Ammonium Sulfate

From Havlin, Beaton, Tisdale and Nelson (1999)

Ammonium Sulfate (NH4)2SO4
Ammonium sulfate represents only about 2% of total N fertilizer use in the United States. The main advantages of (NH4)2SO4 are low hygroscopicity and chemical stability. It is a good source of both N and S. The strongly acid-forming reaction of (NH4)2SO4 in soil can be advantageous in high-pH soils and for acid-requiring crops. Its use can be undesirable in acidic soils already in need of liming. The main disadvantage of (NH4)2SO4 is its relatively low N content (21% N); it is generally too expensive to use as a N source. It can, however, be an economical source of N when transportation costs are low, when it is a relatively inexpensive by product, and when it is used with crops requiring S.