EFFECTIVENESS OF DRAINAGE IN DEVELOPING SALINE SOILS UNDER IRRIGATED AGRICULTURE DURING THE LAST 30 YEARS

Artificial drainage has allowed the leaching and development of modera tely and strongly saline soils under regular irrigation and an increas e in irrigated area by a factor of 1.5. Moreover, construction of a dr ainage network without salt-water collectors led to ecological disturb ances in adjacent pastures and to an increase in the salinity of the r iver water due to the discharge of drainage water into them. The stand ards for the salt loads of the drainage runoff and of the runoff volum es from irrigated lands have not been regulated, and the problems of u tilizing drainage water have not been solved at the level of the requi red exploitation, due to which the effectiveness of the drainage turne d out to be below what was expected. The areas of saline soils and the different hydroreclamation status of lands are given for the republic s of Central Asia and individual parts of river basins.