岩溶洼地小流域泥沙来源地土壤有机质、粒度和磁化率特征及影响因素分析  

Analysis on Characteristics and Influencing Factors of Soil Organic Matter,Particle Size and Magnetic Susceptibility in Source Area of Sediment in Karst Depression

作　　者：雷珊 魏兴萍[1,2] LEI Shan;WEI Xing-ping(College of Geography and Tourism Science,Chongqing Normal University,Chongqing 401331,China;Chongqing Key laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area,Chongqing 401331,China)

机构地区：[1]重庆师范大学地理与旅游学院,重庆401331 [2]三峡库区地表过程与环境遥感重庆市重点实验室,重庆401331

出　　处：《西南农业学报》2020年第7期1538-1544,共7页Southwest China Journal of Agricultural Sciences

基　　金：重庆市自然科学基金(cstc2016jcyiA0150);重庆师范大学研究生科研创新项目(YKC19002)。

摘　　要：【目的】对岩溶洼地小流域泥沙源地土壤有机质、粒度和磁化率进行分析研究,摸清岩溶洼地小流域泥沙源地水土流失状况,为岩溶洼地小流域的水土流失,以及洼地的保护与开发提供一定的依据。【方法】以重庆青木关岩溶槽谷洼地区表层土壤、深层土壤、碎屑岩区土壤侵蚀源地为研究对象,采用野外调查、样品采集、室内分析等相结合的方法,揭示了土壤有机质、粒度和磁化率特征,探讨了土壤有机质、粒度和磁化率的相关性。【结果】①岩溶洼地泥沙来源中土壤的有机质为28.05、25.46、28.05 g/kg,变异系数处于低至中等变异。表层土壤中坡耕地有机质>撂荒地>林地,碎屑岩区土壤有机质林地>撂荒地>泥土路面,碎屑岩林地>碳酸盐岩林地。②3种泥沙来源的土壤其众数粒级都是粉粒组分含量,其次是黏粒组分,再次是砂砾组分,根据粒度组成三角图图解可知,这3种泥沙来源的土壤都属于粉(砂)壤土质地,说明它们这些土壤还处在发育过程中。③表层土壤质量磁化率的变化范围在5.94×10^-8~167.46×10^-8m^3/kg,频率磁化率变化范围为4.62%~10.04%;深层土壤质量磁化率的变化范围在7.68×10^-8~106.03×10^-8m^3/kg,频率磁化率的变化范围为1.96%~13.38%;碎屑岩区质量磁化率的变化范围在6.92×10^-8~108.37×10^-8m^3/kg,频率磁化率的变化范围为变化幅度大2.55%~8.18%,土壤中普遍含有较多的超顺磁颗粒。④表层土壤、和碎屑岩区土壤有机质、磁化率和黏粒、砂粒呈负相关,与粉粒呈正相关并达到最大值。在深层土壤中土壤有机质与黏粒不相关,与粉粒正相关、与砂粒负相关,而磁化率与黏粒砂粒呈负相关,与粉粒呈正相关。【结论】表层土壤、深层土壤、碎屑岩区土壤有机质、粒度和磁化率差异较大,与土壤岩性、植被等具有密切联系,在对洼地的开发与保护时,要因地制宜,分区分段进行开发与治【Objective】The organic matter,particle size and magnetic susceptibility of the soil in the sediment source area of the karst depression small watershed were analyzed and studied to find out the water and soil loss status of the sediment source area in the small watershed of karst depression,and to provide a certain basis for the protection and development of depressions.【Method】The surface soil,deep soil and detrital rock erosion sources in Qingmuguan karst trough valley area of Chongqing was taken as example,using a combination of field investigation,sample collection and indoor analysis,revealing the soil organic matter,the characteristics of particle size and magnetic susceptibility,exploring the correlation of soil organic matter,particle size and magnetic susceptibility.【Result】(i)The organic matter content of the soil in the source of sediment in karst depression was 28.05,25.46,28.05 g/kg,and the coefficient of variation was low to medium variation.Organic matter in slope farmland in topsoil>abandoned land>woodland,clastic rock area soil organic matter woodland>abandoned land>mud pavement,clastic rock woodland>carbonate forest.(ii)The majority of the three kinds of sediment-derived soils are all powder components,followed by the clay component and the gravel component again.According to the triangle diagram of the particle size composition,the soils of the three kinds of sediments were all belonged to silty(sand)loam texture,indicating that these soils were still in the process of development.(iii)The change range of surface soil mass susceptibility was 5.94×10^-8-167.46×10^-8 m^3/kg,the frequency range of susceptibility was 4.62%-10.04%;The change range of deep soil quality susceptibility was 7.68×10^-8-106.03×10^-8 m^3/kg,the frequency susceptibility varies from 1.96%to 13.38%;The mass susceptibility of the clastic rock area varies from 6.92×10^-8 to 108.37×10^-8 m^3/kg.The variation range of frequency susceptibility was 2.55%to 8.18%,and the soil generally contains more superparamagnet

关 键 词：泥沙来源地 有机质 粒度 磁化率 特征分析 

分 类 号：S153.6[农业科学—土壤学]