华北平原长期耕作及秸秆管理方式下土壤碳/氮动态及碳组分、土壤养分的分布特征

发布时间：2024-02-24 00:16

　　农田土壤有机碳和氮素固定是缓解气候变化的重要措施,因此,影响土壤有机碳及氮素等养分平衡的土壤管理方式在全球范围内受到了极大关注。轮作及频繁的耕作可改变秸秆的数量及质量,进而改变土壤养分动态最终影响肥力状况及土壤质量。本研究通过长期定位试验,旨在分析评价不同耕作方式及秸秆还田处理对华北平原麦玉两熟区土壤特性的影响,主要测定指标包括：土壤养分(P、K、Mg、Ca、Mg、Na、Fe、Mn、Cu、Zn)、pH、容重和孔隙度的分布情况,以及土壤有机碳和氮的含量、储量等。试验始于2001年冬小麦季播种前,共设4个处理：翻耕秸秆不还田(PTO)、翻耕秸秆还田(PT)、旋耕秸秆还田(RT)和免耕秸秆还田(NT)。 (1)与PTO、PT目比,NT和RT表层(0-10cm)土壤的有机碳、氮含量较高。各处理,土壤有机碳含量随着土层的加深而下降。相对于PT, NT和RT土壤有机碳、氮含量随土层加深而减少的趋势更为显著(P<0.05)。与PT相比,NT减少了对土壤的机械扰动,较RT和PT显著提高了土壤容重(P<0.05)；从另一方面来讲,NT处理下的土壤孔隙度最低,PT和PTO较NT显著增加了土壤的...

【文章页数】：111 页

【学位级别】：博士

【文章目录】：
摘要
ABSTRACT
CHAPTER 1 Introduction
    1.1 Introduction and background
    1.2 Motivation and problem statement
    1.3 Literature review
    1.4 Overview of soil tillage management and soil carbon
    1.5 Soil tillage effects on other soil properties related to SOC
    1.6 Main objectives
CHAPTER 2 Materials and methods
    2.1 Site description
    2.2 Experimental design
    2.3 Soil sampling
    2.4 Soil analysis
    2.5 Statistical analysis
CHAPTER 3 Effects of tillage systems and residue management on selected soil physical andchemical properties
    3.1 Introduction
    3.2 Effects of different tillage systems ad residue management on soil chemical properties
    3.3 Effects of different tillage systems ad residue management on soil physical properties
    3.4 Discussion
    3.5 Summary
CHAPTER 4 Effects of tillage and residue management on selected soil carbon fractions
    4.1 Introduction
    4.2 Effect of different tillage systems ad residue management on soil carbon fractions
    4.3 Discussion
    4.4 Summary
CHAPTER 5 Effects of tillage and residue management on soil organic carbon concentration, stocksand stratification
    5.1 Introduction
    5.2 The effects of different tillage systems and residue management on soil carbon dynamics
    5.3 Discussion
    5.4 Summary
CHAPTER 6 Effects of tillage and residue management on nitrogen concentration, stocks andstratification
    6.1 Introduction
    6.2 The effects of different tillage systems and residue management on nitrogen dynamics
    6.3 Discussion
    6.4 Summary
CHAPTER 7 Relationship of soil organic carbon and other soil quality parameters as affected bytillage and residue management
    7.1 Introduction
    7.2 Results
    7.3 Discussion
CHAPTER 8 Summary, recommendations and conclusions
References
Acknowledgement
Abridged resume



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