Nitrous oxide production and consumption in serially diluted soil suspensions as related to in situ N2O emission in submerged soils

A simple method for characterizing soil microbial community composition relevant to N2O production and consumption was proposed. Ten-fold series soil dilution was prepared. Nitrate or N2O was provided as the sole electron acceptor. Nitrous oxide concentration in the headspace gas across the serially diluted soil suspensions was measured against controls. Results showed that the patterns of N2O production and consumption across the soil suspensions provided useful information on the microbial community composition relevant to N2O production and consumption in these soils. An independent method, to that proposed here, was also employed to characterize denitrifier community compositions of the same soils. Data indicated that information on the soil microbial community composition characterized by both methods were compatible or mutually supporting and apparently related to in situ N2O emissions. Soil samples from manure (applied with animal manure plus chemical fertilizer) plots had higher denitrification rates than the samples from normal fertilizer (applied with chemical fertilizer only) plots. It was concluded that functional characteristics of soil microbial communities relevant to N2O production and consumption could be characterized at ecological levels and may potentially affect N2O emissions.