Effect of iron plaque on utilization of phosphorus by broad-leaf cattail(Typha latifolia L.) in a lead-contaminated soil

To investigate the effect of iron plaque on phosphorus (P) utilization by broad-leaf cattail (Typha latifolia L.) in a lead (Pb) contaminated soil, we transplanted the broad-leaf cattail seedlings with iron plaque induced at two levels of Fe2+ (20, 100 mg/L) in rhizobags into soils previously treated with four levels of Pb (0, 100, 500, 1000 mg/kg). After the plants grew four weeks under the waterlogged condition, the amounts of iron plaque on roots and P in plants were measured. The results showed that the over-ground and underground biomass of cattail treated with low ferrous (20 mg/L) was 3.5%19.6% and 7.6%39.8% higher than that with high ferrous (100 mg/L), respectively, and decreased with the doses of lead (P0.05), and iron had significantly influence on the over-ground biomass (P0.01). The amounts of iron plaque on new roots were decreased with the increase of lead dose. Phosphorus adsorbed in iron plaque on new roots treated with low ferrous was generally lower than that treated with high ferrous. The concentrations of phosphorus in over-ground and underground part of plants treated by low ferrous was higher than that with high ferrous, except for the Pb 1000 mg/kg treatment. It is concluded that lower amount of iron plaque on roots appeared to be more beneficial for phosphorus utilization by broad-leaf cattail under the condition of this experiment.