Intermediate soil acidification induces highest nitrous oxide emissions

Abstract Global potent greenhouse gas nitrous oxide (N 2 O) emissions from soil are accelerating, with increases in the proportion of reactive nitrogen emitted as N 2 O, i.e., N 2 O emission factor (EF). Yet, the primary controls and underlying mechanisms of EFs remain unresolved. Based on two independent but complementary global syntheses, and three field studies determining effects of acidity on N 2 O EFs and soil denitrifying microorganisms, we show that soil pH predominantly controls N 2 O EFs and emissions by affecting the denitrifier community composition. Analysis of 5438 paired data points of N 2 O emission fluxes revealed a hump-shaped relationship between soil pH and EFs, with the highest EFs…

• UD
  U.S. Department of Agriculture
• NN
  National Natural Science Foundation of China

  Awards: 32001140, 32371626, 32171553
• CP
  China Postdoctoral Science Foundation

  Award: 2022T150325
• NI
  National Institute of Food and Agriculture

  Award: 2018-51106-28773