Relationship between Selected Metal Concentrations in Korean Raspberry (Rubus coreanus) Plant and Different Chemical Fractions of the Metals in Soil

Abstract

The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M MgCl 2 -extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from 0.87 mg kg -1 to 66.82 mg kg -1 .Exchangeable and DTPA-extractable metals ranged between 0.02 and 0.67 mg kg -1 and between 0.05 mg kg -1 and 7.07 mg kg -1 , respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between 1.30 mg kg -1 and 38.82 mg kg -1 and between 0.05 mg kg -1 and 21.51 mg kg -1 , respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.