The importance of the current study lies in (i) its application to the
soils of Peshawar, an important agricultural region which suffers from
endemic Zn deficiency, (ii) the direct comparison of multiple approaches
to determining a capacity term for labile Zn as a predictor of
Zn free ion activity (intensity) and (iii) the investigation of superficial
mixed Zn deposits as the possible origin of labile Zn fractions in such
soils.