ZIF-8 metal organic framework, carboxymethylcellulose and polyvinyl alcohol bio-nanocomposite controlled-release phosphorus fertilizer: Improved P management and tomato growth

Abstract

This study is concerned with the synthesis, characterization, and application of bio-nanocomposite films using a mixture of carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) integrated with zeolitic imidazolate type 8 (ZIF-8) nanoparticles (NPs). The advanced bio-nanocomposites were employed as a coating for triple superphosphate (TSP) fertilizers, and their impact on tomato plant growth was evaluated. The successful integration of ZIF-8 into the composite matrix was determined by distinct changes in Fourier transform infrared (FTIR) spectra, indicating significant structural modifications. Morphological analyses by scanning electron microscopy (SEM) revealed alterations in the surface characteristics of the CMC/PVA films. Furthermore, energy dispersive X-ray (EDX) analysis confirmed the elemental composition of the resulting nanocomposite. The precision-coated TSP fertilizers exhibited a notable enhancement in mechanical strength, as evidenced by their superior resistance to crushing. The coated TSP also exhibited a controlled release of phosphorus over time, prolonging the release of phosphorus for up to 9 days in water and 50 days in soil. In soil, the 0.5 % ZIF-8 NP coating delayed the release of phosphorus, with only 12.29 ± 2.75 % released after five days compared to 96.96 ± 2.03 % for uncoated TSP. The application of coated TSP fertilizers to tomato plants (of the MARIA variety) resulted in a 13.79 % increase in leaf number and a 15.83 % increase in plant height compared to uncoated TSP. This research underscores the pivotal role of advanced coating fertilizers in fostering sustainable and efficient agricultural practices, thereby making a substantial contribution to the advancement of innovative agrochemical solutions.