Date of this Version
This NebGuide focuses on the use of the micronutrients zinc and iron.
Of the 16 elements known to be essential for plant growth, 7 are used in very small amounts and are classified as micronutrients. These are zinc (Zn), iron (Fe), manganese (Mn), copper (Cu), boron (B), molybdenum (Mo) and chlorine (Cl).
Micronutrients are supplied to plants from two sources: 1) soil minerals and 2) organic matter. They are released as the soil minerals break down over a period of time by weathering. The major portion of the micronutrients made available to plants, however, probably comes from the breakdown (mineralization) of the organic matter.
Research studies have demonstrated that Nebraska soils can supply all of the micronutrients needed for plant growth except zinc and iron on some, but not all soils, and boron for alfalfa and sugar beets in a few isolated situations.