Practice exam #3 - QUESTION 2

a) On soils containing iron sulphide, the iron sulphide will oxidize to produce iron oxides and sulphuric acid. Sulphuric acid is one of the most acidic acids in existence, and easily releases its H+ cations into the soil solution, which will drastically lower the soil pH.

b) To reduce H+ release from these soils, you could keep it at saturation for part of the year. This would create anaerobic conditions that cause reductive conditions to dominate that would prevent FeS2 from oxidizing and releasing H+ ions. Alternatively, you could add large amounts of basic compounds like lime to soils to absorb the release H+ ions and offset increases in acidity.

Blaise has a good option, keeping these soils saturated.... preventing oxidation and the release of H⁺ ions in the first place.
As indicated here as well, lime will help nuetralize acidic conditions, but large amounts required.