对大宝山矿区周边酸性多金属污染农田土壤进行了5年的红麻原位种植试验,研究不同改良剂对土壤改良的持效性及其对红麻生长的影响,以探索具重金属耐性的经济作物红麻用于重金属污染土壤大田复垦的可行性和有效性.结果表明:施加改良剂后,红麻能在重金属Pb、Zn、Cu、Cd和As含量分别为1600、440、640、7.6和850mg·kg-1的土壤上定植.其中,白云石和粉煤灰的改良效果优于石灰石和有机肥.施加白云石或粉煤灰后,红麻地上部产量(干质量)为14~15t·hm-2,达到一般农田产量水平,且红麻杆和红麻皮中重金属含量显著降低.红麻韧皮纤维(麻皮)含量达到32%~38%,韧皮纤维中可萃取重金属含量低于《生态纺织品技术要求》的标准,具有潜在的经济效益.白云石/粉煤灰改良红麻复垦的化学-植物联合修复模式是复垦酸性多金属污染农田土壤的有效措施.
A five-year field trial was conducted at the surrounding area of Dabao Mountain Mine to explore the feasibility and availability of using kenaf ( Hibiscus cannabinus), a fiber crop with strong heavy metals tolerance and potential economic value, to reclaim the multi-metal contaminated acidic farmland soil. Different amendments were applied prior to the kenaf planting to evaluate their effects on the soil properties and kenaf growth . After the amendments application, the kenaf could grow well on the heavy metals contaminated soil with the Pb, Zn, Cu, Cd, and As concentrations being 1600, 440,640, 7.6, and 850 mg . kg-1 , respectively. Among the amendments, dolomite and fly ash had better effects than limestone and organic fertilizer. With the application of dolomite and fly ash, the aboveground dry mass production of kenaf reached 14-15 t . hm-2, which was similar to that on normal soils, and the heavy metal concentrations in the bast fiber and stem of kenaf de- creased significantly, as compared with the control. The mass of the bast fiber accounted for 32% - 38% of the shoot production, and the extractable heavy metal concentrations in the bast fiber could meet the standard of ' technical specifications of ecological textiles' in China, suggesting that the bast fiber had potential economic value. It was suggested that planting kenaf combining with dolo- mite/fly ash application could be an effective measure to reclaim the multi-metal contaminated acid- ic farmland soil.