Electromagnetic Field Treated Irrigation Water for Agricultural Reuse: Physicochemical Mechanisms, Soil Salinity Dynamics, and Crop Responses

Electromagnetic field (EMF) treatment of irrigation water has gained attention as a non-chemical conditioning approach to improve irrigation performance under freshwater and saline water conditions. In agricultural applications, EMF treatment is typically applied by passing irrigation water through or near inline magnetic or electromagnetic devices before soil application. Unlike desalination technologies, EMF does not remove salts in irrigation water; it is hypothesized to modify water-soil-ion interactions that influence infiltration, solute mobility, and mineral precipitation kinetics. However, the existing evidence remains fragmented across experimental scales and treatment configurations, with inconsistent reporting of EMF exposure conditions, limited field-scale validation, and uncertainty regarding the underlying mechanisms. This review critically evaluates experimental evidence, proposed mechanisms, and limitations of EMF-treated irrigation water, with particular attention to soil salinity management and its integration with unconventional water reuse. Across laboratory, greenhouse, and limited field studies, EMF-treated irrigation water is most consistently associated with altered wetting behavior and downward salt redistribution, with lower surface-layer salinity reported under selected conditions. However, long-term salt accumulation and groundwater impacts remain unquantified. Reported crop responses include improved ionic balance, enhanced growth, and water productivity, although responses vary among experimental conditions. These outcomes may involve changes in water movement, solute transport, and mineral precipitation behavior, although the contributions of individual mechanisms remain uncertain. EMF treatment cannot substitute for desalination where salinity exceeds crop tolerance thresholds; however, it may serve as a complementary conditioning step within integrated reuse frameworks that combine partial desalination or blending with soil amendments to improve the soil compatibility of unconventional waters. Most available studies involve freshwater or saline/brackish irrigation, with limited direct evidence for reclaimed wastewater applications. Overall, current evidence supports EMF primarily as a condition-dependent modifier of soil–water–salt transport rather than a universally effective treatment. Further research requires standardized treatment reporting, replicated field trials, salt mass balances, and energy and cost assessments.