摘要
以贵州织金县某设施蔬菜基地为例,运用简单相关、主成分分析和路径分析等方法,研究高Cd地质背景区设施菜地蔬菜Cd累积特征,土壤Cd的主要来源、生物有效性及其与土壤pH、有机质(SOM)、碱解氮(NA)等土壤基本理化性质的相关性,并分析土壤Cd生物有效性的主控因子。结果表明,该基地耕作层土壤Cd含量大于贵州省耕作层土壤Cd背景值(0.659 mg·kg^(-1))的点位占比为75.32%,基地设施蔬菜对Cd的累积规律表现为白菜>番茄>豇豆,3种蔬菜均未超标。从食品安全角度考虑,在设施菜地土壤污染风险评价中,土壤有效Cd比土壤全Cd能更准确表征土壤Cd的安全风险。该基地设施菜地Cd主要来源为成土母质风化,其高Cd含量与高施氮量分别是提高土壤Cd生物有效性的直接因子和间接因子,土壤SOM、P和K等养分指标对土壤Cd生物有效性的影响不显著。因此,在高Cd地质背景区发展设施蔬菜栽培,可以考虑种植豇豆,并严格控制氮肥施用量,从而保证“菜篮子”安全。
Using a greenhouse vegetable base in Zhijin County,Guizhou Province as an example,simple correlation,principal component and path analysis were applied to study the characteristics of Cd accumulation in vegetables of a greenhouse vegetable base in a high Cd geological background area.The main sources of soil Cd,its phytoavailability and its correlation with soil pH,soil organic matter(SOM),alkaline nitrogen(NA)and other basic soil physicochemical properties were also studied,and the main controlling factors of soil Cd bioeffectiveness were analysed.The results show that the Cd content in the topsoil of 75.32%of the sites of the base was greater than the background value of soil Cd in the topsoil of Guizhou Province(0.659 mg·kg^(-1)),and the bioaccumulation of Cd in greenhouse vegetables were in the order of cabbage>tomato>cowpea,with none of the three vegetables exceeding National Food Safety Standard(GB 2762-2017).Correlation coefficient(R=0.785)between Cd contents in vegetable fruits(Cd p)and the content of available Cd in soils(Cd A)was higher than that(R=0.508)between Cd p and total Cd(Cd T),implying that Cd A is better than soil Cd T for assessing Cd contamination in vegetable fruits and for predicting the safety risk of vegetable production.The content of Cd between topsoil and subsoil using independent-samples t test showed that the main source of Cd in greenhouse soils was weathering of the parent material in high Cd geological background area,and its high Cd content and high nitrogen application are direct and indirect factors for the increasing of the biological effectiveness of soil Cd.Cd A was correlated significantly with Cd T,pH and available nitrogen(P<0.05),but not with soil organic matter(SOM),available phosphorus and available potassium.Therefore,cowpea can be considered for the development of facility vegetable cultivation in areas with high Cd geological background,and the amount of N fertilizer application should be strictly controlled to ensure the safety of the“vegetable basket”.
作者
柴冠群
杨娇娇
刘桂华
罗沐欣键
范成五
秦松
CHAI Guan-qun;YANG Jiao-jiao;LIU Gui-hua;LUO Mu-xin-jian;FAN Cheng-wu;QIN Song(Institute of Soil and Fertilizer,Guizhou Academy of Agricultural Science,Guiyang 550006,China;College of Agriculture,Guizhou University,Guiyang 550025,China)
出处
《生态与农村环境学报》
CAS
CSCD
北大核心
2021年第7期917-923,共7页
Journal of Ecology and Rural Environment
基金
黔农科院青年基金([2018]94)
贵州省科技支撑计划(黔科合支撑[2017]2577,[2018]2338)。
关键词
高镉地质背景
设施菜地
镉生物有效性
主控因子
氮肥施用量
high Cd geological background
greenhouse soil
Cd phytoavailability
dominant control factor
N-fertilizer application rate
