Interaction of irrigation, drainage and soil salinity in Harran Plain

Abstract

In this study, the possible effects of the use of drainage waters for irrigation to water and salt balance on the soil were investigated in Harran plain. It was observed that open drainage channel waters in the plain had less salt content than subsurface collector drain pipe waters and EC values decreased towards the end of the season. Field observations have shown that existing drainage systems allowed the water table remain at 140-160 cm deep during the irrigation season. In these conditions, the SaltMod computer simulation model predicted the salinity level of the root zone would decrease from 7.0 dS m-1 to 3.0 dS m-1 in 3 years and to 1.5 dS m-1 within 10 years. The model also showed that irrigation waters with an EC value of 1.5 dSm-1 would not cause a change in soil salinity, while irrigation waters with 2.5-3.0 dSm-1, and more would cause an increase in soil salinity.

Keywords

• irrigation
• drainage
• salinity
• salt balance
• harran plain