Ecological restoration in contaminated soils of Kokdzhon phosphate mining area (Zhambyl region, Kazakhstan)

This study provides results of an ecological restoration activity performed in the Kokdzhon phosphate mining of the Zhambyl region (a semi-desert mining area of Kazakhstan). The test area was made by a quarry-hole, about 1.25 hectares wide, that was preliminarily filled with the earthy material of a dump and, subsequently, levelled. The total volume of human transported material (HTM) used was 700 tonnes. Soil samples were taken from 0 to 30 cm depth at 23 sampling sites and several soil quality parameters were determined. In the test area 750 tree species were planted in suitable dug holes: (150 seedlings of Russian Olive; 150 seedlings of Black Saxaul); 150 seedlings of Androsov Elm; 150 seedlings of Salt Cedar; 150 seedlings of Russian Salt Tree). In addition, a mixture of cereal and legume seeds (in equal amount of weight for each species) was seeded in 4 furrows, in between the tree lines. The results of this preliminary activity show a low engraftment of the plants used for the ecological restoration over one year. This could reasonably be due to the unfavourable soil characteristics of the test area that can be regarded as a human transported material (HTM), on which the action of the soil genetic factors, particularly, the biotic one, has yet to play out fully.