A large number of organisms have been identified for their enzymatic action for efficient production of plant nutrients in nano form. The current chapter discusses nanotech-based production of nutrients and their subsequent applications to various agricultural crops. Further, different techniques for characterization of these bioinspired nanoparticles have also been explained. Such nanoparticles have been recommended for foliar application on two-week-old plants. Standardization of vital features like size, shape, and concentration of the nanoparticles for the optimum desirable results has been discussed too. The entry of nanoparticles through the cuticle and stomata, besides other plant parts, has also been ratified in the present study. The outcomes of various experiments evidently demonstrate the environmentally friendly nature of these nanonutrients. These tend to improve nutrient use efficiency—that is, 80–100 times reduction in the use of chemical fertilizers, 10 times increase in stress tolerance of the crops, 18–21 days advancement in crop yield, and 30% more native nutrient mobilization in the rhizosphere. These were found to exhibit positive effects on root length, area, and number of root tips, though there was hardly any definite trend on root diameter. In brief, the application of nanonutrients in suggested doses is expected to increase the crop yield by 12%–54% with minimal adverse effects.