This book is the first laboratory manual to bring together basic procedures for measurement of stable and radioactive isotopes of nitrogen, with specific applications to plant, soil, and aquatic biology. This bench-top reference gives practical coverage of mass and emission spectrometry, nitrogen fixation, nitrification, and identification, organic nitrogen, and the radioactive isotope 13N. Methods are described so that researchers can adapt them, without the aid of outside references, to virtually any task they may encounter in investigations of nitrogen transformation processes. Serves as a practical guide for nitrogen isotope techniques Features studies of nitrogen transformations in terrestrial and aquatic systems Includes basic measurement techniques plus specific applications for stable and radioactive nitrogen isotopes Presents detailed protocols, overviews, and key references Includes fifty figures and sixteen tables Hands-on reference for both students and researchers