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

Abstract

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.

Nanomaterials as Nanofertilizers and Nanopesticides: An Overview

“…[36a] Recently, it is claimed that urea À hydroxyapatite nanohybrids can be a suitable candidate for the delivery of nutrients to plant and boosted growth-related traits. Abeywardana et al [37] displayed that a new nanoseed coating based on zinc-doped urea-HA nanohybrids raised significantly the rate of growth and germination of Zea mays seeds (by 69 % and 19 % respectively).…”

Synthesis and characterization of novel dual-capped Zn–urea nanofertilizers and application in nutrient delivery in wheat

“…4 In contrast to these Zn forms, the advent of nanotechnology has permitted the development of novel Zn types based on the particle size, with markedly different reactivities and bioenvironmental responses. [5][6][7][8] Notably, zinc oxide nanoparticles (ZnO-NPs; #100 nm in at least one dimension) are incorporated into a variety of industrial, medical, and household products, to enhance the quality and functionality of Zn. 9 These NPs are increasingly being explored as fertilizers and pesticides to harness their novel properties in maximizing crop productivity.…”

“…9 These NPs are increasingly being explored as fertilizers and pesticides to harness their novel properties in maximizing crop productivity. 5,7,[10][11][12][13] The increasing number of studies show that Zn-based NPs can enhance plant performance when used at judicious application rates. [5][6][7][8] However, such benets are still far from being maximized for large eld-scale crop production due to the inherent and practical problems associated with micronutrients needed by plants in trace amounts, which are further complicated by the ultra-small size of nanoscale nutrients.…”

“…5,7,[10][11][12][13] The increasing number of studies show that Zn-based NPs can enhance plant performance when used at judicious application rates. [5][6][7][8] However, such benets are still far from being maximized for large eld-scale crop production due to the inherent and practical problems associated with micronutrients needed by plants in trace amounts, which are further complicated by the ultra-small size of nanoscale nutrients. As previously discussed, 6 whereas a conventional fertilizer can be applied by surface broadcast, the inherency of nanoparticles to suspend in air would lead to dri losses, negating the applicability of surface broadcast with dry ZnO-NPs.…”

“…6,8,21 Previous studies reported doping or coating urea with ZnO-NPs. 5,17,18 Such coatings involved using facile systems that involved water or vegetable oil as a binding agent. We hypothesized that dual capping of Zn NPs prior to coating of fertilizer granules would further improve product efficiency through increasing the dispersibility of Zn, as well as controlling the particle size to obtain ultra-small particles ($5 nm).…”