Effect of amorphous silicon dioxide of the behaviour of cadmium in the soil-rice plant system

Abstract

In field trials, the effect of amorphous silicon dioxide on the behavior of Cd in the soil- plant system in low Cd-contaminated flooded paddy soil was studied. The application of amorphous SiO2 resulted in 1,3—1,8 times reduced accumulation of Cd by aboveground organs of rice and 1,8—2,6 times reduced mobile forms of Cd in the soil, which can be explained by Cd sorption on the surface of applied silica or/and the interaction between Cd and monosilicic acid formed as a result of dissolution of SiO₂. Reduction in the Cd mobility was more pronounced within first 2 weeks after SiO₂ application. Amorphous silica increased rice yield by 26,6% in the first season and by 72,9% in the second season. The data received evidences the possibility to decrease the conventional mineral fertilizers application rates without risk of yield reduction by using Si-rich materials. They should become an integral and important part of the implementation of the 4R-STRATEGY of fertilizer application and plant nutrition optimization.