『Abstract
　Four wetland plants were selected to study the effect of Fe plaque formation on phosphorus (P) accumulation in the rhizosphere and P uptake. There were significant positive correlations between the sorbed Fe content in the rhizosphere and the Fe plaque concentration (r²=0.8454, p＜0.01) and between P accumulation and the amount of the sorbed Fe in the rhizosphere (r²=0.8460, p＜0.01). The concentration of the Fe plaque on the root surface of four wetland plants species tested followed the order of Zizaniz cedu Ciflora Turez ＞ Scirpus tabernaemontani Gmel ＞ Iris pseudacorus Linn ＞ Canna indica Linn. The Fe plaque formation increased P uptake, apparently through enhancing the diffusion of P into the roots of the wetland plants; this resulted in increased P concentration in shoots. However, this effect decreased in the higher Fe plaque concentration status, apparently due to physical blocking and immobilization of P by Fe plaque. Therefore, adequate surface coverage of roots of wetland plant by the Fe plaque would increase the uptake of P by wetland plants, which depend on the optimum amendment of Fe. These effects also varied with wetland plant species.

Keywords: Iron (Fe); Fe plaque; Phosphorus (P); Wetland plant』

1. Introduction
2. Materials and methods
　2.1. Soil
　2.2. Rhizobag pot experimental design
　2.3. Analytical methods
　2.4. Statistical analysis
3. Results and discussion
　3.1. Differences in Fe plaque concentration on roots of four wetland plants
　3.2. Fractions of Fe in rhizosphere
　3.3. Concentration in roots and shoots
　3.4. Concentration in the rhizosphere
4. Conclusions
Acknowledgements
References