黃土高原地區(qū)由于降雨不足、土壤肥力差、水土流失嚴(yán)重等因素,導(dǎo)致農(nóng)作物生產(chǎn)能力低下;該地區(qū)大多數(shù)農(nóng)戶普遍采用傳統(tǒng)耕作方法,保護(hù)性耕作并未得到普及。保護(hù)性耕作已被證明是有利于環(huán)境的,并且可以帶來更高的作物產(chǎn)量。然而,保護(hù)性耕作對(duì)作物生產(chǎn)力、土壤和環(huán)境的影響差異,均是基于不同氣候條件、耕作類型、耕作時(shí)間、土壤類型以及作物類型的差異。本研究旨在分析黃土高原保護(hù)性耕作措施對(duì)作物生產(chǎn)力和溫室氣體減排能力的影響。該研究采用3參數(shù)(3p)Logistic,Gompertz,Richards和Weibull模型,利用以下處理方法評(píng)估秸稈和無秸稈處理下的生物量積累[早播春耕小麥(ESW-T);用耕作和秸稈覆蓋(ESW-TS)早播春小麥;春耕小麥正常播種(NSW-T);用耕作和秸稈覆蓋正常播種春小麥(NSW-TS);春播小麥播種(LSW-T)和播種春播小麥播種和秸稈覆蓋(LSW-TS)]。為了對(duì)該地區(qū)春小麥可持續(xù)生產(chǎn)提出全面建議,本研究于2016-2019年間進(jìn)行了田間試驗(yàn),研究了黃土高原西部半干旱寒冷氣候下,保護(hù)性耕作對(duì)土壤性質(zhì)、春小麥產(chǎn)量和溫室氣體排放的影響,并分析了溫室氣體通量對(duì)耕作方式引起的環(huán)境變量...

【文章頁數(shù)】：156 頁

【學(xué)位級(jí)別】：博士

【文章目錄】：
SUMMARY
摘要
CHAPTER 1:INTRODUCTION
    1.1 TRENDS IN CLIMATE CHANGE AND AGRICULTURE RELATED CLIMATE VARIABLES
    1.2 EFFECTS OF CLIMATE ON AGRICULTURE
        1.2.1 EFFECT OF CLIMATE CHANGE ON CROP YIELDS AND FOOD SECURITY
        1.2.2 EFFECT OF CLIMATE VARIABLES ON CROP DEVELOPMENT
        1.2.3 EFFECT OF CLIMATE CHANGE ON SOIL QUALITY
    1.3 EFFECTS OF AGRICULTURE ON CLIMATE CHANGE
        1.3.1 SOIL ORGANIC CARBON SEQUESTRATION
        1.3.2 CROP PRODUCTION AND RELEASES OF GREENHOUSE GASES
            1.3.2.1 CO2 FLUXES IN AGROECOSYSTEMS
            1.3.2.2 NON-CO2 FLUXES IN AGRO-ECOSYSTEMS
    1.4 FACTORS INFLUENCING GHGS EMISSIONS
        1.4.1 SOIL TEMPERATURE
        1.4.2 SOIL WATER CONTENT AND WATER FILLED PORE SPACE
        1.4.3 SOIL BULK DENSITY,SOIL TEXTURE AND STRUCTURE
    1.5 CLIMATE ADAPTATION AND MITIGATION AGRICULTURAL SYSTEMS
        1.5.1 CONSERVATION AGRICULTURE AS CLIMATE ADAPTATION AND MITIGATION STRATEGY
        1.5.2 CONSERVATION TILLAGE
        1.5.3 CONSERVATION TILLAGE AND SOIL QUALITY
        1.5.4 CONSERVATION TILLAGE AND CROP PRODUCTIVITY
        1.5.5 CONSERVATION TILLAGE AND GHG EMISSIONS
    1.6 PROBLEM STATEMENT
    1.7 RESEARCH OBJECTIVE
    1.8 HYPOTHESIS
    1.9 FRAMEWORK OF THE STUDY
    1.10 ORGANIZATION OF THE STUDY
CHAPTER 2:MATERIALS AND METHODS
    2.1 DESCRIPTION OF STUDY AREA
    2.2 EXPERIMENTAL DESIGN
        2.2.1 EXPERIMENT1 (2016)
        2.2.2 EXPERIMENT2 (2017-EARLY2019)
    2.3 SAMPLING AND DATA MEASUREMENTS
        2.3.1 SOIL SAMPLING
        2.3.2 SOIL WATER CONTENT,SOIL TEMPERATURE,BULK DENSITY,SOIL WATER STORAGE,AND POROSITY
        2.3.3 SOIL ORGANIC CARBON(SOC)AND TOTAL NITROGEN(TN)
        2.3.4 NITRATE NITROGEN AND AMMONIUM NITROGEN
        2.3.5 SAMPLING AND MEASUREMENT OF BIOMASS AND GRAIN YIELD
        2.3.6 GAS SAMPLING AND FLUX MEASUREMENTS
        2.3.7 CALCULATION OF CARBON FLUX COMPONENTS
        2.3.8 CALCULATION OF GLOBAL WARMING POTENTIAL(GWP)AND GREENHOUSE GAS INTENSITY(GHGI)
    2.4 STATISTICAL ANALYSIS
        2.4.1 GENERAL STATISTICAL ANALYSIS
        2.4.2 DESCRIPTION OF NONLINEAR GROWTH MODELS
        2.4.3 STATISTICAL DESCRIPTORS AND ANALYSIS FOR MODEL EVALUATION
CHAPTER 3:EFFECT OF MULCHING AND SOWING TIME ON SOIL PHYSICAL AND CHEMICAL PROPERTIES
    3.1 SOIL MOISTURE CONTENT AND AVAILABLE NITROGEN
    3.2 Plant growth indexes, yield and yield components
    3.3 NONLINEAR MODELING OF SPRING WHEAT BIOMASS GROWTH
        3.3.1 MODEL CONVERGENCE
        3.3.2 ROBUSTNESS OF THE CANDIDATE MODELS AND MODEL SELECTION
        3.3.3 MODEL SIMULATIONS
CHAPTER 4:EFFECT OF CONSERVATION TILLAGE ON SOIL PHYSICAL AND CHEMICAL PROPERTIES
    4.1 SOIL WATER CONTENT
    4.2 SOIL BULK DENSITY AND POROSITY
    4.3 WATER FILLED PORE SPACE AND SOIL WATER STORAGE
    4.4 TEMPORAL VARIATIONS OF SOIL WATER CONTENT AND SOIL TEMPERATURE
    4.5 SOIL ORGANIC CARBON(SOC)
    4.6 TOTAL NITROGEN(TN)
CHAPTER 5:EFFECT OF CONSERVATION TILLAGE ON GRAIN AND BIOMASS YIELD
    5.1 GRAIN YIELD
    5.2 ROOT AND ABOVEGROUND BIOMASS
    5.3 CORRELATION BETWEEN GRAIN YIELD AND SOIL PHYSICAL AND CHEMICAL PROPERTIES
CHAPTER 6:EFFECT OF CONSERVATION TILLAGE AND SEASON ON VARIATIONS OF GREENHOUSE GAS FLUXES IN SPRING WHEAT AGROECOSYSTEMS ON THE SEMI-ARID WESTERN LOESS PLATEAU
    6.1 GREENHOUSE GASES ACROSS TREATMENTS
        6.1.1 ECOSYSTEM RESPIRATION
        6.1.2 CH₄ FLUX
        6.1.3 N₂O FLUX
    6.2 SEASONAL VARIATIONS OF GHG EMISSIONS
        6.2.1 ECOSYSTEM RESPIRATION
        6.2.2 CH₄ FLUX
        6.2.3 N₂O FLUX
    6.3 AVERAGE CUMULATIVE GHG FLUXES
        6.3.1 NET CARBON DIOXIDE–C FLUX COMPONENTS
        6.3.2 CUMULATIVE CH₄ FLUX
        6.3.3 CUMULATIVE N₂O FLUX
    6.4 GLOBAL WARMING POTENTIAL(GWP)AND GREENHOUSE GAS INTENSITY(GHGI)
    6.5 RESPONSE OF GHG FLUXES TO SOIL PROPERTIES,CROP AND BIOMASS YIELD
        6.5.1 RESPONSE OF ECOSYSTEM RESPIRATION TO SOIL WATER CONTENT AND SOIL TEMPERATURE
        6.5.2 RESPONSE OF CH₄ FLUX TO SOIL WATER CONTENT AND SOIL TEMPERATURE
        6.5.3 RESPONSE OF N₂O FLUX TO SOIL WATER CONTENT AND SOIL TEMPERATURE
        6.5.4 CORRELATION BETWEEN GRAIN YIELD AND GHG FLUXES
        6.5.5 Correlation between soil organic carbon, total nitrogen and GHG fluxes
    6.6 TEMPERATURE SENSITIVITY OF ECOSYSTEM RESPIRATION
CHAPTER 7:DISCUSSIONS
    7.1 EFFECT OF STRAW MULCHING AND SOWING TIME ON SOIL PROPERTIES AND WHEAT PRODUCTIVITY AND GROWTH
    7.2 EVALUATION AND SELECTION OF THE BEST NON-LINEAR REGRESSION MODEL FOR CROP GROWTH SIMULATION
    7.3 EFFECT OF NO-TILL AND STRAW MULCH ON SOIL PROPERTIES
    7.4 EFFECT OF CONSERVATION TILLAGE ON CROP PRODUCTIVITY
    7.5 EFFECT OF TILLAGE AND SEASON ON ECOSYSTEM RESPIRATION AND NET C-FLUX
    7.6 EFFECT OF TILLAGE AND SEASON ON CH₄-FLUX
    7.7 EFFECT OF TILLAGE AND SEASON ON N₂O-FLUX
    7.8 EFFECT OF TILLAGE ON GWP AND GHGI
CHAPTER 8:GENERAL CONCLUSIONS,RECOMMENDATIONS AND FUTURE WORKS
    8.1 CONCLUSIONS AND RECOMMENDATIONS
    8.2 FUTURE WORKS
REFERENCES
Appendix
Acknowledgements
PERSONAL RESUME
Publications
BRIEF INTRODUCTION OF SUPERVISOR



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