摘要
由于不同区域土壤理化性质存在差异以及不同蔬菜种类对重金属的吸收能力不同,利用我国现行的土壤环境质量标准进行评价时发现,土壤与蔬菜重金属超标情况往往存在不一致的现象,使得我国现行的土壤环境质量评价标准并未能切实保证蔬菜安全生产需求。因此,有必要针对特定区域的特定种类的农作物进行蔬菜-土壤重金属累积相关性研究,并据此建立更符合实际且科学合理的产地环境土壤重金属限量值。本研究以芸薹类叶菜中在广东地区种植较为普遍的菜心(Brassica campestris ssp.chinensis var.utilis Tsen et Lee)和小白菜(Brassica campestris ssp.chinensis Makino)为代表,大量采集广东地区镉污染呈不同程度的蔬菜产地原状土壤开展盆栽实验,分别建立了芸薹类叶菜类蔬菜可食用部分镉含量与土壤镉全量及土壤有效态镉含量的相关关系,并建立蔬菜镉含量与土壤镉全量及有效态镉的最优回归方程。然后,依据《食品中污染物限量》(GB2762─2012)中叶菜的镉限量值推算出广东地区芸薹类叶菜安全种植的产地土壤镉全量和有效态镉含量限量值分别为1.22和0.43 mg·kg-1。最后,结合大田采样中大量的土壤-蔬菜对应数据对该限量值进行了验证,证明盆栽试验所得结果与大田采样数据具有较好的一致性,对指导当地农产品安全生产和农田土壤有效利用具有较强的针对性和准确性。
Due to the diverse soil physic-chemical properties in different regions and discrepancy of heavy metal absorption capacity in different vegetables, the inconsistent phenomenon of heavy metal over-standard rates in soil and vegetable samples often exists during environment evaluating by the current environmental quality standard in China. It means that our current soil environmental quality evaluation criteria could not meet the real demand of ensuring the safe vegetable production. Therefore, it is very necessary to study the heavy metal accumulation correlation of the specific vegetable varieties and their producing soils in the specific region, and establish some more practical and scientific soil heavy metal pollution thresholds. In this study, the widely grown Brassica campestris ssp. chinensis var. utilis Tsen et Lee and B. campestris ssp. chinensis. Makino in Guangdong region were chosen as the study objects to represent Brassica leaf vegetables. Large amounts of Cd polluted in-situ soil with different pollution degrees in Guangdong were collected to carry out the pot culture experiment. We analyzed the correlations between the Cd concentrations of Brassica leaf vegetables and the total Cd or available Cd concentrations of soils and established their optimal regression equations. And then, according to the Cd safety threshold of leafy vegetables in the national standard Maximum Limits of Contaminants in Food, the soil safety thresholds of the total and available Cd concentrations were calculated as 1.22 and 0.43 mg·kg-1, respectively. Additionally, a lot of field samplings were carried out and verified that the soil safety thresholds in the pot-experiment were consistent with field sampling values, which would be significant and precise to guide the local agri-product safety production and effective utilization of agricultural soil.
出处
《生态环境学报》
CSCD
北大核心
2016年第4期705-710,共6页
Ecology and Environmental Sciences
基金
广东省自然科学基金项目(2015A030313571)
2014年度省公益研究与能力建设专项(2014A020208069)
广东省农业科学院院长基金项目(201418)
关键词
重金属污染
有效态镉
安全阈值
相关性分析
芸薹属
heavy metal pollution
available Cd
safety threshold
correlation analysis
Brassica
