title: Diurnal variations of nitrogenase activity in the field.
abstract: Nitrogenase activity was determined in situ by repeated assays at regular intervals to compare the patterns of diurnal variations occurring in a rice field, a grassland, and a peanut field. In the rice field only one peak occurred (mid-day), whereas the other systems exhibited typical two-peak patterns, which were suspected to be induced by climatic conditions or possibly by a specific rhythm of exudation. Observed data on diurnal variations in nitrogenase activity were fitted to different models of diurnal variation comprised of computed periodic curves.
mesh_terms: D000114:Acetylene / Q000378:metabolism; D000704:Analysis of Variance; D010367:Arachis; D001419:Bacteria / Q000201:enzymology*; D002940:Circadian Rhythm; D002980:Climate; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000378:metabolism*; D012275:Oryza; D010084:Oxidation-Reduction; D010944:Plants; D006109:Poaceae; D012988:Soil Microbiology
chemical_list: D009591:Nitrogenase; D000114:Acetylene