Studies were conducted to examine the contents of heavy metals in vegetables and soils sampled from three fields that have different cropping history (continuous vegetable culture, vegetable culture after discarding apple trees, vegetable culture at newly opened field).
Five kinds of vegetables (spinach, lettuce, crown daisy, Chinese cabbage, welsh onion) plus two kinds of wild edible plants (Artemisia asiatica and Capsella brusa-pastoris) and soils were analyzed to examine the contents of five kinds of heavy metals (Cd, Cu, Pb, Zn and Cr).
1. Heavy metals contained (Cu 3.95∼50.75 ppm, Zn 7.9∼28.75 ppm, Pb 1.0∼9.75 ppm) in soil of the discarded apple orchard were markedly more than those of the other two fields.
2. The contents of Cd, Pb and Cr were relatively low without exception. Cd in the soil of new vegetable field was detected in the trace amount 0.14 (trace 1∼10.8)ppm.
3. No obvious tendency was found in contents of the heavy metals in soils of the different vegetable fields.
4. Cu sad Zn contents is vegetables were markedly high where Cd, Pb and Cr were detected in the trace amount (0.01∼0.001 ppm).
5. No significant difference was found between the contents of heavy metals detected in vegetables and in the wild edible plants.
6. The content of Cu and Zn were highest in vegetables crown at the discarded apple orchard and in those produced at the field of continuous vegetable culture, respectively.
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