干湿变化，氮肥，DCD和水稻秸秆对稻田土壤N 2 O,CH 4 和CO 2 排放的影响

发布时间：2023-06-18 00:45

　　氧化亚氮(N20),甲烷(CH4)和二氧化碳(CO2)是农田排放的主要温室气体(GHG)。温室气体从土壤到大气的生成和释放主要受人为活动和自然过程的影响。耕地土壤水分状况可能在耕作过程中随时间波动从而导致土壤性质的变化。土壤湿度/含水量是微生物活动的重要参数。硝化细菌需要土壤孔隙中存在氧气。可预测的是土壤水分状况的变化会影响碳(C)和氮(N)在土壤中的周转,从而影响温室气体的排放。为了了解不同水分含量(淹水和湿润(60%WFPS)对土壤温室气体的排放影响,我们进行了几项室内培养实验。旨在为探索与土壤温室气体排放有关的重大科学技术问题提供科学依据。土壤采自于湖北省咸宁市的油菜-水稻轮作的水稻土壤。风干后的土壤用来进行不同处理(有无DCD、肥料和有机物(秸秆)组合)的室内培养实验。在25℃下分别进行连续淹水,连续湿润和淹水-湿润的处理。将硅胶置于培养瓶的顶部空间来吸收水分,从而实现从淹水到湿润的转化。在所有实验中定期采集土壤样品来分析土壤性质和气体浓度。pH通过pH计测定,微生物生物量碳(MBC)和溶解性有机碳(DOC)通过总有机碳分析仪((vario TOC cube,Elementar...

【文章页数】：101 页

【学位级别】：硕士

【文章目录】：
Abbreviations
Abstract
摘要
Chapter 1: Background and Literature Review
    1.1 An overview
    1.2 N₂O emissions
    1.3 CH₄ emissions
    1.4 CO₂ emissions
    1.5 Aims and objectives
Chapter 2: Material and Methods
    2.1 Materials
        2.1.1 Soil
        2.1.2 Rice straw
        2.1.3 Fertilizer and DCD
    2.2 Methods
        2.2.1 Soil analysis
        2.2.2 Analysis of gas fluxes
Chapter 3: Effect of flooding-wetting events on soil N₂O, CH₄ and CO₂emissions
    3.1 Introduction
    3.2 Materials and Methods
        3.2.1 Experimental design
        3.2.2 Statistical analysis
    3.3 Results
        3.3.1 N₂O emissions
        3.3.2 CH₄ emissions/uptake
        3.3.3 CO₂ emissions
        3.3.4 Dissolved organic carbon
        3.3.5 Soil pH
        3.3.6 Concentrations of mineral nitrogen (NH4
+-N and NO3
--N)
    3.4 Discussion
        3.4.1 N₂O emissions
        3.4.2 CH₄ emissions/uptake
        3.4.3 CO₂ emissions
    3.5 Conclusions
Chapter 4: Effects of change in water regime on soil N₂O, CH₄ and CO₂emissions following addition of DCD and N fertilizer
    4.1 Introduction
    4.2 Materials and Methods
        4.2.1 Experimental design
        4.2.2 Statistical analysis
    4.3 Results
        4.3.1 N₂O emissions
        4.3.2 CH₄ emission/uptake
        4.3.3 CO₂ emissions
        4.3.4 Concentrations of mineral nitrogen (NH4
+-N and NO3
--N)
        4.3.5 Dissolved organic carbon
        4.3.6 Microbial biomass carbon
    4.4 Discussion
        4.4.1 N₂O emissions
        4.4.2 CH₄ emission/uptake
        4.4.3 CO₂ emissions
    4.5 Conclusion
Chapter 5: Change in water regime effect on soil GHG's emissions withrice straw and fertilizer addition
    5.1 Introduction
    5.2 Material and Methods
        5.2.1 Soil
        5.2.2 Experimental design
        5.2.3 Statistical analysis
    5.3 Results
        5.3.2 N₂O emissions
        5.3.3 CH₄ emission/uptake
        5.3.4 CO₂ emissions
        5.3.5 Soil NH4
+-N and NO3
--N
        5.3.6 Dissolved organic carbon
        5.3.7 Microbial biomass carbon
    5.4 Discussion
        5.4.2 N₂O emissions
        5.4.3 CH₄ emission/uptake
        5.4.4 CO₂ emissions
    5.5 Conclusion
Chapter 6: General Discussion
    6.1 N₂O emissions
    6.2 CH₄ emissions/uptake
    6.3 CO₂ emissions
    6.4 Summary and future perspectives
References
Acknowledgements



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