Nitrogen FixationNitrogen IsotopesNitrogen CompoundsNitrogen CycleBlood Urea NitrogenNitrogen DioxideReactive Nitrogen SpeciesNitrogen OxidesPII Nitrogen Regulatory ProteinsCarbonAmmoniaNitratesFertilizersQuaternary Ammonium CompoundsGlutamate-Ammonia LigaseUreaSoilNitrogen Mustard CompoundsNitrogenaseSymbiosisAmino AcidsBiomassPlant RootsGlutamineAcetylenePlant LeavesDigestionBacterial ProteinsAmmonium CompoundsGlutamate SynthaseGene Expression Regulation, BacterialAllantoinNitritesPhosphorusCulture MediaMolecular Sequence DataRoot Nodules, PlantNitrate ReductaseDenitrificationPoaceaePhotosynthesisCyanobacteriaEcosystemAnimal FeedGenes, BacterialOxidation-ReductionMedicago sativaKetoglutaric AcidsBacteriaFermentationSoil MicrobiologyNutritional RequirementsRhizobiumGlutamate DehydrogenaseGATA Transcription FactorsSinorhizobium melilotiSoybeansAir PollutantsCarbon DioxideRumenMutationGene Expression Regulation, FungalTreesAgricultureSulfurPlant ShootsNitrificationHydrogen-Ion ConcentrationManureEnergy MetabolismFabaceaeParenteral Nutrition, TotalFreezingAtmosphereNitrate ReductasesAir PollutionGlutamate Synthase (NADH)Body WeightPlantsDietBase SequenceGasesZea maysAmino Acids, EssentialParenteral NutritionEnvironmental MonitoringPanicumAmmonium ChlorideAzotobacterOxygenTime FactorsOxidoreductasesNitric OxideNitrous OxideModels, BiologicalPlant ProteinsSeawaterCrops, AgriculturalOzoneFeces