基于GIS的沱江中游土壤全氮空间变异特征及其影响因素研究

Spatial Distribution Charateristics of Soil Total Nitrogen and Its Influence Factors in Middle Reaches of Tuojiang River Based on GIS

本研究基于ArcGIS 9.3平台,运用地统计学方法研究了沱江中游表层土壤全氮(STN)的空间变异分布特征及影响因素。结果表明,沱江中游土壤全氮含量为(1.06±0.02)g·kg-1,呈对数正态分布;研究区内水稻土(1.43±0.49)g·kg-1全氮含量极显著高于紫色土(0.93±0.32)g·kg-1(P<0.01),其空间分布具有明显异向性,西北部为带状分布,中部及南部呈团块状分布。成土母质显著影响了全氮的含量(P=0.000),随侵蚀程度的增强,土壤全氮含量降低。不同土地利用类型土壤全氮含量顺序为菜地、灌溉水田、果园、旱地、荒草地、有林地。土壤全氮含量与pH呈显著负相关(P=0.036),与有机质含量呈极显著正相关(P=0.000)。

Based on the geographic information systems,in this paper,the spatial distribution characteristics of the soil total nitrogen （STN） and the influencing factors of the surface soil in the middle reach of Tuojiang river were studies by the means of geostatistics method.The results showed that the concentration of STN in the middle reach of Tuojiang river was （1.06 ±0.02） g · kg-1 and lognormal distribution.The STN concentration was significantly higher in paddy soil （1.43 ±0.49） g· kg-1 than that in purple soil （0.93 ±0.32） g · kg-t （P ＜ 0.01）.The spatial distribution had the distinct characteristics of anisotmpy,which tended to be zonal distribution in the northwest and clumped in the central and southem part.The STN concentration of different parent materials was significantly influenced by soil erosion intensities （P =0.000） and decreased with the increase of erosion status.According to the different types of land use,the order of STN con centration from high to low was vegetable field,hrigated land,orchard,arid land,grassland and forest land.There was signiflcantly negative correlation （P =0.036） between STN concentration and pH and significantly positive correlation （P =0.000） between STN concentration and organic matter content.