Efficiency of zinc oxide nanoparticles as controlled release nanofertilizer for rice (Oryza sativa L)

Zinc oxide nanoparticles (ZnONPs) are emerging as a promising zinc (Zn) fertilizer for crops. These nanoparticles possess large specific surface areas, which facilitate efficient sorption and act as slow-release fertilizers. Zinc is a crucial dietary component for humans, animals, and crops. In the present study, ZnONPs were synthesized using a chemical approach to achieve desirable nanoparticle characteristics. The synthesized nanoparticles were then characterized using various techniques including particle size analyzer, zeta potential, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, Scanning Electron Microscope (SEM), and Transmission Electron Microscopy (TEM). Energy dispersive X-ray spectroscopy (EDAX) confirmed that the ZnONPs contained 80% of zinc. The release of Zn from ZnONPs was observed to be sustained for 600 h, compared to 504 h for zinc sulfate, as determined by a percolation reactor. To evaluate the alleviation of Zn insufficiency and enriched Zn fortification, a pot culture experiment was conducted using the rice hybrid CO(R) 51 as the test crop in Zn-deficient soil. The overall findings of the research endorse that ZnONPs exhibit high Zn content and release slowly into the soil solution, thereby enhancing the Zn use efficiency of rice crops.