Study of Caesium Uptake and its Interaction Effect with Potassium in Corn and Potato

137Cs is one of the products of nuclear fission. Due to its energetic gamma-ray emission along with the decay and long half-life, it is one of the most important environmental radionuclides. Transfer of radionuclides from air, soil and freshwater to the foodchain of the mankind will endanger the human health. Potassium, as an essential macronutrient for plants due to the similarity of its hydrated radius to that of the caesium, has the similar behavior in soil and plant. So, in this study, the relationship between caesium and potassium in soil and plant and the ability of caesium uptake was investigated. A pot experiment in a factorial design, based on randomized complete block, was performed with two plant species; Dent corn (Zea mays L. var. indentata), Akbari potato (Solanum Tuberosum), 3 levels of 133Cs (0, 17 and 34 mgkg-1 of soil from caesium nitrate) and 3 levels of potassium (0, 22.5 and 45 mgkg-1 of soil from potassium sulfate), containing 6kg soil per pot with three repeats. The results showed that the effects of the plant species, caesium and potassium treatments are significant (P<0.01). The average amount of caesium in corn and potato were, respectively, 29.55 and 9.15 mgkg-1 dry matter. By increasing the amount of caesium to 17 and 34 mgkg-1 of soil, increased the plant's absorption of caesium by 227% and 537%, respectively, compared with the controlled one. The interaction effect of caesium and potassium treatments in the amount of caesium of the plant was significant (P<0.01). The results showed that the increase of the potassium in excess of the plantsʼ need in 22.5 and 45 mgkg-1 of soil, the treatment of potassium has reduced the caesium uptake by 53% and 37%, respectively, compared with the controlled one.