| 节水灌溉和控释肥施用耦合措施对单季稻田CH4和N2O排放的影响 |
| 摘要点击 1924 全文点击 604 投稿时间：2021-03-30 修订日期：2021-05-21 |
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| 中文关键词 稻田 节水灌溉 控释肥 甲烷(CH4) N2O 产量 |
| 英文关键词 paddy field water-saving irrigation controlled-release fertilizer CH4 N2O rice yield |
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| 中文摘要 |
| 以我国华东地区典型单季稻水稻田（江苏宜兴）的原柱状土为研究对象，通过两年土柱观测试验，研究不同灌溉管理模式（长期淹水CF、间隙灌溉II、控制灌溉CI）和氮肥施用（不施氮CK、尿素Urea和控释肥CRF）耦合措施对水稻生长期内CH4和N2O排放和产量的影响，以期优选典型单季稻田减排增效的水肥管理模式.结果表明，两种节水灌溉方式（CI和II）均显著影响稻田土壤CH4和N2O排放量及二者的综合温室效应（GWP）和排放强度（GHGI），与CF相比，II和CI均显著提高了N2O排放量（P<0.05），降低了CH4排放量（P<0.05），进而二者的GWP和GHGI分别显著降低28.9%~71.4%和14.3%~70.4%（P<0.05）；两种节水灌溉模式相比，CI较II模式呈现较好的CH4减排优势，排放总量降低了57.7%~91.8%，而二者的N2O排放量无显著性差异（P>0.05），最终CI对GWP和GHGI的减排效应略优于II模式2.0%~56.2%.施用氮肥（Urea和CRF）均显著促进N2O排放18.4%~2547.8%（P<0.05），其中CRF处理N2O排放量均略高于Urea处理32.7%~78.6%，但无显著性差异（P>0.05）；CH4排放总量对施氮处理的响应随水分管理模式的不同而不同，总体而言，施用CRF较Urea对稻田土壤GWP和GHGI均无显著影响（P>0.05）.相关分析表明，2018年CF模式的Urea处理和II模式的Urea、CRF处理中N2O排放通量与田面水NH4+-N浓度分别呈现显著（P<0.05）和极显著的正相关关系（P<0.01），而二者在2019年CI模式的CK和CRF处理中呈现相反规律；2018年CI模式下CK、CRF处理的N2O排放通量与田面水NO3--N浓度呈极显著的正相关关系（P<0.01）.节水灌溉和氮肥施用对水稻产量均呈显著影响（P<0.05），与CF相比，两种节水灌溉模式（II、CI）水稻产量均下降了14.7%~37.7%；CRF处理较Urea处理略提高水稻产量2.5%~7.4%（P<0.05）.综合考虑稻田土壤GWP、GHGI和水稻产量，节水模式与控释肥施用对稻田土壤减排增产的耦合效应仍有待进一步研究. |
| 英文摘要 |
| By the method of static closed chamber-gas chromatography (GC), a two-year greenhouse experiment was launched using an intact soil core of single cropping rice in East China to explore the synergistic effects of water-saving irrigation and controlled-release fertilizer (CRF) application on CH4 and N2O emissions during rice growth, with the aim of establishing water and fertilization management regimes with effects on yield promotion and greenhouse gas mitigation. Nine treatments included three different types of nitrogen fertilizer application (no nitrogen[CK], urea[Urea], and controlled release fertilizer[CRF]) and three different types of irrigation management (continuous flooding[CF], intermittent irrigation[II], and controlled irrigation[CI]). The two-year results showed that two of the water-saving irrigation management types (II and CI) significantly affected CH4 and N2O emissions from paddy soil and their global warming potential (GWP) and greenhouse gas intensity (GHGI). Compared with CF, II and CI both increased the N2O emission and decreased CH4 emissions, resulting in the reduction of GWP and GHGI by 28.9%-71.4% and 14.3%-70.4%, respectively (P<0.05). Compared to II, CI had better CH4 emission mitigation potential, with reductions of 57.7%-91.8%; however, there was no significant difference in N2O emissions. Finally, the mitigation of the CI method on GWP and GHGI was slightly better than that of the II method by 2.0%-56.2%. Compared with CK, N application significantly promoted N2O emission by 18.4%-2547.8% (P<0.05) in two years, in which N2O emissions were slightly higher by 32.7%-78.6% in CRF than those in Urea treatments; however, no significant difference was found (P>0.05). The response of total CH4 emissions to N application varied with different water management practices. In general, no significant differences were found in CH4 emissions, GWP, or GHGI in the paddy soil between CRF and Urea application. Correlation analysis showed that in 2018, N2O emission fluxes of the Urea treatment of the CF model and the Urea and CRF treatment of the II model were all significantly positively correlated with NH4+-N concentration in floodwater (P<0.01). By contrast, in 2019, a negative correlation was found in the CK and CRF treatments of the CI model (P<0.05). N2O emission fluxes of the CK and CRF treatments of the CI model in 2018 were significantly positively correlated with NO3--N concentration in floodwater (P<0.01). Water-saving irrigation and N application both had significant effects on rice yield. Compared with that of the CF method, the rice yield showed a decreasing trend by 14.7%-37.7% under the two water-saving irrigation modes (II and CI). Compared with that of the Urea treatment, CRF application increased rice yield by 2.5%-7.4%; however, no significant difference was found (P>0.05). Considering the GWP, GHGI, and rice yield results, the coupling effect of water-saving irrigation and CRF application on the GWP mitigation and yield promotion in paddy fields requires further investigation. |
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