Background: Conventional chemical fertilizers enhance agricultural output but deteriorate
soil quality and fertility while causation of health and environmental issues. Therefore, the continual
use of chemical fertilizers is not sustainable. Control release nanofertilizer is one of the solutions to said
issues. Nanofertilizers use metallic nanoparticles and toxic cross-linkers (e.g. Glutaraldehyde, Glyoxal
and Methacrylic Acid), which also pose risks to health and the environment. Synthetic, nonbiodegradable
costly raw material based nanofertilizers will also create new-generation-waste in the
future, which is not sustainable.
Objective: Development of an environment-friendly nanofertilizer for prolonged control release of plant
macronutrients-Nitrogen, Phosphorous and Potassium (NPK).
Methods: Chitosan was obtained from the deacetylation of chitin, which was extracted from the shrimp
exoskeleton. Micro/nanoparticles of chitosan were synthesized with the ionotropic gelation method, excluding
toxic cross-linkers. Macronutrient loaded nanoparticles were impregnated to micro and nanopores
in activated coir fiber followed by coating with a natural exudate water diffusional barrier.
Macronutrient release behaviour and efficacy of control release fertilizer were studied against conventional
Results: Mean size of nanoparticles was 100 nm. FTIR analysis showed the macronutrient interaction
with micro/nanoparticles of chitosan. Macronutrients were incorporated into nanoparticles at 12% loading
efficiency and 20% entrapment efficiency. The developed fertilizer showed control release of macronutrients
even beyond 90 days, whereas commercial fertilizer showed an initial burst lasting a negligible
release after 30 days. Results from pot trials indicated that nanofertilizer enhances the yield performance
of rice plants against commercial fertilizer.
Conclusion: A green nanofertilizer can be developed with a simple method using biocompatible, biodegradable,
non-toxic and renewable natural based raw materials to prolong the control release of plant
macronutrients excluding toxic chemicals. Since the starting materials are coir fiber and shrimp exoskeleton,
which is a waste, it could significantly reduce the production cost hence present study discloses
an economically sound, environment-friendly and socially responsible nanofertilizer.