John M. Jemison, Jr., Extension water quality and soil specialist, University of Maine Cooperative ExtensionReviewed and updated by Dana Hill, DVM, MS, Ph.D., DACVP, University of Maine Cooperative Extension For information about UMaine Extension programs and resources, visit extension.umaine.edu.Find more of our publications and books at extension.umaine.edu/publications/. Table of Contents Introduction Sources of Nitrate in