广西水耕人为土黏粒矿物组成及其空间分布特征  

Clay Mineral Composition and Spatial Distribution of Stagnic Anthosols in Guangxi

作　　者：欧锦琼 黄伟濠 卢瑛 李博 阳洋 唐贤 贾重建 秦海龙 OU Jinqiong;HUANG Weihao;LU Ying;LI Bo;YANG Yang;TANG Xian;JIA Chongjian;QIN Hailong(College of Natural Resources and Environment,South China Agricultural University/Guangdong Provincial Key Laboratory of Land Use and Consolidation,Guangzhou 510642,China)

机构地区：[1]华南农业大学资源环境学院/广东省土地利用与整治重点实验室,广州510642

出　　处：《土壤》2020年第6期1290-1297,共8页Soils

基　　金：国家科技基础性工作专项重点项目(2014FY110200);国家自然科学基金项目(41271233)资助。

摘　　要：黏粒矿物影响着土壤理化性质,可指示成土因素特征和土壤发生发育过程/强度,也是中国土壤系统分类的基层单元土族矿物学类型划分的重要依据。本研究选择了广西不同纬度和成土母质的18个代表性水耕人为土的剖面,应用X射线衍射(XRD)方法分析了其典型水耕氧化还原层(Br层)的黏粒矿物组成及其空间分布特征,并确定了其中“黏质”剖面的土族控制层段矿物学类型。结果表明:①供试土壤的黏粒矿物主要包括高岭石、伊利石、三水铝石、1.42 nm过渡矿物、蒙脱石和蛭石等,依次分别出现在100%、88.9%、72.2%、61.1%、44.4%和38.9%的剖面中。②黏粒矿物组成在纬度空间分布上具有明显规律性特征。随着纬度降低,土壤黏粒中的高岭石增加,伊利石、蒙脱石、1.42 nm过渡矿物逐渐减少;纬度>23°N区域内,成土母质对黏粒矿物组成影响明显。③纬度23°N是黏粒矿物组成和土族矿物学类型分界线,<23°N区域,黏粒矿物均以高岭石为主,是“黏质”剖面的土族控制层段的主要矿物学类型;>23°N区域,黏粒矿物组成以高岭石、蒙脱石、伊利石或1.42 nm过渡矿物为主,因成土母质不同而异,“黏质”剖面的土族控制层段矿物学类型包括高岭石混合型、混合型和伊利石型。Clay minerals in soil affect soil physiochemical properties,indicate soil-forming factor characteristics,soil genesis process and intensity,and is important to distinguish mineralogy classes of soil family in Chinese Soil Taxonomy.In this paper,18 soil profiles of Stagnic anthosols derived from different parent materials in different latitudes in Guangxi were investigated,clay mineral compositions and spatial distribution in hydragric horizon(Br)of each profile was analyzed by X-ray diffraction(XRD)and applied to distinguish mineralogy classes for soil family classification of clayed soil profiles.The results showed that:1)clay minerals in Stagnic anthosols in Guangxi mainly consisted of kaolinite,illite,montmorillonite,gibbsite,vermiculite and 1.42 nm intergradient minerals.The percent of occurrence of kaolinite,illite,gibbsite,1.42 nm intergradient minerals,montmorillonite and vermiculite were 100%,88.9%,72.2%,61.1%,44.4%and 38.9%respectively.2)the composition of clay minerals has obvious regularity in latitude spatial distribution,with the increase of altitude,relative percentage of kaolinite decreased,while frequency of occurrence and relative percentage of illite,montmorillonite or 1.42 nm intergradient minerals increased.Parent materials obviously affected clay mineral composition in soils in the north area of 23°N latitude.3)Latitude 23°N was dividing-line of clay mineral composition and mineralogy classes.In the south area of 23°N latitude,clay mineral composition in soils with different parent materials was dominated by kaolinite,mineralogy classes for the identification of soil families of clayed soil profiles was kaolinitic or kaolinitic mixed.In the north area of 23°N latitude,clay mineral composition dominated with kaolinite,montmorillonite,illite or 1.42 nm intergradient minerals,and mineralogy classes for the identification of soil families of clayed soil profiles included kaolinitic mixed,mixed or illitic.

关 键 词：水耕人为土 黏粒矿物 空间分布 土族矿物学类型 广西 

分 类 号：S151[农业科学—土壤学]