Aging effect on the mobility and bioavailability of copper in soil
LU Anxiang , ZHANG Shuzhen , QIN Xiangyang , WU Wenyong , LIU Honglu
DOI:
Received February 29, 2008,Revised July 07, 2008, Accepted , Available online
Volume 21,2009,Pages 173-178
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Aging e ect on the mobility and bioavailability of copper (Cu) was investigated using a spiked soil with di erent incubation periods
from 3 to 56 d. Wheat was planted and earthworms were cultured separately in the incubated soils. The mobility of Cu in soil was
evaluated by a chemical fractionation scheme and the toxicity and bioavailability were assessed by measuring the biomass and Cu
concentration in tissues. Results showed that aging had a significant e ect on Cu fraction distribution, of which Cu tended to incorporate
from the exchangeable into more stable fractions such as the reducible and oxidisable fractions. However, aging had little e ect on Cu
bioavailability to wheat and earthworm. Comparing the soil being incubated for 3 d and 56 d, Cu concentration in wheat roots decreased
from 14.5 to 12.8 mg/kg, and no significant changes in Cu concentration were observed in both wheat shoots and earthworms. The Cu
concentration was around 2.0 and 50 mg/kg for wheat shoots and earthworms, respectively, irrespective of soil incubation time. The
CaCl2-extractable Cu had a linear relationship with Cu concentration in wheat roots (R2 = 0.65, P < 0.05), but no linear relationship can
be found for wheat shoots and earthworms. Biological control may be more crucial for Cu accumulation in organism than the changes
in soil Cu fraction caused by aging.
