Intrepid Trio®, or sulfate of potash magnesia, is a low-chloride, OMRI-listed potassium fertilizer. A neutral-pH fertilizer with less than 2.5 percent chloride, Trio has an analysis of 22 percent potash, 11 percent magnesium and 22 percent sulfur. Each granule supplies potassium, sulfur and magnesium in the same ratio, ensuring that all three minerals are available to the plant when needed. Its combination of soluble and slow-release nutrients support crop production season-long. The granular grade used in Midwestern BioAg blends mixes well with other fertilizer materials for even distribution of nutrients.