The heavy metal fraction extracted with the chelating
agent DTPA can be considered as potentially available
to plants. The amount of Cd extracted with DTPA depended
on the organic amendment applied to the soil
(Table 5), the highest values being observed in the soils
amended with both doses of C2. In general, this fraction
did not vary greatly during the 120 days of incubation,
which indicates that Cd did not precipitate in the
course of time and that there was still a risk of its absorption
by plants after 4 months