Assessment of Options for the Sustainable Use of Agricultural Drainage Water For Irrigation in Egypt by Simulation Modelling

Abstract

The water management simulation model DRAINMOD-S was applied to simulate different strategies for using agricultural drainage water for irrigation over a 20-year period. The irrigation strategies considered were: (i) fresh/non-saline water as the baseline for comparison; (ii) drainage water of different salinities; (iii) cyclic use of fresh water and drainage water; (iv) deficit irrigation combined with controlled drainage; and (v) interseasonal cyclic use of drainage water and fresh water (2 years drainage/2years fresh). The study area was in the North-West Delta of Egypt which already uses fresh canal water blended with agricultural drainage water for irrigation. The most common 2-year crop rotation in the area of wheat–maize–berseem–cotton was simulated. Four different drainage water salinities (4, 8, 12, 16 dS m−1) were simulated and three different options for the freshwater/drainage water cycle. Better results were found, yields being maintained, for the strategies of deficit irrigation combined with controlled drainage, cyclic use of agricultural drainage water of 4–12 dS m−1 with fresh water and the inter-seasonal cycling of drainage and fresh water. These results provide a set of sustainable options for using agricultural drainage water for irrigation. Copyright © 2016 John Wiley & Sons, Ltd.