What is "ammonium sulfate"

alt. (context US inorganic compound English) An inorganic chemical compound, (NH₄)₂SO₄, commonly used as a fertilizer and as a food additive (E517) used as an improving agent. n. (context US inorganic compound English) An inorganic chemical compound, (NH₄)₂SO₄, commonly used as a fertilizer and as a food additive (E517) used as an improving agent.

Ammonium sulfate (American English; ammonium tetraoxosulfate (VI) is the IUPAC-recommended spelling; and ammonium sulphate in British English), (NH)SO, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen and 24% sulfur.