Biogeochemical Cycle and Residue of Extraneous Rare Earth Elements in Agricultural Ecosystem
来源期刊：JOURNAL OF RARE EARTHS2004年第5期
论文作者：王秀丽 丁士明 王立军 梁涛 张朝生 张国梁
Key words：pedology; input and output; cycle and residue; rare earths;
Abstract: Four groups of field experiments including foliage dressing with a regular amount of rare earth elements(REEs),soil dressing with a regular amount of REEs,soil dressing with a triple regular amount of REEs and the control were carried out in Panggezhuang Village,Daxing County,Beijing,where REE fertilizers are widely applied. The input and output fluxes of all kinds of REEs in the soil and plant system were measured using ICP-MS. The results show that the total amount of REEs carried by rain,snow,irrigation water,composite fertilizer and dust is at a very low level in the control field,which is only about 19.3 g·nm-1 per year. The amounts of REE input in the fields with application of extraneous REEs are much higher than that under control. The total amounts of REE input in the fields with foliage dressing and soil dressing are 9.7 and 106 times higher than that under control,respectively. However,the total outputs of REEs via wheat and infiltrated water are quite similar among the four experimental fields. Uptake of wheat is the main way of output and concentrations of REEs in different organs follow a descending order of roots>leaves>stems>crusts>seeds. Based on calculation,the amount of REE output is slightly higher than that of input in the control field,which implies that it is hard for REEs to accumulate in the soils without application of REE fertilizers. In the fields with the application of extraneous REEs,the amount of REEs in soils can increase with the increasing input of REEs. If REE-fertilizers are applied regularly via soil dressing with the ordinary amount,the concentrations of REEs in the surface soils may double in 159 years. The speed of REE accumulation with foliage dressing is much lower than that with soil dressing,and it needs 2008 years to double the concentrations of REEs in surface soils.
王秀丽1，丁士明2，王立军2，梁涛2，张朝生2，张国梁2
(1.Institute of Geology,Chinese Academy of Sciences,Beijing 100029,China;
2.Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China)
Abstract:Four groups of field experiments including foliage dressing with a regular amount of rare earth elements(REEs),soil dressing with a regular amount of REEs,soil dressing with a triple regular amount of REEs and the control were carried out in Panggezhuang Village,Daxing County,Beijing,where REE fertilizers are widely applied. The input and output fluxes of all kinds of REEs in the soil and plant system were measured using ICP-MS. The results show that the total amount of REEs carried by rain,snow,irrigation water,composite fertilizer and dust is at a very low level in the control field,which is only about 19.3 g·nm-1 per year. The amounts of REE input in the fields with application of extraneous REEs are much higher than that under control. The total amounts of REE input in the fields with foliage dressing and soil dressing are 9.7 and 106 times higher than that under control,respectively. However,the total outputs of REEs via wheat and infiltrated water are quite similar among the four experimental fields. Uptake of wheat is the main way of output and concentrations of REEs in different organs follow a descending order of roots>leaves>stems>crusts>seeds. Based on calculation,the amount of REE output is slightly higher than that of input in the control field,which implies that it is hard for REEs to accumulate in the soils without application of REE fertilizers. In the fields with the application of extraneous REEs,the amount of REEs in soils can increase with the increasing input of REEs. If REE-fertilizers are applied regularly via soil dressing with the ordinary amount,the concentrations of REEs in the surface soils may double in 159 years. The speed of REE accumulation with foliage dressing is much lower than that with soil dressing,and it needs 2008 years to double the concentrations of REEs in surface soils.
Key words:pedology; input and output; cycle and residue; rare earths;
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