The project DrivNOS aims to understand how nitrous oxide (N2O) emissions from streams, and the underlying processes driving them, are altered by nitrogen (N) pollution and soil properties, particularly iron content and pH. Streams have been highlighted as significant but poorly constrained sources of N2O, a greenhouse gas ∼300 times more potent than carbon dioxide. DrivNOS will identify potential N2O emission hotspots in streams located in contrasting catchments (nature areas and intensive agriculture), characterise production pathways and determine how N pollution interacts with iron content and pH to alter the emission of N2O from streams.