Effect of plant intercropping system on remediation of cadmium contaminated farmland soil—A case study on the southern Jiangsu province area
In the study,soybean(Glycine max(L.)Merr.),rape(Brassica napus L.)and wheat(Triticum aestivum L.)were used as the subjects,intercropped with Cd hyperaccumulators,i.e.Sedum plumbizincicola,Sedum alfredii,Amaranthus tricolor L.and Solanum nigrum L.,to investigate the remediation effects of various intercropping patterns on Cd polluted farmland soil in southern Jiangsu Province.The findings revealed that intercropping with rape,the Cd concentrations in the hyperaccumulator plants were enhanced,among which Sedum alfredii increased the most,and the Cd concentrations in aboveground parts increased by 24.4％compared with monoculture.After intercropping with wheat,Cd concentration in Sedum alfredii was increased,the Cd concentrations in aboveground parts increased by 2.75％compared with monoculture,but the Cd concentrations of Solanum nigrum and Amaranthus tricolor did not change significantly,indicating that intercropping with rape or wheat could promote the absorption of Cd by Sedum alfredii.Intercropping with Sedum alfredii decreased the Cd concentration in soybean roots,and intercropping with Amaranthus tricolor and Solanum nigrum significantly decreased the Cd concentration in soybean stems and leaves.Under the intercropping mode,the Cd concentration of rape roots and stems decreased significantly,and the Cd concentration of leaves was not significantly affected by intercropping.Intercropping significantly reduced the Cd concentration of wheat,suggesting that intercropping could inhibit the absorption of Cd by crops.The total accumulation of Cd and the removal rate of Cd in soil under Sedum alfredii-rape model were the highest,which were 1343μg/pot and 16.4％.Sedum alfredii-wheat was the second,with 1053μg/pot and 9.8％.In summary,the intercropping pattern of Sedum alfredii-Brassica napus/Triticum aestivum were the suitable model.This study screens out a plant intercropping remediation model suitable for Cd-contaminated farmland soil in southern Jiangsu province area and provide technical support for both safe production and remediation of Cd-contaminated farmland soil in the region.
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