Metal Availability and Chemical Properties in the Rhizosphere of Lupinus albus L. Growing in a High-Metal Calcareous Soil
Fecha
2009Disciplina/s
Ciencias AmbientalesMateria/s
Heavy metalsLupinus albus
Phytoimmobilisation
Rhizosphere
Soil contamination
Resumen
Chemical processes in the rhizosphere play
a major role in the availability of metals to plants. The
objective of this study was to assess the potential of
white lupin (Lupinus albus L.) for the phytoimmobilisation of heavy metals in a calcareous soil with high
levels of Zn and Pb (2,058 and 2,947 μg g−1
,
respectively) by evaluating the chemical changes in
the rhizosphere, relative to bulk soil, which modify
the solubility of heavy metals. Plants were cultivated
for 74 days in specially designed pots (rhizopots) in
which rhizosphere was sampled easily under controlled conditions. White lupin accumulated high
concentrations of Mn in the shoots (average of
4,960 μg g−1
), well above the normal concentration
in plants (300 μg g−1
). But the metal concentrations
found in shoots were not at toxic levels. Rhizosphere
soil showed a significantly greater redox potential
(245 mV) and water-soluble organic carbon content
(34.6 μgCg−1
) than bulk soil (227 mV; 27.6 μg C
g−1
...