ABSTRACT
An additional 9% is applied as dry, direct-application materials that usually are handled through bulk blend outlets. In fact, diammonium phosphate is such an ideal ingredient for blends that its development in the early 1960s often is credited with major responsibility for the growth of bulk blending. In addition to the major nutrient materials mentioned, a number of other materials often are incorporated in bulk blends by simple addition during the dry-mixing operation. Miscellaneous materials frequently added include secondary nutrients, such as sulfur and magnesium materials; micronutrients, such as zinc, boron, copper, and manganese compounds; herbicides; pesticides; anticaking conditioners; and seeds. The degree of moisture protection required by fertilizer materials in bulk-blend plants depends to a large extent on the critical humidity of the particular material. Outside the United States, bulk blending has met with various degrees of an adoption.
