<p>Soil salinity severely constrains maize productivity, especially in arid and semi-arid regions with calcareous and salt-affected soils. Conventional strategies often fail to restore soil health and sustainably enhance crop resilience. Although biochar, vermicompost and silicon individually alleviate salinity stress, their integrated use under naturally saline field conditions remains underexplored. This study evaluated whether their combined application could synergistically improve maize performance by enhancing ionic homeostasis, antioxidant defense and water and nutrient status. A field trial was conducted on naturally saline soil (EC = 9.6 dS m⁻¹; pH = 8.2; sandy loam) using salt-tolerant (Dekalb-8148) and salt-sensitive (S-626) maize genotypes. Treatments included: control, 60 t ha⁻¹ biochar (6% w/w), 50 t ha⁻¹ vermicompost (5% w/w), 100&#xa0;kg&#xa0;ha⁻¹ silicon (as calcium silicate) and their combinations. Co-application significantly improved root/shoot biomass, leaf area (by 125.7% in Dekalb-8148 and 81.3% in S-626) and photosynthetic efficiency (higher SPAD values). These gains were mechanistically linked to enhanced relative water content (27.9–81.5%), membrane stability (23.5–48.2%) and K⁺/Na⁺ ratios (36.6% and 69.0%, respectively). Antioxidant enzyme activities (SOD, POD, CAT and APX) markedly increased, especially in S-626, indicating superior oxidative stress mitigation. There was also a significant increase in the yield components (cob length, 100-grain weight and grain yield per cob), where S-626 showed a greater relative response. Principal component and correlation analyses supported the close association between growth, physiological, biochemical and yield characteristics. The results showed that organic and inorganic amendments complemented each other in reducing the effects of salinity in agroecosystems and this effect offers a viable and sustainable solution for improving the tolerance of maize and facilitating genotype-specific control of salt agroecosystems.</p>