Underground Migration of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ Deposited during the Growth of Major Crop Plants

주요 작물의 생육중에 침적한 $^{54}Mn,\;^{60}Co,\;^{85}Sr,\;^{137}Cs$ 의 지하이동

  • Published : 1996.03.30


Underground migration of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ in paddy and upland conditions was studied through two years' greenhouse experiment. At early and late growth stages of rice, soybean, Chinese cabbage and radish, a mixed solution of the radionuclides was applied to the water or soil surfaces of the culture boxes filled with an acidic loamy-sandy soil for the upper 20cm. Soil was sampled in layers upto $15{\sim}20cm$ down after harvest. Soil concentrations of the radionuclides decreased exponentially with increasing soil depth and more than 80% of the radioactivities remained in top $3{\sim}4cm$. The mobility of the radionuclides decreased in the order of $^{85}Sr>^{54}Mn>^{60}Co{\geq}^{137}Cs$. Downward migrations of the radionuclides were the greatest in rice soil and the lowest in soybean soil which was fertilized with the least amount of N, P and K. Differences in depth profiles between two application times indicate that the amount of daily migration from $0{\sim}1cm$ layer to the lower area decreases with increasing time after deposition. By a simultaneous addition of KCl and lime following the earlier application, downward migration in soybean, Chinese cabbage and radish soils changed little or retarded more or less but that in rice soil accelerated a little.