摘要
【目的】分析广西桂平市稻田生态区的土壤酸化和镉污染风险程度,为保障粮食质量安全和完善土壤环境质量评价指标体系提供参考依据。【方法】调查广西桂平市稻田生态区土壤的酸化和镉污染现状,对土壤pH的变异及土壤镉的分布情况进行分析,并以741个稻田土壤样本及其对应的稻米样本为对象,分别采用GB 15618—2018《土壤环境质量标准》和GB 15618—1995《土壤环境质量标准》两种国标对稻田土壤的镉污染风险进行分类评定,比较稻田土壤镉含量和稻米镉含量超标或不超标的吻合与背离程度。【结果】广西桂平市稻田pH≤6.5的酸性土壤占比79.35%,土壤镉含量范围为0.004~2.456 mg/kg,平均值0.191 mg/kg,变异系数102.63%,在广西稻田生态区中土壤全镉的水平相对较低,需管制的土壤镉中重度污染区占比较小。按照GB 15618—2018得出的土壤镉超标率较GB 15618—1995降低7.16%(绝对值,下同),评价结果吻合度(置信概率)(87.84%)提高4.58%,背离度(否定概率)同步降低4.58%,但两种国标的置信概率均未达显著水平(P>0.05)。【结论】广西桂平市稻田生态区土壤酸化严重,但稻田土壤镉的污染程度较低,需管制的土壤镉中重度污染区占比较小。除矿区周边稻田外,稻米镉暴露可能起因于稻田土壤的酸化。
【Objective】The risk degree of soil acidification and cadmium pollution in the paddy field ecological area of Guiping,Guangxi was analyzed to provide reference for ensuring food quality safety and improving the evaluation index system of soil environmental quality.【Method】The present situation of soil acidification and cadmium pollution in the paddy field ecological area of Guiping was investigated.The variation of soil pH and the distribution of soil cadmium were analyzed.The 741 paddy field soil samples and their corresponding rice samples were taken as objects.Two national standards,GB 15618—2018 Environmental Quality Standard for soils and GB 15618—1995 Environmental Quality Standard for soils,were adopted to classify and evaluate the risk of cadmium pollution in paddy field soil,and to compare the degree of consistency and deviation between excessive and non-excessive cadmium contents in paddy field soil and rice.【Result】In Guangxi,Guiping paddy fields of acidic soil(pH≤6.5)accounted for 79.35%,soil cadmium content was in the range of 0.004-2.456 mg/kg,average 0.191 mg/kg,the variation coefficient of 102.63%.The level of total cadmium in the paddy ecosystem of Guangxi was relatively low,and the proportion of moderately and severely polluted areas requiring control was relatively small.According to GB 15618—2018,the over-standard rate of cadmium in soil was 7.16%lower than that in GB 15618—1995(absolute value,the same below),the consistency(confidence probability)(87.84%)of the evaluation results was increased by 4.58%,and the deviation(negative probability)was reduced by 4.58%,but the confidence probability of the two national standards did not reach the significant level(P>0.05).【Conclusion】Soil acidification is serious in the paddy field ecological area of Guiping,Guangxi,but the pollution degree of cadmium in paddy field soil is low,the heavy and moderate pollution areas of soil cadmium are relatively small.In addition to the paddy fields around the mining area,cadmium exposure to rice may be due to the acidification of paddy soil.
作者
朱志军
杨寿山
杨泽忠
李霞
莫秋霞
刘钊扬
李兴林
郭映云
覃海全
ZHU Zhi-jun;YANG Shou-shan;YANG Ze-zhong;LI Xia;MO Qiu-xia;LIU Zhao-yang;LI Xing-lin;GUO Ying-yun;QIN Hai-quan(Guiping Agricultural and Rural Bureau,Guiping,Guangxi 537200,China;Guiping Science and Technology Bureau,Guiping,Guangxi 537200,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2019年第7期1466-1471,共6页
Journal of Southern Agriculture
基金
中央财政农业资源及生态保护补助资金项目（财农〔2014〕32号）
关键词
稻田土壤
稻米
土壤酸化
镉污染
风险评价
广西桂平
paddy soil
rice
soil acidification
cadmium pollution
risk assessment
Guiping,Guangxi
作者简介
朱志军(1963-),高级农艺师,主要从事农业资源与环境、作物营养与施肥研究工作,E-mail:zzj2902@yeah.net
