Effects Of N,P,K On The Absorption And Transfer Of Strontium From Cichoriumintybus L.

As a fission product of uranium,strontium exists widely in radionuclide contaminated area,and seriously threaten the natural environment and people's life.The plants remediating the soil contaminated by radionuclide were screened,and chelating agents were used to improve the efficiency of phytoremediation.However,few studies have been conducted on the use of nitrogen,phosphorus and potassium fertilizers to improve phytoremediation efficiency.The purpose of this study is to explore effects of N,P,K on the absorption and transfer s of Sr from the chicory,and to provide a scientific fertilization method to improve the efficiency of phytoremediation on the Sr contaminated area.The study used pot experiment method with 2 kg dry soil per pot,set up three Sr concentrations 50,150,250 mg/kg^-1,four fertilization concentrations 0,50,150,250mg/kg^-1under each Sr concentration and 0 mg/kg^-1was the control group,three repeats per treatment.This study was designed to study the influence of different types and dosages of fertilizer on the photosynthesis,dry weight,absorption and transfers of Sr from the seedling,the first regenerate plantlets and the second regenerate plantlets.The study shows:?1?Different types and dosages of N,P,K had different biological effects on chicory in Sr polluted soil.Averaged three Sr concentrations,compared with CK,N 250mg/kg^-1greatly increased the F_v/F_m of seedlings,meanwhile others increased less or reduced.Compared with CK,N,P,K significantly improved the dry weight of seedlings,especially when used N 150mg/kg^-1.N had a significantly effect on the dry weight of the first regenerate plantlets and the second regenerate plantlets,especially under the 250mg/kg^-1concentration.P had less effect on the dry weight of the first regenerate plantlets,but it affected the second regenerate plantlets enormously.The dry weight had been rarely increased or reduced under K.?2?N,P,K had different effects on the Sr content and accumulation of seedlings under different Sr concentrations.Under 50mg/kg^-1Sr concentration,N 250mg/kg^-1showed the highest content andaccumulation of Sr in the seedlings;under 150mg/kg^-1Sr concentration,N 250mg/kg^-1showed the highest content and the N150mg/kg^-1showed the highest accumulation of Sr in the seedlings;under 250mg/kg^-1Sr concentration,N 250mg/kg^-1showed the highest content and accumulation of Sr in the seedlings.Averaged three Sr concentrations,compared with CK,N 50mg/kg^-1made the Sr content of seedlings increase by 10.5%,the accumulation increase by 84.5% under N 250mg/kg^-1.?3?The first regenerate plantlets had different reactions on Sr content and accumulation.Under 50mg/kg^-1Sr concentration,N 150mg/kg^-1showed the highest content and the N250mg/kg^-1showed the highest accumulation of Sr in the first regenerate plantlets;under 150mg/kg^-1Sr concentration,N 150mg/kg^-1showed the highest content and accumulation of Sr in the first regenerate plantlets;under 250mg/kg^-1Sr concentration,N 250mg/kg^-1showed the highest content and accumulation of Sr in the first regenerate plantlets.Averaged three Sr concentrations,compared with CK,N 150mg/kg^-1made the Sr content of the first regenerate plantlets increase by 38.7%,the accumulation increase by 110.5% under N250mg/kg^-1.?4?The second regenerate plantlets showed different reactions to N,P,K under different Sr concentrations.Under 50mg/kg^-1and 150mg/kg^-1Sr concentration,N250mg/kg^-1showed the highest content and accumulation of Sr in the second regenerate plantlets;under 250mg/kg^-1Sr concentration,N 150mg/kg^-1showed the highest content and N250 showed the highest accumulation of Sr in the second regenerate plantlets.Averaged three Sr concentrations,compared with CK,N 250mg/kg^-1made the Sr content and accumulation of the second regenerate plantlets increase by 15.7%,46.8%respectively.In Sr polluted soil,N,P,K had different effects on the absorption and accumulation of the seedlings,the first regenerate plantlets and the second regenerate plantlets,so we should pay more attention to the types and dosages of fertilizer which could highly improve the remediation efficiency.In terms of the content of Sr in the seedlings and regenerate seedlings,the study showed that the seedlings >the first regenerate plantlets>the second regenerate plantlets;after N,P,K had been used,the promoting effect were N>K>P.In the terms of the accumulation of Sr in the seedlings andregenerate seedlings,the effects of N,P,K on the leaf and whole plant were N>P>K.Therefore,N could promote the remediation efficiency of seedlings and regenerate seedlings in the Sr contaminated soil.