Method of studying the degradation of soil macroaggregates based on the self-absorption of 137Cs β radiation

• Published in: Eurasian soil science Vol. 46; no. 4; pp. 386 - 392
• Main Authors: Fokin, A. D., Torshin, S. P.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.04.2013
• Subjects: Earth and Environmental Science; Earth Sciences; Geotechnical Engineering & Applied Earth Sciences; Soil Physics; dark gray soil; radiometric measurements; pot experiment
• ISSN: 1064-2293; 1556-195X
• DOI: 10.1134/S1064229313040029

A method was proposed for studying the degradation of soil aggregates in time from the absorption of 137 Cs β-radiation by a soil sample. The method is based on the difference in the recorded β radiation intensities depending on the distribution of 137 Cs between the surface of the aggregates and the nonaggregated soil material. At the localization of the radionuclide on the surface of the soil aggregates, the counting rate will significantly exceed that for the samples containing a similar amount of the radionuclide uniformly distributed throughout the soil volume. This effect is due to the insignificant range of the mild β radiation in the soil (less than 1 mm depending on the radiation energy). Relatively clear calibration graphs under the selected conditions of the radiometric measurements were obtained for the aggregates whose sizes were in the range of 3–10 mm. Under natural conditions, the 7- to 10-mm aggregates of a dark gray clay loamy soil under a forest belt decomposed by 50–65% at a depth of 10 cm and by 23–32% at a depth of 30 cm. The more intense degradation of the soil aggregates of the same size was observed under the conditions of a pot experiment.