https://doi.org/10.37229/fsa.fja.2025.06.17

Water scarcity and salinity are major constraints to sustainable agriculture in Egypt, especially in newly reclaimed areas. This study therefore explores alternative strategies to reduce salt stress in irrigation water and soil and enhance marjoram yield in sandy loam soils. To explore sustainable approaches for mitigating salinity stress, two factorial experiments in a split-plot design were conducted during the 2023 and 2024 growing seasons on the North Coast of Egypt. This study assessed the effects of magnetically treated water, thiamine (B1), folic acid (B9), and their interactions on marjoram (Origanum majorana L.) grown under saline well water irrigation (6.57 dS m⁻¹). Irrigation was applied through a surface drip system using an A100S magnetic device at 35% of field capacity depletion. Application of folic acid (B9, 2 mg L⁻¹) and thiamine (B1, 75 mg L⁻¹) significantly enhanced marjoram growth, essential oil yield and quality, increased total carbohydrates and nutrient contents (N, P and K), and reduced Na and proline levels compared with the control. Magnetized water enhanced essential oil composition, carbohydrate accumulation, and nutrient uptake, while reducing Na, proline, and p-cymene contents compared with the control. The interaction between magnetized water and B vitamins led to a significant improvement in the growth of the marjoram plant and the production of its essential oil and main components, with an increase in carbohydrate and nutrient content (N, P, K) and a decrease in proline and sodium compared to the other treatments. Based on the obtained results, the integration of magnetized water with B-vitamin treatments can be recommended as a sustainable agronomic practice to improve vegetative growth, essential oil composition, and nutritional quality of marjoram plants.