Innovative Approaches for Sustainable Zinc Nutrition and Crop Yield Enhancement in Pea Plants Using Zinc Oxide Nanoparticles

Zinc (Zn) possesses nutritional importance for humans, animals, and plants, making it a crucial element in their dietary requirements. In the current study, the effect of zinc oxide nanoparticles (ZnONPs) solution at four different concentrations (0, 0.5, 1.0 and 5.0 g/L) at 20-day interval on pea plants grown in Zn-deficient soil was assessed for remediation of Zn deficiency and enhanced Zn fortification. Zinc oxide nanoparticles were synthesized by using sol-gel method and characterized by UV-Vis spectroscopy, Fourier transform infrared (FTIR), Scanning Electron Microscopy (SEM), and X-Ray diffraction (XRD) and EDX pattern. The soil samples were analysed for microbial counts, chemical properties, dehydrogenase activity and vegetative characteristics, nutrient profile, and yield parameters according to their respective methods. The change of solution colour to off-white confirmed the synthesis of ZnONPs. ZnONPs were characterized by UV-Vis spectroscopy with a broad peak at 380 nm. The presence of NH/OH, C-H, C-C, C-O, C-N, Cl-C-O functional groups were confirmed by FTIR spectrum. The crystalline structure with hexagonal arrangements was described by the XRD pattern. The EDX pattern of ZnONPs showed the zinc composition as 45.9% and oxygen was 54.05%. The SEM images showed that the size of ZnONPs was of 37 nm. The application of ZnONPs at a concentration of 5.0 g/L significantly improved the growth and yield parameters. However, the highest value for root characteristics was attained with the application of ZnONPs at a concentration of 1.0 g/L. The microbial soil counts and enzyme activities such as viable cell counts, and dehydrogenase activity was highest at 5.0 g/L ZnONPs treatment. The treatment of ZnONPs successfully reverted the symptoms of Zn-deficiency besides the improvement of the Zn content of plant, although the response was concentration dependent. These findings indicate that ZnONPs can be effectively used for remediation and Zn fortification in pea plants cultivated under low soil Zn concentrations. The present study emphasizes the potential of ZnONPs to address micronutrient deficiencies, promote crop growth, and enhance soil health, offering a sustainable and controlled approach to zinc applications in agriculture.