Content of cesium-137 in the soil cover of Central and Southern Tajikistan

The content of cesium-137 in the soil cover of the central and southern parts of Tajikistan was studied. The study area of the regions of the republic is about 45,000 km2. 92 soil samples from the Central and Southern parts of the republic were collected from cultivated and uncultivated fields to a depth of 25 cm from the ground surface. Each sample at the sampling point was cleared of stones, roots and other inclusions. The sample was dried to an air-dry state, crushed and sieved through a sieve with a hole diameter of 2 mm. When measuring the samples, we used a standard 1 L Marinelli beaker. Measurements of the specific activity of cesium-137 in soil samples were carried out on a gamma spectrometer based on highly pure germanium. The maximum content of cesium-137 was observed in soil sample No. 1 of the Kamarob area of the Rasht district, which specific activity in the sample is 148 Bq / kg. The minimum specific activity of cesium-137 is observed in soil samples from the Tajikabad district. The dependence of the concentration of cesium-137 on the topography in the region under study has been established. In some of the investigated samples, the cesium-137 isotope was not detected (sample no. 2 from the Ayvaj area of the Shahritus district and sample no. 4 from the Farkhor district). The dynamics of the distribution of cesium-137 on the soils of uncultivated fields and soils of cultivated fields of the Khatlon region of Tajikistan has been studied. It was found that the content of the isotope of cesium-137 in the treated fields differs from the untreated ones. It has been determined that in the soils of cultivated lands, the content of cesium-137 is concentrated at a depth of 20-25 cm. At the foot of the mountains and clay soils, a relatively high content of the isotope of cesium-137 is observed in comparison with plains and sandy soils.