青菜-土壤生态系统中氚水的迁移与分布动态  

The Migration and Distribution of Tritium Water in Chinese Cabbage(Brassica chinensis)-Soil Ecosystem

作　　者：史建君[1] 陈晖[2] 

机构地区：[1]浙江大学原子核农业科学研究所农业部核农学重点开放试验室,杭州310029 [2]浙江工程学院信息电子学院,杭州310033

出　　处：《生态学报》2002年第8期1260-1265,共6页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 (3 9870 1 5 0 ) ;浙江省自然科学基金资助项目 (3 980 3 2 )

摘　　要：采用模拟污染物的同位素示踪技术研究了两种引入方式 (模拟灌溉和降雨 )下氚水在青菜 -土壤模拟生态系统中的迁移与分布动态。测定了植物和土壤样品中两种形态氚 (自由水氚和结合态氚 )的比活度。以探明氚水在青菜 -土壤系统中的行为特性、不同引入方式对青菜吸收和积累氚水的影响。结果显示 :引入土壤中的氚水 ,不仅在系统各分室间转移和分配 ,而且迅速向系统外散逸 ;以自由水氚和结合态氚形式存在于青菜组织中 ,以吸湿性水氚和结晶水氚存在于土壤 ,其中自由水氚 (或吸湿性水氚 )远大于结合态氚 (或结晶水氚 ) ;青菜茎中的总氚比活度高于叶和根中的比活度 ;运用示踪动力学分室模型原理对实验数据进行拟合得 :土壤中的比活度 Cs(模拟灌溉 ) =91 .5 9e- 0 .10 0 2 t+99.91 e- 9.110 5t和 Cs(模拟降雨 )= 78.0 9e- 0 .5115t+48.2 7e- 0 .0 4 75t;青菜植株中的比活度 Cv(模拟灌溉 ) =5 43 .5 2 (e- 0 .10 0 2 t-e- 9.110 5t)和 Cv(模拟降雨 ) =647.0 7e- 0 .5115t+2 41 .2 8e- 0 .0 4 75t;方差分析结果表明各回归方程较好地反应了氚水在青菜In this study, tritium water was administered into simulated Chinese cabbage( Brassica chinensis )\|soil system in mode of simulated irrigation and rainfall to study its migration and distribution in each component of the system. The objective of this study are: (1) to evaluate accumulation and distribution of tritium water in Chinese cabbage when treated with different method; (2) to clarify distribution of tritium water in soil profile.\;Four concrete pools with dimensions of 1m×1m×0\^3m were constructed outdoor. Two hundred ninety kg of soil with moisture content of 21 74% was filled into each pool. And soil depth was about 24 cm. Thirty Chinese cabbage seedlings, 8~10 cm in height, were transplanted into each pool. 3200 mL of tritium water with a specific activity of 1 7355×10 4 Bq/mL was introduced into each pool 30 days after transplanted. In two pools, tritium water was sprayed on foliage surface to simulate rainfall; and in the other two pools, it was sprayed on soil surface to simulate irrigation. The samples were collected at the time intervals of 0 25, 1, 3, 7, 14, 21 and 28 days after treatment. Three seedlings were collected from each pool, the roots were rinsed with tap water, and the water remaining on their surface was removed with an absorbent paper. They were divided into root, petiole and foliage. And then they were cut into small pieces after measuring the weight of each part. Twenty grams samples from each part were put into 100ml matrass for free water tritium distilled. In the meantime, three soil columns were collected from each pool with soil sampler. Each soil column was sectioned into three equal parts, each part was pulverized, mixed thoroughly, and then 30 g of soil sample was weighed into 100ml matrass for tritium of hygroscopic distilled. Every sample had 3 replications.\;The free water tritium and tritium of hygroscopic were distilled using constant temperature distillation, And the bound tritium and crystalline water using oxidation burning method. The radioactivity was m

关 键 词：青菜-土壤生态系统 氚水 迁移 分布动态 非线性回归 放射生态 

分 类 号：S181[农业科学—农业基础科学]