Emissions of nitrous oxide from soils

Abstract

Potential changes in the concentration of nitrous oxide (N2O) in the atmosphere have sparked considerable interest because of the proposed role of N2O in regulating stratospheric ozone levels, and in contributing to the atmospheric greenhouse effect. A substantial portion of the atmospheric N2O is thought to result from microbial transformations of inorganic forms of nitrogen in soils; N2O is an intermediate in denitrification (reduction of NO-3 to N2) and is formed during nitrification (oxidation of NH+4 to NO-3) in soils, although the mechanism is unclear. Several models have predicted that input of nitrogen into cropland, either from commercial fertilizers or N-fixing leguminous crops, could sufficiently increase emissions of N2O from soils to deplete stratospheric ozone levels1-3 and raise average world temperatures4. We report here N2O emissions from mineral and organic soil sites in New York and from organic soil sites in the Florida Everglades Agricultural Area. © 1982 Nature Publishing Group.