Streams and rivers have been highlighted as significant but poorly constrained sources of nitrous oxide (N2O), a greenhouse gas ≈300 times more potent than carbon dioxide. A large share of stream N2O emissions arises from the use of nitrogen (N) fertilizers by agriculture and therefore most of the research on N2O emissions from streams has focused on agricultural areas, especially on fertile calcareous soils having near-neutral pH.However, recent research suggests that streams located in regions having low pH (