Natural Environment Monitoring 2011, No 12, 117-124
MIGRATION AND DISTRIBUTION OF LEAD AND CADMIUM IN THE PROFILES OF THE TWO MAIN SOIL RECLAMATION GROUPS IN AKDALA IRRIGATION AREA
Azimbay Otarov, Bogusław Wiłkomirski
Negative influence of heavy metals on individual element of agrocenoses located on arable soils depends on soil features. The investigations of heavy metal migration have great pure and ap-plied importance. Former investigations in Akdala region have outlined four reclamation groups of soils. The division of soils into reclamation groups is based on their main genetic features – hypsometric position, lythologic structure, mechanical content and water-physical properties that define a homogeneous feature of reclamation activities in the operational period. Only two of these group have real practical importance. The first group includes mainly weak saline soils of light mechanical content located on river bed banks of the dead river beds of the Ili river and its ducts, suitable for growing all zoned crops without conducting prior reclamation activities. The second group includes saline soils with various degrees of salinity and heavy mechanical structure located on the negative elements of the relief – depression between channels and their slides and slopes, suitable for development in irrigation and conducting special land improvements under all zoned crops, especially for rice. In the area of soils belonging to the above groups the representative locations have been chosen. 32 soil profiles were selected, from which 148 soil samples were collected. In all the samples the concentrations of lead and cadmium were determined using ASA method. In the profile of both arable and virgin soils of the first reclamation group lead is distributed by the eluvial-illuvial type. Eluvial horizon, from which lead is removed is arable horizon, and illuvial where lead is accumulated is sub-arable horizon. A sub-arable illuvial horizon constitutes a geochemical barrier to lead migration in the profile of these soils. In the profile of the second reclamation group of soils, lead is distributed by the accumulative type, subtype – regressive-accumulative. The horizon of lead accumulation and geochemical barrier have heavy mechanical structure and the arable horizon is relatively rich in humus. In the profile of all the studied soils cadmium is distributed by accumulative type. There is also the horizon of cadmium accumulation, and the geochemical barrier is arable horizon relatively enriched with humus. In addition arable soils of both reclamation groups contain higher amounts of the studied metals than their virgin analogues.