黑土稻田CH4与N2O排放及减排措施研究

通过对黑土稻田CH₄和N₂O排放的观测,发现水稻生长季CH₄和N₂O排放量低于全国其它地区稻田.CH₄和N₂O排放之间存在互为消长关系(r=-0.513,P<0.05).但在同样施肥水平条件下,间歇灌溉与长期淹灌相比,CH₄排放明显减少而N₂O略有增加,其相对综合温室效应被大大减少且水稻产量未受影响.为此,间歇灌溉可作为减少稻田温室气体排放的水分管理措施.另外,通过对CH₄和N₂O排放的相关微生物过程探讨,揭示产甲烷菌数与CH₄排放间呈显著性正相关(R²=0.82,P<0.05),硝化菌数和反硝化菌数与N₂O排放有重要关系.

CH4 and N2O emissions from phaeozem rice field and their mitigative measures

Determinations on the CH₄ and N₂O emissions from phaeozem rice field showed that their emission amount in rice growing season was much lower than any other regions in China.There was trade-off relationship between CH₄ and N₂O emissions(r=-0.513,P<0.05). Under the same fertilization,compared with continual irrigation, intermittent irrigation could reduce significantly CH₄ emission and increase N₂O emission,but the overall warming potential of greenhouse effect was reduced greatly,while rice yield was not affected.Therefore,intermittent irrigation was an effective irrigation measures to reduce greenhouse gas emissions from rice field. In addition,investigations on CH₄ and N₂Oemissions and their related microbial process showed a positive relation between methanogens number and CH₄ emission(R²=0.82,P<0.05),and the important relationship between the numbers of nitrifiers and denitrifiers and N₂O emissions.