Natural Sulfate of Potash, Magnesia

Natural Sulfate of Potash, Magnesia (2MgSO₄ • K₂SO₄), commonly referred to as Sul-Po-Mag or K-Mag (these are brand names), is a natural mineral salt, called langbeinite, and typically contains 22 percent potash, 11 percent magnesium and 23 percent sulfur. Like sulfate of potash, langbeinite is slowly soluble but is an acceptable material to use in the production of certified organic crops and the practice of organic land care.

Natural Sulfate of Potash, Magnesia – View MSDS (pdf)