Potassium-Magnesium Sulfate

K₂SO₄·MgS0₄, potassium-magnesium sulfate fertilizer. Its gray crystals contain 24–26 percent K₂O and 11–18 percent MgO and dissolve easily in water. Potassium-magnesium sulfate fertilizer is weakly hygroscopic, does not pack, and spreads well. It is especially effective on sandy and sandy-loam soils for crops that are sensitive to chlorine (potatoes, buckwheat, legumes, fruits, and berries).