Abstract
In this study, biodegradable slow-release fertilizer (SRF) hydrogels were synthesized from hydroxyl propyl methyl cellulose (HPMC), polyvinyl alcohol (PVA), glycerol and urea (SRF1) and HPMC, PVA, glycerol, urea and blended paper (SRF2). The fertilizer hydrogels were characterized by SEM, XRD and FTIR. The swelling capacity of the hydrogels in both distilled and tap water as well as their water retention capacity in sandy soil were evaluated. The hydrogels had good swelling capacity with maximum swelling ratio of 17.2 g/g and 15.6 g/g for SRF1 and SRF2 in distilled, and 14.4 g/g and 15.2 g/g in tap water, respectively. The water retention capacity of the hydrogels in sandy soil exhibited higher water retention when compared with soil without the (SRFs). The soil with the hydrogels was found to have higher water retention than the soil without the hydrogels. The slow-release profile of the hydrogels was also evaluated. The result suggested that the prepared fertilizer hydrogels has a good controlled release capacity. The blended paper component in SRF2 was observed to aid effective release of urea, with about 87.01% release in soil at 44 days compared to the pure urea which was about 97% release within 4 days. The addition of blended paper as a second layer matrix was found to help improve the release properties of the fertilizer. The swelling kinetic of the hydrogel followed Schott’s second order model. The release kinetics of urea in water was best described by Kormeye Peppas, suggesting urea release to be by diffusion via the pores and channels of the SRF, which can be controlled by changing the swelling of the SRF. However, the release mechanism in soil is best described by first order kinetic model, suggesting that the release rate in soil is depended on concentration and probably on diffusion rate via the pores and channels of the SRF.
Highlights
The world population is growing rapidly and is expected to reach 9.5 billion by the end of 2050 [1]
SEM technique was used to observe the surface morphologies of the hydrogel (SRF1, technique was used to observe the surface morphologies of the hydrogel and the starting materials (HPMC), and the results are presented in Figure(SRF1, 1
From and the starting materials (HPMC), and the results are presented in Figure 1A, it can be seen that hydroxyl propyl methyl cellulose (HPMC) powder is a porous spongy particle like1.materials
Summary
The world population is growing rapidly and is expected to reach 9.5 billion by the end of 2050 [1]. Desertification and land degradation caused by heavy flooding have diminished arable land and threatened global food security [2]. Global food requirements have risen and is likely to double by. To meet the increasing food demand, the agricultural sector is bound to use even larger quantities of fertilizer that have being demonstrated to have serious undesirable environmental impacts [1]. The use of conventional or mineral fertilizers tends to reach 2.5 million tonnes with subsequent growth of 1.8 percent per year for its demand and supply gap [4]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
