2006 Annual Report 4d.Progress report. This report serves to document research conducted under a reimbursable agreement between ARS and The Fertilizer Institute. Additional details of research can be found in the report for the parent project 1265-12000-037-00D, Risk Assessment and Remediation of Soil and Amendment Trace Elements. A presentation of results was made at the American Society of Agronomy as part of a Symposium on Contaminants in Fertilizers. Progress was made on publishing three manuscripts reporting parts of the work, and a detailed review paper is still being prepared for a peer-reviewed journal to summarize the process of risk assessment for Cd in fertilizer products, and alternatives for reducing potential risks. One aspect of phosphate fertilizers which may allow food-chain transfer of Cd in the applied fertilizers is the high ratio of Cd to Zn, about 1:6, which is much higher than soils (about 1 to 200 g Cd per g Zn). Addition of Zn to soils with high Cd:Zn ratio can significantly reduce Cd accumulation by tested plants, and can inhibit Cd absorption in animals which ingest the crops. Improved understanding of the many protections against transfer of excessive bioavailable Cd into diets is critical to evaluation of allowable Cd levels in all soil amendments, including phosphate fertilizers.