橘园坡位变化对红壤胶体颗粒组成及胶体磷含量的影响  

Influence of slope positions on the composition and phosphorus content variation in colloidal particles of citrus orchard red soil

作　　者：刘卓玲 王艳玲[1] 张佳敏 李欢 高磊[2] LIU Zhuoling;WANG Yanling;ZHANG Jiamin;LI Huan;GAO Lei(School of Ecology and Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China;State Key Laboratory of Soil and Sustainable Agricultural Development,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 211135,China)

机构地区：[1]南京信息工程大学生态与应用气象学院,南京210044 [2]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京211135

出　　处：《农业环境科学学报》2025年第2期409-419,共11页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(42077087,42077012)。

摘　　要：为明确坡位变化对红壤胶体颗粒组成及胶体磷含量的影响,本研究以江西鹰潭孙家典型红壤小流域观测站内位于坡顶、坡上、坡中及坡底的橘园红壤为研究对象,基于Stoke′s定律采用水分散-虹吸法依次获得粒级为<0.1、0.1~<0.45、0.45~<1μm及1~5μm的胶体颗粒,对比分析了各坡位橘园红壤中胶体颗粒的分布比例、有机质、非晶质氧化铁(Feo)、非晶质氧化铝(Alo)及胶体颗粒所携带的磷素(Pcoll)的含量变化差异;以坡顶橘园红壤为例,借助于热场发射电子扫描显微镜、X射线能量色散谱仪(SEM-EDS)和X射线衍射仪(XRD)观察了各粒级胶体颗粒的微观形貌及元素富集特征;明确了各粒级胶体颗粒的组成矿物及相对比例。结果表明:不同坡位橘园红壤中1~5、0.45~<1、0.1~<0.45μm胶体颗粒的分布比例分别为20.1%~24.8%、4.1%~6.1%、0.2%~0.6%;且随坡位降低,1~5μm胶体颗粒的分布比例呈先增加后降低的趋势,0.45~<1μm与0.1~<0.45μm胶体颗粒则呈降低-增加-降低的趋势。随橘园坡位的降低,各粒级胶体颗粒内有机质和Alo占比呈先增加后降低的趋势,以坡中和坡上有机质占比分别为最低与最高,而坡顶和坡上Alo的占比分别为最低与最高;Feo占比呈先降低后增加的趋势,以坡上和坡中的占比分别为最低与最高。随胶体颗粒粒级的减小,各粒级胶体颗粒内有机质与Feo占比呈先降低后增加的趋势,Alo占比则呈先增加后降低的趋势。不同坡位橘园红壤中各粒级Pcoll含量为0.66~1.57 g·kg^(-1),且均随坡位降低呈先降低后增加的趋势,坡中各粒级Pcoll含量最低,坡底Pcoll含量最高;且胶体粒径越小,Pcoll含量相对越高。通过SEM-EDS观察到坡顶橘园红壤中0.1~<0.45μm胶体颗粒的结合程度最好,颗粒排列紧实呈团状,<0.1μm胶体颗粒的结合程度最差,颗粒呈分散状,而1~5μm和0.45~<1μm胶体颗粒呈片状散落排布,结合程度相仿;磷主要赋存于1~5μm和In order to clarify the effect of slope position change on the composition of colloidal particles and the content of phosphorus in red soil.In this study,based on Stoke′s law,the"water disperse-siphoning method"was used to obtain soil particle of<0.1,0.1-<0.45,0.45-<1μm and 1-5μm colloidal particles,in citrus orchard at the flat top,top,middle and bottom of the slope of the Sunjia typical red soil watershed in Yingtan,Jiangxi Province.The distribution ratio of colloidal particles,organic matter(OM),amorphous iron oxide(Feo),amorphous alumina(Alo)and the content of colloidal phosphorus(Pcoll)in red soil of citrus orchard were compared and analyzed.Taking the red soil of citrus orchard on the flat top of slope as an example,the micromorphology and element enrichment characteristics of colloidal particles of various sizes were observed by means of emission scanning electron microsoopy,and X-ray energy spectrometer(SEM-EDS)and X-ray diffractometer(XRD).The constituent minerals and relative proportions of colloidal particles of each size were determined.The results showed that the distribution ratio of 1-5,0.45-<1,0.1-<0.45μm colloidal particles was 20.1%-24.8%,4.1%-6.1%,0.2%-0.6%in citrus orchard red soil at different slope positions,respectively.With the decrease of slope position,the distribution proportion of 1-5μm colloidal particles increased first and then decreased,while that of 0.45-<1μm and 0.1-<0.45μm colloidal particles showed a trend of reduced-increased-decrease.As the decrease of citrus orchard slope position,the proportion of OM and Alo in colloidal particles increased first and then decreased and the proportion of OM in the middle and top slopes was the lowest and the highest,while the proportion of Alo in the flat top and top slopes was the lowest and the highest,respectively.The proportion of Feo in the top and middle slopes was the lowest and the highest,respectively.With the decrease of colloidal particle size,the proportion of OM and Feo in each colloidal particle size showed a trend of f

关 键 词：橘园红壤 坡位变化 胶体磷 矿物组成 有机-无机胶结物质 

分 类 号：S153.6[农业科学—土壤学]