Abstract:Taking Cd contaminated rice soil as the research object, a pot experiment was conducted to study the effects of various combination application of selenium (Se, 0.5 and 1.0 mg/kg) and fulvic acid (FA, 0.6 and 1.2 g/kg) on the uptake and accumulation of cadmium (Cd) in rice and the mechanism, and to provide a scientific basis for the safe utilization of rice contaminated by Cd. The results showed that single application of Se increased soil pH by 0.08 to 0.23 units, reduced CaCl2 extractable Cd in soil by 8.6% to 20.9%, decreased the concentration of Cd in aboveground organs of rice by 29.4% to 39.5%. Additionally, single application of Se could effectively reduce the accumulation of Cd in rice and inhibited the translocation of Cd to above ground tissues and rice grain. For the treatments applied FA only, soil pH was significantly decreased, while the concentrations of soil CaCl2-Cd, the Cd and Se in rice organs (except the Cd concentration in leaves and brown rice treated with low amount of FA), and the Cd distribution in different organs were not significantly influenced. The effect of combined application of Se and FA on soil pH was related to the dosage of two. High amount of Se combined with FA significantly reduced the CaCl2 extractable Cd in soil by 16.5% to 21.9%. Combined application of Se and FA significantly inhibited the translocation of Cd to aboveground organs and rice grain, and was more effectively in reducing the accumulation of Cd in brown rice. Compare with the control, Cd concentrations of rice in the two treatments applied with high amount of Se combined with FA were significantly decreased by 38.1% and 50.2%, respectively. In conclusion, the application of Se could effectively reduce the accumulation of Cd in brown rice, while the combined application of Se and FA had better effect.