Solar-powered saline groundwater management for sustainable agriculture

Many rural areas in Iraq suffer from saline groundwater, which is limiting agricultural development. The latitude of this study site has a similar climate to the Moora to Katanning region of Western Australia in the south west wheat belt. Other similarities include rising saline groundwater levels, low winter rainfall, and high evaporation with a high sun-shine duration. A strategy incorporating solar pumping of saline groundwater to shallow ponds incorporating a novel evaporation reduction technique, and subsequent dilution with winter rainfall to produce brackish quality water suitable for livestock and irrigation has been developed in Alexandria and is described in this paper. The site for this research is situated at 32.00 N; 44.35 E in rural of Alexandria, where the national electricity grid is not available to power groundwater pumps. Solar pumping from a depth of 14m is used to fill three interconnected ponds of approximately 115m diameter and 0.35 to 2.6m in depth. Approximately 130,000m3 of saline groundwater (1,200mS/m, 6600mg/L) is pumped to the ponds each season which when diluted with average winter rainfall of 500-650mm/ year provides a resultant shandy of water which can be classified as moderate /brackish (850 mS/m). This is suitable for irrigation of date palms and alfalfa crops and for livestock. The system is made viable through the innovative use of date palm leaves which are floated out over the ponds as a mat and reduce evaporation by over 80% of net pan evaporation.