Agricultural Technologies for Enhancing the Phytoremediation of Cadmium-Contaminated Soil by Amaranthus hypochondriacus L.

Three pot experiments were carried out to evaluate the phytoextraction efficiency of cadmium (Cd) by an amaranth (Amaranthus hypochondriacus L.). To enhance phytoremediation potential, this study examined the effect of fertilization, repeated harvests, and growth time on the efficiency of Cd removal from soil. The result showed that fertilizing with NPK increased dry biomass by a factor of 4.2, resulting in a large increment of Cd accumulation. Repeated harvests had a significant effect on the plant biomass and thus on overall Cd removal and an optimal cutting position influenced the amount of Cd extracted from soils. Plant growth time was found to significantly affect the amount of Cd extracted by A. hypochondriacus. This study indicates that A. hypochondriacus has great phytoremediation potential in Cd-contaminated soil. For best practice, the recommendation is to maximize the phytoextraction efficiency of A. hypochondriacus by repeated harvests, harvesting at the squaring stage (soon after the flower begins to appear), and apply NPK compound fertilizer as base application.