秸稈還田下氮肥減施對農(nóng)田土壤溫室氣體排放的影響
發(fā)布時間：2018-08-03 07:07
【摘要】：研究不同秸稈還田方式配施不同施氮量下冬小麥農(nóng)田CO_2、CH_4和N_2O的排放及凈增溫潛勢(Net global warming potential,△GWP),有助于科學(xué)評價秸稈還田和減氮在減緩全球變暖方面的作用,為制定田間合理的減排措施提供依據(jù)。本文以黃淮海區(qū)域小麥田為研究對象,應(yīng)用靜態(tài)箱—?dú)庀嗌V法于2015年9月至2016年6月監(jiān)測了不同秸稈還田方式和氮肥處理下冬小麥土壤CO_2、CH_4和N_2O的排放通量,估算了溫室氣體排放總量。試驗設(shè)3種秸稈還田方式(CK—秸稈不還田、MS—秸稈-菌渣還田、DS—秸稈直接還田)配施3種施氮量(N_1—210、N_2—255、N_3—300kg N·hm~(-2))共組成9個處理,應(yīng)用靜態(tài)箱—?dú)庀嗌V法監(jiān)測了不同處理下冬小麥土壤CO_2、CH_4和N_2O的排放通量,估算了溫室氣體排放總量。試驗期間記錄了每項農(nóng)事活動機(jī)械燃油量、灌溉耗電量、施肥量和秸稈焚燒量,依據(jù)溫室氣體排放系數(shù)統(tǒng)一轉(zhuǎn)化為等當(dāng)量CO_2;測定籽粒產(chǎn)量和生物量,計算凈初級生產(chǎn)力;根據(jù)每個分項最終計算出9個處理的凈增溫潛勢。研究得出的結(jié)論如下:(1)黃淮海區(qū)域冬小麥農(nóng)田土壤是CO_2和N_2O的排放源,是CH_4的弱吸收匯。CO_2約排放8715kgCO_2·hm~(-2),N_2O大約排放508kgCO_2·hm~(-2),CH_4大約吸收22kgCO_2·hm~(-2)。(2)秸稈還田和高施氮量處理會顯著促進(jìn)CO_2排放;MS處理會降低CH_4的吸收量,N1處理更有利于CH_4的吸收;DS處理和減量施氮都可以顯著降低N_2O排放量。(3)秸稈焚燒會排放大量溫室氣體,約為5156kgCO_2·hm~(-2),相當(dāng)于冬小麥土壤溫室氣體的直接排放量;農(nóng)田管理措施引起的溫室氣體間接排放量為3208kgCO_2·hm~(-2),超過直接排放量的1/3,不容忽視。MS和DS處理可以顯著提高籽粒產(chǎn)量16.1%和14.3%(P0.01),而減氮不會對其產(chǎn)生顯著影響(P0.05)。(4)秸稈不同還田方式和施氮處理下的△GWP均為負(fù)值,分別為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),是溫室氣體“匯”。MS和DS處理下的△GWP分別為-14174 kgCO_2·hm~(-2)和-11565 kg CO_2·hm~(-2),可以顯著加強(qiáng)冬小麥農(nóng)田土壤對全球變暖的減緩效應(yīng)�？紤]到減氮對作物產(chǎn)量沒有顯著影響,因此推薦菌渣或秸稈直接還田搭配210 kg·hm~(-2)施氮量,是既能保證作物產(chǎn)量又能顯著緩解溫室效應(yīng)的雙贏組合。
[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，
本文編號：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，
本文編號：2160978
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