摘要
【目的】探究一次性施肥技术对油菜-水稻复种系统CH_4和N_2O排放及其特征的影响并分析其影响因素,综合计算全球增温潜势,以期了解一次性施肥技术对温室气体排放的贡献大小,从而为温室气体减排提供科学依据和技术参考。【方法】针对长江中下游地区典型的油菜-水稻复种模式,在荆州太湖港农场(30.36N,112.08E)油菜-水稻复种试验田设置了5个处理:对照处理(CK)、农民习惯施肥处理(FP)、优化施肥处理(OPT)、一次性尿素基施处理(UA)和一次性控释肥基施处理(CRF),重复3次。采用静态暗箱-气相色谱法对整个油菜-水稻季的CH_4和N_2O排放通量进行监测,并测定土壤种植前后的理化性质与作物产量。【结果】(1)N_2O和CH_4的排放均具有明显的水稻季排放高、油菜季排放低的季节动态变化规律。各处理N_2O排放通量在油菜季的变化范围为-4.08—35.51μg N·m^(-2)·h^(-1),水稻季则为-16.52—193.30μg N·m^(-2)·h^(-1),年平均排放通量3.66—23.70μg N·m^(-2)·h^(-1);各处理CH_4的通量变化在油菜季的排放量为-0.08—0.05 mg C·m^(-2)·h^(-1),水稻季则为-0.54—4.81 mg C·m^(-2)·h^(-1),年平均排放通量0.42—0.66 mg C·m^(-2)·h^(-1);(2)N_2O年排放总量从高到低依次是FP、CRF、OPT、UA、CK,分别为1.31、1.19、1.04、0.82、0.37 kg N·hm^(-2),排放系数介于0.14%—0.25%,均低于IPCC的推荐值1%。两个一次性施肥处理的UA和CRF相比同等施氮量的OPT处理,均能有效减少CH_4年排放量29.0%和29.9%, UA处理同时能减少21.2%的N_2O年排放总量,而CRF处理却增加了14.8%的N_2O年排放总量;(3)在同等施氮量的条件下,一次性施肥CRF比OPT显著增加油菜产量10.6%,而对水稻产量的影响不显著。温室气体排放强度呈现油菜季低,而水稻季高的特征,油菜和水稻季中各处理差异均不显著,油菜季中CRF和UA的排放强度最低为0.038 kgCO_(2-eq)·kg^(-1),OPT最高为0.057kgCO_(2-eq)·kg^(-1),水稻季UA最小为0.07 kgCO_(2-eq)·kg^(-1),FP最高达到了0.13 kgCO_(2-eq)·kg^(-1);(4)综合两种气体的全球增温潜势(100 a),用GWP表示,在相同施氮量下,两个一次性施肥处理UA和CRF的GWP均较OPT处理减少了28.0%和18.2%(P<0.05),一次性基施尿素对降低温室效应更有效。【结论】对于长江中下游典型农田而言,一次性基施普通尿素或一次性基施控释尿素的措施,可以在保持作物产量的同时,降低了农田温室气体排放,可作为水稻-油菜复种系统的一种环境友好型施肥推荐技术。
【Objective】The objective of this paper was to explore the impacts of one-off fertilization on CH4 and N2O emissions and its impacting factors in rape-paddy replanting system to calculate global warming potential,and to understand the contribution of one-off fertilization to the greenhouse gas emission,so as to provide scientific basis and technical reference for greenhouse gas emission reduction.【Method】Based on the typical rape-paddy replanting system in the middle and lower reaches of the Yangtze River,the experiments were set up in the(30.36N,112.08E)rape-paddy replanting test field in Taihu port farm of Jingzhou from October 2015 to September 2016 with 5 treatments,including Control treatment(CK),Farmers'Practice treatment(FP),Optimal fertilizer treatment(OPT),Urea fertilizer treatment(UA)and Controlled release fertilizer treatment(CRF),with 3 replicates.In the whole growth period,the static chamber gas chromatography method was used for determination of CH4 and N2O emission flux.Before and after planting,the physicochemical properties of soil and yield of the crop were measured.【Result】(1)The emissions of N2O and CH4 had obvious seasonal dynamics of high in paddy season and low in rape season.The fluxes of N2O varied-4.08-35.51μg N·m^-2·h^-1 and varied-16.52-193.30μg N·m^-2·h^-1 in the paddy season.The average annual emission flux varied 3.66-23.70μg N·m^-2·h^-1;the fluxes of CH4 varied-0.08-0.05 mg C·m^-2·h^-1 in rape season.The fluxes of CH4 in rice season varied-0.54-4.81 mg C·m^-2·h^-1.The annual average flux varied 0.42-0.66 mg C·m^-2·h^-1.(2)The amounts of N2O emissions from high to low were FP,CRF,OPT,UA,and CK,respectively,and the value of them was 1.31,1.19,1.04,0.82 and 0.37 kg N·hm^-2,respectively.The emission factors were a range in 0.14%-0.25%,all values were lower than 1%,which were IPCC Recommended.Compared with OPT treatment with the same amount of nitrogen input,the two one-off fertilization UA and CRF treatments could effectively reduce CH4 emissions by 29.0%and 29.9%,respectively,at the same time UA treatment can reduce the 21.2%N2O emissions,but CRF treatment increased 14.8%N2O emissions.(3)Under the same amount of nitrogen application,one-off fertilization CRF significantly increased the yield of rape by 10.6%,while the effect on paddy yield was not significant.The characteristics of the GHGI showed low in rape season,high in rice season,but there was no significant difference in treatments between rape and rice season.The minimum GHGI of CRF and UA in rape season was 0.038 kgCO2-eq·kg^-1,OPT was maximum with 0.057 kgCO2-eq·kg^-1,the minimum of UA in rice season UA was 0.07 kgCO2-eq·kg^-1,and FP was maximum with 0.13 kgCO2-eq·kg^-1.(4)The Global Warming Potential of the two gases were integrated with the GWP(100 year scale),under the same nitrogen application amount,one-off fertilization UA and CRF were better than OPT significantly reduced the GWP 28.0%and 18.2%(P<0.05),and the one-off fertilization of urea was more effectively reduce the effect of greenhouse gas.【Conclusion】For the typical farmland in the middle and lower reaches of the Yangtze River,one-off fertilization of common urea or control-release urea could reduce greenhouse gas emissions while maintained crop yield,but it still needs to be verified by long-term experiments.
作者
徐驰
谢海宽
丁武汉
戴震
张婧
王立刚
李虎
XU Chi;XIE HaiKuan;DING WuHan;DAI Zhen;ZHANG Jing;WANG LiGang;LI Hu(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences/Key Laboratory of Agricultural Non-point Source Pollution Control,Ministry of Agriculture/Joint Research Laboratory for Sustainable Agro-ecosystem Research between Chinese Academy of Agricultural Sciences and University of New Hampshire(CAAS-UNH),Beijing 100081)
出处
《中国农业科学》
CAS
CSCD
北大核心
2018年第20期3972-3984,共13页
Scientia Agricultura Sinica
基金
国家重点研发计划(2016YFE010110
2016YFD0201204
2018YFD0800402)
国家自然科学基金(41671303)
中央级公益性科研院所基本科研业务费(1610132016042)
国家公益性行业(农业)科研专项(201303103)
关键词
一次性施肥
油菜-水稻复种系统
温室气体
全球增温潜势
one-off fertilization
rape-paddy replanting system
greenhouse gas
global warming potential