[Intercropping Arundo donax with Woody Plants to Remediate Heavy Metal-Contaminated Soil].

A greenhouse experiment was conducted to study the potential of intercropping Arundo donax with Broussonetia papyrifera or Morus alba to remediate heavy metal-contaminated soil. The results showed that intercropping the herbaceous plant A. donax with woody plants B. papyrifera or M. alba was beneficial for plant growth on heavy metal-contaminated soil. This can effectively enhance the comprehensive enrichment capacity of heavy metals and improve soil enzyme activities. The photosynthetic pigment contents in the leaves of A. donax, B. papyrifera, and M. alba decreased along with remediation time under monoculture treatment for each plant. However, compared with 90 d cultivation, the chlorophyll-a and carotenoid contents in B. papyrifera leaves and chlorophyll-b and carotenoid contents in M. alba leaves under intercropping treatment after 270 d cultivation were only slightly changed. Furthermore, chlorophyll-a, chlorophyll-b, and carotenoid contents in M. alba leaves under intercropping treatment were significantly (P<0.05) increased by 99.1%, 177.1%, and 119.9%, respectively, compared with monoculture-treated M. alba, and the total biomass of M. alba increased significantly (P<0.05) by 26.1%. Compared with monoculture-treated A. donax, the total accumulation amounts of Pb and Zn in the shoots of combined plants was significantly (P<0.05) enhanced by 171% and 124% under intercropping treatment of A. donax with B. papyrifera. Compared with monoculture-treated M. alba and A. donax, the total accumulation amounts of As and Pb in the shoots of intercropped plants were significantly (P<0.05) enhanced by 150% and 76.5%, respectively, under intercropping treatment of A. donax with M. alba. Moreover, the fractions of As, Cd, Pb, and Zn in contaminated soil slightly changed under intercropping treatment of A. donax with B. papyrifera or M. alba, and soil urease, acid phosphatase, and total phosphatase activity was superior to part of the monoculture treatments after 270 d cultivation. The results further suggested that intercropping A. donax with B. papyrifera or M. alba could be effectively used for heavy metal-contaminated soil remediation, while simultaneously improving the biological quality in contaminated soil.