Study on stable isotope ratio of environmental pollutants behavior in agricultural ecosystem

研究非农业领域污染物对农业生产领域的影响是一个非常重要和迫切的研究课题。此外，许多污染物（甲烷、硝酸盐离子等）从农田中泄漏出来。建立消除这些污染物的方法是非常重要的。第一年对同位素比值（^<15>N,^<34>S,^<18>O）的分析技术进行了讨论和研究训练。建立研究点，开展水稻、小麦、豆类等农作物采集、地下水连续采样及离子组分分析、水田甲烷气体爆发机理及酸雨输送过程研究。在第三年对第二年的研究对象进行了更详细的研究。研究摘要如下：(1)硝态氮离子浓度随季节变化，主要取决于化肥用量、作物堆肥用量和宅基地废水用量。(2)亚铁和硫酸铵对稻田甲烷爆发有抑制作用。(3)收集和分析了日本和中国大陆的酸雨。森林雨中硫酸盐离子浓度最高，硫酸盐离子和硝酸盐离子被认为浓度很高。(4)大气中多芳烃的析出量与收集点有关，随距离产生点的远近而逐渐减少。森林雨中多芳烃的降水量高于森林外雨。实践微量同位素比值分析是环境化学污染物示踪研究中一种非常有用的分析方法

Research on influence of pollutants from non agricultural field to agricultural production fields is a very important and urgent research theme. Also, many pollutants breakout from agricultural fields (methane, nitrate ion, etc.). Establishment of a elimination method of these pollutants is very important.Analysis technics of isotope ratio (^<15>N,^<34>S,^<18>O) was discussed and trained as research during the first year. Research sites were set up, collection of agricultural crops (rice, wheat, beans etc.), continuous under ground water sampling and ion components analysis of it, outbreak mechanisms of methane gas from paddy field and transportation process of acid precipitation (acid rain) were researched in the 2nd research year. More detail study on the 2nd year research subjects were done in the 3rd research year. Research abstracts are as follows : (1) Nitrate ion concentration was changeable with seasons, depending on how much of chemical fertilizers is used and composts for crop production and waste water from housing sites. (2) Methane outbreak from paddy field was inhibited with ferrous and ammonium sulfate. (3) Acid rain of Japan and main land China were collected and analyzed. Sulfate ion concentration was most high and sulfate ion and nitrate ion in the forest rain was recognized as having very high concentration. (4) Precipitation amount of polyaromatic hydrocarbons from the atmosphere depended on collection point and these amounts gradually decreased with distance from the generation point. Precipitation amount of polyaromatic hydrocarbon in the forest rain was higher than outside rain of forest.Practiced minuteness isotope ratio analysis is distinctively a very useful analysis method for tracing study of environmental chemical pollutants