Abstract: The effects of soil drying-wetting alternation on nitrous oxide (N₂O) emission from oasis farmland were analyzed, which could provide the basis for optimizing irrigation and fertilization and reducing N₂O emission of oasis farmland. A laboratory incubation experiment was performed to determine the effect of soil drying-wetting alternation on its N₂O emission from oasis farmland in arid area. The 100 g dried soil was placed in a 730 mL mason jar, then the mason jar was placed in a 25 ℃ incubator, and the nitrogen content and soil moisture content were strictly controlled through connecting a syringe with a three-way valve to extract gas from the mason jar. The result are as follows: ① Soil drying-wetting alternation influenced significantly the cumulative N₂O emission of oasis farmland soil. Without fertilization, the cumulative N₂O emission of dryly-treated soil was 1.28 times of that of wetly-treated soil; ② Compared with non-nitrogen treatment, fertilization promoted significantly the soil N₂O emission, the highest N₂O emission occurred after nitrogen was applied for 0-4 days, and then the soil N₂O emission was reduced obviously; ③ The N₂O emission rate of the wetted soil was significantly higher than that of the dried soil after nitrogen was applied. The cumulative N₂O emission of wetted soil was 2.07 mg·kg^-1, and it was 1.16 times of that of dried soil. Therefore, the soil N₂O emission from oasis farmland could be reduced by properly prolonging the time interval of drip irrigation and fertilization.

Key words: oasis farmland, soil drying-wetting alternation, nitrogen application, N₂O emission