摘要
在江苏省中部平原南部选取一个30 km×45 km方形区域为研究区,按照套合采样方法,采集178个耕作层土样,分析土壤有机质含量和机械组成,运用地统计学和GIS技术研究苏中平原区表层土壤有机质含量空间变异特征,利用相关分析和方差分析探讨区域内土壤有机质含量空间变异的影响因素。统计结果表明,研究区土壤有机质含量为28.51±7.80 g/kg,变异系数为27.31%,属中等变异强度;地统计分析表明,研究区土壤有机质含量存在强烈的空间自相关性,结构变异占主导作用,各向异性显著,在39°和219°方向上变异程度最剧烈,土壤有机质含量自东北向西南呈递减趋势。研究区土壤有机质含量空间变异主要受土壤质地、成土母质、地形等因素影响,其中土壤质地是空间变异的主要影响因素。
In this research,a square area（32°20′17″-32°44′50″N,119°53′37″-120°14′4″E）,about 1 350 km2, was chosen as a case in the south of the middle Jiangsu plain.A total of 178 soil samples were collected according to nested scenario＇s,for the analysis of SOM content and soil mechanical composition.And furthermore, spatial variability of SOM in the surface layer was analyzed using the Geostatistical and GIS method,and its dominating factors,too,by means of correlation analysis and analysis of variance.The result suggested that the SOM content varied in the range of 28.51±7.80 g/kg with a coefficient of variation being 27.31%,a moderate level.Geostatistical analysis suggests that the study area was very strong in spatial autocorrelation and the semi-variogram was best fitted by spherical model,which was significant in anisotropy and the anisotropy ratio was 1.30.The variation at 39° and 219° in direction was the most severe,and the spatial heterogeneity range at the direction was 33.26 km.The variation at 129° and 309° in direction was the slightest,and the spatial heterogeneity range at the direction was 43.08 km.The structural factors played a dominating role in spatial variability of SOM.SOM in the area was distributed in a band,of which high content was in the northeast, in which the area of more than 30 g/kg accounting for 42% of the total area.But low content was in the southwest part.Correlation coefficients between SOM and soil mechanical composition were-0.548 for sand,0.534 for silt and 0.259 for clay,respectively,indicating the degree of correlation between SOM and sand was the strongest,followed by silt and clay.Analysis of variance showed that parent material and soil type effected spatial variability of SOM significantly.Soil generated in the lake sediment had higher SOM content than that in the alluvial deposit.Soil type with high in clay and silt content had higher SOM content than that with sand content.Soil mechanical composition played a key role in spatial variability of the study area.
出处
《地理科学》
CSCD
北大核心
2013年第1期83-89,共7页
Scientia Geographica Sinica
基金
江苏省基础研究计划(BK2008058)
科技部国际科技合作项目(2010DFB24140)
中国科学院战略性先导科技专项子课题(XDA0505050303)资助
关键词
土壤有机质
空间变异
地统计学
土壤质地
成土母质
soil organic matter
spatial variability
Geostatistics
soil texture
parent material
