title: Nitrogen fixation in lake sediments: contribution to nitrogen budget of Lake Mendota.
mesh_terms: D000114:Acetylene; D002849:Chromatography, Gas; D005030:Ethylenes; D005618:Fresh Water; D006371:Helium; D008697:Methane; D009586:Nitrogen Fixation; D010084:Oxidation-Reduction; D012987:Soil; D013696:Temperature; D014867:Water; D014922:Wisconsin
chemical_list: D005030:Ethylenes; D012987:Soil; D014867:Water; D006371:Helium; D000114:Acetylene; D008697:Methane