Abstract: Microwave digestion-flame atomic absorption spectrometry method was used to determine the concentrations of Zn, Cu and Cr in Water Chestnut Soil. It was provided references for improving bioavailability, planting management and quality of water chestnut. The detection limitation, accuracy and precision of the method were validated, the contents of Zn, Cu and Cr was analyzed. Besides, the pollution degree and ecological risk of Zn, Cu and Cr of the studied water chestnut soil were analyzed by means of single pollution index and potential ecological risk index. The results showed that the range of Zn concentration soils is between 63.9~126.8 mg/kg, the average concentration is 83.8 mg/kg, the range of Cu concentration in soils is between 9.1~18.9 mg/kg, the average concentration is 12.6 mg/kg, the range of Cr concentration in soils is between 1.2~26.8 mg/kg,the average concentration is 11.4 mg/kg. Based on the environmental quality standard of soils for edible agricultural products, Zn, Cu and Cr concentration in soil was at clean level. Moreover, the results of potential ecological risk index showed that the potential ec-ological risk degree of Zn, Cu and Cr was characterized by order of Cu>Zn>Cr. On the whole, the pollution risk degree of Zn, Cu and Cr in water chestnut area soil is low.

Key words: water chestnut, soil, atomic absorption spectrometry, Zn, Cu, Cr, contamination evaluation