Nanoparticle-Mediated Foliar Fertilization: Assessing the Agronomic Performance of Ca, B, Mg, and Zn Suspensions on Early Performance in Maize

Abstract Purpose: This study aimed to evaluate the agronomic efficiency of nanoparticle suspension fertilizers containing Ca, B, Mg, and Zn when applied by foliar fertilization to maize in contrast to commercial product and reagent grade salts. Methods: We conducted two greenhouse experiments, with and without soil fertilization with B and Zn, to evaluate the effects of four foliar treatments: a test suspension, a commercial product, a reagent grade salt, and control. We evaluated the plant height, leaf number, stem diameter, SPAD index, and dry mass of the aerial parts and roots. Additionally, we determined the contents and accumulation of K, Ca, Mg, B, Fe, Mn, and Zn in the aerial parts. Results: The commercial and test suspension products increased the stalk diameter. Under conditions with soil-applied boron, the commercial product and the Ca/B suspension were most effective, promoting greater accumulation of K, Ca, Mg, and B in the aerial part. Overall, the suspensions containing Ca, B, Mg and Zn presented agronomic efficiencies comparable to those of the other products evaluated. Conclusion: Foliar application of Ca, B, Mg or Zn alone was not enough to meet the nutritional requirements of maize in soils with low availability of B and Zn. The commercial product outperformed the suspensions, especially when integrated with soil B and Zn fertilization. The best agronomic responses were associated with this combined soil and foliar approach. The tested suspensions require optimization to match the efficiency of established commercial formulations. This study reinforces the strategic importance of integrated nutrient management.