【摘要】 电导率在探讨城市土壤基本化学性质、盐渍化程度、肥力质量特征和污染特点方面有重要意义。利用电导率仪测定南京市道路、绿地和菜地土壤电导率,并通过描述性统计分析、垂直分布特征探讨和电导率与其他土壤理化指标的相关分析及在此基础上展开的逐步回归和通径分析,研究土地利用方式对城市土壤电导率垂直分布的影响。结果表明:南京市主城区土壤电导率最高值0.641 mS/cm,并无盐渍化现象,但由于受人为干扰的程度存在较大差异,道路和菜地土壤电导率变异系数较大(分别为65.40%和72.60%),而绿地土壤电导率变异系数较小(21.05%);土壤电导率的垂直分布具有各自鲜明的特点:道路土壤电导率表层较高,表层以下无一定规律;菜地土壤自耕作层向下电导率逐渐降低;绿地土壤无明显趋势。土壤电导率影响因素在不同的土地利用方式间也存在差异:道路土壤电导率受频率磁化率和活性铁等控制,绿地土壤电导率受总有机碳和活性铁等控制,而菜地土壤电导率受总有机碳、全磷和游离铁等控制。由于所研究影响因子仅能解释电导率总变异的40.72%~58.86%,今后还需从城市土壤离子组成等方面进一步深入研究土壤电导率的影响因子。更多还原

【Abstract】 Soil electrical conductivity(EC) is important to research soil chemical property,salinization degree,fertility,and pollution feature.In this paper,EC of soil sampled from road,green land and vegetable land were measured by meter.Descriptive statistics,vertical distribution of EC,correlation analysis between EC and other physical chemical properties,stepwise regression and path analysis were conducted for road soil,green land soil and vegetable soil in urban Nanjing,China.The results showed that the maximum value of EC is 0.641 mS/cm,which is not salinized,however,coefficient of variation of EC of road soil(65.40%) or vegetable soil(72.60%) is bigger than that of green land soil(21.05%),and they have distinguishing feature in vertical distribution of EC,respectively.EC is higher in top road soil,and gradually drop with depth increasing in vegetable soil,but there is no specific trend in green land soil.There are different influencing factors under different land use type.Frequency depended susceptibility and active iron(Feo) play import role in road soil.Total organic carbon(TOC) and Feo are important to EC in green land soil.However,TOC,total phosphorus(TP) and free iron(Fed) act important role in vegetable soil.In future,correlation between EC and ion component and other physical and chemical properties must to be analyzed because the impact factors selected in this study can only interpreted the 40.72%～58.86% of total EC variation.更多还原