Effects of Amended Fe Oxide and Fe Plaque On Uptake of As and Pb in Paddy Rice Seedlings

• Main Authors: Jia-Chi Wang, 王嘉琪
• Other Authors: Kai-Wei Juang
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/huwcc9

碩士 === 國立嘉義大學 === 農藝學系研究所 === 105 === In previous researches, iron plaque on rice root surface was proposed that it can sequester metals and influence metal uptake by rice plant (Oryza sativa L.). Iron plaque formation is due to radial oxygen loss (ROL) and reduced soluble Fe2+ oxidants on roots. In order to adapt to anaerobic conditions in paddy field, rice transfers O2 to its roots for respiration resulting in O2 diffusing toward rhizosphere. This oxidative layer may also play a barrier to heavy metals. In this study, we used rhizo-bags to represent this area and aimed to investigate the absorptions of As and Pb by rice plant related to rhizosphere iron oxides and root iron plaque via rhizo-bag pot experiments. The results showed that the uptake of As or Pb by rice plant were significantly decreased with (1) iron amendment in As or Pb contaminated soil and (2) organic added in red soil with As or Pb spiked. Furthermore, the amount of iron oxides in rhizosphere and iron plaque was significantly increased. More As or Pb was sequestrated in rhizosphere and iron plaque. However, heavy metal uptake by rice plants was increase with 1500 mg kg-1 Fe amendment. Plants might be secondary injured caused by excess iron added or the decrease of soil pH.