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通过田间试验研究不同土表覆盖处理旱作和水作水稻全生育期内土壤微量气体的排放。结果表明 ,旱作稻田当季N2 O的排放总量是水作稻田的 5～ 6倍 ,而水作稻田CH4 的排放总量是旱作稻田的8～ 1 9倍。不同覆盖旱作处理N2 O的排放总量为 :裸露 >覆膜 >盖草 ,CH4 排放总量为 :覆膜 >裸露 >盖草。水作稻田CH4 的排放与水稻生育期关系密切 ,以分蘖盛期的 5 0mgm- 2 h- 1为最大。旱作稻田N2 O的排放与施氮关系密切 ,其排放通量峰值出现的时间因施氮时期不同而异 ,基肥的峰值 (2 1 1 6 7μgm- 2 h- 1)出现在施肥后第 1 1d ;分蘖肥的峰值 (4 3 94 3 μgm- 2 h- 1)出现在施肥后第 9～ 1 0d ;穗肥的峰值则在施肥后的第 6d出现 ,达 3 3 3 5 0 μgm- 2 h- 1。
Field experiments were conducted to study the effects of different soil surface covering treatments on soil micro-gas emissions during the whole growth period of paddy and rice. The results showed that the total amount of N 2 O released from paddy fields during the season was 5 ~ 6 times that of paddy fields, while the total CH 4 emission from paddy fields was 8 ~ 19 times of that of paddy fields. The total discharge of N2 O under different coverage of dry cultivation was: bare> covered> covered grass, and the total emission of CH4 was: covered> naked> covered grass. The CH4 emission from paddy field is closely related to the rice growth stage, with the maximum of 50mgm-2 h-1 in tillering stage. Nitrogen emissions from paddy fields are closely related to nitrogen application. The peak time of emission fluxes varies with the period of nitrogen application. The peak value of base fertilizer (2 1 1 6 7μgm-2 h-1) appears in the first 1d; the peak of tillering fertilizer (4 3 94 3 μgm-2 h-1) appeared on the 9th ~ 10th day after fertilization; the peak of panicle fertilizer appeared on the 6th day after fertilization, reaching 3350 μgm-2 h- 1.