污泥堆肥对园林植物合果芋(Syngonium podophyllum)生长及重金属吸收累积的影响

Effects of sewage sludge compost on the growth and heavy metal accumulation in landscape plant Syngonium podophyllum

采用盆栽试验探究污泥堆肥施用量对园林植物合果芋(Syngonium podophyllum)生长及重金属积累的影响,以期为污泥堆肥的园林利用提供参考依据。结果表明:污泥堆肥施用比例≥30%时,显著促进合果芋的株高生长和生物量积累;在纯污泥条件下,合果芋的N、P和K吸收量和重金属Cu、Zn、Pb和Cd的积累量均达到最大值;污泥堆肥施用量对合果芋的重金属富集和转移系数有显著影响,合果芋对Cu、Zn和Pb的富集和转移能力相比Cd较弱;当污泥施用量≤30%时,合果芋地上部、地下部对Cd的富集系数均大于1,有望成为污泥园林利用过程中Cd提取的有效候选植物;总体来看,合果芋对重金属的富集系数大小表现为Cd>Zn>Cu>Pb,与重金属污染程度排名一致;合果芋对污泥堆肥有较好的适应性和耐重金属能力,施用30%污泥堆肥既促进合果芋生长又降低土壤重金属污染的风险。

We investigated the impacts of application rates of sewage sludge compost（ SSC） on the growth and capacity of heavy metal accumulation in Syngonium podophyllum with a pot experiment,with the aim to provide a reference of SSC application in landscape construction. The results showed that the plant height growth and biomass accumulation were significantly increased under proportions of SSC to substrates ≥30%. The maximum accumulation of N,P,K,Cu,Zn,Pb and Cd in S. podophyllum occurred in the treatment of 100% SSC. The application rate of SSC had significant effects on the bioaccumulation factor（ BAF） and translocation factor（ TF） of heavy metals in S. podophyllum. Accumulation and transfer capacity of S. podophyllum for Cu,Zn,Pb were lower than those for Cd. When the application rate of SSC was ≤30%,the BAF of Cd in both aboveground and belowground parts of S. podophyllum were above 1,suggesting that S. podophyllum would be an ideal candidate for Cd extraction when SSC is used as garden fertilizer. In summary,BAFs for heavy metals in S. podophyllum ranked as Cd 〉 Zn 〉 Cu 〉 Pb,which was consistent with the heavy metal concentrations in the substrate. S. podophyllum showed good adaptation to SSC and resistance to heavy metals. The application rate of 30% not only promoted the growth of S. podophyllum,but also reduced the risk of heavy metal contamination in soil.