Abstract

The irrigation water quality is influenced by the concentration and composition of soluble salts present affecting agricultural production in arid and semiarid regions. this study aimed to evaluate groundwater and determine the sodium adsorption ratio (SAR) and residual Sodium Carbonate (RSC), in the Sidi-Farag area, specifically the police farms (formerly) located south of Benghazi city in July 2024. The study employed the Gibbs diagram and the Piper diagram to characterize the groundwater and demonstrate the hydro-geochemical influence. ,five groundwater samples were randomly taken from different sites in The area covering approximately 350 hectares in the study area. The study's statistical findings demonstrate that all irrigation water values were within the permissible limits outlined in the (FAO) Irrigation Standards (Ayers & Westcot, 1985) and showed the following order: Na+>Ca++>Mg++>K+and Cl- > HCO3- >SO42-. The agricultural water quality was assessed using SAR and falls into the Excellent category with SAR <10. Based on the negative RSC value (-3.0), it is unlikely that the water is unlikely to lead to sodium accumulation issues in the soil by using these sources. finally, The Gibbs diagram indicates that the occurrence of ion dissolution in groundwater due to evaporation and precipitation is greater than that caused by rock dominance or any other sources. Based on the Piper diagram analysis, the groundwater was classified into Na, Ca, Cl, Mg, and CaHCO3 types.