The elaboration of techniques of multi-element instrumentation neutron activation analysis for assessment of biogeochemical and ecological state of soils

The work is dedicated to study of element content, element distribution regularities and their mobile forms in soils and plants(particularly cotton-bush) of Uzbekistan using refined INAA and X-ray structural methods of analysis and to the assessment of biogeochemical and environmental states of soils. Multielement( more than 20) analysis capability of INAA has been used for large scale studies of soil states. This method has been applied to sampling, reactor irradiation and estimation of partial errors of produced radionuclides. Optimal versions of INAA were developed for chemical element content determinations on a large scale in plants and some fertilizer. X-ray structural method for studies of mineral part of soils has been upgraded and 8 minerals have been studied in standard and in Central Fergana meadow soils. A complex approach for estimation of soil biogeochemical and environmental states has been suggested. The role of contacting natural media in accumulation of elements in the soil of cotton plantations has been studied and chemical fertilizers were found to be the main source of those elements. As a result the degrees of soil contamination by a number of heavy metals( such as Sb, Br) and by rare earths have been studied using different methods. In order to exclude the influence of industrial pollutions the experimental sites for studies of horizontal and vertical element distributions in soils were chosen far from industrial centres. (author). 6 tabs. 4 figs