水稻에 對한 cadmium化合物의 形態에 따른 被害濃度 및 cadmium 吸收程度를 究明하기 爲하여 Cd(NO₃)₂, CdCl₂, CdSO₄, CdCO₃ 및 CdS 等의 化合物을 土壤에 Cd로서 0, 5, 10, 25, 50ppm 處理하여 水稻의 收量에 미치는 濃度와 水稻體中의 cadmium 含量을 調査한 바 그 結果는 다음과 같다. 1) 土壤中 cadmium 處理濃度가 높을수록 植物體 莖葉 및 玄米中 cadmium 含量은 增加하였으나 收量은 높은 濃度에서 減小되었다. 2) 收量減收를 가져오는 土壤中 Cd의 濃度는 Cd (NO₃)₂ : 12.9ppm, CdSO₄ : 21.5ppm, CdCl₂ : 25.8ppm CdCO₃ : 33.2 ppm, CdS : 97.6 ppm 이었다. 3) 玄米中 cadmium 含量이 1.0ppm이 되는 土壤中 Cd의 濃度는 cd(NO₃)₂ : 13.8ppm, CdCl₂ : 14.4ppm, CdCO₄ : 16.9ppm, CdDO₃ : 19.2ppm이었다. 4) cadmium의 玄米吸收量/地上部吸收量比는 最高 分蘖期 28%, 幼穗形成期 20%, 收穫期 15%이었다. 5) 幼穗形成期 植物體 莖葉中 cadmium 含量과 玄米中 cadmium 含量과의 關係는 Y=0.067-0.0028χ+0.007χ²으로 高度의 有意性이 있었다. 6) 溶解度가 낮은 cadmium 化合物이 試驗後 土壤中 可溶性 cadmium 合量이 낮았다.

A pot experiment was conducted to clarify the Cd uptake and levels affecting yield loss according to the growth stages of rice plant. The cadmium was treated with several Cd compounds Cd (NO₃)₂, CdCl₂, CdSO₄, CdCO₃ and CdS at various concentrations of 0,5,10,25, and 50 ppm in soils. The increasing rate of Cd compounds applied to soils increased the Cd content in plant as well as grains but the yield was decreased at high cadmium levels. Cd concentration in soil which could affect the yield decrease were 12.9 ppm for Cd(NO₃)₂; 21.5 ppm, CdSO₄; 25.8 ppm, CdCl₂; 33.2 ppm, CdCO₃; and 97.6 ppm, CdS respectively. Cd concentration in soil reaching at 1 ppm of Cd content in brown rice were 13.8 ppm from Cd(NO₃)₂; 14.4 ppm, CdCl₂; 16.9 ppm, CdSO₄; and 19.2 ppm, CdCO₃, respectively. Cd content in brown rice could be expected with the Cd content in plant at panicle formation stage.