It’s a big subject!
Thanks Suella for the link, it’s most interesting.
One thing I notice is that Merfield does not define biochar, though I guess he (and everyone else) mean it’s impregnated with microbes e.g. from fungi. Otherwise we are simply discussing charcoal and why not call it that Mark, rather than uncharged biochar? At least you are clear that it is uncharged.
“Locking carbon into soil” – so? Merfiled’s point is valid for me, that burning the wood has removed a lot of goodness. Composted wood chip is surely better value, as practiced by Iain Tolhurst.