黔中喀斯特坡耕地土壤含水量对土力学性质的影响  

Effect of Soil Moisture Content on Soil Mechanical Properties in Karst Slope Cropland of Central Guizhou

作　　者：罗爽 黄选华[1] 高华端[1] LUO Shuang;HUANG Xuan-hua;GAO Hua-duan(College of Forestry,Guizhou University,Guizhou Guiyang 550025,China)

机构地区：[1]贵州大学林学院,贵州贵阳550025

出　　处：《西南农业学报》2020年第12期2879-2884,共6页Southwest China Journal of Agricultural Sciences

基　　金：国家自然科学基金“喀斯特坡耕地浅层孔(裂)隙水文过程及土壤侵蚀响应机制”(41671275)。

摘　　要：【目的】喀斯特坡耕地土壤侵蚀过程及机理与其土力学性质息息相关,土壤水分特征特别是含水量在成因上较大程度控制着土力学性质的变化,从而影响土壤侵蚀过程,研究黔中地区坡耕地土壤含水量对土力学性质影响规律,为该地区坡耕地的侵蚀过程提供参考依据。【方法】通过野外调查及室内试验的方法,分析喀斯特坡耕地土壤自然含水量对内摩擦角、黏聚力和紧实度的影响规律。【结果】黔中地区喀斯特坡耕地内摩擦角随自然含水量的增加而减小;黏聚力随自然含水量的增加呈先增加后减小趋势,石灰岩区耕作层、犁底层黏聚力的峰值分别为24.09、23.32 kPa,白云岩区耕作层、犁底层黏聚力的峰值分别为23.57、23.64 kPa;自然含水量对紧实度的变化无显著影响。【结论】土壤内摩擦角及黏聚力对自然含水量较为密切,紧实度对自然含水量的敏感程度低,土壤抗剪强度对土壤侵蚀的影响明显。喀斯特地区坡耕地前期降水对土壤侵蚀过程比较重要。【Objective】The erosion process and mechanism of soil in karst slope cropland are closely related to its soil mechanical property. Soil moisture characteristics, especially water content, control the variation of soil mechanical properties to a great extent, thereby affecting soil erosion process. Studying the effect rules of soil moisture content to soil mechanical properties in slope cropland of Central Guizhou is to provide a reference for erosion process of slope cropland in the study area. 【Method】Field investigation and indoor experiment methods are employed to analyze the effect rules of soil natural moisture content to internal friction angle, cohesion and compaction in karst slope cropland. 【Result】 The internal friction angle decreases with increase of natural moisture content in karst slope cropland of Central Guizhou, while cohesion showed a first rising and then decreasing trend with increase of moisture content. The peak value of cohesion in plough layer and plow sole of limestone areas was 24.09 and 23.32 kPa,respectively. The peak value of cohesion in plough layer and plow sole of dolomite areas was 23.57 and 23.64 kPa,respectively. Natural moisture content had no obvious effect on variation of compaction. 【Conclusion】 Soil internal friction angle and cohesion are closely related to natural moisture content, and compaction is less sensitive to natural moisture content. Soil shearing strength has obvious effect on soil erosion. The precipitation at early stage in slope cropland of karst areas is important to soil erosion process.

关 键 词：喀斯特坡耕地 自然含水量 内摩擦角 黏聚力 紧实度 

分 类 号：S152.7[农业科学—土壤学]