SUBSURFACE DRAINAGE AND SALT LEACHING IN IRRIGATED LAND IN SOUTH-EAST TURKEY

With respect to the expansion of waterlogging and salinity increase in irrigated areas of Turkey, this study was conducted to monitor and assess the effects of a subsurface drainage system on salt leaching in the Harran plain. The field experiment was carried out near Akcakale province, in Sanhurfa, from 2001 to 2004. The subsurface drainage system reduced the salinity by about 80% in the topsoil (20 cm depth), at the end of the experimental period. Winter precipitation had no significant effect on salt leaching. A statistically significant relationship was found between the amount of drainage water and the salt leaching (R-2 = 0.970). An exponential relationship was further detected between drainage water (D-dw)/soil depth (D-s) vs. remaining salt/initial salt values (C/C-0) (R-2 = 0.764). Copyright (C) 2008 John Wiley & Sons, Ltd.