Question about soil pH?

Question

Was wondering if someone could help with the following question? Why are pHkcl values usually significantly lower than the pHh2O values? Its not just because KCl is more acidic than H2O is it?

Thanks

Answer 1

KCl solutions extract the AL3+ from the exchange complex of soil. Al3+ solvated has highly acidic properties. This is called potential acidity of soils. That is why pH in KCl solutions is lower than in water at the same ratio soil solution.