This text is a reference source covering the chemical elements that are nutrients for plants and animals. It deals with the concentrations and transformations of these elements in soils, grassland plants, and ruminant aniamls, particularly cattle and sheep. For each element, the following data are given: forms occurring in soil, factors that affect availability and concentration, uptake and distribution in grassland plants, role in animal nutrition, amounts and forms excreted by grazing animals, and concentrations needed by ruminant animals.