This study aimed to better understand the impact of different bauxite residues (BR) on the germination and the development of Sinapis alba (white mustard). Unamended BR from Provence, France (PRO), and Guinea (GUI) bauxite were selected, and modified bauxite residues from PRO and GUI (MBR-PRO and MBR-GUI) were obtained by gypsum application and repeated leaching, in order to reduce their pH, electrical conductivity (EC), and exchangeable sodium percentage (ESP). Germination rates were monitored in soil-BR mixtures with increasing concentrations of BR. A rhizotron experiment was done, where Sinapis alba was allowed to develop in a layer of soil on the top of a layer of bauxite residue. To assess the impact of the residue on root development, the WhinRhizo® software was used to measure the architectural traits of roots. Peroxidase and fluorescein hydrolase activities were also assessed on the roots grown either in the soil or in the residue layers. Results showed that (i) bauxite residue origin, (ii) bauxite residue modification by gypsum, and (iii) bauxite residue concentration had significant effects on the germination, the root development and architecture, and the enzymatic activities of the roots of Sinapis alba. The PRO residue had a far stronger phytotoxic effect compared to the GUI residue on every measured variable. The toxic effect was strongly modulated by the origin of bauxite residue. The gypsum application efficiently reduced the phytotoxic effect of the residues, but significant negative effects on the different variables were still recorded.

本研究旨在更好地了解萌发和发展不同铝土矿残留物（BR）的影响，白芥（白芥）。选取法国普罗旺斯（PRO）和几内亚（GUI）的未改性 BR 铝土矿，通过施石膏和重复浸出获得 PRO 和 GUI 改性铝土矿残留物（MBR-PRO 和 MBR-GUI），以减少它们的pH、电导率 (EC) 和可交换钠百分比 (ESP)。随着 BR 浓度的增加，在土壤-BR 混合物中监测发芽率。做了一个根管实验，其中白鳍金枪鱼允许在铝土矿残渣层顶部的土壤层中发育。为了评估残留物对根系发育的影响，使用 WhinRhizo® 软件来测量根系的结构特征。过氧化物酶和荧光素水解酶活性也在土壤或残留层中生长的根上进行了评估。结果表明，(i) 铝土矿渣来源，(ii) 石膏对铝土矿渣的改性，以及(iii) 铝土矿渣浓度对白杨的萌发、根系发育和结构以及酶活性有显着影响. 与 GUI 残留相比，PRO 残留对每个测量变量具有更强的植物毒性作用。铝土矿残留物的来源强烈调节了毒性作用。石膏应用有效地降低了残留物的植物毒性作用，但仍记录了对不同变量的显着负面影响。