Nitrous oxide emission from temperate meadow grassland and emission estimation for temperate grassland of China

Nitrous oxide emission from temperate meadow grassland was measured using a closed chamber method at two experimental sites in China. In the four-month measurement period, the N₂O fluxes in mown meadow grasslands of the Songnen Plain and of the Kerqin Steppe were on average 41.1 and 7.9 g N₂O-N m^–2 h^–1, respectively. Considering the influence of grassland type and degradation extent, an empirical formula was constructed, with which the annual N₂O emission from temperate grassland of China was estimated as 40.4 Gg N. Meadow grassland, accounting for 14.0% of the total grassland area, contributed 28.4% of the total N₂O emission.