| 土壤酸度对稀土元素在小麦体内的生物可利用性及分馏效应的影响 |
| 摘要点击 2449 全文点击 2148 投稿时间：2000-11-03 修订日期：2001-02-15 |
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| 中文关键词 土壤酸度 稀土元素 生物可利用性 分馏效应 |
| 英文关键词 soil pH value rare earth elements(REEs) bioavailability fractionation |
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| 中文摘要 |
| 采用盆栽实验,研究了土壤酸度对稀土元素在小麦体内的生物可利用性及分馏效应的影响.结果表明:小麦体内稀土含量与pH之间呈二次方程的关系,在实验pH范围内,随pH值升高小麦体内稀土含量逐渐降低,每种稀土含量随pH变化程度表现为:Ce>La>Nd>Sm>Gd>Yb>Tb>Eu,表明Ce对pH值更为敏感,Eu最小.土壤中3种稀土形态的含量顺序为B2(NH2OHHCl提取态)>B3(H2O2-NH4Ac提取态)>B1(HAc提取态),随着酸度的降低,B1有向B2、B3转化的趋势.线性回归和多元逐步回归分析表明不同形态的稀土对小麦吸收的贡献程度因单个稀土元素的不同而不同,但B1态是主要的生物可利用态.小麦体内轻重稀土之间分馏系数与pH值呈负线性相关,土壤酸度越大,分馏系数越大. |
| 英文摘要 |
| The effect of soil pH value on the bioavailability and fractionation of rare earth elements (REEs) in wheat seedling ( Triticum aestivum L.) were investigated. The results showed that the concentration of REEs in wheat decreased with increasing pH value, and their inter relationship was best expressed as quadratic equation, with correlation coefficients from 0.6003 to 0.9572. The response of individual elements to pH value change tended to be Ce>La>Nd>Sm> Gd>Yb>Eu, with Ce most sensitive to changing pH conditions and Eu lest. Chemical fractionation indicated that the order of REEs concentration in three fractions could be as follows: B2(NH2OH·HCl extraction)>B3(H2O2 NH4Ac extract)>B1(HAc extract). The increase of pH value resulted in transformation from B1 to B2 and B3. Multiple regression analysis was utilized to obtain the regression equations for prediction plant uptake of REEs. B1 fraction was most available to wheat. Meanwhile, it was found that the fractionation factors of REEs in wheat were negatively correlated with the soil pH value. |
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