地下水浅埋区层状土壤结构对包气带硝态氮累积和淋失的影响  

Effects of layered soil on the accumulation and leaching of nitrate-nitrogen in shallow groundwater regions

作　　者：王士军 田路遥 刘丙霞[2] WANG Shijun;TIAN Luyao;LIU Bingxia(Gansu Academy of Agri-Engineering Technology,Wuwei 733006,China;Center for Agricultural Resources Research,Institute of Ge-netics and Developmental Biology,Chinese Academy of Sciences/Key Laboratory of Agricultural Water Resources,Chinese Academy of Sciences,Shijiazhuang 050022,China;Yanggu No.1 High School,Liaocheng 252000,China)

机构地区：[1]甘肃省农业工程技术研究院,武威733006 [2]中国科学院遗传与发育生物学研究所农业资源研究中心/中国科学院农业水资源重点实验室,石家庄050022 [3]聊城市阳谷县第一中学,聊城252000

出　　处：《中国生态农业学报（中英文）》2023年第1期125-135,共11页Chinese Journal of Eco-Agriculture

基　　金：国家重点研发计划项目(2021YFD1700500);国家自然科学基金项目(41530859);河北省杰出青年基金项目(D2019503072);河北省优秀青年科学基金项目(D2021503018)资助。

摘　　要：农业过量施肥造成包气带硝态氮(NO_(3)^(-)-N)累积与地下水NO_(3)^(-)-N污染加剧,明确非均质层状土壤结构对NO_(3)^(-)-N迁移过程的影响对防止地下水硝酸盐污染具有重要意义。华北低平原区非均质层状土壤结构分布广泛,地下水埋藏浅,NO_(3)^(-)-N淋滤路径短,是地下水污染的敏感区域。本研究选择位于河北省沧州市南皮县的3个非均质层状土壤结构剖面(P1:含多个薄黏壤土夹层的无施肥草地;P2:含多个薄黏壤土夹层的农田;P3:含140 cm厚黏壤土夹层的农田)和1个对照剖面(P4:相对均质的粉壤土农田),研究层状土壤结构以及农业施肥对包气带NO_(3)^(-)-N累积与淋失规律的影响。结果表明,NO_(3)^(-)-N累积分布层位与黏壤土层深度和厚度相关,3个非均质层状土壤剖面NO_(3)^(-)-N含量均高于相对均质粉壤土剖面,且非均质农田中P3剖面NO_(3)^(-)-N含量峰值(238 mg∙L^(-1))和累积层厚度(100~250 cm)均最大。2018年雨季8—9月含黏壤土夹层剖面NO_(3)^(-)-N淋失量:P3(319.2 kg∙hm^(-2))<P1(383.9 kg∙hm^(-2))<P2(554.7 kg∙hm^(-2)),说明在雨季含厚黏壤土夹层剖面对包气带NO_(3)^(-)-N淋失的阻控效果显著优于含多个薄黏壤土夹层的剖面(P<0.05)。受层状沉积结构和地下水浅埋深的影响,P2浅层地下水NO_(3)^(-)-N浓度的超标率与平均增长速率(93%和2.14 mg∙L^(-1)∙d^(-1))显著高于P4(21%和0.53 mg∙L^(-1)∙d^(-1))(P<0.05)。研究明确了层状土壤剖面对NO_(3)^(-)-N运移具有阻滞作用且黏壤土夹层越厚阻滞作用越强,地下水NO_(3)^(-)-N浓度受包气带层状土壤结构和地下水埋深二者的综合控制。研究结果可为地下水浅埋区地下水硝酸盐污染防治提供科学依据。Excessive nitrogen application in agriculture causes the accumulation of nitrate-nitrogen(NO_(3)^(-)-N)in the vadose zone and intensifies nitrate pollution in groundwater.Heterogeneous layered soil is relatively common in nature and plays an important role in controlling pollutants entering groundwater from the surface.Heterogeneous layered soil exists in the low plain area of North China which is sensitive to groundwater pollution owing to its shallow groundwater burial and short nitrate leaching path.Thus,it is important to clarify the influence of the heterogeneous layered soil structure on the NO_(3)^(-)-N migration process to prevent nitrate pollution in groundwater.In this study,four typical soil profiles,heterogeneous and relatively homogeneous,and two land use types were selected in Nanpi County,Hebei Province.The four typical soil profiles included three heterogeneous layered soils(P1,P2,P3),one relatively homogeneous profile(P4),and two land uses,which were unfertilized grassland with multiple 30 cm thin clay soil interlayers(P1),fertilizing farmland with multiple 30 cm thin clay soil interlayers(P2),fertilizing farmland with 140 cm thick clay soil interlayers(P3),and fertilizing farmland with relatively homogeneous silty loam(P4).The effect of layered soil on the accumulation and leaching of NO_(3)^(-)-N was studied by analyzing the relationship between the physical and chemical properties of different layered soil profiles and NO_(3)^(-)-N content in soil profiles and groundwater.The results showed that the vertical distribution of NO_(3)^(-)-N was affected by the depth and thickness of the clay loam soil layer.The NO_(3)^(-)-N contents in the three heterogeneous layered soil profiles were higher than that in the homogeneous profile with silt loam.In the three heterogeneous layered soil profiles,P3 with a 140-cm clay soil interlayer,its'peak content of NO_(3)^(-)-N(238 mg·L^(-1))and the accumulation layer thickness(100-250 cm)were the highest.In the rainy season of 2018(from August to September),the

关 键 词：层状土壤结构 黏壤土夹层 硝态氮 累积与淋失 浅层地下水 河北低平原 

分 类 号：S153[农业科学—土壤学] X523[农业科学—农业基础科学]