Vázquez S, Carpena R O, Bernal M P
Department of Agricultural Chemistry, Facultad de Ciencias, Universidad Autónoma de Madrid, Ctra Colmenar Km 15, 28049 Madrid, Spain.
Environ Pollut. 2008 Mar;152(2):373-9. doi: 10.1016/j.envpol.2007.06.018. Epub 2007 Jul 25.
White lupin (Lupinus albus L.) is an annual crop that has been used for phytostabilization of acidified multi-contaminated soils. Once the culture cycle is over, after shoot harvesting, a progressive transference of contaminants from roots to soil may take place as decomposition of roots occurs. An incubation experiment with Cu, Zn, Cd, and As-loaded roots of white lupin and soils with different pH values and concentrations of these contaminants from the area affected by a mine spill at Aznalcóllar (near Seville, Spain) was performed in order to assess the effect of the decomposition of the roots to the pH and (NH4)2SO4-extractable levels of these pollutants in the soils. Pollutants loaded-roots were mineralized (56 d) at a ratio similar to animal manures (15.8-19.4% of total organic carbon) in soil. The estimated root inputs of contaminants in comparison to their extractable concentrations in soil were high, especially in the control, non-contaminated and neutral contaminated soils. However, the extractable concentrations of the toxic elements in the soil were mainly governed by soil pH. Hence, the correction and maintenance of the soil pH within the range 5-6 after lupin culture is essential for long-time phytostabilization of acidified multi-contaminated soils.
白羽扇豆（Lupinus albus L.）是一种一年生作物，已被用于酸化多污染土壤的植物稳定修复。一旦种植周期结束，在地上部分收获后，随着根系的分解，污染物可能会从根系逐渐转移到土壤中。开展了一项培养试验，使用来自西班牙塞维利亚附近阿兹纳科利亚尔一处受矿渣泄漏影响地区、负载铜、锌、镉和砷的白羽扇豆根系，以及不同pH值和这些污染物浓度的土壤，以评估根系分解对土壤中这些污染物的pH值和硫酸铵可提取水平的影响。负载污染物的根系在土壤中以与动物粪便相似的比例（占总有机碳的15.8 - 19.4%）进行矿化（56天）。与土壤中可提取浓度相比，估计的根系污染物输入量很高，尤其是在对照、未受污染和轻度污染的土壤中。然而，土壤中有毒元素的可提取浓度主要受土壤pH值的控制。因此，在白羽扇豆种植后将土壤pH值校正并维持在5 - 6的范围内，对于酸化多污染土壤的长期植物稳定修复至关重要。
