This study shows that soil CEC and organic matter
content are the two important factors that can aect the
adsorption and desorption of Cu(II) and Pb(II) on the
paddy soils. The highest adsorption and desorption of
Cu(II) and Pb(II) observed for the 15-Year paddy soil can
be attributed to its highest CEC among the soils tested.
Long-term cultivation of rice can lead to an accumulation
of organic matter in the paddy soils and result in a decrease
in the percentage of the desorption of Cu(II) and Pb(II)
from the paddy soils. This in turn can decrease the mobility
of the adsorbed Cu(II) and Pb(II) in the paddy soils. Soil
organic matter has a stronger eect on the adsorption and
desorption of Cu(II) as compared to Pb(II) because the
organic matter has a higher anity for Cu(II) than for
Pb(II)