Many Iowa fields require nitrogen (N), phosphorus (P), and potassium (K) fertilization for optimum crop production. Crops remove large amounts of these nutrients from the soil, and large amounts of fertilizers often need to be applied. Fertilizer application methods and application equipment commonly used to supply these nutrients are adapted to large fertilizer application rates. These methods include broadcast application of granulated or fluid fertilizers with or without incorporation into the soil with tillage, injection of fluid fertilizers into the soil, or deep banding of granulated fertilizers. The P and K fertilizers usually are applied before planting crops, while N fertilizers for com are applied before and (or) after planting the crop. Also, most producers apply once before planting corn the P and K fertilization rates recommended for the 2-year com-soybean rotation.