Compound fertilizers contain two or more nutrients and are also known as multinutrient fertilizers (Nitrogen, P2O5 and K2O). A complex fertilizer refers to a compound fertilizer formed by combining ingredients to react chemically. Compound fertilizers can also be produced by blending two or more granular fertilizers of similar size. Such products retain the physical and chemical characteristics of individual compounds. They are made by mixing basic fertilizers derived from ammonia with salts containing phosphorus or potassium.