黑土团聚体的孔隙结构特征与有机碳矿化的关系研究
发布时间：2018-08-02 17:53
【摘要】：土壤团聚体是土壤结构的基本单元,土壤功能的实现离不开土壤团聚体,团聚体结构与土壤有机碳(Soil organic carbon,SOC)动态变化之间联系密切。土壤团聚体结构特征与有机碳矿化之间的关系研究有利于我们更加精确阐述团聚体在有机碳动态变化中起到的作用,进而更加全面地解释团聚体固碳机制。计算机断层扫技术(Computed tomography,CT)的快速发展为土壤结构和团聚体结构研究提供了新的技术支撑。本论文以东北典型中层黑土上建立的保护性耕作长期定位试验土壤和自然土壤为研究对象,系统分析了1-2mm大团聚体(以下简称大团聚体)和0.053-0.25mm微团聚体(以下简称微团聚体)内部,大团聚体间和微团聚体间,以及全土尺度上的孔隙结构特征,并结合团聚体结合的有机碳(SOC)、易氧化性有机碳(Readily oxidized organic carbon,ROC)以及SOC矿化速率进行相关性分析,定量评价黑土团聚体结构与有机碳矿化之间的关系,以期揭示不同耕作方式下黑土团聚体对有机碳的固定机制。主要研究结论如下:(1)自然土壤与不同耕作方式下黑土大团聚体和微团聚体孔隙结构存在差异。自然土壤大团聚体10-30μm孔径孔隙度、100μm孔径孔隙度和总孔隙明显高于不同耕作方式下黑土大团聚体,而孔隙数量则显著小于耕作土壤。然而,总体来看,自然土壤大团聚体和微团聚体内部孔隙结构与免耕下土壤结构差异较大,而与垄作下对应参数值极为接近,说明垄作具有增强团聚体稳定性,促使其向着趋近于自然土壤良好结构发展的潜力。(2)自然土壤和免耕下原状土体在100-500μm孔径孔隙度、孔隙长度以及比表面积等参数存在显著性差异。大团聚体间孔隙结构与原状土体十分相似,是土壤结构组成的主体骨架。微团聚体间孔隙度和孔隙数量均以100-500μm孔径孔隙为主,且与原状土体和大团聚体间结构存在显著差异,而且微团聚体间结构不能成为组成团聚体间结构的重要支架,只能起到调节作用。然而,不容忽视的是微团聚体颗粒较小,填补了团聚体间较大孔隙,能够促使整体孔隙结构向中小孔隙方向发展。(3)自然土壤大团聚体100μm和总孔隙度与SOC和ROC存在较好的相关性,常规性耕作和保护性耕作与团聚体结合碳和ROC相关性较差。大团聚体内部10-30μm孔径孔隙度、孔隙数量和比表面积在提升团聚体结合碳和ROC含量上起着积极作用。总孔隙度和100μm孔径孔隙度、中轴均长、节点面积和半径以及弯曲度等参数的增大不利于团聚体结合碳和ROC固定。微团聚体内孔隙结构与有机碳的关系明显差于大团聚体,仅总孔隙度和10-30μm孔径孔隙度与有机碳存在显著相关关系。(4)大团聚体间孔隙结构与有机碳之间的相关关系要比微团聚体明显,二者共同作用影响全土孔隙结构与有机碳的关系。大团聚体间30-60μm、100-500μm、500μm孔径孔隙度与团聚体结合碳存在很好的相关关系,而微团聚体间仅表现出30-60μm孔径孔隙度、节点面积和半径与团聚体结合碳呈现出一定的相关性。同时,一个稳定地团聚环境和充足碳源输入条件下大团聚体吸附微团聚体,或者在大团聚体内部形成微团聚体,是有效隔绝微团聚体表面碳被分解,以大团聚体核心碳形式固定下来的有效固碳形式。(5)全土尺度上60-100μm和100-500μm孔径孔隙度、孔隙数量、孔隙长度、节点数量、比表面积和弯曲度均与有机碳存在很好的相关关系。60-100μm孔径和100-500μm孔径孔隙有利于有机碳的积累。孔隙数量、节点数量、孔隙长度和弯曲度对于土壤中有机碳和易氧化性有机碳调节作用明显。而且,全土中孔隙间结构是有机碳进入的重要通道,中轴长度、弯曲度与SOC呈显著正相关(P0.01),其数值增长增加了有机质进入后分布的范围,而比表面积与SOC呈显著负相关(P0.01),其比值增加减少了固定有机质的孔隙面积。(6)不同尺度上的土壤结构特征与有机碳的关系影响参数不同,但大团聚体及其大团聚体间结构对整个土体结构和有机碳影响较大,而微团聚体由于其本身的稳定性,对整个土体影响区别于大团聚体。综合来看,土壤结构与有机碳的关系是多个参数共同作用的结果,而非单一某个参数可以决定的。因此建立可以表征这一相互关系的综合指标,将是我们下一步需要深入研究的内容。
[Abstract]:Soil aggregate is the basic unit of soil structure. The realization of soil function can not be separated from soil aggregate. The structure of soil aggregates is closely related to the dynamic changes of soil organic carbon (Soil organic carbon, SOC). The relationship between the structure characteristics of soil aggregates and the mineralization of organic carbon is helpful for us to elaborate the aggregate in the organic matter more accurately. The rapid development of Computed tomography (CT) provides a new technical support for the study of soil structure and aggregate structure. Soil and soil as the research object, 1-2mm large aggregates (hereinafter referred to as large aggregates) and 0.053-0.25mm microaggregates (hereinafter referred to as microaggregates), interaggregates and microaggregates, as well as the pore structure characteristics of the whole soil, combined with aggregate organic carbon (SOC), oxidizing organic carbon (Readil) The correlation analysis of Y oxidized organic carbon, ROC) and the mineralization rate of SOC was carried out to quantitatively evaluate the relationship between the structure of black soil aggregates and the mineralization of organic carbon in order to reveal the fixed mechanism of organic carbon in the black soil aggregates under different tillage. The main conclusions are as follows: (1) the black soil aggregates under the natural soil and the different tillage methods The pore structure of the microaggregates is different. The pore porosity of 10-30 mu m of natural soil aggregates, the pore size of 100 mu and the total pore are obviously higher than that of the black soil aggregates under different tillage ways, while the number of pores is significantly smaller than that of the cultivated soil. The soil structure varies greatly under the tillage, but it is very close to the corresponding parameter values under the ridge. It shows that the ridge culture has the enhancement of the stability of the aggregate. (2) the pore size, the pore length and the specific surface area of the natural soil and the free soil under no tillage exist at the pore size of the 100-500 m pore size, the pore length and the specific surface area. The pore structure of the large aggregate is very similar to the original soil, which is the main skeleton of the structure of the soil. The porosity and the number of pores among the micro aggregates are mainly 100-500 m pore pore, and there are significant differences with the structure of the original soil and the large aggregate, and the structure of the micro aggregate can not become a constituent aggregate. The important support of the structure can only play a regulatory role. However, it is not to be ignored that the small aggregate particles are smaller and fill the larger pores between the aggregates, which can promote the overall pore structure to develop in the direction of small and medium pores. (3) there is a good correlation between the 100 m and the total porosity of the natural soil aggregates and the total porosity, the conventional tillage and the protection. The correlation between carbon and ROC in combination with aggregate is poor. The porosity, pore quantity and specific surface area of 10-30 mu m in the large aggregate play an active role in increasing the aggregate carbon and ROC content. The total porosity and the pore size of 100 mu, the middle axis are long, and the enlargement of the node area and radius, and the bending degree are unfavorable to the masses. The relationship between pore structure and organic carbon in microaggregates is significantly worse than that of large aggregates. There is a significant correlation between the total porosity and the porosity of 10-30 mu m pore size and organic carbon. (4) the correlation between the pore structure and organic carbon between the large aggregates is more obvious than that of the microaggregates, and the common effect of the two groups affects the whole soil. The relationship between pore structure and organic carbon. There is a good correlation between the porosity of 30-60 mu m, 100-500 mu m, 500 mu m pore size and aggregate carbon, while the pore size and radius of the micro aggregate show a definite correlation with the aggregate carbon. At the same time, a stable agglomeration environment is found. It is an effective form of carbon sequestration that can effectively isolate carbon from the surface of microaggregates and be fixed in the core carbon form of large aggregates. (5) pore size, pore length, pore length, pore size, pore length, and pore size are 60-100 m and 100-500 mu m in the whole soil scale. The number of nodes, the surface area and the degree of bending have a good relationship with organic carbon. The pore size and the pore size, the number of nodes, the length of the pores, and the bending degree are obvious to the organic carbon and the oxidizable organic carbon in the soil. The pore structure of the whole soil is good. The pore structure of the whole soil is.60-100. The important channel of organic carbon entry, the length of the axis and the degree of bending is significantly positive correlation with SOC (P0.01), and its numerical increase increases the range of the post distribution of organic matter, while the specific surface area has a significant negative correlation with SOC (P0.01). The increase of the ratio decreases the pore space of the fixed organic matter. (6) the soil structure characteristics and organic carbon in different scales The influence of the relationship is different, but the structure of the large aggregate and its large aggregate has a great influence on the whole soil structure and organic carbon, and the influence of the micro aggregate on the whole soil is different from the large aggregate because of its stability. Therefore, the establishment of comprehensive indicators to characterize the relationship will be the next step we need to further study.
【学位授予单位】：中国科学院研究生院（东北地理与农业生态研究所）
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152;S153
本文编号：2160214
[Abstract]:Soil aggregate is the basic unit of soil structure. The realization of soil function can not be separated from soil aggregate. The structure of soil aggregates is closely related to the dynamic changes of soil organic carbon (Soil organic carbon, SOC). The relationship between the structure characteristics of soil aggregates and the mineralization of organic carbon is helpful for us to elaborate the aggregate in the organic matter more accurately. The rapid development of Computed tomography (CT) provides a new technical support for the study of soil structure and aggregate structure. Soil and soil as the research object, 1-2mm large aggregates (hereinafter referred to as large aggregates) and 0.053-0.25mm microaggregates (hereinafter referred to as microaggregates), interaggregates and microaggregates, as well as the pore structure characteristics of the whole soil, combined with aggregate organic carbon (SOC), oxidizing organic carbon (Readil) The correlation analysis of Y oxidized organic carbon, ROC) and the mineralization rate of SOC was carried out to quantitatively evaluate the relationship between the structure of black soil aggregates and the mineralization of organic carbon in order to reveal the fixed mechanism of organic carbon in the black soil aggregates under different tillage. The main conclusions are as follows: (1) the black soil aggregates under the natural soil and the different tillage methods The pore structure of the microaggregates is different. The pore porosity of 10-30 mu m of natural soil aggregates, the pore size of 100 mu and the total pore are obviously higher than that of the black soil aggregates under different tillage ways, while the number of pores is significantly smaller than that of the cultivated soil. The soil structure varies greatly under the tillage, but it is very close to the corresponding parameter values under the ridge. It shows that the ridge culture has the enhancement of the stability of the aggregate. (2) the pore size, the pore length and the specific surface area of the natural soil and the free soil under no tillage exist at the pore size of the 100-500 m pore size, the pore length and the specific surface area. The pore structure of the large aggregate is very similar to the original soil, which is the main skeleton of the structure of the soil. The porosity and the number of pores among the micro aggregates are mainly 100-500 m pore pore, and there are significant differences with the structure of the original soil and the large aggregate, and the structure of the micro aggregate can not become a constituent aggregate. The important support of the structure can only play a regulatory role. However, it is not to be ignored that the small aggregate particles are smaller and fill the larger pores between the aggregates, which can promote the overall pore structure to develop in the direction of small and medium pores. (3) there is a good correlation between the 100 m and the total porosity of the natural soil aggregates and the total porosity, the conventional tillage and the protection. The correlation between carbon and ROC in combination with aggregate is poor. The porosity, pore quantity and specific surface area of 10-30 mu m in the large aggregate play an active role in increasing the aggregate carbon and ROC content. The total porosity and the pore size of 100 mu, the middle axis are long, and the enlargement of the node area and radius, and the bending degree are unfavorable to the masses. The relationship between pore structure and organic carbon in microaggregates is significantly worse than that of large aggregates. There is a significant correlation between the total porosity and the porosity of 10-30 mu m pore size and organic carbon. (4) the correlation between the pore structure and organic carbon between the large aggregates is more obvious than that of the microaggregates, and the common effect of the two groups affects the whole soil. The relationship between pore structure and organic carbon. There is a good correlation between the porosity of 30-60 mu m, 100-500 mu m, 500 mu m pore size and aggregate carbon, while the pore size and radius of the micro aggregate show a definite correlation with the aggregate carbon. At the same time, a stable agglomeration environment is found. It is an effective form of carbon sequestration that can effectively isolate carbon from the surface of microaggregates and be fixed in the core carbon form of large aggregates. (5) pore size, pore length, pore length, pore size, pore length, and pore size are 60-100 m and 100-500 mu m in the whole soil scale. The number of nodes, the surface area and the degree of bending have a good relationship with organic carbon. The pore size and the pore size, the number of nodes, the length of the pores, and the bending degree are obvious to the organic carbon and the oxidizable organic carbon in the soil. The pore structure of the whole soil is good. The pore structure of the whole soil is.60-100. The important channel of organic carbon entry, the length of the axis and the degree of bending is significantly positive correlation with SOC (P0.01), and its numerical increase increases the range of the post distribution of organic matter, while the specific surface area has a significant negative correlation with SOC (P0.01). The increase of the ratio decreases the pore space of the fixed organic matter. (6) the soil structure characteristics and organic carbon in different scales The influence of the relationship is different, but the structure of the large aggregate and its large aggregate has a great influence on the whole soil structure and organic carbon, and the influence of the micro aggregate on the whole soil is different from the large aggregate because of its stability. Therefore, the establishment of comprehensive indicators to characterize the relationship will be the next step we need to further study.
【学位授予单位】：中国科学院研究生院（东北地理与农业生态研究所）
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152;S153
【参考文献】
相关期刊论文 前2条
1 潘根兴;中国土壤有机碳和无机碳库量研究[J];科技通报;1999年05期
2 潘根兴;周萍;李恋卿;张旭辉;;固碳土壤学的核心科学问题与研究进展[J];土壤学报;2007年02期
，本文编号：2160214
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