PurposeSoil amendments such as compost (Comp) and biochar (Bio) are vital for soil restoration while enhancing plant resilience to abiotic stresses. Therefore, the present study investigated the effect of Comp and Bio on the properties of saline soil and the productivity of wheat under deficit irrigation.MethodsWheat was cultivated in a saline field (soil had electrical conductivity = 6.23 dS m(-)1) during the 2023/24 and 2024/25 seasons. The experiment comprised three irrigation regimes, i.e. 100, 80, and 60% of crop evapotranspiration (ETc) and three soil amendment treatments, i.e. control, Comp, and Bio. The experimental design was a split-plot layout in randomized complete block arrangement with three replications.ResultsDeficit irrigation induced significant reductions in plant height, spike length, chlorophyll content (SPAD), water status (membrane stability index and relative water content), tissue nutrient concentration, straw yield and grain yield. In contrast, soil amended either with Comp or Bio mitigated these negative effects across all measured parameters relative to control. Application of Comp or Bio enhanced soil physicochemical properties, leading to significant improvements in plant growth, physiological performance, water use efficiency (WUE), 100-grain weight, harvest index, grain yield, and tissue concentrations of nitrogen, phosphorus, potassium, and calcium. Relative to the control, grain yield increased by 17.9% and 33.3% under Comp and Bio, respectively. Furthermore, both amendments maintained leaf nutrient homeostasis under stress, as evidenced by elevated K+/Na+ and Ca2(+)/Na+ ratios as key indicators of improved ionic balance.ConclusionCollectively, these results demonstrate that organic amendments such as Comp or Bio represent a viable and sustainable strategy for reclaiming saline soils, mitigating deficit water stress, and boosting wheat productivity and WUE under arid and semi-arid agro-ecosystems.