摘要
摘要:探讨有机物料还田对冬小麦田温室气体排放特性的影响，对提高经济效应和环境效应有积极意义。本研究应用静态箱-气相色谱法对秸秆还田（J）、秸秆还田+牛粪（JF）和秸秆还田+菌渣（JZ）3种有机物料还田下分别施氮肥243 kg（N）·hm^-2（减氮10%，N1）、216 kg（N）·hm^-2（减氮20%，N2）对冬小麦农田N₂O、CO₂和CH₄的排放通量进行监测，探讨了不同施肥措施对麦田温室气体累积排放量、增温潜势的影响。试验期间同步记录每项农事活动机械燃油量、施肥量和灌溉量，测定产量，地上部生物量，估算农田碳截留。结果表明，冬小麦农田土壤N₂O和CO₂是排放源，是CH₄的吸收汇，氮肥施入、灌溉以及强降水促进了土壤N₂O和CO₂的生成，却弱化了CH₄作为大气吸收汇的特征。牛粪+秸秆（JF）处理N₂O和CO₂排放总量最高，分别为3.5 kg（N₂O-N）·hm^-2和19 689.67 kg（CO₂-C）·hm^-2，但CH₄的吸收值最大，为5.33 kg（CH₄-C）·hm^-2，均显著高于菌渣+秸秆（JZ）和秸秆（J）处理（P < 0.05）；各处理N₂O和CO₂的总量随施氮量的增加呈升高趋势，CH₄的总量随施氮量的增加而呈降低趋势。JFN2、JN2和JZN2处理农田综合增温潜势（GWP）均为负值，表明有机物料还田且减氮20%条件下农田生态系统为大气的碳汇，麦季净截留碳1 038~2 024 kg·hm^-2，其他处理GWP值均为正。JZN2处理小麦产量为8 061 kg·hm^-2，显著高于JFN2处理（P < 0.05）。综上所述，JZN2处理不仅能够保证小麦产量，且对环境效应最有利，为本区域冬小麦较优的施肥管理模式。
关键词:秸秆还田/
菌渣/
牛粪/
减氮/
冬小麦田/
温室气体/
产量/
全球增温潜势
Abstract:Exploring the impact of returning organic materials to the soil on greenhouse gas emission characteristics of winter wheat fields can help to improve economic and environmental consequences. Based on 3 modes of organic material return (JF:straw return and cow dung; J:straw return; JZ:straw return and mushroom dregs) and 2 nitrogen levels (N1:243 kg·hm^-2; N2:216 kg·hm^-2), the fluxes of N₂O, CO_2, and CH₄ in winter wheat fields were monitored using the static chamber method and gas chromatography, and the effects of the different fertilization measures on cumulative greenhouse gas emissions and warming potential of wheat fields were studied. During the experimental period, the amount of fuel consumed by farm machines and the power consumed during irrigation and fertilizer application were recorded and transformed to their carbon equivalents using a transformation coefficient. In addition, crop yield and aboveground biomasses were measured and carbon sequestration calculated. The total GWP under each of the 6 treatments were estimated based on the identified parameters of the greenhouse effect. The results indicated that wheat fields served as sources of N₂O and CO₂ and sinks of CH₄. Nitrogen application and adequate irrigation increased CO₂ and N₂O in the soil, but weakened the characteristics of CH₄ as an atmospheric absorption sink. The total amounts of N₂O and CO₂ emitted were highest in the JF treatment, at 3.5 kg (N₂O-N)·hm^-2 and 19 689.67 kg (CO₂-C) hm^-2 respectively, and the absorption value of CH₄ in this treatment was 5.33 kg (CH₄-C) hm^-2, significantly higher than in both of the JZ and J treatments. The total amounts of N₂O and CO₂ in each treatment increased, and the total amount of CH₄ decreased, with an increase in the nitrogen application rate. The GWP of JFN2, JN2, and JZN2 treatments were all negative, which indicated that the farmland ecosystem is an atmospheric carbon sink when organic materials were returned to the field; nitrogen was reduced by 20%, and the carbon interception by wheat was 1 038-2 024 kg·hm^-2. The GWP values were positive and the JZN2 treatment-treated wheat yield was 8 061 kg·hm^-2, significantly higher than that of the JFN2 treatment. In summary, JZN2 treatment could ensure wheat yield and had the most favorable environmental effects, and thus was the best fertilization management model for winter wheat in this region
Key words:Straw returning/
Mushroom dregs/
Cow dung/
Nitrogen reduction/
Winter wheat field/
Greenhouse gas/
Yield/
Global warming potential



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