长江三角洲地区滩涂土壤盐分空间分布特征研究

盐碱地盐分空间分布精准识别及形成机理解析对盐碱地科学利用具有重要意义。针对传统点状采样监测方法工作量大、代表性差和检测费用高等问题，本研究采用电磁感应仪精准调查技术对上海崇明某滩涂农场进行土壤盐分空间分布评估，全面快速获得盐分空间分布信息，解析土壤盐分形成机理，进而分类分区分级指导农业生产和科学精准改良。结果表明：土壤表观电导率(EC_a)和土壤盐分含量呈显著线性正相关关系(R²>0.9,P<0.05),土壤表观电导率的变化可以用来表征土壤盐分含量的变化；通过克里金插值研究区内土壤盐分的空间变异分布状况发现，研究区土壤盐分空间分布不均匀，有近80%区域存在轻中度盐碱化问题；通过定点取样土壤盐碱剖面评价，发现研究区土壤盐分具有较强的表聚性和变异强度，且变异系数随土壤深度增加不断减小；将表观电导率解译出的土壤盐分和土壤pH、有机质含量及主要组成离子含量进行相关性分析，剖析出该区域盐渍化类型以硫酸盐型为主，海水浸渍侧渗和地下水返盐影响是该区域盐渍化形成的主要原因。本研究实现了对土壤盐碱化快速、大范围、科学且动态的监测，对于全面提升盐碱地农...

Spatial distribution characteristics of soil salinity in coastal saline-alkali area in Yangtze River Delta

Accurate recognition and mechanism analysis on spatial distribution of soil salinity are of great significance for scientific utilization of saline-alkali land.To solve the problems of heavy workload,poor representativeness and high detection cost from the conventional method,this study used the electromagnetic instrument to assess the spatial distribution of soil salinity in a typical farm in Chongming coastal area,Shanghai,so as to provide guidance for agricultural production as well as scientific and accurate improvement according to the salinity classification and salinization mechanism.The results showed that there was a significant positive linear correlation between the apparent electrical conductivity(ECa)and soil salt content(R2>0.9,P<0.05),indicating that ECa would be used to characterize the variation of soil salinity.The spatial distribution and variation of soil salinity in the area was obtained by Kriging interpolation,and found that the spatial distribution of soil salinity was not uniform,and nearly 80%of the areas was with mild to moderate salinization.The evaluation of soil salinity profiles by spot sampling showed that soil salinity in this area was with a strong surface aggregation and spatial variation,and the coefficient of variation decreased with the increase of soil depth.Correlation analysis of interpreted soil salinity,soil pH,organic matter content,and major constituent ion content was conducted to dissect salinization types and formation mechanisms.The main salinization in this area was sulfate type,and the influences of seawater infiltration and groundwater re-salinity were the main reasons for the formation of salinization.The study provides a rapid,large-scale,scientific and dynamic monitoring for soil salinization,which is of great significance in promoting the utilization technology and realizing the efficient and sustainable utilization of saline-alkali land.