21-0-0-24S Ammonium sulfate is an ingredient in most mixed fertilizers that contains 24% sulfur. It is a dry crystalline material in which the nitrogen is all in the ammonium form.
Ammonium sulfate is chiefly the ammonium salt of sulfuric acid. It shall not contain less than twenty and five-tenths percent (20.5%) nitrogen. (AAPFCO)
