不同水旱轮作方式对稻田甲烷排放影响的研究

用密闭箱法研究了不同水旱轮作方式对稻田甲烷排放的影响。１９９４ 年—１９９５ 年连续两年观测结果表明， 稻田甲烷排放的季节变化与前作有关， 前作是水稻的稻田移栽后即有大量甲烷排放，而前作是旱作蔬菜的水稻生长前期几乎没有甲烷排放，且旱作时间越长甲烷排放越迟，峰值越小。稻田甲烷平均排放通量结果表明，单季早稻和单季晚稻显著低于常规连作，而水旱年间轮作只显著减少早稻甲烷排放，对晚稻甲烷排放影响较小。

Effects of Different Rice-vegetable Rotation Systems on CH4 Emission From Paddy Soils

Using closed chamber method effects of the different rice -vegetable rotation systems on CH4 emission were studied . The results of 1994 and 1995 observation showed that seasonal variation of CH4 emission was related to preceding crops. When preceding crop was rice, a great deal of CH4 fluxes was found shortly after rice was transplanted. However, when preceding crop was vegetable, CH4 emission was rather little during the early stage of rice growth, and the longer the period of upland cropping was, the later CH4 was emitted and the lower CH4 emission peak was. The results of mean CH4 fluxes showed that CH4 fluxes from the paddy soils of rice -vegetable-vegetable (RVV) or vegetable- rice -vegetable (VRV) were both remarkably lower than those from rice-rice-vegetable (RRV). But year-return rotations (YR) only reduced CH4 emission from spring-rice fields and had less effects on that from autumn- rice fields.