Comparisons of NH₄⁺, NO₃^- and H₂PO₄^- uptake kinetics in three different macrophytes in waterlogged condition

In a kinetic experiment, the absorption of NH₄⁺, NO₃^- and H₂PO₄^- by three different emergent macrophytes (Canna generalis, Cyperus papyrus, Colocasia tonoimo) in waterlogged condition were analyzed in relation to values of landscape esthetics and economic value. Based on the analysis, the uptake rate of H₂PO₄^- was highest in C. generalis. In fact, C. generalis continued to absorb H₂PO₄^- in even low ion concentration conditions. This suggested that C. generalis successfully coped with a wide range of H₂PO₄^- concentration. On the other hand, the uptake rate of NO₃^- was highest in C. papyrus. It was, however, not able to successfully adapt to low nutrient conditions (as C. generalis). The highest uptake rate of NH₄⁺ was also in C. papyrus, and even of low concentrations of NH₄⁺. Also, NH₄⁺ absorption was lowest in C. generalis. The application scope of three plants on restoration of polluted water varied with ion absorption characteristics of the plants. C. generalis did generally well in all levels of H₂PO₄^- polluting water. C. papyrus, on the other hand, was only suitable for pre-treatment of seriously NO₃^- polluting water. Then C. generali was usable in maintaining water quality after improvement to a certain degree. C. papyrus was applicable in various concentrations of NH₄⁺ polluting water. C. generalis grew better in water environments that were less polluted by NH₄⁺.