Phs.Org:Where does charcoal, or black carbon, in soils go?
Here is a report on a study of where charcoal in the soil goes. The report says it doesn't stay in the soil, it dissolves and enters the water, eventually the ocean. The researchers say we need to carefully study the results of adding biochar to fields until we fully understand the effects.

Bill Gill

C is not the speed of light in a vacuum.
C is the universal speed limit.