title: Nitrogen mineralization and assimilation at millimeter scales.
abstract: The assimilation (uptake or immobilization) of inorganic nitrogen (N) and the production of ammonium (NH(4)(+)) from organic N compounds are universal functions of microorganisms, and the balance between these two processes is tightly regulated by the relative demands of microbes for N and carbon (C). In a heterogeneous environment, such as soils, bulk measurements of N mineralization or immobilization do not reflect the variation of these two processes in different microhabitats (1μm-1mm). Our purpose is to review the approaches that can be applied to measure N mineralization and immobilization within soil microhabitats, at scales of millimeter (using adaptations of (15)N isotope pool dilution and IRMS-isotope ratio mass spectrometry) to micrometer (using SIMS-secondary ion mass spectrometry).
authors.affiliation: Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon, USA.
authors.forename: David D
authors.initials: DD
authors.lastname: Myrold
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pett-Ridge
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Bottomley
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D017753:Ecosystem; D007554:Isotopes / Q000032:analysis; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000032:analysis; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000737:chemistry; D058441:Rhizosphere; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D018629:Spectrometry, Mass, Secondary Ion
chemical_list: D007554:Isotopes; D009587:Nitrogen Isotopes; D000644:Quaternary Ammonium Compounds; D012987:Soil; D009584:Nitrogen