Investigation On Agronomic And Microbial Enhancement Of Cd And Pb Phytoextraction From Soil By Sedum Alfredii H And The Technology Mode

In present study,pot and field experiments were conducted to investigate on agronomic and microbial enhamcement of phytoextraction for Cd and Pb from soils by the hyperaccumlator Sedum alfredii Hance.The comparative study on the phytoextraction efficiency of Cd and Pb by different formula organic fertilizers under different contamination levels indicated that application of organic fertilizer with WDRA had the most significant effect on the increase of biomass and Cd and Pb accumulation in S.alfredii Hance.1%doage of WDRA formula organic fertilizer could increase the Cd and Pb extraction amount of S.alfredii by 62.3%-141.7%and 55.1%-118.2%,respectively,and the effect was significantly better than common commercial organic fertilizer.Further analysis showed that this effect was probably associated with biomass increase of S.alfredii.Under field condition,highest increasing of Cd and Pb accumulation by S.alfedii was noted by applying endophytes SaMR12 at plant density of 300,000 plants per hectare.Compared to the treatment without spraying,the extraction amount of Cd and Pb were increased by 63.22%and 29.09%in enhanced treament,respectively.Further analysis showed that SaMR 12 significantly improved the extraction efficiency of heavy metals mainly by increasing the biomass and heavy metal concentration in aboveground part of S.alfredii.Compared with the remediation effect of the agronomic and microbial combination intensification technology model in two field experiments,it was found that the efficiency of Cd and Pb extraction by S.alfredii was the highest in Quzhou when combined formula organic fertilizer application with foliar spay of endophyte.After one season of S.alfredii remediation,around 365.65g of Cd and 69.90g of Pb per hectare could be removed from soils under intensive treatment in the Quzhou,which was increased by 136.84%and 104.31%compared to conventional treatment.At the same time,the extraction efficiency of Cd and Pb in Xinchang was also significantly improved.The results of this study have certain guiding significance for the remediation of Cd and Pb contaminated soil by S.alfredii under field conditions.