Zinc-Doped Hydroxyapatite–Urea Nanoseed Coating as an Efficient Macro–Micro Plant Nutrient Delivery Agent

Application of micronutrients through seed amendments is an interesting option for field crops, allowing a uniform distribution of fertilizers in a seed batch. This process can be further improved by developing advanced materials for seed coatings that have the ability to carry out the delivery of plant nutrients with greater precision leading to enhanced germination. Herein, we disclose a novel nanoseed coating based on zinc-doped urea–hydroxyapatite nanohybrids synthesized via a one-pot in situ sol–gel synthetic route. The formation of a substituted solid with an altered chemical environment and the lattice shrinkage of hydroxyapatite nanoparticles due to the successful doping of zinc and urea incorporation were evident from characterization studies. The developed nanoseed coating was effective in increasing the rate of growth of Zea mays seeds by ∼69% and the germination rate by 19%, claiming its suitability as a potential candidate for the delivery of nitrogen, phosphorus, and zinc at the seedling stage.