Title : Development of novel hydrogel based on alginate grafted with polyacrylamide for slow-controlled release fertilizer (SCRF)
In order to reduce the cost of fertilizers as well as their influence on the environment, scientists are paying more and more attention to slow-release or controlled-release fertilizers, which are prepared from abundantly available biodegradable natural materials such as biopolymers.
Based on this context, a novel hydrogel was prepared by encapsulation of NPK using a cross-linked sodium alginate grafted with polyacrylamide (PAM) for application as slow- controlled release fertilizer. The prepared S-CRF beads were characterized by Fourier- transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM). Swelling capacity and water retention were also evaluated. The fertilizer release behavior was evaluated in water and the results showed that the fertilizers displayed an improved NPK release properties according to the European standard EN 13266. These fundings indicated that the grafting of PAM onto alginate skeleton enhanced the controlled release behavior of NPK fertilizer with a maximum release rate of 65% (nitrogen) ; 52% (phosphorus) ; and 43% (potassium) for 56 days.
These good characteristics revealed that the prepared S-CRF beads can be practically used in agricultural applications.
Keywords: Alginate, NPK, polyacrylamide, S-CRF