浅埋滴灌条件下优化施氮对春玉米田温室气体排放的影响

以传统漫灌常规常量追氮为对照（CK），采用静态暗箱-气相色谱法测定浅埋滴灌下常量追氮（T₁）和优化追氮（T₂：70%常量追氮）春玉米田生育期内CO₂、N₂O和CH₄排放特征，探究西辽河平原浅埋滴灌条件下优化施氮对春玉米田土壤温室气体排放的影响。结果表明，T₁和T₂处理玉米产量无显著差异，均显著高于CK（P<0.05）。相同施氮量下，浅埋滴灌相比传统漫灌N₂O排放量增加11.78%，CH₄吸收量降低34.78%；T₂较T₁处理CO₂和N₂O排放量分别减少13.15%和20.27%。相同施氮量下，与CK相比，T₁处理降低了温室气体排放强度（GHGI）（P<0.05），浅埋滴灌T₂处理GHGI较T₁处理降低10.46%；CK和T₁处理综合增温潜势（GWP）均显著高于T₂（P<0.05）；T₁和T₂处理净生态系统经济预算（NEEB）均显著高于CK（P<0.05）。综合来看，浅埋滴灌下T₂处理，既降低了GHGI和GWP，又保证了较高玉米产量和NEEB，是西辽河平原玉米兼顾高产、高效和生态的水氮管理模式。

Effects of Optimal Nitrogen Application on Greenhouse Gas Emissions in Spring Maize Fields under Shallow Drip Irrigation

In order to explore effects of optimized nitrogen application on the greenhouse gas emissions in spring maize fields under the shallow drip irrigation in the Xiliaohe Plain, characteristics of CO₂, N₂O and CH₄ emission during the growth period of the constantnitrogen topdressing(T₁) and optimized nitrogen topdressing(T₂:70% constant nitrogen topdressing) under shallow drip irrigation were determined using method of static dark box-gas chromatography and adopting conventional irrigation with conventional constant nitrogen topdressing as a control (CK). The results showed that there was no significant difference in maize yield between T₁ and T₂ treatments, both of which were significantly higher than CK(P<0.05). Compared with the traditional irrigation under the N₂O emission of shallow drip irrigation increased by 11.78% and the CH₄ uptake was reduced by 34.78%; compared with T₁, the CO₂ and N₂O emissions of T₂ reduced by 13.15% and 20.27%, respectively. Under the same nitrogen application, the shallow drip irrigation reduces GHGI(P<0.05)compared with traditional irrigation, and the GHGI of T₂ decreases by 10.46% compared with that of T₁; the GWP of CK and T₁ were significantly higher than that of T₂(P<0.05); the NEEB of T₁ and T₂ were significantly higher than that of CK(P<0.05). In general, the treatment of T₂ reduces GHGI and GWP, and ensure higher maize yield and NEEB, which is a water and nitrogen management model for maize in the Xiliaohe plain that combines high yield, high efficiency and ecology.