Chitosan-Based Polyion Multilayer Coating on NPK Fertilizer as Controlled Released Fertilizer

Abstract

Low efficiency of conventional fertilizer (quick release fertilizer) application in agricultural sectors has caused environmental pollution and health problems. A method to overcome the drawback of the conventional fertilizer is by controlled release fertilizer (CRF) preparation. CRF is expected to be able to fulfil the nutrient demand of targeted plants. The objective of this research is to prepare CRF by coating NPK fertilizer with multilayer chitosan-polyanion using alginate, pectin, and sodium tripolyphosphate (TPP). In addition, the effect of the layer arrangement modification of material on the rate of nitrogen release was also studied. The mechanical strength of coated fertilizer was analysed by compressive stress test and the properties of the fertilizer coating was observed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The nitrogen release study shows that multilayer of chitosan-alginate (CA)5, chitosan-pectin (CP)5, and chitosan-TPP (CT)5 as coating material was able to increase the compressive stress and decrease the nitrogen release of coated fertilizer. These results are supported by the FTIR analysis which exhibits the formation of ionic interaction between amine group of chitosan and carboxyl group of alginate in chitosan-alginate (CA)5 layer, carboxyl group of pectin in chitosan-pectin (CP)5 layer, and phosphate of TPP in chitosan-TPP (CT)5 layer. On the other hand, the modification of the arrangement of chitosan-alginate layers showed that the fertilizer with the alternating layer arrangement (CA)5 was able to optimally increase the compressive strength. The mathematical model for the nitrogen release of coated fertilizer is also prepared and simulated with the MATLAB software. The simulation results showed that the nitrogen release of coated fertilizer followed the proposed diffusion mechanism. The obtained diffusivity coefficient value in the layer of chitosan-alginate (CA)5 is 2.0933 × 10−6 cm2/s, 2.5606 × 10−6 cm2/s in chitosan-TPP (CT)5 layer, and 3.7256 × 10−6 cm2/s in chitosan-pectin (CP)5 layer.

Simulation of Nitrogen Release from Chitosan/Local Organic Fertilizer Composite as Slow-Release Fertilizer

“…Therefore, it can be concluded that chitosan as binder was able to decrease the nitrogen release rate of the prepared fertilizer. This result can also be compared to a previous experiment reported by Kusumastuti et al (2019) The simulation result of nitrogen release with some empirical equation is shown in Figure 5 where the constant value is shown in Table 3. From Figure 5 a, b and c, the nitrogen release data follow the diffusion-relaxation and diffusion-erosion model rather than zero order kinetic model.…”

“…Furthermore, the application of inorganic fertilizer needs high-cost labor due to several times of fertilization usage in one cycle of planting periods (Zhang et al, 2018). França et al, 2018;Jannoura et al, 2014;Kusumastuti et al, 2019;Wang et al, 2018;Zhao et al, 2016 -Zahrani, 1999;Purnomo et al, 2018).…”

“…Apart from that, chitosan is an organic material that has a potential as a binder. Some studies said that chitosan as a coating material on NPK fertilizer was able to decrease the nitrogen release and improve its mechanical strength (Kusumastuti et al, 2019). Chitosan is a polysaccharide which consists of glucosamine and N-acetyl glucosamine with β1-4 glycosidic bonding (Mardyaningsih et al, 2014;Rinaudo, 2006).…”

Vinasse-Based Slow-Release Organo-Mineral Fertilizer with Chitosan-Bentonite Matrix

“…Chitosan is one of the biobased materials which has a high potential to be used as a matrix in the slow-release fertilizer. Multilayer chitosan mixed with alginate, pectin, and sodium tripolyphosphate (TPP) produced a nitrogen release controlling mechanism (Kusumastuti et al, 2019). Chitosan blended with montmorillonite clay (MMt) microparticles were capable to maintain the concentration of the potassium release in the soil (Messa et al, 2019).…”

Chitosan in modern agriculture production

“…The overwhelming demand for food in line with the ever-increasing global population has given rise to additional exploration to produce sufficient food with sustainable agriculture to satisfy consumers' current nutritional needs (Zhang et al 2017). Fertilisers are crucially important for delivering nutrients to plants to produce high-quality crops for food security (Kusumastuti et al 2019). Similarly, pesticides are chemicals used to eliminate pests and pathogens.…”