On Absorption and Distribution of Sr-90 by Lowland Rice and Wheat Plants

[摘要] 1). Lowland rice plants grown on the soil applied with labeled Sr absorbed until their middle stage of spike differentiation 92.2 percent of the element of the total amount absorbed till the harvest time the quantities being denoted in counts per minute. The absorbed Sr-90 was distributed in the ratio of 38.4 % in the roots, 41.8 % in the culm and 19.8 % in the spike. Sr-90 adsorbed by soil colloid micelle which was extracted with 1 N-KCl solution amounted from 10 to 20 times of that free in the soil being extracted with pure water. 2). Absorptin of Sr-90 by wheat plants was also studied Sr-90 being administered into the nutrient solution was mostly absorbed by the wheat plant until its middle stage of spike dfferentiation. The absorbed ratios for root, culm and spike were similar respectively to the above mentioned absorbing ratios in lowland rice, as shown in the diagram. With a higher concentration of Sr-90 in the nutrient solution in exchange of that of calcium, an increase in the absorption of the former was observed. Frow those results, the present authors consider that Sr-90 is absorbed distinctively in the edible fraction of those crops, without regards to comparatively increased supply of calcium in the nutrient solution, and recognize that labeled strontium woulld become one of the most important contaminating isotope in soil

[学科分类] 农业科学（综合）