The main chemicals reported for soil amelioration include
gypsum, phosphogypsum, flue gas desulfurization gypsum, calcium
chloride, sulfuric acid, sulfur, iron pyrite, and aluminum sulfate
Among
these substances, gypsum-like solid Ca2+ amendments are the
most common chemicals applied to large areas. Gypsum and
desulfurized gypsum application followed by freshwater leaching
ameliorates hard saline–sodic soils and enhances the grain yield of
rice