DEPTH DISTRIBUTION OF ^sup 137^Cs IN ANTHROSOL FROM THE EXPERIMENTAL FIELD "RADMILOVAC" NEAR BELGRADE, SERBIA

Abstract This is a preliminary study of the depth distribution of 137Cs radionuclides in cultivated anthrosol soil of a 15-year old peach tree plantation at the experimental field "Radmilovac" near Belgrade. Before planting, the soil was ploughed at the depth of 1 m. The soil had not been annually ploughed, irrigated and treated with mineral fertilizers for three years before sampling. Activity concentration for 137Cs ranged from 1.8 Bq kg-1 to 35 Bq kg-1. Along the soil depth it varied highly, reaching as high a total variation coefficient as 83 %. Radiocaesium distribution patterns depended on the extent of soil mixing in the plough layer, as it was mechanically transferred from the surface to the lower soil layers during cultivation. 137Cs was associated with humus content and fixation to clay fractions in the soil. Our results single out soil's hygroscopic water as a valuable parameter for 137Cs behaviour that could be used commonly if the measurement is standardised.