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 mug 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.