Bioavailability of Cadmium to Oil Sunflower after Addition of Organic Acids

doi:10.13522/j.cnki.ggps.2017.04.002

Abstract：Pot experiments grown with oil sunflower were conducted to investigate the impact of citric acid on bioavailability of cadmium.Citric acid at concentrations of 1,2,3,4,5 and 6 mmol/kg was added to the pots 20,30,40,50 d after the sunflowers were planted.The results showed that citric acid enhanced the bioavailability of cadmium.Adding citric acid 20 d and 30 d after the planting was most efficient to increase the bioavailability of cadmium.The accumulation coefficient of cadmiumin the plant under all citric acid treatments was higher than that in the control,peaking by adding 1 mmol/kg citric acid after the plant grew 40 d or 50 d.The transfer coefficient was maximum by adding 4,5 and 6 mmol/kg citric acid after the plant grew 50 d.Organic acids can enhance the movement of cadmium from the below-ground to the above-ground.In conclusion,our results indicated that adding citric acid at concentration of 1,2,3,4,5 and 6 mmol/kg after plant grew 20 d and 30 d,then adding another 1 mmol/kg citric acid when plant was 40 d,and finally adding a further 4～6 mmol/kg citric acid at 50 d considerably improved the uptake of cadmium by oil sunflower.