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CH_(4)和N_(2)O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CH_(4)和N_(2)O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N_(2)O排放量(P<0.05),降低了CH_(4)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CH_(4)减排优势,排放总量降低了57.7%~91.8%,而二者的N_(2)O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N_(2)O排放18.4%~2547.8%(P<0.05),其中CRF处理N_(2)O排放量均略高于Urea处理32.7%~78.6%,但无显著性差异(P>0.05);CH_(4)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N_(2)O排放通量与田面水NH_(4)+-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N_(2)O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.
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 CH_(4) and N_(2)O 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 CH_(4) and N_(2)O emissions from paddy soil and their global warming potential(GWP)and greenhouse gas intensity(GHGI).Compared with CF,II and CI both increased the N_(2)O emission and decreased CH_(4) 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 CH_(4) emission mitigation potential,with reductions of 57.7%-91.8%;however,there was no significant difference in N_(2)O 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 N_(2)O emission by 18.4%-2547.8%(P<0.05)in two years,in which N_(2)O 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 CH_(4) emissions to N application varied with different water management practices.In general,no significant differences were found in CH_(4) emissions,GWP,or GHGI in the paddy soil between CRF and Urea application.Correlation analysis showed that in 2018,N_(2)O 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 NH_(4)+-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).N_(2)O 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.
作者
王永明
徐永记
纪洋
冯彦房
WANG Yong-ming;XU Yong-ji;JI Yang;FENG Yan-fang(School of Applied Meteorology,Nanjing University of Information Science&Technology,Nanjing 210044,China;Key Laboratory of Argo-Environment in Downstream of Yangtze Plain,Ministry of Agriculture and Rural Affairs,Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2021年第12期6025-6037,共13页
Environmental Science
基金
国家自然科学基金项目(42077043)
江苏省基础研究计划(自然科学基金)项目(BK20191400)
江苏省农业科技自主创新资金项目(CX(20)3178)
江苏省科研与实践创新计划项目(KYCX20_0982)。
