Water-Limited Agriculture In Oman: Soil Moisture Variability, Treated Wastewater Reuse, And Crop Establishment In The Al Batinah Region

Abstract

This study investigates soil moisture dynamics, water quality, and crop performance in the Al Batinah region of Oman, where agriculture relies on traditional falaj irrigation systems and increasingly considers treated wastewater as a supplementary source. Field experiments were conducted across two sites with varying proximity to recharge sources and one control field, focusing on root-zone soil moisture, watermelon germination, and chlorophyll content. Water quality parameters (pH, EC, TDS, nitrate, sulfate, chloride, and heavy metals) were monitored alongside remote sensing indicators, including soil moisture, soil temperature, and NDVI trends (2000–2024). Results revealed clear temporal variation, with soil moisture peaking in August due to reduced evapotranspiration, offering favorable conditions for germination and early growth. Spatial analysis showed that fields near wadis maintained consistently higher soil moisture, supporting site-specific irrigation strategies. While treated wastewater offers a potential solution for water scarcity, elevated salinity and contaminants negatively affected crop establishment, emphasizing the need for careful monitoring and dilution. Long-term satellite observations indicated rising soil moisture, sustained high soil temperatures, and modest NDVI improvements, reflecting irrigation-driven greening. Overall, the findings highlight the critical role of water quality and site-specific management in sustaining agriculture under arid conditions.