Conducting the screening and replanting of crops with low accumulation of heavy metals can effectively reduce the risk of heavy metal accumulation in agricultural products. However, current research focuses more on the screening of crops with low accumulation of a single heavy metal. Target crops also focus more on single-type crops and varieties. Research on the accumulation differences in arsenic and cadmium in different crop types and the priority recommendation list for the planting of low-accumulation crops is limited. This study used a combination of literature data meta-analysis and field survey methods to conduct the relevant work. The results showed that the range of arsenic and cadmium content in rice grains was 0.11-0.624 mg·kg-1 and 0.01-1.935 mg·kg-1, respectively. Under the same pollution level, rice had a relatively higher risk of accumulating arsenic and cadmium than that in maize and leafy vegetables, fruit vegetables, and root and tuber vegetables. Some leafy vegetables had significantly higher arsenic and cadmium levels, and the difference in arsenic and cadmium accumulation ability between varieties of leafy vegetables was greater than that of other types of crops. The risk of arsenic and cadmium accumulation in the edible parts of maize, fruit vegetables, and root and tuber vegetables after replacing rice cultivation was more significant. Based on the above results, a priority recommendation list for the planting of low-accumulation crops based on pollution level was constructed. Field survey results showed that the list was reasonable to a certain extent. The relevant results of this study can provide effective reference for the optimization of crop type or variety selection and safe production in arsenic and cadmium-polluted soils.
Keywords: arsenic and cadmium compound contamination; low accumulation; maize; planting regionalization; rice; vegetable.