Yara PZ065GU12 Sulfate of Potash Granular 0-0-50 50 lbs, white granule that provides 50% potash and 17% sulfur to crops. This potassium sulfate fertilizer is chloride-free and has a low salt index, less than half that of muriate of potash. Potassium Sulfate is suitable for applications into fertility systems primarily for grapevines, tree crops, and vegetables.