黔中地区坡耕地土壤机械组成对界限含水量的影响  

Influence of Soil Mechanical Composition on the AtterbergLimits in the Slope Farmland of Central Guizhou

作　　者：罗爽 高华端[1] 陶倩 胡嘉钰 杨懿 LUO Shuang;GAO Hua-duan;TAO Qian;HU Jia-yu;YANG Yi(College of Forestry,Guizhou University,GuiYang 550025,China)

机构地区：[1]贵州大学林学院,贵州贵阳550025

出　　处：《土壤通报》2020年第3期580-586,共7页Chinese Journal of Soil Science

基　　金：国家自然科学基金项目(41671275)资助。

摘　　要：土壤界限含水量作为重要的土壤力学指标,直接影响着坡耕地土壤抗冲性和土壤侵蚀过程。土壤机械组成与界限含水量特征值存在因果关系;研究两者间关系,有助于阐明坡耕地土壤侵蚀机理。以黔中3种主要岩性区坡耕地为研究对象,用野外调查及室内试验的方法,探讨了土壤机械组成对界限含水量的影响。结果表明:3种母岩区坡耕地土壤塑限为石灰岩区(30.49%)>紫色砂岩区(24.12%)、砂页岩区(20.50%),土壤液限为石灰岩区(56.30%)>紫色砂岩区(43.09%)>砂页岩区(32.80%),塑性指数为石灰岩区(26.03%)>紫色砂岩区(18.97%)>砂页岩区(12.29%)。石灰岩区坡耕地土壤粗砂含量、粉粒含量与液限、塑性指数呈负相关,黏粒含量与液限、塑性指数呈正相关;紫色砂岩区坡耕地粗砂含量与液限、塑性指数呈显著负相关,粉粒含量、黏粒含量与液限、塑性指数呈显著正相关;砂页岩区坡耕地粗砂含量与液限、塑性指数呈显著负相关,黏粒含量与液限、塑性指数呈显著正相关。不同岩性分布区坡耕地的界限含水量存在差异,成土母岩的差异是造成3种坡耕地土壤界限含水量差主要原因。Atterberglimit is an important index of soil mechanics,which directly impacts the soil anti-scourability and the process mechanism of soil erosion in the slope farmland.The relationships between mechanical composition and Atterberg limits were analyzed in the 3 common slope farmlands of central Guizhou,in order to clarify the mechanism of soil erosion process.The results showed that the plastic limit of slope farmland in the 3 lithology areas decreased as the order of limestone area(30.49%)>purple sandstone area(24.12%),sandy shale area(20.50%),the liquid limit as limestone area(56.30%)>purple sandstone area(43.09%)>sandy shale area(32.80%),and the plasticity index aslimestone area(26.06%)>purple sandstone area(18.97%)>sandy shale area(12.29%).The contents of coarse sand and silt were negatively correlated with the liquid limit and plasticity index,while the content of clay was positively correlated with them in the slope farmland of limestone area.The contents of coarse sand were negatively correlated with liquid limit and plasticity index,while the contents of slit and clay were positively correlated with them in the slope farmland of purple sandstone area.The contents of coarse sand were negatively correlated withliquid limit and plasticity index,while the contents of clay were significantly correlated with them in the slope farmland of sandy shale area.There are differences in the Atterberg limit of slope farmland in different parent rock areas,and the difference of parent rock is the main reason for the difference in the Atterberg limit of three kinds of slope farmland.

关 键 词：坡耕地 土壤机械组成 液限 塑性指数 

分 类 号：S15[农业科学—土壤学]