The study aimed to evaluate superparamagnetic iron oxide nanoparticles (SPIONS) as nanofertilizers to enrich Allium cepa vegetable productivity. The nanofertilizer was synthesized using iron salts and a weak base. Characterization via powder X-ray diffraction (PXRD), UV-Vis spectroscopy, and magnetometry confirmed Fe3O4-based nanomaterial formation. Germination assays were conducted in Petri dishes, each containing 50 seeds, with four groups tested: deionized water (G1), Fe2+ solution (G2), Fe3+ solution (G3), and SPION suspension (G4). Germination rates were 70 % for G1, 62 % for G4, 58 % for G2, and 44 % for G3. Root growth analysis demonstrated superior development in G4, indicating stimulation. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) determined higher Fe absorption in Allium cepa enriched with nanoparticles compared to non-enriched vegetables. Thus, it is concluded that the nanoparticle exhibits promising effects as nanofertilizer.