Use of kitosan for controlled release of nitrogen fertilizers

Commercial fertilizers used traditionally cause environmental pollution by accumulating in the soil or mixing with the waters through leaks. To solve this problem, controlled release fertilizers have been developed, but due to the use of petroleum-derived polymers in this type of commercially produced controlled fertilizers, these toxic polymers are taken by the plant or accumulated in the soil, resulting in both human health and adverse effects on the environment. In order to prevent these problems, in the present study, controlled release fertilizers were developed by using coating materials of biological origin (mainly chitosan and additionally cellulose and molasses). In this context, in this thesis, three different coated new fertilizer systems were produced for nitrogen-based urea and 15-15-15 fertilizers. These are powder, film and disc forms. Samples in different forms produced after coating were characterized using fourier transform infrared spectrometry (FT IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), determination of their elemental composition (EDS), X-ray diffraction method (XRD) techniques. The percentages of soil degradation of the samples were determined. The results obtained showed important results, especially in urea, and their potential for industrial use was revealed.