| The present thesis discussed the effects of applying coal ash at different level to the meadow brown soil in pot experiments (model experiment and trace experiment)using wheat as an index crop. The study on the migration characteristic of naturally-occurring radionuclid 226Ra and 228Ra from the soil mixed with coal ash to the plant was carried out by means of measuring the specific activity of 226Ra and 22~Ra in the soil and plant using a HPGe y spectrometer analyzer.The results were observed as follows:1.The contents of organic carbon and available phosphorus (P) increased notably as the coal ash was applied .The range of content for organic carbon was 0.71 ~?.93(%) and for available P was 26.1 6~? 1 .39(ppm),while the amount of applying coal ash varied in the range of 0?75t1hm2.2.As the applied coal ash ranged from 0 to 675 t/hm2, the content of available nitrogen (N ) in soil decreased , but pH value increased.The range of content of available N varied from 60.21 to 41 .41(ppm),and pH value of the soil varied in the range of 7.7 1~?.03.3.The plant hight,root weight,grain weight and biological yield increased after applying coal ash at the dosage of 0?50t/hm2. While the applying coal ash reached the level of 675t1hm2,there was a significantly inhibiting effect on the growth of wheat.4.The study of the trace experiment showed that the significant relationships existed between the specific activity of 226Ra and 228Ra in the soil and that of 226Ra and 228Ra in the root, repectively.There were also good relationships existed between the specific activity of 226Ra and 228Ra in soil and that of 226Ra and 228Ra in the grain, respectively.The specific activity of 226Ra and 228Ra in the grain was in one order lower than that of 226Ra and 228Ra in the root.As the specific activity of 226B~ and 228Ra was in the range of 24.80挆387.42BqIKg and 40.82?03.15 Bq/Kg, the range of transfer factor(TF) of 226Ra and 228Ra from soil to root varied from 0.532 to 0.493 and 0.505 to0.208, respectively. At the same time the range of TF value of 226Ra and 228Ra from soil to grain varied from 0.04 1 to 0.O3Oand 0.009 to 0.035, respectively. It was observed that the decreasing order of TF value of 226Ra and 228Ra was root >grain.5.The specific activity of 226~ and 228Ra in soil increased as the amount of coal ash increased and good relationships existed between them, respectively. AfterIIIaPplying coal ash, The "'Ra and "'Ra in soil exiSted mainly in the non-exchangeable form. At the same dosages of coal ash aPplying, the specific activityof exchangeable 22'Ra was higher than that of 22'Ra in soil.6. ln model experiment, with increasing the specific activity of 226Ra and n8Ra in the soil, thespecific activity of 226Ra and 22sRa in the root increased, respectively. A similar trendaPpeared comparing the variation of the specific activity of 226Ra and 228Ra in rootin model experiment with that of the trace experiment as the specific activity of"'Ra and zz'Ra in the soil increased. The sPecific activity of the 22'Ra in the grainand in the root was increased with the variation of that of 22gRa in soil aPplied coalash, while the good relationships existed between them, respectively The 226Raaccumulation in grain was in one order less than that of 22'Ra in root. The resultSof model experiment showed that the range of the TF value of '2'Ra and "'Rafrom the soil to the root was in the range of 0.534~0.325 and 0.56l~0.369,respectively. The range of TF of 226An and 228Ra from soil to grain were0.043~0.020 and 0.0l0~0.05l, respectively. It was also observed that thedecreasing order of TF value of 226Ra and 22sRa was root>grain. ms observationwas similar tO the results in the trace experimeni.7. The TF value of 226Ra and 228Ra from soil to the whole plant(wheat) was in therange of 0.081~0.06l and 0.082ro. l16, respectively in the model experiment,andthe range was 0.082ro.064 for 22'Ra and 0.073ro.053 for "'Ra, respectively in thetrace experiment. ln addition, the...
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