Soil testing query:

Can anyone tell me how a *c.mole/kg* (centimole per kilo) relates to a *mg/kg* in soil sampling?
[I've searched but not found.]

~ I'm attempting to decipher difference between: 8280 mg/kg and 0.02 c.mole/kg

Your input is greatly appreciated (info needed for educating some new people regarding already deployed geoengineering).