摘要
采用同位素示踪技术研究了土壤-青菜生态系统中125I的生物地球化学迁移与转化机制,并运用箱式模型分析了125I的动态变化。研究结果表明,引入土壤的125I随深度而衰减,绝大部分滞留在土壤0～10cm表层内,125I的滞留量与土壤质地有关;青菜通过根部能很快吸收土壤中的125I,并可将大部分转运至地上部分,青菜各部位125I的富集系数为根>茎>叶柄>叶,嫩叶中富集的125I明显大于老叶;土壤和青菜中125I的动态分布服从指数变化方程,土壤和青菜中的碘可以相向迁移,青菜中碘的积累量即为土壤和青菜中碘迁移量的差值。
The behavior of biogeochemical transportation and translation of ^125Ⅰ in soil-Chinese cabbage ecosystem was studied by using isotope-tracer techniques, and the dynamic transformation of ^125Ⅰ was analyzed by application of model-box method. The results show that most of ^125Ⅰ concentrated in surface layer （0 - 10 cm from surface）, and decreased rapidly with depth due to precipitation. The content of ^125Ⅰ in the soil related to the character of the soil. ^125Ⅰ could be absorbed rapidly by Chinese cabbage root and most of the absorbed ^125Ⅰ was transported to the shoot. The enrichment factor of ^125Ⅰ in different tissue types ranks as root 〉 stem 〉 petiole 〉 leaf. The ^125Ⅰ taken up from surface soil concentrated more in the tender leaf than in the old leaf. The dynamic distribution of concentration of ^125Ⅰ in the soil-crop ecosystem can be described successfiffiy using exponential equation. ^125Ⅰ in each compartment could move to each other and the content of ^125Ⅰ in crop was the difference of transportation.
出处
《地球化学》
CAS
CSCD
北大核心
2007年第5期525-532,共8页
Geochimica
基金
国家自然科学基金(40373043)
