Evaluation of Synthesized Nanoscale Fe Carriers for Enhanced Wheat Crop Nutrition in a Typic Ustifluvents

Iron (Fe) is a key micronutrient for wheat growth, but in soil types like Typic Ustifluvents (Calcareous soil), Fe deficiency hampers crop yields. Traditional iron-based fertilizers show low efficiency, around 1–5%. To tackle this, innovative nano iron fertilizers were synthesized through chemical and biological processes. Nano Fe and nanoclay materials (< 100 nm) contained 5.05%, 0.96%, and 4.47% of total Fe content, respectively. A pot experiment was conducted using nanoscale Fe (chemical and biological methods) and iron containing nanoclay polymer composite (Fe-NCPC) in wheat crops (HD 2967) in Typic Ustifluvents soils. Different levels of nano Fe were tested against FeSO₄·7H₂O, Fe-NCPC, Fe-NPs (Bio.), and Fe-NPs (Chem.). The recommended dose of iron (RDFe) (100%, 50%, and 25%) and foliar spray of (0.004%) nano Fe notably boosted DTPA-Fe and enhanced soil enzymatic activities in wheat rhizosphere. This led to improved Fe fractionation in soil, increased Fe recovery efficiency (ARFe) (7.92%), and agronomic efficiency (AEFe) (0.40 g g⁻¹) under foliar (biological and chemical synthesis Fe-NPs) 0.004% or soil application (Fe-NCPC 100%) of nano Fe. The innovative Fe-NCPC 100% enhanced crop yield (6.13 g pot⁻¹), nutrient uptake (0.89 mg pot⁻¹), enzymatic activities, DTPA-Fe (38.20 mg pot⁻¹), and Fe use efficacy (ARFe and AEFe) due to controlled Fe release, preventing competitive inhibition for absorption sites. Similarly, RDFe 100% through biologically and chemically synthesized nano Fe improved nutrient use efficiency (ARFe & AEFe) and plant growth by releasing root exudates like phytosiderophores, which chelate nutrients, increasing their DTPA-Fe availability in the soil solution. Recommended dose of Fe 100% by Fe-NCPC, Fe-NPs (Bio.), and Fe-NPs (Chem.) significantly enhanced the Fe pools in Typic Ustifluvents soil as compared to FeSO₄·7H₂O. Future research should be done on long-term interactions between nanoscale Fe carriers and other essential nutrients in specific Typic Ustifluvents soils to further understand their effects.