农业生态系统中同位素示踪技术及发展趋势

在土壤侵蚀研究中，^137Cs、^210Pb和^7Be示踪技术已得到广泛应用，^210Pb主要用在沉积速率的测定及沉积年代的示踪研究上，^137Cs特别适用于大面积的水土流失普查和土壤侵蚀普查，^7Be用于短期内土壤侵蚀研究。在土壤肥效和植物营养元素研究中，常用^13C、^32P和^15N及其化合物示踪定量评价土壤养分，追踪植物对养分的吸收、运转、分配和代谢过程。在环境污染方面，用重金属如Pb、Hg、Cd、Zn等元素的同位素判别污染物质来源，研究污染历史和污染元素在土-水-气-植物中的迁移转化以及在动物有机体内的迁移累积。文章综述了同位素示踪技术在上述方面的应用现状和发展趋势。

The application of isotopic tracing technology to agricultural ecosystem

The method of isotopic tracing is characterized by its peculiar ability to trace, high sensitivity and simple detective means, so it has been used in several fields widely. In soil erosion, 210Pb is mostly applied in measuring the velocity of sediment and its period, 137Cs is applied in surveying soil erosion on a large scale, while 7Be in researching soil erosion in a short period. In fertility of soil and the distribution of nutrient in the soil-plant system, 13C, 32P, 15N and their compounds are applied in evaluating the soil nutrient quantitatively and tracing its adsorption, transfer, and distribution in plant. In environment pollution, some heavy metal isotopes, such as Pb, Hg, Cd, and Zn, are applied in the judgement of pollutant sources, tracing the contaminative history, the removal and transfer of pollutant in the soil-water-air-plan system, the transfer and accumulation of pollutant in animals. The article summed isotopic tracing characteristics, and reviewed its applied progress and tendency in above-mentioned fields.