Abstract: Based on the investigation of selenium (Se) bioavailability in some Chinese typical areas, transformation processes of Se speciation and fractions in soil were systematically studied, and their effects on bioavailability were clarified. The factors affecting the bioavailability of Se in soil-plant system were discussed, including the speciation of Se, soil properties, plant types and varieties. A method for determination of Se fractions and valences was set up. The differences of chemical extracting method and diffusive gradients in thin-films (DGT) for determination bioavailability of Se in soil were also compared. Finally, this paper made a forecast of the future development for related researches.

Key words: soil, selenium, fractions transformation, bioavailability, plant

摘要： 在对一些典型地区环境硒调研的基础上，系统研究了硒在土壤中形态和价态转化，探讨了硒在土壤固液相中的分配及其与土壤性质的关系；明确了土壤中硒的转化对其生物有效性的影响；系统归纳了硒的形态、土壤性质、植物的品种和种类等影响硒有效性的因素；建立了将形态和价态相结合的土壤硒形态测定方法，并对测定硒有效性的化学浸提法和梯度扩散薄膜技术（DGT）进行了比较。最后，提出了相关研究未来的发展方向。

关键词: 土壤, 硒, 形态转化, 生物有效性, 植物