Abstract

To evaluate the potential of native plants for phytoremediation, a field survey of terrestrial plants growing in a phosphorus (P) mining area in Shifang, China, was conducted to identify the variation of mineral composition in the soil and plants. The mineral composition [nitrogen (N), P, potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn)] of roots and shoots and the rhizosphere soil were determined. To quantify the relative contribution of each component to the overall correlation, path analyses were carried out. The results indicate that the P accumulators (Polygonum hydropiper and Pilea sinofasciata) had an advantage in mineral composition. In roots, the highest concentrations of Mg, Fe and Cu were found in P. hydropiper, and the highest concentrations of Ca were found in P. sinofasciata. Moreover, P. sinofasciata demonstrated the highest concentrations of Ca and Fe in shoots, which were 2.4 and 4.4 times higher than the mean of all other species. High concentrations of Fe and Mn were also found in the shoots of P. sinofasciata. In the roots of both plants, Fe had the highest negative direct effect on P, while Ca had a higher positive direct effect on P. In shoots, N had a higher positive direct effect on P, and K had a negative direct effect on P. Interactions between nutrients are important for determining the optimum nutrition for P accumulators.

Key words: Interaction, mineral composition, nutrient, phosphorus accumulator, phytoremediation.