Kinetics of slow release of nitrogen fertiliser from multi-layered nanofibrous structures

Leila Javazmi,Gavin J Ash,Tobias Low,Anthony Young

doi:10.1038/s41598-021-84460-x

Abstract

Fertilisers are essential in modern agriculture to enhance plant growth, crop production and product quality. Recent research has focused on the development of delivery systems designed to prolong fertiliser release. This study introduces a new technology to encapsulate and release molecules of fertilisers by using multi-layered electrospun nanofibre as a carrier. Single-layer poly L-lactic acid (PLLA) nanofibres loaded with urea were fabricated using electrospinning. Triple-layer nanofibrous structures were produced by electrospinning polyhydroxybutyrate (PHB) nanofibres as external layers with PLLA nanofibres impregnated with urea fertiliser as the middle layer. Scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR) were employed to characterize the morphology of electrospun nanofibres. Urea release dynamic was analysed using a total nitrogen instrument (TNM-1). The results indicated that triple-layered urea-impregnated nanofibrous structures led to lower initial rate of nitrogen release and slower release rate of cumulative nitrogen which extended for more than three months. It is concluded that triple-layer nanofibrous structures have the potential for slow release delivery of fertilisers.

Highlights

Fertilisers are essential in modern agriculture to enhance plant growth, crop production and product quality
Custom electrospinning apparatus was used to produce single-layered poly L-lactic acid (PLLA) nanofibres loaded with different concentrations of urea
The PLLA solution was fixed at 5% (w/w), while urea was loaded at 10%, 20%, and 40% (w/w), relative to the mass amount of PLLA, and transferred to a 1 mL syringe with an attached 18-gauge blunt tip needle

Summary

Introduction

Fertilisers are essential in modern agriculture to enhance plant growth, crop production and product quality. Electrospun nanofibres are ideal porous membranes given their open-pore structure (tens of nanometres to one micrometre), high surface area and high gas permeability. Such nanofibres have been used in areas as diverse as filtrations, nanocomposites, drug delivery, biomedical, medical prostheses, fuel cells, sensors, and protective clothing[5,8]. Recent investigations have focused on the development of systems using different materials that prolong the release of fertilisers[11] These systems aim to minimise soil contamination by controlling fertiliser release using low cost sustainable m aterials[10]. Urea is a cost-effective solid nitrogen-based fertiliser used to promote plant growth and increase crop production. Significant research efforts have focused on prolonged-released systems that minimise adverse environmental impacts and increase the efficiency of urea fertiliser u se[16]

Methods

Results

Conclusion