Down To Earth Organic Azomite SR Powder Formula Soil Enhancer, 50-Pound Slow-Release grade of AZOMITE volcanic minerals with particle sizes ranging from 4 to 200 mesh. Ideal for blending with other fertilizer materials and amendments as a trace mineral resource to help meet complete plant nutritional needs Proven to increase crop yield, quality and overall plant growth Carefully blended from organic nutrients in the ideal proportions without the use of synthetics, growth stimulants or low quality fillers Highest quality ingredients help provide an effective and environmentally friendly approach to plant care, crop fertilization and soil management