Nitrogen FixationNitrogen IsotopesNitrogen CompoundsNitrogen CycleBlood Urea NitrogenNitrogen DioxideReactive Nitrogen SpeciesNitrogen OxidesPII Nitrogen Regulatory ProteinsCarbonAmmoniaNitratesFertilizersQuaternary Ammonium CompoundsGlutamate-Ammonia LigaseUreaSoilAmino AcidsNitrogen Mustard CompoundsNitrogenaseMolecular Sequence DataSymbiosisBiomassBacterial ProteinsPlant RootsPlant LeavesCulture MediaGlutamineDigestionAcetyleneKineticsGene Expression Regulation, BacterialTime FactorsPhosphorusMutationOxidation-ReductionBase SequenceNitritesAllantoinAnimal FeedGlutamate SynthaseHydrogen-Ion ConcentrationAmmonium CompoundsPoaceaePhotosynthesisGenes, BacterialRoot Nodules, PlantEcosystemFermentationCyanobacteriaNitrate ReductaseDenitrificationAmino Acid SequenceBacteriaCattleDietMedicago sativaEscherichia coliNutritional RequirementsTemperatureCarbon DioxideModels, BiologicalSoybeansSoil MicrobiologyKetoglutaric AcidsBody WeightEnergy MetabolismRumenSpecies SpecificityTreesRNA, MessengerGlutamate DehydrogenaseAir PollutantsSulfurAgricultureLiverGene Expression Regulation, FungalPlantsFabaceaeCarbon IsotopesZea maysFreezingOxygenSinorhizobium melilotiRhizobiumGATA Transcription FactorsPlant ShootsWaterFecesOxidoreductasesSaccharomyces cerevisiaePlant ProteinsManureDNA, BacterialSwineNitrificationEnvironmental MonitoringPhylogenyNitric OxideTranscription, Genetic