Disease Team, on behalf of Dr. Hartman:
“I see some leaf mottling - could be virus, but that would have to be tested to determine. Most likely it is a nutrient issue since it is showing up at higher rates of the biochar. If it is a nutrient issue, that may be difficult to diagnose without some nutrient analysis being completed testing the low vs. higher rates with symptoms. Perhaps Eric has some experience in this.”
SMART Farm Team, on behalf of Dr. Sedivy:
The symptoms that the partner is experiencing may be completely unrelated, but please find below an excerpt from the linked paper: https://www.hindawi.com/journals/jchem/2019/4506314/
“
Since biochar production is from a range of feedstock sources, some contaminants can be present including PAHs, POPs, HMs, and organic compounds; therefore, there is an important consideration in the context of adding biochar to agricultural soils [80] due to negative effects on soil properties and function. These contaminants may also end up in the biochar depending on the pyrolysis conditions or the use of processing conditions that may favor their production [81]. High rates of biochar application in the soil can affect micro-organism survival rates, including plants and animals, thus necessitating testing of biochars effects before the application on agricultural fields to avoid detrimental effects [82]. However, the negative implications and harmful effects on the ecological system due to the continued use of biochar have not been wholly understood [83]. There is a need to identify suitable feedstock for the production of biochar from a range of biomass as provided for by European Biochar Certificate (EBC) in the positive list of biomass feedstock approved for use in producing biochar [84].
“
