1)  MgSO4 industrial uses include leather tanning, explosives, pulp and paper, porcelain making.
2)  Agriculturally, MgSO4 is an important fertilizer because magnesium is a major component of chlorophyll. It is most commonly used in potted plants and magnesium-hungry plants such as tomato, potato, rose, etc. MgSO4 has a much higher solubility compared to other fertilizers.
3)  It can be used as an oral laxative.
4)  MgSO4 (Epsom salt) can also be used as bath salts.