滨海垦区表层盐渍土理化性质和盐分离子动态特征  

Characteristics of Physicochemical Properties and Salt Ion Evolution of Surface Saline Soils in Coastal Reclamation Areas

作　　者：路迅 李建国 潘霞 岳亚朋 王松林 左希爱 徐璐 LU Xun;LI Jianguo;PAN Xia;YUE Yapeng;WANG Songlin;ZUO Xiai;XU Lu(School of Geography,Geomatics and Planning,Jiangsu Normal University,Xuzhou,Jiangsu 221116,China)

机构地区：[1]江苏师范大学地理测绘与城乡规划学院,江苏徐州221116

出　　处：《土壤》2024年第2期398-405,共8页Soils

基　　金：国家自然科学基金项目(42271287,42371053);江苏省海洋科技创新项目(JSZRHYKJ202212);自然资源部滨海盐碱地生态改良与可持续利用工程技术创新中心开放基金项目(HYCX202306);江苏省研究生科研与实践创新计划项目(KYCX23_2904)资助。

摘　　要：江苏沿海地区拥有面积广阔的围垦区,对围垦区盐渍土理化性质变化规律的研究有助于把握滨海围垦区土壤质量变化规律和特征。本研究通过采集32个江苏省盐城市不同围垦年限的土壤表层样品,对滨海垦区表层盐渍土理化性质、盐分离子含量、钠吸附比(SAR)、电导率(EC)等土壤质量关键指标进行分析,结果表明:(1)在百年以上的围垦过程中,滨海垦区表层盐渍土的C/N和p H均呈现出先上升后下降的趋势,拐点在围垦后20a左右,其中土壤C/N远低于我国传统耕地的平均水平;总有机碳(SOC)和全氮(TN)含量在围垦过程中整体呈现上升趋势;(2)EC和SAR呈快速降低的趋势,围垦至40 a左右时,土壤质量基本达到传统耕地的土壤质量水平,盐分离子普遍降至1g/kg左右;NO_(3)^(–)与NO_(2)^(–)均为土壤中的重要氮素形态,NO_(3)^(–)含量呈现先稳定后显著下降趋势,在围垦至100 a以上时显著下降;NO_(2)^(–)在围垦至20 a左右时显著上升,围垦至40 a左右时显著下降;百年围垦过程中,盐渍土盐分组成由氯化物盐土转变为氯化物硫酸盐土;(3)滨海盐渍土中理化性质与围垦年限对盐分离子演化存在复杂的关系,土壤围垦年限、pH-EC和SOC-TN含量3组组分的共同作用对盐分离子变化贡献度最大。Coastal of Jiangsu has vast reclaimed regions.Exploring evolution dynamics of saline soil properties following reclamation can benefit to understanding characteristics of soil quality variations in coastal reclamation zones.In this study,32 surface soil samples were collected from different reclamation zones in Yancheng City,Jiangsu Province to analyze the main soil quality indicators,including physicochemical properties,salt ion content,sodium adsorption ratio(SAR),and electrical conductivity(EC),etc.The results showed that:1)In the hundred-year scale,indicators of coastal soil C/N and pH initially increased then declined,with a turning point of around the 20th year after reclamation.C/N ratio was significantly lower than the mean of traditional cultivated lands of China.Soil organic carbon(SOC)and total nitrogen(TN)contents generally increased over the reclamation time;2)Both EC and SAR were in a rapid decreasing trend.Soil quality overall reached soil quality level of traditional cultivated lands of China in the 40th year after reclamation and soil salt content generally decreased to about 1 g/kg.Soil NO_(3)^(-)and NO_(2)^(-)were the two main nitrogen forms in all soils.Soil NO_(3)^(-)content kept stable initially and then decreased significantly when it was reclaimed for over 100 years.However,soil NO_(2)^(-)content increased within 20 years after reclamation and then declined significantly in 40 years reclamation.Notably,coastal saline soils transformed from chlorinated salt soils to a combination of chlorides and sulfates ones over hundred-years of reclamation;3)Complex relationships were found among salt ions evolution,soil physicochemical properties variations and reclamation time following reclamation.The combined contributions of reclamation time,pH-EC factor and total SOC-TN factor was greatest to the evolution of salt ions in the reclaimed soils.

关 键 词：滨海垦区 围垦年限 土壤理化性质 盐分离子 

分 类 号：S151.9[农业科学—土壤学] S156[农业科学—农业基础科学]