However, one should be
aware that the added biochar basically contributes to the cation
exchange capacity of the soil (e.g. Liang et al., 2006), and therefore
the adsorbed Na+ doesn’t become unavailable to plants but the Na+
equilibrium concentration of the soil solution will be lowered. Since
Na+ is not among the cations, which are strongly adsorbed to negatively
charged surfaces in the soil (e.g. Scheffer and Schachtschabel,
1979), it would be expected that the adsorption capacity/durability
over time is limited.