Phosphate Rock and Fertilizer (IMAGE) Duke University Caption A person's hands cup a sample of pelletized agricultural fertlizer and a piece of the phosphate rock from which it is created. Credit Robert Hill, Duke University Usage Restrictions none License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.