Influence of six nitrification inhibitors on methane production in a flooded alluvial soil

The influence of six nitrification inhibitors (NI) on CH4 production in an alluvial soil under flooded condition was studied in a laboratory incubation experiment. The inhibition of CH4 production followed the order of sodium azide > dicyandiamide (DCD) > pyridine > aminopurine > ammonium thiosulfate > thiourea. Inhibition of CH4 production in DCD-amended soils was related to a high redox potential, low pH, low Fe2+ and lower readily mineralizable carbon content as well as lower population of methanogenic bacteria and their activity. In the presence of higher levels of urea N (40 mug), the inhibitory effect of DCD was only partially alleviated. Results indicate that several NIs can differentially regulate CH4 production in a flooded alluvial soil.