Effect of Temperature on the Behavior of Slow Release Fertilizer from ENR-50/RH/Urea Composites

Generally, chemical fertilizer is considered as a one of the most significant materials for increasing food production. However, the fast release of the conventional fertilizer could effect negatively on the plants. Thus, the idea of using controlled release method in the agriculture application has emerged recently due to the efficiency of fertilizers can be improved by the controlled-release method. The objective of this work is to synthesize a new Slow Release Fertilizer from three different materials; the first one is urea, which is the conventional fertilizer, the second one is the rice husk (RH), which represents the carrier material, and the third one is epoxidized natural rubber (ENR-50), which represents the coating material. This work was divided into three series. The first series is the production of RH/Urea beads. RH was treated with alkaline NaOH at 1wt.% according to the weight of RH. The treated RH was then mixed with urea that produced treated RH/urea beads. In the second series, 200 mg of ENR-50 was applied to produce thicknes of coating material for treated RH/urea beads. In the third series, treated RH/urea beads coated with 200 mg of ENR-50 were subjected to the released behavior at different temperature in the water. After that, the prepared samples were characterized using Scanning Electron Microscopy (SEM) and UV-visible spectroscopy. Results suggested that the increasing of temperature has increased the rate of urea release of SRF samples in the water. Furthermore, the SRF sample at 35, 45, and 55 °C showed shorter time of release at 40, 34, and 17 day as compared to 47 day of SRF at room temperature.