化肥减施和绿肥还田对水稻土中团聚体的有机碳和粘土矿物的影响
发布时间：2023-09-17 17:56
各种长期定位施肥试验中,评估土壤有机碳(SOC)在团聚体的固定保存以及它的稳定过程对于实现可持续农业系统至关重要。本课题依托湖南南县10年长期定位试验,在中国南方潮土性水稻土上进行研究,以不同紫云英用量(MV;15t,22.5t,30t和37.5t)和化肥用量(F;100%,80%和60%)做各处理搭配,旨在评估0-20cm土壤水稳性团聚体(WSA)及其稳定性指数;团聚体中有机碳的密度分组(f LOC,c-i POC,f-i POC和m SOC)对于团聚体的物理保护机制,以及土壤化学性质和粘土矿物的变化。结果表明,与CK和F处理相比,在37.5t+F80处理(提高76.7%和10.1%)和30t+F60处理(提高80.6%和12.5%)中,土壤大团聚体(0.25～2 mm)显著提高(P<0.05)。在37.5t+F80处理(提高51.4%和22.7%)和30t+F60(提高54.3%和22.7%)处理下,平均重量直径(MWD)和几何平均直径(GMD)显著提高。与CK相比,22.5t+F80、37.5t+F80和30t+F60处理的土壤有机碳含量显著增加,分别增加了31.0%、38...
【文章页数】：101 页
【学位级别】：硕士
【文章目录】：
中文摘要
Abstract
List of Abbreviations
1.Introduction
1.1.Conceptual overview of the research
1.1.1.Global status and importance of rice production
1.1.2.Consequences of long-term excessive use of chemical fertilizers
1.1.3.Green manuring:Chinese milk vetch in paddy soils
1.1.4.Soil carbon sequestration mechanisms and SOC density fractions
1.1.5.Effects of fertilization on soil aggregation and aggregate stability
1.1.6.Effects of fertilization on carbon sequestration and density fractions
1.2.Clay mineralogy:Definition
1.2.1.Role of clay minerals in soil
1.2.2.Effects of organic and mineral fertilization on clay mineralogy
1.3.Novelty and purpose of the study
1.3.1 Novelty
1.3.2.Research objectives
1.4.Schematic overview of the study
2.Material and methods
2.1.Experimental description and sampling
2.2.Determination of soil aggregation
2.3.Soil organic carbon fractionation
2.4.SOC analysis and calculations
2.5.Determination of soil chemical characteristics
2.6.Separation of soil clay fraction
2.7.Determination of elemental composition of clay fraction
2.8.Clay mineralogical Analysis
2.9.Statistical analysis
3.Results
3.1.Soil chemical properties
3.1.1.Soil p H
3.1.2.Primary nutrient contents
3.1.3.Relationship between soil p H and soil nutrient characteristics
3.2.Soil aggregation and soil organic carbon
3.2.1.Distribution and stability of water stable aggregates
3.2.2.Distribution of SOC density fractions
3.2.3.SOC in bulk soil,aggregates and enrichment
3.2.4.SOC contents in density fractions
3.2.5.Hierarchical agglomerative cluster analysis
3.2.6.Relationship among aggregation,SOC contents,and density fractions
3.3.Clay minerals
3.3.1.Clay mineralogical identification
3.3.2.Modifications in XRD patterns
3.3.3.Relative contents of clay minerals
3.3.4 Relationship among soil chemical properties,SOC and clay minerals
4.Discussion
4.1.Changes in soil properties
4.2.Soil aggregate stability and organic carbon sequestration
4.3.Clay mineralogical modifications
5.Conclusion and future perspectives
5.1.Conclusion
5.2.Future perspectives
6.References
Acknowledgements
本文编号：3847874
【文章页数】：101 页
【学位级别】：硕士
【文章目录】：
中文摘要
Abstract
List of Abbreviations
1.Introduction
1.1.Conceptual overview of the research
1.1.1.Global status and importance of rice production
1.1.2.Consequences of long-term excessive use of chemical fertilizers
1.1.3.Green manuring:Chinese milk vetch in paddy soils
1.1.4.Soil carbon sequestration mechanisms and SOC density fractions
1.1.5.Effects of fertilization on soil aggregation and aggregate stability
1.1.6.Effects of fertilization on carbon sequestration and density fractions
1.2.Clay mineralogy:Definition
1.2.1.Role of clay minerals in soil
1.2.2.Effects of organic and mineral fertilization on clay mineralogy
1.3.Novelty and purpose of the study
1.3.1 Novelty
1.3.2.Research objectives
1.4.Schematic overview of the study
2.Material and methods
2.1.Experimental description and sampling
2.2.Determination of soil aggregation
2.3.Soil organic carbon fractionation
2.4.SOC analysis and calculations
2.5.Determination of soil chemical characteristics
2.6.Separation of soil clay fraction
2.7.Determination of elemental composition of clay fraction
2.8.Clay mineralogical Analysis
2.9.Statistical analysis
3.Results
3.1.Soil chemical properties
3.1.1.Soil p H
3.1.2.Primary nutrient contents
3.1.3.Relationship between soil p H and soil nutrient characteristics
3.2.Soil aggregation and soil organic carbon
3.2.1.Distribution and stability of water stable aggregates
3.2.2.Distribution of SOC density fractions
3.2.3.SOC in bulk soil,aggregates and enrichment
3.2.4.SOC contents in density fractions
3.2.5.Hierarchical agglomerative cluster analysis
3.2.6.Relationship among aggregation,SOC contents,and density fractions
3.3.Clay minerals
3.3.1.Clay mineralogical identification
3.3.2.Modifications in XRD patterns
3.3.3.Relative contents of clay minerals
3.3.4 Relationship among soil chemical properties,SOC and clay minerals
4.Discussion
4.1.Changes in soil properties
4.2.Soil aggregate stability and organic carbon sequestration
4.3.Clay mineralogical modifications
5.Conclusion and future perspectives
5.1.Conclusion
5.2.Future perspectives
6.References
Acknowledgements
本文编号：3847874
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