Nitrogen fertiliser-induced changes in N2O emissions are attributed more to ammonia-oxidising bacteria rather than archaea as revealed using 1-octyne and acetylene inhibitors in two arable soils

Abstract

Nitrification is believed to be one of the major sources of N2O production emitted from soil. Previous studies showed that both ammonia-oxidising bacteria (AOB) and archaea (AOA) can produce N2O via nitrification but their relative contributions are still poorly defined. Here, we used acetylene, an inhibitor of AOB and AOA ammonia monooxygenase (AMO), and 1-octyne, a selective inhibitor that specifically inhibits AOB AMO, to investigate how AOB versus AOA contribute to N2O emissions in two distinct arable soils. Soil amended with ammonium (NH4 +) increased N2O emissions to a greater extent than nitrate (NO3 −), and acetylene had a greater impact on N2O emissions in NH4 +-treated soils than t..