Biobased Materials for the Development of Biodegradable Slow-Release Fertilizers

According to the regulations of the European Parliament on fertilizer products, by July 2024, all substances used for coating fertilizers should be biodegradable. A series of coated fertilizers was prepared, which differed in the amount of applied coating layer. The core of the composition was granular ammonium nitrate, which contains 27% nitrogen. The effects of the amount of oil layers were examined. The article shows the results of IR testing and Iodine Value of the materials used. The coated fertilizer was evaluated for the release of nutrients under water conditions according to the standard ISO 21263, and the water samples were taken after every day for a 7-day period. The nitrogen content was analysed by elemental analysis. Microscopic pictures of the fertilizer composition were taken before release. The obtained product had potential controlled-release properties and was environmentally friendly. The tested material shows high potential as a component of a two-layer coated fertilizer. This type of fertilizer could be particularly useful in agricultural and horticultural applications.