Preparation and characterization of slow-release fertilizer encapsulated by starch-based superabsorbent polymer

Dongling Qiao, Hongsheng Liu, Long Yu, Xianyang Bao, George P. Simon, Eustathios Petinakis, Ling Chen

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126 Citations (Scopus)


To enhance the effectiveness of fertilizers, a novel double-coated slow-release fertilizer was developed using ethyl cellulose (EC) as inner coating and starch-based superabsorbent polymer (starch-SAP) as outer coating. For starch-SAPs synthesized by a twin-roll mixer using starches from three botanical origins, a reduced grid size and an increased fractal gel size on nano-scale (i.e., increased stretch of 3D network) contributed to increasing the water absorbing capacity with a reduced absorbing rate and thus improving the slow-release property of fertilizer. The fertilizer particles coated with starch-SAP displayed well slow-release behaviors. In soil, compared to urea particles without and with EC coating, the particles further coated with starch-SAP showed reduced nitrogen release rate, and in particular, those with potato starch-SAP coating exhibited a steady release behavior for a period longer than 96 h. Therefore, this work has demonstrated the potential of this new slow-release fertilizer system for improving the effectiveness of fertilizers.

Original languageEnglish
Pages (from-to)146-154
Number of pages9
JournalCarbohydrate Polymers
Publication statusPublished - 20 Aug 2016


  • Different botanical origins
  • Nutrient slow-release
  • Slow-release fertilizer
  • Starch-based superabsorbent polymer

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