The Evolution of Screening Systems for Optimum Granular Fertilizer Product Quality

Until around the 1980's, the accepted typical size distribution standards for granular fertilizer was Tyler 6 to 16 (1.18-3.35 mm) in the U.S. and 1-4 mm in many other parts of the world. However, in order to avoid caking dust problems during handling operations and to improve the evenness of fertilizer distribution from mechanical spreaders, fertilizer product quality expectations in the marketplace have changed. Attention has been focused on eliminating small granules, moving towards a much more closely sized product and generally increasing the median size of granular products.