EFFECT OF NITROGEN FERTILIZER ON GROWTH AND CADMIUM ACCUMULATION IN<i>SEDUM ALFREDII</i>HANCE

Abstract

We characterized the effect of nitrogen (N) fertilizer on root morphology, photosynthetic pigments and cadmium (Cd) accumulation in a series of hydroponic experiments by using hyper-accumulating ecotype of Sedum alfredii H. (HE) and non-hyperaccumulating ecotype (NHE) plants. Cd accumulation in both ecotypes increased with increase of N levels until it reached the peak at 16 mM and then decreased suddenly. Among all the three N forms tested, ammonium sulfate [(NH4)2SO4] was found to be an optimum choice. Based on these findings, a pot experiment was also conducted to evaluate the effect of three N fertilizers on phytoextraction from a slightly Cd-contaminated soil by the hyper-accumulating plant Sedum alfredii H.