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题名	土壤母质特性和结构性与土壤退化的关系研究——以长江上游地区几种典型退化土壤为例
作者	宫阿都
学位类别	硕士
答辩日期	2001
授予单位	中国科学院水利部成都山地灾害与环境研究所
授予地点	北京
导师	何毓蓉
关键词	土壤结构性 土壤母质特性 土壤退化 长江上游地区
学位专业	土壤学
中文摘要	该文从土壤母质特性和土壤结构性这两个决定性内因入手,通过对长江上游地区典型退化土壤的分析研究,探讨了导致土壤退化,其内因是土壤母质与土壤结构基础的缺陷,外因是生态环境的失衡和人为过度利用,其动力是严重的土壤侵蚀的作用.该文选定长江上游地区的三种典型退化土壤母质特性与土壤退化的相互关系,以期为期质量恢复和肥力重建提供一定的理论依据.
英文摘要	The upper region of the Yangtz Valley which was one of the most important commercial agricultural regions and the forestriest regions for conservation of soil and water has very important position in the sustainable development strategy. In these years because of the increasing population, the decreasing of the cultivated farms and the original weak environment, these general problems had appeared that the contradiction between the humans and the lands was intensified and the productivity of lands reduced, etc. Now the lands with more obvious soil degradation had exceeded 70 percent, which has been one of the barrier factors to execute the west developing strategy and the modernization construction, so these questions about soil degradation must be emphasized fairly. Soil degradation which was influenced by the natural conditions and the artificial activities was a complex problem. It's influenced by the internal causes including the regional geological environment such as the parent materials and the external causes including the environment conditions & the ways of land use. Essentially soil properties themselves were the most important factors. In this dissertation, properties of soil parent materials and soil structure were chosen as the main internal causes to probe the reasons of soil degradation by studying the typical degraded soils in the upper region of the Yangtz Valley. It was discovered by the studies that the internal causes of soil degradation in this region were the flaw of soil parent materials and soil structures, the external causes were the unbalance of the Eco-system and the excessive land use, the driving force was the serious soil erosion. In this dissertation, three typical soils in the upper region of the Yangtz Valley including the Dry-red soils, the Vertisols and the Purple soils were chosen as the study objects, the comparative method was chosen as the main study method of this dissertation, which was hoped to provide a certain theory basis for the quality recovery and fertility reconstruction of the degraded soils by studying the relationships between the properties of soil parent materials and soil structures and soil degradation. The Dry-Hot Valley of the Jinsha River was one of the typicallest soil degradation regions of China. The Dry-red soils and the Vertisols widely distributed in Yuanmou County of this region had the typicality of soil degradation, while the purple soils which widely distributed in the region had a certain representity. So the typicality and the representity were given attention to, he internal causes and the external causes were combined in the study thinking, which made it more comprehensive and scientific. These conclusions were indicated by the study. 1. The influence of soil parent materials to soil degradation (1) The different types of soil parent materials influenced soil degradation types. For example, the soils from the parent materials of purple arenaceous shale usually displayed fragmentalization or barrenization degradation characters. While the degradation types of soils from the friable sediments of Quaternary period often displayed hardenization, Vertisolization or heavylization characters. (2) The layer constitution of different parent materials types. Soils from deep arenose parent materials had the obvious fragmentalization characters,for example, soils from K_(2j) had a lot of coarse mineral particles and usually formed the sand-agglomeroplcsmic microfabric. The fragmentalization of deep pelite parent materials was for more weathering rock fragments, for example, though soils from J_3s had the very high clay content, the rock fragments wasn't easy to appear pelitization, which made the soils often form fragment-agglomeroplcsmic microfabric. Soils from the internbedding of sandstone and mud shone had different degradation types, if the overlying horizon was the heavy sandstone and formed the composite with hard upper layer and soft under layer, which mainly leaded to medium-degree even heavy-degree construcality degradation, if the overlying horizon was the slight mud stone sandstone and formed the composite with soft upper layer and hard under layer, which mainly leaded to medium-degree even heavy-degree construcality or physicality degradations such as fragmentalization and barrenization. (3) The particle size composition type of parent materials influenced soil degradation. Through some study it's founded that he particle size composition ratio of parent materials was very near to that of soils from parent materials to the objects of the dissertation,so parent materials controlled the soil panicle characters and influenced soil degradation. The typicallest soils were Vertisols and Purple soils. (4) The mineral composition of parent materials also influenced soil structure and the abundance of soil nutritive elements directly ,furthermore influenced soil degradation. 2. The influence of soil struture to soil degradation (1) The influence of soil pore space states to soil degradation was showed at the composition ratio of the pore space. Usually the undegraded soils had the balanced pore space ratio, while the ratio of the degraded soils were seriously unbalanced, or excessively big pore space related to gragmentalization and went against keeping soil water and fertilizer, or excessively micro-pore space related to compactization and affected soil perviousness. (2) There were close relationships between soil structural degradation and soil disperity, soil aggregatity, soil porosity, soil bulk density, among these factors, soil mechanical composition and soil aggregation composition decided soil degradation speed and degree. The study results indicated the measuring indexes such as dispersion ratio, erosion ratio, aggregation rate, aggregation state, structure deterioration ratio, erodibility index(E_(VA)), soil porosity can reflect the degree of soil degradation better. Generally, there was the positive significance and correlation between soil degradation and soil dispersion ratio, soil structure deterioration ratio, etc. and the negative ones between soil degradation and soil aggregation rate, soil capillary porosity, etc. So such indexes as dispersion ratio, structure deterioration ratio, aggregation rate and capillary porosity could be used as one of the indicators to embody soil structurality and soil degradation status. (3) The study on the degraded soils by the fractal theory had proved the fractal dimensions of soil particle size distribution could reflect the structure states and degradation degrees of the degraded soils objectively, so they could be used as a comprehensive quantitive index to evaluate the structure of the degraded soils. There were the obvious significance and correlation between fractal dimensions of soil particle size distribution and the mechanical composition and micro-aggregate composition of the degraded soils. Generally, higher the content of <0.001mm clay and lower that of >0.25mm microaggregate, higher the fractal dimensions and worse the structure property of soil. To the same soil degradation series, higher the fractal dimensions, more serious the degradation degree. (4) The studies of the dissertation also showed the familiarest microfabric were fragment-agglomeroplcsmic, sand-agglomeroplcsmic, porphyropectic or compactcakyric -gelatinatic, etc. which was corresponding with soil fragmentalization and compactization. In addition, the O.M. and microaggregate of the degraded soils was hardly checked in the microscope, it's possible that some layers were lack or the combinations of soil layers were bad. 3. The steps of fertility recovery of the degraded soils. The cultivated steps, biological steps and engineering steps should be combined to improve soil structure, get rid of soil obstacle layers, popularize the scientific cultivation systems and cultivation steps, prevent soil degradation and improve soil productivity. On the arrangement of study content, the dissertation were composed of three parts, altogether seven chapters. The first part was the comprehensive literature reports, the progress and trend of the internal and external studies on soil degradation, soil structurality, etc. were introduced. The second part included five chapters, in which it was introduced that the technical route and study methods firstly, next the influences of soil parent materials to soil degradation by the type combination, particle size composition and the mineral composition, then the relationships between soil degradation and soil structurality such as soil profile combination characters, the general structure characters, the microstrucmre and ultra-microstructure characters were also introduced, finally the steps of fertility recovery and reconstruction to degraded soils were probed. The third part was the conclusion and discussion.
语种	中文
学科主题	土壤学
公开日期	2010-10-08
分类号	S158.1
内容类型	学位论文
源URL	[http://ir.imde.ac.cn/handle/131551/2044]
专题	成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前）
推荐引用方式 GB/T 7714	宫阿都. 土壤母质特性和结构性与土壤退化的关系研究——以长江上游地区几种典型退化土壤为例[D]. 北京. 中国科学院水利部成都山地灾害与环境研究所. 2001.

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