The use of caesium-137 to assess soil losses from agricultural fields (Orel region)

Abstract

The paper presents the results of experimental studies of the intensity of overburden delivery from agricultural fields in the districts of the Orel region for the period from 1963 to 2020. The isotope of cesium-137 of global and Chernobyl origin was used to detect at depth the overburdens that came from the fields to the depression complex in 1963, 1986, and 2020. According to the thickness of the overburden layer, the intensity of overburden delivery was determined for the periods 1963-1986 and 1986-2020. The authors found that in 1963-1986, the intensity of soil material losses from arable land was 2.00 cm/year in Znamensky district, 1.83 cm/year in Mtsensky district, and 1.56 cm/year in Orlovsky District. In the period 1986-2020, there was a significant decrease in the rate of erosion. Soil losses in the fields of Znamensky district decreased by 6.9 times; in the fields of Mtsensky district – by 3.89 times; Orlovsky district – by 1.56 times. The decrease in the intensity of soil losses is explained by the increase in the frequency of thaws in the winter season in 1986-2020 compared with 1963-1986. In 1963-1986, the number of years with the maximum monthly temperature in January and February above zero degrees did not exceed 5-7. In 1986-2020, the number of such years increased to 17-19. Reduction of soil freezing and a decrease in melt runoff led to a reduction in soil losses.