JoeReal

Biochar incorporated into the soil through time improves nutrient use efficiency of the plants. Nutrients could come from the air, water, animals, other plants, decaying matter, has been transported by wind or water, or from upwelling and other mass transport processes, and the easiest most obvious way is introduced intentionally by man from somewhere else. Whatever nutrients there are, they will not easily leach out from soils that have high biochar content, and the retention of those nutrients would be longer, giving it enough time for absorption by plants.

And for aggressive crop production, nutrients should be applied to balance out what has been taken. The more you harvest, the more you put in, until one or more factors become a limiting factor.

Nothing comes from nothing, and biochar has nothing directly to do with it, I think that this is the point that Richard is trying to make.