东南景天与不同植物混作对土壤重金属吸收的影响

将超富集东南景天(Sedum alfredii)与具有不同根系特征的玉米、黑麦草、大豆混作在受Zn、Cd、Pb污染的土壤中,研究不同组别的混作对重金属吸收的效果.结果表明,在本试验条件下,与玉米和大豆的混作显著地提高了东南景天地上部分对Zn的吸收,由单种的15345mg/kg分别增至18673,17266mg/kg;与黑麦草的混作没有显著影响东南景天对3种重金属的吸收.混作后显著地降低了玉米和黑麦草对Cd和Zn的吸收.结合生物量的增加,与玉米和大豆混作处理中东南景天地上部3种重金属的吸收总量(按半盆计)分别约为单种的1.68~1.87倍,说明通过混作可提高超富集植物对重金属的吸收.

Effect of co-cropping Sedum alfredii with different plants on metal uptake

Plants with different root system such as maize, ryegrass and soybean were respectively co-cropped with Sedum alfredii, a Cd and Zn hyperaccumulator, in a pot experiment with heavy metal contaminated soil, aiming to investigate the effect of different combined system on metal uptake by the two co-cropped plants. Under the conditions of the pot experiment, co-crop with maize and soybean increased Zn uptake by S. alfredii from 15345mg/kg for mono-crop to 18673, 17266mg/kg, respectively for the two co-crops. Co-crop with ryegrass had no significant effect on Cd, Pb and Zn uptake by S. alfredii. Co-crop with S. alfredii significantly decreased Cd and Zn uptake by maize and ryegrass. Considering with biomass production, Cd/Pb/Zn total uptake (per half pot) by the hyperaccumulator co-cropped with maize and soybean was 1.68~1.87 times of that mono-crop. The metal uptake by the hyperaccu- mulator can be improved by co-cropping.