale monitoring and reporting tools, it might become a more tractable avenue in future.”
I’ve highlighted two important sentences. Comments: The authors don’t seem to have considered continuous application scenarios. Examples: biochar as an animal feed supplement; biochar as a nutrient carrier in fertilser applications; biochar produced for ‘free’ and over time by the farmer from treefall or crop residues. I’m hoping pressure will grow for more research now, due to growing climate change pressures, water quality and a change of govt. thinking. Your support and efforts could help with this.