Understanding the Mobilization of a Nitrification Inhibitor from Novel Slow Release Pellets, Fabricated through Extrusion Processing with PHBV Biopolymer.
J Agric Food Chem
; 67(9): 2449-2458, 2019 Mar 06.
Article
em En
| MEDLINE
| ID: mdl-30724561
ABSTRACT
Dicyandiamide (DCD) has been studied as a stabilizer for nitrogen fertilizers for over 50 years. Its efficacy is limited at elevated temperatures, but this could be addressed by encapsulation to delay exposure. Here, poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) was investigated as a biodegradable matrix for the encapsulation of DCD. Cylindrical â¼3 mm × 3 mm pellets were fabricated through extrusion processing with 23 wt % DCD. Release kinetics were monitored in water, sand, and both active and γ-irradiated agricultural clay loam soils. Raman maps showed a wide particle size distribution of DCD crystals and indicated that Hitachi's classic moving front theory did not hold for this formulation. The inhibitor release kinetics were mediated by four distinct mechanisms (i) initial rapid dissolution of surface DCD, (ii) channeling of water through voids and pores in the PHBV matrix, (iii) gradual diffusion of water and DCD through layers of PHBV, and (iv) biodegradation of the PHBV matrix. After â¼6 months, 45-100% release occurred, depending on the release media. PHBV is shown to be an effective, biodegradable matrix for the long-term slow release of nitrification inhibitors.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poliésteres
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Agroquímicos
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Nitrificação
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Guanidinas
Idioma:
En
Revista:
J Agric Food Chem
Ano de publicação:
2019
Tipo de documento:
Article