岩溶区土壤有机质空间变异性分析  

Spatial variation analysis of soil organic matter in karst area

作　　者：张春来[1] 陆来谋 杨慧[1] 黄芬[1] ZHANG Chunlai;LU Laimou;YANG Hui;HUANG Fen(Institute of Karst Geology,CAGS/Key Laboratory of Karst Dynamics,MNR&GZAR,Guilin,Guangxi 541004,China;Guangxi Huantou Jinyi Environmental Technology Co.,Ltd.,Nanning,Guangxi 530299,China)

机构地区：[1]中国地质科学院岩溶地质研究所/自然资源部、广西岩溶动力学重点实验室,广西桂林541004 [2]广西环投金溢环境科技有限公司,广西南宁530299

出　　处：《中国岩溶》2022年第2期228-239,共12页Carsologica Sinica

基　　金：国家自然科学基金重点项目(41530316);广西科技计划项目(桂科AD20297090);中国地质调查评价项目(DD2016032403)。

摘　　要：采用GIS和地统计学研究土壤有机质(SOM)的空间分布、影响因素和预测是指导农业生产、环境治理和土壤碳储计量的重要手段。基于广西马山县北部岩溶区表层土壤(0~20 cm)的441个SOM数据,建立普通克里格(OK)、回归克里格(RK),以及结合辅助变量的地理加权回归克里格(GWRK)、残差均值(MM_OK)和中值(MC_OK)均一化克里格的5种模型,并比较其预测精度,旨在探讨岩溶区SOM制图中地统计学方法的适用性。结果表明:(1)SOM的变异系数为37.30%,属于中等空间变异;(2)岩溶区SOM空间变异受土地利用方式、土壤类型和地形因子等因素共同影响,SOM高值区分布在西北部、西部和东部等石灰土分布的岩溶区和水田,低值区位于北部红水河沿岸的冲积土地带;(3)RK、GWRK、MM_OK和MC_OK对SOM解释能力均较优,可用于岩溶区SOM预测制图。结合辅助变量因子的GWRK预测模型能有效消除空间变异因素的影响,克服岩溶区SOM含量的空间非平稳性,从而提高SOM含量模型的稳定性和精度,同时MC_OK模型能提高预测的准确度。As an important parameter for soil quality assessment,soil organic matter(SOM)can provide nutrients for crops,strengthen soil fertility,and improve soil physicochemical properties.Besides,SOM also plays an important role in restricting the activity of heavy metal elements and pesticide residues,and in regulating CO2 in soil.Therefore,the study on spatial distribution of SOM,its influence factors and prediction by GIS and geostatistical analysis is important in agricultural practice,environmental management and the measurement of soil carbon storage.The content of SOM is easily affected by the factors such as geological background,climate change,agricultural activities and land use change.Hence the complexity and non-stationarity of the spatial variability of SOM will make it difficult for the quantitative prediction.The high heterogeneity of SOM and insufficient sampling data in the karst area also leads to low accuracy of spatial prediction.Guangxi is one of the areas with the most widely distributed karst areas in China.Typical karst landforms are developed in the northern part of Mashan county,with a range of land use and parent materials.Different patterns of land use include paddy field,dry land,shrub land,forest land,orchard and grassland,accounting for 10.55%,29.39%,29.49%,12.86%,0.70%and 0.66%respectively.Paddy fields,consisting of paddy soil,are located in karst valleys;dry lands,consisting of red soil,brown lime soil,and alluvial soil,are distributed at the bottom of slopes and karst depressions on both sides of the valley;shrubland and forest land,mainly consisting of brown lime soil and red soil,spread over mountains.A total of 441 SOM data,with 8 high-density topsoil(0-20 cm)samples per km2 on average,were obtained in the geochemical survey of land quality in the northern karst area of Mashan county,Guangxi in 2017.The data facilitates the spatial prediction of highly heterogeneous SOM in karst areas.In this paper,qualitative variables such as land uses and soil types were converted into quantitative

关 键 词：土壤有机质 地理加权回归 空间分布 岩溶 

分 类 号：S153[农业科学—土壤学]