Abstract: A laboratory incubation was conducted to investigate the N₂O emission rates of saline soils collected from the Yellow River Delta of China under different water and N treatments. For the soils with the salinity from ECe = 6.4 mS·cm^-1 to ECe = 126.5 mS·cm^-1, their N₂O emission rates under different water conditions (50% WHC, 80% WHC, and 4 cm water depth) and without N amendment were very low, often below the detection limit. After applying 0.4 mg N·g^-1 soil of NH₄NO₃, the N₂O emission rate of sandy moderately saline soil at 50% WHC and at 4 cm water depth was 41.0 μg N₂O·kg^-1 soil·d^-1 and 364.6 μg N₂O·kg^-1 soil·d^-1, respectively, being comparable to that of non-saline soils under the similar conditions, and the N₂O emission rate of sandy strongly and extremely saline soils was 43%-65% and 23%-48% of that of sandy moderately saline soil, respectively. By contrast, the N₂O emission rate of Namended loamy saline soils was very low, from 0.91 to 37.1 μg N₂O·kg^-1 soil·d^-1. The  high potential of N₂O production and its strong dependence on nitrogen amendment and soil texture in saline soils suggested that the effects of soil salinity on N₂O emission were mainly controlled by the limitation of C and N supply rather than the microbial factors.

Key words: leaf economics spectrum, plant functional type, functional trait.