不同农业措施下冬小麦田N_2O排放通量的特征

Characteristics of N_2O Flux in Winter Wheat Field under Different Field Managements

利用静态自动箱连续观测系统对冬小麦农田翻耕（对照）、秸秆覆盖、免耕、秸秆深施和有机肥5种农业措施条件下N2O排放通量进行了监测。结果表明，各处理中N2O高排放通量均在12：00—17：00，低排放通量在0：00—3：00；冬小麦孕穗期N2O排放通量与气温和土壤5cm处温度显著相关；拔节期的水肥同期会导致15～20d的N2O排放高峰。不同农业措施N2O排放量大小顺序是有机肥〉免耕〉秸秆覆盖、秸秆深施和对照，差异极显著，而秸秆覆盖、秸秆深施和对照三种措施之间N2O排放量差异不明显。研究结果对估算不同农业措施下冬小麦田N。O的排放量有一定的参考价值。

The characteristics of the nitrous oxide flux in the winter wheat field under different field managements, such as tillage （CK） , straw cover, non-tillage, straw deep fertilization and organic manure application was monitored by the static automated chamber and field continuous measurement system. The results showed that the high N2O flux occurred from 12：00 to 17：00, while the low N2O flux was from 0：00 to 3：00. N2O flux during spike formation stage of winter wheat was significantly correlated with the air temperature and the soil temperature at 5 cm depth. The synchronous irrigation and fertilization during jointing stage of winter wheat would lead to a 15 - 20 days N2O flux peak. The amount of N2O emission under different field managements during growing period of winter wheat from high to low was arranged in turn organic manure applica- tion, non -tillage, straw cover, straw deep fertilization and tillage, and their differences were extremely significant. However, the differences of N2O emission amount among the treatments of straw cover, straw deep application and tillage were not significant.