Slow-released urea (SRU) is produced by encapsulating urea granules in a hydrophobic (or less water-soluble) material like polymer or inorganic (sulfur, gypsum and phosphate) material. It is a green approach that not only minimizes the nitrogen loss due to volatilization and leaching but also changes the kinetics of nitrogen release, which in turn provides the crops with nutrients at a rate that is more congruent with the metabolic activities of the plant. However, common materials used to produce SRU are non-biodegradable, brittle, or hydrophilic. Moreover, the production of SRU requires the usage of harmful solvents to dissolve the polymers for coating. Inverse vulcanized copolymers are green and sustainable copolymers with high sulfur content, and better thermal stability produced using a facile solvent-free method. Currently, monomers use to produce these copolymers are non-biodegradable, expensive, or have demand in the food market. Herein, we reported the synthesis of sulfur enriched slow-release fertilizer from a copolymer produced using non-edible oil via inverse vulcanization method. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of the copolymer based on disappearance of C=C and C=C-H peaks at 1660 and 3009 cm-1, indicating the utilization of double bond for the formation of the C-S bond. The slow-release fertilizer (SRF) was produced by mechanically mixing the polymer with urea powdered using a mechanical mixer at a speed of 150 rpm for 10 mins. The produced SRF was then characterized using FTIR and scanning electron microscopy (SEM) to confirm that no reaction took place and to investigate the distribution of the nitrogen on the surface of the copolymer. The appearance of new peaks associated with urea in the spectrum of the SRF in addition to the unchanged peaks of copolymers confirmed the successful formation of the SRF. However, the SEM-EDX revealed that the nitrogen distribution on the surface of the copolymer was not uniform. Sulfur enriched SRF has been successfully produced using a facile solvent free method. The slow-release properties of these SRF will be investigated in future study. © 2023 Author(s).