title: Preparation and characterization of slow-release fertilizer encapsulated by starch-based superabsorbent polymer.
abstract: 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 96h. Therefore, this work has demonstrated the potential of this new slow-release fertilizer system for improving the effectiveness of fertilizers.
authors.affiliation: Centre for Polymer from Renewable Resources, South China University of Technology, Guangzhou, PR China; Department of Materials Engineering, Monash University, Clayton, Australia; CSIRO, Manufacturing, Melbourne, Australia.
authors.forename: Dongling
authors.initials: D
authors.lastname: Qiao
authors.affiliation: Centre for Polymer from Renewable Resources, South China University of Technology, Guangzhou, PR China.
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Liu
authors.affiliation: Centre for Polymer from Renewable Resources, South China University of Technology, Guangzhou, PR China; Department of Materials Engineering, Monash University, Clayton, Australia. Electronic address: felyu@scut.edu.cn.
authors.forename: Long
authors.initials: L
authors.lastname: Yu
authors.affiliation: Centre for Polymer from Renewable Resources, South China University of Technology, Guangzhou, PR China.
authors.forename: Xianyang
authors.initials: X
authors.lastname: Bao
authors.affiliation: Department of Materials Engineering, Monash University, Clayton, Australia.
authors.forename: George P
authors.initials: GP
authors.lastname: Simon
authors.affiliation: CSIRO, Manufacturing, Melbourne, Australia.
authors.forename: Eustathios
authors.initials: E
authors.lastname: Petinakis
authors.affiliation: Centre for Polymer from Renewable Resources, South China University of Technology, Guangzhou, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
keywords: Different botanical origins; Nutrient slow-release; Slow-release fertilizer; Starch-based superabsorbent polymer