三峡库区碎石含量对紫色土容重和孔隙特征的影响

发布时间：2018-03-03 18:06

本文选题：紫色土　切入点：碎石　出处：《土壤学报》2017年02期 　论文类型：期刊论文

【摘要】：土壤容重和孔隙分布特征是土壤重要的基本物理性质,但有关含碎石土壤的物理性质以及碎石含量对土壤结构影响的研究尚不多见。三峡库区紫色土中存在大量的碎石,为了深刻了解和评价土壤中碎石对容重与大孔隙形成的可能作用,通过野外调查、典型土样采集和室内分析实验,探讨了三峡库区典型土地利用类型下土壤中的碎石体积含量以及不同粒径碎石的基本物理性质及其对土壤容重和孔隙特征的影响。结果表明:土壤中碎石的孔隙度和饱和含水率随着碎石粒径的减小而增大,小碎石本身具有一定的持水、供水性能;碎石含量对土壤的总容重、细土容重有显著影响,随着碎石含量的增加,土壤的总容重逐渐增加,而细土容重与碎石含量呈线性负相关关系,土壤中碎石的存在有利于改善土壤的结构;土壤孔隙分布特征与碎石含量密切相关,随着碎石含量的提高,土壤总孔隙度和毛管孔隙度呈减少趋势,而非毛管孔隙度即大孔隙呈增加趋势,碎石的存在有利于改善土壤的透水性能。本研究为山区农用地灌溉与水分管理提供了科学依据。
[Abstract]:Soil bulk density and pore distribution are important basic physical properties of soil, but there are few studies on the physical properties of macadam soil and the influence of crushed stone content on soil structure. There is a large amount of crushed stone in purple soil of the three Gorges Reservoir area. In order to deeply understand and evaluate the possible effect of crushed stone on bulk density and macropore formation in soil, field investigation, collection of typical soil samples and laboratory analysis experiments were carried out. The volume content of crushed stone in soil, the basic physical properties of gravel with different particle sizes and its influence on bulk density and pore characteristics of soil under typical land use types in the three Gorges Reservoir area are discussed. The results show that the pore size of crushed stone in soil is very high. The degree and saturated moisture content increase with the decrease of gravel particle size. The aggregate content has a significant effect on the total bulk density of soil and the bulk density of fine soil. With the increase of crushed stone content, the total bulk density of soil increases gradually. There is a linear negative correlation between the bulk density of fine soil and the content of crushed stone, and the existence of crushed stone in soil is beneficial to improve the soil structure, the distribution of soil pore is closely related to the content of crushed stone, and the content of crushed stone increases with the increase of the content of crushed stone. Soil total porosity and capillary porosity showed a decreasing trend, while non-capillary porosity, that is, macroporosity, showed an increasing trend, and the existence of gravel was beneficial to improve soil permeability. This study provided scientific basis for irrigation and water management of agricultural land in mountainous areas.
【作者单位】：西南大学资源环境学院三峡库区生态环境教育部重点实验室;华中农业大学资源与环境学院水土保持研究中心;
【基金】：国家自然科学基金项目(41401298) 中央高校基本科研业务费专项(XDJK2013C152) 高等学校博士学科点专项科研基金新教师类课题(20130182120015)共同资助~~
【分类号】：S152.5

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