title: Use of variations in natural nitrogen isotope abundance for environmental studies: a questionable approach.
mesh_terms: D001272:Atmosphere; D004777:Environment; D005308:Fertilizers; D009584:Nitrogen; D009587:Nitrogen Isotopes; D011868:Radioisotopes; D012987:Soil; D014877:Water Pollution, Chemical
chemical_list: D005308:Fertilizers; D009587:Nitrogen Isotopes; D011868:Radioisotopes; D012987:Soil; D009584:Nitrogen