Effects of Intercropping of Two Ecotypes of Sedum alfredii on Their Plant Growth and Zinc Uptake from Soils

The non-hyperaccumulating ecotype of Sedum alfredii Hance was intercropped with the Zn-hyperaccumulating ecotype to study the effect of different root interaction on their plant growth and Zn uptake by using different barrier separation, no barriers, mesh barriers, and PVC barriers. The results showed that significant differences were observed on the shoot and root biomass, and root Zn concentra- tion in the non-hyperaccumulating ecotype of Sedum alfredii with different extent of rhizosphere interaction. The shoots mass of the non-hyperaccumulating ecotype of Sedum alfredii significantly increased by about 25% compared with the PVC treatment. Compared with the other two treatments, root Zn concentration in the non-hyperaccumulating ecotype and soil NH4COOH extractable Zn concentration increased significantly when the roots of two hyperaccumulating ecotype were divided by mesh barrier, but shoot and root biomass of the non-hyperaccumulating ecotype decreased significantly.