title: Availability of soil ammoniacal nitrogen to Azotobacter and its effect on nitrogen fixation.
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001395:Azotobacter / Q000254:growth & development / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002452:Cell Count; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation; D012987:Soil; D012988:Soil Microbiology
chemical_list: D012987:Soil; D002244:Carbon; D000641:Ammonia; D009584:Nitrogen