菌肥及泥炭土浸提液对植物提取土壤Cd的影响

采用温室盆栽试验，研究菌肥和泥炭土浸提液对东南景天生物量、Cd富集特征、土壤Cd有效性和土壤理化性质及对后茬水稻在落干条件下水稻Cd的影响。结果表明，菌肥和泥炭土浸提液均能提高东南景天对土壤重金属的提取效率，其中施用两次液体菌肥的效果最好，东南景天对Cd提取量为0.34 mg·pot^-1，是对照的3.1倍，泥炭土浸提液处理的东南景天Cd提取量为0.32 mg·pot^-1，是对照的2.9倍，这两种处理对Cd的提取率较高，达到13%~15%，土壤全量Cd的降低幅度达到17.55%~20.41%。东南景天收获后种植水稻，落干条件下促进了水稻对Cd的吸收，稻米和茎叶的Cd提取量较对照增幅分别为30.31%~396.24%和12.36%~257.65%，其中在菌肥及泥炭土浸提液联合处理下水稻对Cd的吸收最大，稻米和茎叶的Cd含量分别为2.14 mg·kg^-1和2.88 mg·kg^-1，水稻地上部对Cd总提取率达到3.15%。因此，施用两次菌肥是提高东南景天提取土壤Cd的有效措施，菌肥与泥炭土浸提液联合施用在落干条件下显著强化了水稻对土壤Cd的提取。

Effects of bacterial fertilizer and peat soil extract on soil Cd extracted by plants

A greenhouse pot experiment was used to study the effects of bacterial fertilizer and peat extract solution on the biomass and cadmium enrichment characteristics of Sedum alfredii, the Cd availability and physical and chemical properties of the soil, and the Cd content of the subsequent rice crop under dry conditions. The results showed that, bacterial fertilizer and peat soil extract improved the extraction efficiency of heavy metals from the soil by Sedum alfredii, and applying two liquid bacterial fertilizers had the greatest effect. The amount of Cd extracted by Sedum alfredii was 0.34 mg·pot^-1, which was 2.1 times greater than that of the control, and the amount of Cd extracted by Sedum alfredii treated with peat extract was 0.32 mg·pot^-1, which was 1.9 times greater than that of the control. The phytoextraction rates of Cd were higher for these two treatments, reaching 13%-15%, and the reduction in total soil Cd content ranged from 17.55% to 20.41%. Compared with the control, Cd extraction by rice grains and straw increased by 30.31%-396.24% and 12.36%-257.65%, respectively. Cd uptake by rice was highest under the combined treatment of bacterial fertilizer and peat extract, resulting in a Cd content of 2.14 mg·kg^-1in the rice grains and 2.88 mg·kg^-1 in the straw. The total Cd extraction rate of rice shoots reached 3.15%. Therefore, the double application of microbial fertilizer is an effective measure to enhance the phytoextraction of Cd from the soil by Sedum alfredii, and the combination of microbial fertilizer with peat extract has the potential to promote the phytoextraction of Cd by rice under dry conditions.