Integrated Nano- and Bio-Fertilizer Strategy to Improve Wheat Productivity under Salinity Stress Using Taguchi Optimization Approach

Purpose Soil salinity adversely affects wheat at multiple growth stages, including germination and reproduction, by inducing osmotic stress and ion toxicity. These conditions disrupt nutrient uptake and reduce yield. Nanotechnology, especially nano-fertilizers, offers promising strategies to improve stress resilience by enhancing nutrient use efficiency. This study aimed to investigate the interactive effects of nano-silica (NSi), iron fertilizers—nano-iron (NFe) and soluble iron (SFe)—and Bacillus bacteria on wheat performance under saline conditions. Method A Taguchi L8 orthogonal array design was used to evaluate the individual and combined effects of four treatments (NSi, NFe, SFe, and Bacillus bacteria) on wheat cultivated in saline soil. Uptake and transfer factors (TF) of essential micronutrients, including zinc (Zn) and iron (Fe), were measured to assess treatment performance. Results Among the tested variables, the type of iron fertilizer was the most influential, followed by NSi and Bacillus bacteria. Salinity stress significantly reduced Zn and Fe uptake. However, applying NSi at 600 mg kg⁻¹ with NFe (without Bacillus) or with SFe in the presence of Bacillus resulted in optimal nutrient uptake and translocation. These combinations improved both uptake and TF of key micronutrients under stress. Conclusion Integrating nano-fertilizers with beneficial microbes can effectively alleviate the adverse effects of salinity on nutrient absorption in wheat. This combined approach shows strong potential for enhancing plant nutrition and supporting sustainable crop production in salt-affected environments.