A water insoluble micronutrient fertilizer, methods of producing, and methodsof using the same are provided. Thefertilizer may comprise at least one first micronutrient selected from thegroup consisting of chromium, cobalt, copper, iron,man-ganese, and zinc, a polyphosphate； and optionally at least one secondmicronutrient selected from the group consisting of boron,chlorine, iodine, molybdenum or selenium. The fertilizer compounds arepreferably water insoluble, dilute acid soluble, andfree--flowing powders. The method of production consists in dissolving acompound of the first micronutrient in phosphoric acid at atemperature between 90 and 165 °C, neutralization and drying.
