Soil Pb and Cd Accumulative Characteristics in Swamp Cabbage（Ipomoea aquatica Forsk.）and Their Environmental Critical Values in Production Area for Food Security
WU Qi1, YANG Fei1, JI Hui1, ZHANG Wei-jian1, 2*
1Institute of Applied Ecology, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China; 2Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Abstract：Plumbum（Pb）, cadmium（Cd）accumulative characteristics in swamp cabbage
（Ipomoea aquatica Forsk.）under 2 types of soils（paddy and alluvial soils）were studied by potted experiment, and their environmental critical values for food security in its production area were also discussed. The results showed that: the accumulative amounts of Pb and Cd in swamp cabbage were correlated with added amount of Pb and Cd in soil. The accumulative amounts in stem were much higher than those in leaf. Under paddy and alluvial soil comdition, the average levels of Pb in stem were 3.86 and 2.02 times of those in leaf, and the average levels of Cd in stem were 3.58 and 4.73 times of those in leaf, respectively. Under same treatment level, Pb and Cd in paddy soil were easily accumulated by crop than in alluvial soil. In paddy soil, the Pb and Cd contents in leaf of swamp cabbage were 4.88 and 2.56 times of those in alluvial soil, and Cd contents were 3.04 and 4.02 times of those in alluvial soil, respectively. according to national standards for maximum contamination level in food（GB 2762—2005）, the environmental critical values of soil Pb in paddy field was 57.83 mg·kg-1, and the environmental critical values of soil Pb and Cd in alluvial field were 77.02 mg·kg-1 and 0.47 mg·kg-1, respectively for safe swamp cabbage growing. These critical values were both significantly higher than those in the national standards for soil security（HJ 332—2006）.
吴琦，杨菲，季辉，张卫建. 土壤重金属Pb和Cd在蕹菜中的累积特征及产地环境安全临界值[J]. 中国蔬菜, 2010, 1(10): 29-34.
WU Qi;YANG Fei;JI Hui;ZHANG Wei-jian;*. Soil Pb and Cd Accumulative Characteristics in Swamp Cabbage（Ipomoea aquatica Forsk.）and Their Environmental Critical Values in Production Area for Food Security. , 2010, 1(10): 29-34.
