Reactions in Soil Solution

Inorganic ions can exist as hydrated ions in solution, with the form of the ion being determined by its charge (z) and size (r), expressed as the ionic potential z /r. Ions with a small ionic potential ( approximately six) are present in solution as the hydrated ion e.g. in soil solution, 

Those with a high-ionic potential ( 20) form soluble oxyanions e.g. phosphate, nitrate, sulfate). 

The chemical speciation of the ions is highly dependent on pH and redox potential. Phosphorus, for example, exists as orthophosphate anions  

Interactions between ions in solution can be considered in two ways. Long-range interactions, those 0.5 nm, are accounted for by the 

At infinite dilution, i = [i], i.e. ji— 1. Ionic interaction increases with concentration and the square of the ionic charge, which is described by the ionic strength of the solution (7)  

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Table 2.4 Some Important Reduction Half-Reactions in Soil Solutions...

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