| 초록 |
The aim of this study to investigate the behavior of urea discharge from slow-release urea fertilizer with carrier of bentonite and zeolite minerals on different simulated soil solutions such as acid soil, neutral soil and saline soil. The formed beads and the controlled release ammonium process due to special structure of bentonite, zeolite and membrane forming from alginate and crosslinker calcium chloride. The characterization of products were determined by using XRD, XRF, BET, SEM, as well as swelling study. The other characteristics like entrapment efficiency, bead mass, bead size were also calculated. The content of urea present in simulated soils environment at the certain period of time and mechanism for the release of urea were determined using HPLC. The release of the bentonite-based formations was slower than the zeolite-based formulations from all simulated soils environment. Especially, the ammonium ion release rate in saline soil environment was faster than neutral soil and acid soil. It was found that the mechanism of ammonium ion release occurred through the first order kinetic model. |
