Pasture Soils Contaminated with Fertilizer-Derived Cadmium and Fluorine: Livestock Effects

Pasture-based livestock production is a major system of agriculture in many parts of the world. Approximately one-fifth of the world’s land area is used for livestock production, twice the area used for growing crops. Grazing livestock occupy approximately 3.5 billion ha of permanent pasture (FAO Statistics 2006). In the more intensively stocked pastures, pasture production has been increased through introduction of improved pasture species and regular application of fertilizers. In ryegrass and clover-based pastures, common in temperate climates, the main nutrients applied in fertilizers have been phosphorus (P) and sulfur (S). Nitrogen, sulfur, and potassium fertilizers are relatively free of contaminants, but P fertilizers, e.g., single and triple superphosphate (SSP, TSP), and diammonium phosphate (DAP) often contain many contaminants derived from the phosphate rocks (PR) used in their manufacture. If not managed appropriately, these fertilizer contaminants may cause adverse effects on livestock health, food quality, and environment.