Optimizing Oilfield Produced Water Reuse for Sustainable Irrigation: Impacts on Soil Quality and Mineral Accumulation in Plants

Effective management of produced water (PW), a by-product of oil extraction in Oman, is crucial for sustainable water use and environmental protection. PW contains petroleum residues, heavy met-als, and salts, requiring treatment before reuse. In the Nimr oil field, PW is partially treated through constructed wetlands with reed grass. This study evaluates the feasibility of reusing treated PW for irrigation by assessing its effects on soil quality and mineral accumulation in plants under different irrigation conditions. Field experiments were at Sultan Qaboos University (SQU) and Nimr wet-lands treated PW (TDS ~6,500–7,000 mg/L) along with lower-salinity water sources. Soil amend-ments (biochar and gypsum) were tested for salinity mitigation. Results showed that PW irrigation significantly increased boron and major cations (Na, K, Ca, Mg) in soil and plant tissues, leading to higher soil salinity and potential decline in soil health. While biochar reduced boron levels, neither amendment improved plant growth or nutrient uptake. Plants irrigated with PW exhibited signs of salinity stress, including reduced leaf development and premature senescence. These findings highlight both the potential and challenges of PW reuse for irrigation. Adaptive irrigation strategies and soil management practices are essential to maximize benefits while mitigating long-term soil salinity risks.