Preparation and characterization of multifunctional slow release fertilizer coated with cellulose derivatives
Manxian Zhang, Jisheng Yang
Abstract
To enhance the effectiveness of fertilizers, a novel double-coated multifunctional slow-release fertilizer (DMSRF) was developed using urea as the core, ethyl cellulose (EC) as inner coating and cellulose-based superabsorbent polymer (cellulose-SAP) adsorbing biochemical inhibitors dicyandiamide (DCD) and thiourea as outer coating. The cellulose-SAP was synthesized by acid-pretreated cellulose grafted acrylic acid and acrylamide, and was characterized by FTIR, TGA and C13-NMR. The water absorbency, water-retention and adsorption for DCD and thiourea of cellulose-SAP were studied. The cellulose-SAP not only showed excellent water absorbency and water-retention capacity of soil, but could significantly adsorb biochemical inhibitors. In soil, compared with urea, the DMSRF exhibited a steady release behavior for a period longer than one month. In contrast with the coated materials un-adsorbed biochemical inhibitors, the DMSRF could control the nitrate content to a lower level. The study showed that the DMSRF not only has the functions of water retention and slow-release, but also inhibits the conversion of ammonium nitrogen to nitrate nitrogen.