Synthesis, characterization, and controlled release property evaluation of alginate-based encapsulated NPK fertilizers

• Main Author: Mesias, Vince St. D.
• Format: text
• Language: English
• Published: Animo Repository 2017
• Subjects: Alginates; Sustainable agriculture; Fertilizers
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/5636
• Institution: De La Salle University

Sustainable agriculture needs an adequate amount of nutrients for crop growth in the form of fertilizers. This study successfully prepared alginate-based encapsulated NPK fertilizers in the form of carboxymethyl cellulose/alginate (CMC/Alg NPK) and chitosan/alginate (Chi/Alg NPK). It involved preparation, characterization, chemical analysis of NPK, release studies, and fertilizer efficacy evaluation. Fourier transform infrared (FTIR) and fluorescence spectroscopic methods, scanning electron microscopy (SEM), particle size analysis and zeta potential measurements showed the successful formation of spherical particles with varying sizes via crosslinking. Release curves showed that both forms of alginate-based NPK conform to the standards of controlled release fertilizer with a maximum release rate of 40% for Chi/Alg NPK and 50% for CMC/Alg NPK in 30 days. Investigation of the release mechanism using Korsemeyer- Peppas mathematical model showed that the release of nutrients is governed by both coating material relaxation and diffusion process. Controlled release behavior was demonstrated by both forms of alginate-based encapsulated NPK fertilizers upon efficacy evaluation for two months.