Agriculture Reference
In-Depth Information
Figure 8. Time-variation of trace element concentrations in plant roots and aerial parts following PG
application.
Chicory was demonstrated to be a potential indicator plants for heavy metal contaminated
soils (Aksoy 2008; Simon et al. 1996) particularly for Cd. Due to the high rate of Cd transfer,
concentration of Cd in leaves was higher than in roots.
According to Simon et al. (1996), Cd concentrations in all chicory plant parts grown in
Cd-amended soils, were substantially higher than in controls following the order: leaf > root.
Moreover, Chicory leaves growing on soil amended with PG had approximately an average of
2.0 mg kg
-1
of Cd in all parcels (Figure 8), exceeds the normal levels (0.1-1 mg kg
-1
), and
exceeding the tolerable level (0.5 mg kg
-1
) recommended for livestock (Chaney 1989).
Transfer coefficient of Cu, Pb and Zn were relatively constant with time. Cu level in
leaves was within the normal range (3-20 mg kg
-1
) (Chaney 1989) and showed no significant
difference between parcels and reference. Several studies have reported restricted transport of
Cu from contaminated soils to aboveground parts in different species (Ait Ali et al. 2002;
Arduini et al. 1996; Dominguez et al. 2008). Pb in leaves was above the normal levels (2-5
mg kg
-1
) in all parcels and showing significant difference with the reference, but not
exceeding the toxic level for livestock (30 mg kg
-1
) (Chaney 1989).
Though Zn concentration in leaves presented a significant difference between parcels and
reference, its concentration remained within the normal values (15-150 mg kg
-1
) (Chaney
1989). In fact, Zn is a micronutrient whose absorption was closely regulated by plants
(Madejon et al. 2007).
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