石灰性土壤与作物系统中重金属的迁移运转及安全阈值研究  

Migration and safety thresholds of heavy metals in calcareous soil and crop systems

作　　者：路港滨 俄胜哲 袁金华[2] 刘雅娜[1] 张鹏 赵晓龙[1] LU Gangbin;E Shengzhe;YUAN Jinhua;LIU Yana;ZHANG Peng;ZHAO Xiaolong(College of Resources and Environment,Gansu Agricultural University,Lanzhou 730070,China;Institute of Soil and Fertilizer and Water-Saving Agriculture,Gansu Academy of Agricultural Sciences,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学资源与环境学院,甘肃兰州730070 [2]甘肃省农业科学院土壤肥料与节水农业研究所,甘肃兰州730070

出　　处：《土壤与作物》2025年第1期84-94,共11页Soils and Crops

基　　金：甘肃省农业科学院重点研发项目“甘肃主要土类理想土壤肥力定向培育关键技术研究”(2022GAAS39);国家重点研发计划项目“河西走廊小麦玉米安全生产技术标准研究”(2017YFD0801103).

摘　　要：建立土壤重金属安全阈值是保障我国农产品质量安全的重要措施。本研究在田间条件下,通过研究金昌市、张掖市和白银市三地Cr、Cd、Pb、As和Hg五种重金属在玉米和小麦不同器官的富集转运特点,建立作物根、茎、籽粒与土壤Cr、Cd、Pb、As、Hg总量的关系,确定玉米及小麦种植系统中的安全阈值。结果显示,小麦植株中Cr、Cd、Pb、As和Hg的富集规律一致:根>茎>籽粒,玉米植株中Cr、Pb、As和Hg的富集规律同样为根>茎>籽粒,而Cd的富集规律为茎>根>籽粒。采用回归分析方法,建立作物籽粒重金属与土壤重金属总量之间的回归模型,预测种植玉米土壤中Cr、Cd、Pb、As和Hg全量的安全阈值分别为434、12.8、378、231、9.74 mg·kg^(-1);小麦土壤中Cr、Cd、Pb、As和Hg总量的安全阈值分别为119、1.49、115、149、15.8 mg·kg^(-1)。经多因素逐步回归分析,土壤pH、有机质、土壤碳酸钙和重金属总量是影响玉米籽粒Cr、Cd、Pb、As、Hg含量的重要因素,可用对数模型拟合,拟合程度达显著水平;而上述因素对小麦籽粒中Cr、As含量无明显的影响,利用此方程能更好地预测石灰性土壤玉米、小麦籽粒中的重金属含量。Establishing safety threshold of heavy metal in soil is important to ensure quality safety of agricultural products in China.This study investigated the enrichment and transport characteristics of five heavy metals:Cr,Cd,Pb,As and Hg in different organs of maize and wheat in Jinchang City,Zhangye City,and Baiyin City under field conditions.The relationship between crop roots,stems,grains,and the total amount of soil Cr,Cd,Pb,As and Hg was established to determine the safety threshold in maize and wheat planting systems.The enrichment pattern of Cr,Cd,Pb,As and Hg in wheat different organs is consistent in the order of root>stem>grain.Similarly,the enrichment pattern of Cr,Pb,As and Hg in corn plants is in the order of root>stem>grain,while the enrichment pattern of Cd is in the order of stem>root>grain.The regression model between heavy metals in grain and the total amount of heavy metals in soil is established by regression analysis method.The prediction safety threshold of Cr,Cd,Pb,As,and Hg total amounts obtained through these regression model for corn is 434,12.8,378,231,9.74 mg·kg^(-1) in soil,respectively.While corresponding total amount safety threshold for wheat is 119,1.49,115,149,15.8 mg·kg^(-1),respectively.Through multiple factor stepwise regression analysis,it is found that soil pH,organic matter,soil calcium carbonate,and total heavy metal content are important factors affecting the Cr,Cd,Pb,As and Hg contents of corn grains.Logarithmic models could be used to fit,and the degree of fitting is significant.However,the above factors have no significant impact on the Cr,As contents in wheat grains.Using this equation can better predict the heavy metal content in calcareous soil corn and wheat grains.

关 键 词：小麦 玉米 重金属 安全阈值 

分 类 号：S512[农业科学—作物学] S513