Salt affected soils under cotton-based irrigation agriculture in southern Kazakhstan

Soil salinity of the irrigated soils in a cotton farm of Kazakhstan was studied aimed to provide background for reconstruction of collection-drainage system of whole region and preventing soil deterioration. The experimental data obtained for 2012-2014 were plotted for the development of the map of soil salinity (1:10000) seasonally and vertically. In spring 2014 the area under medium saline soil in 0-20 cm layer decreased from 79.5 to 57.7%; the area of weakly saline soils increased from 20.5 to 34.6%. In autumn and winter periods the area of strongly saline soils decreased from 25.6 to 14.1%. The area of non-saline soils was 7.7%. The changes in the ions amount, both vertically and seasonally, occur with transport of salts along soil profile driven by temperature gradients and the level of ground water, i.e., in spring from up to down, and in autumn and winter, contrary from down to up.