秸秆还田下氮肥减施对农田土壤温室气体排放的影响
发布时间：2018-08-03 07:07
【摘要】：研究不同秸秆还田方式配施不同施氮量下冬小麦农田CO_2、CH_4和N_2O的排放及净增温潜势(Net global warming potential,△GWP),有助于科学评价秸秆还田和减氮在减缓全球变暖方面的作用,为制定田间合理的减排措施提供依据。本文以黄淮海区域小麦田为研究对象,应用静态箱—气相色谱法于2015年9月至2016年6月监测了不同秸秆还田方式和氮肥处理下冬小麦土壤CO_2、CH_4和N_2O的排放通量,估算了温室气体排放总量。试验设3种秸秆还田方式(CK—秸秆不还田、MS—秸秆-菌渣还田、DS—秸秆直接还田)配施3种施氮量(N_1—210、N_2—255、N_3—300kg N·hm~(-2))共组成9个处理,应用静态箱—气相色谱法监测了不同处理下冬小麦土壤CO_2、CH_4和N_2O的排放通量,估算了温室气体排放总量。试验期间记录了每项农事活动机械燃油量、灌溉耗电量、施肥量和秸秆焚烧量,依据温室气体排放系数统一转化为等当量CO_2;测定籽粒产量和生物量,计算净初级生产力;根据每个分项最终计算出9个处理的净增温潜势。研究得出的结论如下:(1)黄淮海区域冬小麦农田土壤是CO_2和N_2O的排放源,是CH_4的弱吸收汇。CO_2约排放8715kgCO_2·hm~(-2),N_2O大约排放508kgCO_2·hm~(-2),CH_4大约吸收22kgCO_2·hm~(-2)。(2)秸秆还田和高施氮量处理会显著促进CO_2排放;MS处理会降低CH_4的吸收量,N1处理更有利于CH_4的吸收;DS处理和减量施氮都可以显著降低N_2O排放量。(3)秸秆焚烧会排放大量温室气体,约为5156kgCO_2·hm~(-2),相当于冬小麦土壤温室气体的直接排放量;农田管理措施引起的温室气体间接排放量为3208kgCO_2·hm~(-2),超过直接排放量的1/3,不容忽视。MS和DS处理可以显著提高籽粒产量16.1%和14.3%(P0.01),而减氮不会对其产生显著影响(P0.05)。(4)秸秆不同还田方式和施氮处理下的△GWP均为负值,分别为CKN1:-4359kgCO_2·hm~(-2),CKN_2:-5663kgCO_2·hm~(-2),CKN3:-2747kgCO_2·hm~(-2),MSN1:-16964kgCO_2·hm~(-2),MSN_2:-13089kgCO_2·hm~(-2),MSN3:-12469,DSN1:-10899,DSN_2:-14582kgCO_2·hm~(-2),DSN_2:-9212kgCO_2·hm~(-2),是温室气体“汇”。MS和DS处理下的△GWP分别为-14174 kgCO_2·hm~(-2)和-11565 kg CO_2·hm~(-2),可以显著加强冬小麦农田土壤对全球变暖的减缓效应。考虑到减氮对作物产量没有显著影响,因此推荐菌渣或秸秆直接还田搭配210 kg·hm~(-2)施氮量,是既能保证作物产量又能显著缓解温室效应的双赢组合。
[Abstract]:The study on the emission of CO2CHS _ 4 and N _ 2O and the potential of (Net global warming potential, GWP), in winter wheat farmland under different straw returning methods and different nitrogen application rates is helpful to scientifically evaluate the effects of straw returning and nitrogen reduction on the mitigation of global warming. It provides the basis for making reasonable emission reduction measures in the field. From September 2015 to June 2016, the emission fluxes of CO2CH4 and N2O in winter wheat soil were monitored by static box-gas chromatography in Huang-Huai-Hai region from September 2015 to June 2016. The total amount of greenhouse gas emissions is estimated. Three kinds of straw returning methods (CK-straw not returning to field, MS-straw residue returning to field, DS-straw returning directly) and three kinds of nitrogen application amount (N1-210N2-255N3-300kg / hm ~ (-2) were set up in the experiment. The emission fluxes of CO2CH4 and NSTO in winter wheat soil under different treatments were monitored by static box-gas chromatography, and the total greenhouse gas emissions were estimated. During the experiment, the mechanical fuel consumption, irrigation energy consumption, fertilizer application and straw incineration of each agricultural activity were recorded and converted to equal equivalent CO2 according to the greenhouse gas emission coefficient. The grain yield and biomass were measured and the net primary productivity was calculated. The net warming potential of 9 treatments was calculated according to each item. The conclusions are as follows: (1) the soil of winter wheat field in Huang-Huai Sea region is the emission source of CO_2 and N _ 2O. 8715kgCO_2 hm-2 ~ (-2) N _ 2O emission from CH_4 is a weak absorption sink of CH_4. About 508kgCO_2 hm-2 ~ (-2) Ch _ (2) Ch _ (4) about absorbing 22kgCO_2 hm ~ (-2). (_ 2 straw return to the field and high nitrogen application treatment can significantly promote CO_2 emission MS treatment can reduce CH_4 uptake and N _ (1) treatment is more beneficial to CH_4 absorption DS treatment and reducing application. Nitrogen can significantly reduce N2O emissions. (3) Straw incineration emits a lot of greenhouse gases. About 5156kgCO_2 hm ~ (-2), which is equivalent to the direct emission of greenhouse gas from winter wheat soil. The indirect greenhouse gas emissions caused by farmland management measures were 3208kgCO_2 hm-2, which exceeded 1 / 3 of the direct emissions. The treatments of .MS and DS could significantly increase grain yield by 16.1% and 14.3% (P0.01), but nitrogen reduction would not have a significant effect on it (P0.05). (4). The GWP of field and nitrogen application was negative, 鍒嗗埆涓篊KN1:-4359kgCO_2路hm~(-2),CKN_2:-5663kgCO_2路hm~(-2),CKN3:-2747kgCO_2路hm~(-2),MSN1:-16964kgCO_2路hm~(-2),MSN_2:-13089kgCO_2路hm~(-2),MSN3:-12469,DSN1:-10899,DSN_2:-14582kgCO_2路hm~(-2),DSN_2:-9212kgCO_2路hm~(-2),鏄俯瀹ゆ皵浣撯，
本文编号：2160978
[Abstract]:The study on the emission of CO2CHS _ 4 and N _ 2O and the potential of (Net global warming potential, GWP), in winter wheat farmland under different straw returning methods and different nitrogen application rates is helpful to scientifically evaluate the effects of straw returning and nitrogen reduction on the mitigation of global warming. It provides the basis for making reasonable emission reduction measures in the field. From September 2015 to June 2016, the emission fluxes of CO2CH4 and N2O in winter wheat soil were monitored by static box-gas chromatography in Huang-Huai-Hai region from September 2015 to June 2016. The total amount of greenhouse gas emissions is estimated. Three kinds of straw returning methods (CK-straw not returning to field, MS-straw residue returning to field, DS-straw returning directly) and three kinds of nitrogen application amount (N1-210N2-255N3-300kg / hm ~ (-2) were set up in the experiment. The emission fluxes of CO2CH4 and NSTO in winter wheat soil under different treatments were monitored by static box-gas chromatography, and the total greenhouse gas emissions were estimated. During the experiment, the mechanical fuel consumption, irrigation energy consumption, fertilizer application and straw incineration of each agricultural activity were recorded and converted to equal equivalent CO2 according to the greenhouse gas emission coefficient. The grain yield and biomass were measured and the net primary productivity was calculated. The net warming potential of 9 treatments was calculated according to each item. The conclusions are as follows: (1) the soil of winter wheat field in Huang-Huai Sea region is the emission source of CO_2 and N _ 2O. 8715kgCO_2 hm-2 ~ (-2) N _ 2O emission from CH_4 is a weak absorption sink of CH_4. About 508kgCO_2 hm-2 ~ (-2) Ch _ (2) Ch _ (4) about absorbing 22kgCO_2 hm ~ (-2). (_ 2 straw return to the field and high nitrogen application treatment can significantly promote CO_2 emission MS treatment can reduce CH_4 uptake and N _ (1) treatment is more beneficial to CH_4 absorption DS treatment and reducing application. Nitrogen can significantly reduce N2O emissions. (3) Straw incineration emits a lot of greenhouse gases. About 5156kgCO_2 hm ~ (-2), which is equivalent to the direct emission of greenhouse gas from winter wheat soil. The indirect greenhouse gas emissions caused by farmland management measures were 3208kgCO_2 hm-2, which exceeded 1 / 3 of the direct emissions. The treatments of .MS and DS could significantly increase grain yield by 16.1% and 14.3% (P0.01), but nitrogen reduction would not have a significant effect on it (P0.05). (4). The GWP of field and nitrogen application was negative, 鍒嗗埆涓篊KN1:-4359kgCO_2路hm~(-2),CKN_2:-5663kgCO_2路hm~(-2),CKN3:-2747kgCO_2路hm~(-2),MSN1:-16964kgCO_2路hm~(-2),MSN_2:-13089kgCO_2路hm~(-2),MSN3:-12469,DSN1:-10899,DSN_2:-14582kgCO_2路hm~(-2),DSN_2:-9212kgCO_2路hm~(-2),鏄俯瀹ゆ皵浣撯，
本文编号：2160978
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