1 Introduction Nitrous oxide (N2O) is a potent greenhouse gas with a global warming potential approximately 298 times greater than that of carbon dioxide over a 100-year timescale (Ravishankara et al. 2009). Paddy fields, characterised by regular flooding and drying cycles, are significant anthropogenic sources of N2O emissions. The reduction of N2O to N2, catalysed by microorganisms carrying the nosZ genes, represents the only known biological sink for this greenhouse gas (Thomson et al. 2012).
