This paper encloses results of field tests carried out on two types of organic soils. Activities of caesium, originating from global fallout as well as from the Chernobyl power plant breakdown, were measured for these two soils. Radioactive caesium is present to a depth of 40 and 70 cm, in black soil and in peat, respectively, although the highest activity was found in the topmost layers. Caesium originating from the Chernobyl accident constitutes about 70% of the total activity in the 0-10 cm layers of the soils. The vertical migration rates of caesium from both sources were also measured. In the case of peat soil, the migration rates of the Chernobyl caesium as well as that from global fallout were found to be similar and amounted to 0.2 cm/year. In the case of black soil, the differences were more pronounced (0.34 and 0.14 cm/year, respectively).
Results of the physico-chemical analysis of both tested soils are also included in this work.