The importance of isomorphous substitution is that it produces a net negative charge in clays. This charge must be balanced by positive charged ions from solution. This is important to retention of plant nutrients (soil fertility) and the retention of charged polutants.

What is an isomorphous substance?

Crystals of isomorphous substances are almost identical. ... The substances sometimes crystallize together in a solid solution. Isomorphous substances usually have similar chemical formulas, and the polarizability and ratio of anion and cation radii are generally comparable (see ion).

What is isomorphous replacement technique?

Isomorphous replacement occurs when different ions yield slightly soluble crystals in a geometric form similar to the analyte.