Assessment Of Treated Wastewater And Traditional Falaj Water On Watermelon Seed Germination And Seedling Vigor In Arid Agriculture

Abstract

Salinity and water quality are critical factors affecting agricultural productivity, particularly in semi-arid regions with limited freshwater resources. This study investigates the effects of irrigation water quality including falaj water, treated wastewater, and control conditions on seed germination, crop performance, and soil salinity dynamics across four locations at varying distances from the sea. Field experiments using watermelon seeds revealed that falaj water consistently produced higher germination rates (up to 100%), whereas treated wastewater showed reduced and variable germination (10–80%), highlighting the negative impact of elevated salinity, total dissolved solids (TDS), and heavy metals. Farmer interviews corroborated field observations, indicating increasing salinity effects closer to the coast, with some lands abandoned due to severe salt accumulation. Water quality assessments showed high electrical conductivity (2117–3750 μS/cm), elevated chlorides (250–400 mg/L), and high TDS levels, which correlate with reduced germination and crop stress. GIS-based spatial mapping further highlighted heterogeneity in water quality and salinity across sites, emphasizing the need for targeted irrigation and salinity management strategies. The study underscores the importance of careful water source selection, pre-treatment of wastewater, salinity-tolerant crops, and improved irrigation practices to maintain crop productivity in salt-affected areas.