Effects of Different Nitrogen(N)Sources on Cadmium(Cd)Absorption and Accumulation by Rape
The greenhouse pot experiment was adopted to discern the effects of different nitrogen sources on cadmium uptake and accumulation by rape.The results showed that after applying NH4+-N,the Cd con-tent and enrichment coefficient in the aboveground and root parts of rapeseed increased significantly compared to the control.The pH and total Cd content in the rhizosphere of rapeseed decreased significantly compared to the control.The exchangeable Cd content in the rhizosphere of rapeseed increased significantly compared to the control,while the content of insoluble Cd such as carbonate bound and iron manganese bound decreased compared to the control.The decrease in rhizosphere pH could transform insoluble Cd in the rhizosphere into exchangeable Cd,thereby increasing the absorption and accumulation of Cd by the roots.After NO3-N treat-ment,the Cd content decreased,the rhizosphere pH and total Cd content increased,and the exchangeable Cd content decreased compared to the control.However,the carbonate bound and iron manganese bound states increased compared to the control,and the difference was not significant.
Nitrogen sourceCadmium absorptionPH in rhizosphereCadmium morphology