Slow-release fertilizers based on starch acetate/glycerol/polyvinyl alcohol biocomposites for sustained nutrient release

In an effort to enhance the efficiency of fertilizer use and minimize their negative impact on the environment, a novel biomass-based, functional slow controlled-release fertilizer was used for more sustainable agriculture. Here, different biocomposites (CFI-3) based on starch acetate (SA)/polyvinyl alcohol (PVA)/Glycerol (GLY) from aqueous formulations were proposed as an outer hydrophobic coating with different layers for the control of phosphorus (P) and nitrogen (N) releases from diammonium Phosphate fertilizers (DAP). The coating films were analyzed by FTIR, the morphological structures of coated fertilizers were characterized by SEM and EDX, and revealed the formation of a cohesive film and a good adhesion between DAP fertilizer and coating film. The release rate of P and N nutrients in water was investigated by UV-Vis spectrophotometer. The time to reach maximum concentration of N release is 2.4 and 3.2 times than the corresponding uncoated DAP, when the DAP is covered with CF-3 (70 wt% of SA) single-layer (1L) and double-layer (2L) respectively, indicating an improvement slower N release properties. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study aimed to reduce the negative impact of fertilizers on the environment and improve the sustainability of agriculture by using a novel biomass-based, functional slow controlled-release fertilizer. Different biocomposites were proposed as an outer hydrophobic coating to control the release of phosphorus and nitrogen from diammonium Phosphate fertilizers, showing improved slow release properties. The coated fertilizers exhibited cohesive films and good adhesion, leading to slower nitrogen release compared to uncoated DAP.