摘要
应用放射性同位素示踪技术研究了１２５Ⅰ在农业生态系统中的行为，包括水稻对１２５Ⅰ的吸收、运输、分配；１２５Ⅰ在土壤中的迁移和水生植物对１２５Ⅰ的吸收、运转、分配，并计算出１２５Ⅰ在土壤中的垂直分布和１２５Ⅰ在水生生态系统中动态变化的数学模型．结果表明：水稻能吸收１２５Ⅰ，并可将吸收到的一半以上运转至地上部；成熟期谷粒中１２５Ⅰ的积累量最低，仅占全株的０１８％；１２５Ⅰ在土柱中迁移２７ｄ后，大部分分布在表层，分布随深度而呈指数规律递减；供试的４种水生植物中，矮慈菇（ＳａｇｉｔａｒｉａｐｙｇｍａｅａＭｉｑ．）对水体中１２５Ⅰ吸收最快，富集系数最大，到试验结束时达８５７９，可用来净化水体中１２５Ⅰ的污染，１２５Ⅰ在水生生态系统中的动态变化符合ｙ＝Ａｅｂｔ变化规律．
he behaviour of 125Ⅰ in agro-ecosystem was studied by using radioisotopes tracer techniques.The studies included the absorpiton of 125Ⅰin rice,the moving of 125Ⅰ in soils of South China sub-tropical region,and the absorption of 125Ⅰ in aquatic plants.In addition,the mathematical models of the vertical distribution of 125Ⅰ in soils and the dynamic variation of 125Ⅰin aquatic ecosystem were calculated.The results showed that:125Ⅰ could be absorbed by rice,and more than half of the absorbed 125Ⅰ could be transfered to the shoot.In mature stage,the accumulation of 125Ⅰin rice grain was the lowest,taking up about 0.18% of the whole plant.Twenty seven days after vertical moving in soil column,the 125Ⅰ was distributed in every layer of the soil column,but most of it remained in the topsoil .The distribution of 125Ⅰ in the soil column decreased with the depth in the way of y=Aebx.The arrowhead (Sagittaria pygmaea Miq)was the fastest in absorbing 125Ⅰamong the four tested aquatic plants.Its concentration factor for 125Ⅰ was the biggest ,being by the end of the test.The dynamic variation of 125Ⅰ in aquatic-ecosystem followed the formula of y=Aebt.
出处
《华南农业大学学报》
CAS
CSCD
北大核心
1998年第2期64-70,共7页
Journal of South China Agricultural University
关键词
碘125
农业生态系统
吸收
分配
迁移
数学模型
125Ⅰ
agro-ecosystem
absorption and distribution
transference
mathematical models
