Preparation of slow release encapsulated insecticide and fertilizer based on superabsorbent polysaccharide microbeads

Abstract

AbstractThe use of encapsulated fertilizers and pesticides is a key approach for slowing the release of agrochemicals, while simultaneously reducing costs and environmental problems. The use of hybrid systems for encapsulation in organic‐based agriculture, which enables the release of agrochemicals in a single application, has been a growing field. In this approach, a formulation of Bacillus‐thuringiensis as bio‐pesticide and nitrogen, phosphorus, and potassium fertilizer (fish emulsion, potassium nitrate, and potassium phosphate) were formulated using superabsorbent polymers microbeads based on sodium alginate (ALG) then evaluated for release. Different formulations were prepared using 15 wt% of Bt, fish emulsion, nitrogen, and phosphorus. The encapsulated microbeads were prepared by wet‐extrusion processing using sodium alginate as the superabsorbent polymer and calcium chloride as the gelling agent. The resulting beads were characterized in terms of size, morphology, water uptake, and biodegradability. The results showed that the prepared microbeads have narrow size distributions (1.2 to 2.1 mm) and increased water uptake (1,200–3,200%). Moreover, loaded microbeads were analyzed using inductively coupled plasma‐optical emission spectroscopy and Elementar CHNS analyzer to obtain the fertilizer grades as (6.2–0.8–1.05), (0–6.3–6.4), and (0.62–0–2.4) for the one loaded with fish emulsion, for potassium phosphate loaded beads, and for potassium nitrate loaded beads, respectively.