Ammonium sulfate is an inorganic chemical compound with the chemical formula (NH4)2SO4. It contains 21 percent nitrogen in the form of ammonium ions and 24 percent sulfur as sulfate ions. The purified material takes the form of white granules or crystals. It is commonly used as a fertilizer and as an agricultural spray adjuvant for water-soluble pesticides. It is also used in the preparation of other ammonium salts.