Recently, fluorescent carbon dots (CDs) from the family of carbon nanomaterials have attracted considerable interest in agriculture. The purpose of this study was to compare the effects of a slow-release Zn fertilizer based on carbon dots (Zn-NCDs) to commercial fertilizers (ZnSO4 and Zn-EDTA) on bread wheat (cv. Sirvan) growth in calcareous soil. Zn-NCDs was synthesized using citric acid, urea, and ZnCl2 and identified utilizing instrumental analysis. Then, the stability of the new nano-fertilizer was tested at different pH levels and its ability to slowly release micronutrient Zn in the soil was evaluated. The greenhouse experiment was completely randomized, composed of 4 treatments and 3 replications. Treatments consisted of various Zn sources (ZnSO4, Zn-EDTA, and Zn-NCDs) and treatment without Zn as a control. After maturity, the plant tissues were collected to measure the growth and yield parameters, the concentration of Zn and N, and the content of chlorophyll. Zn-NCDs with a small particle size and high surface area have a greater capacity to hold nutrients, reducing the loss of excess fertilizer. Zn-NCDs significantly as a slow-release fertilizer increased the Zn concentration in grains by 78.83% and 29.73% compared to ZnSO4 and Zn-EDTA treatments, respectively. Additionally, Zn-NCDs treatment significantly increased N and chlorophyll content, morphological parameters, and yield while decreasing phytic acid concentration compared to commercial Zn fertilizers. Incorporating Zn into CDs is a new strategy to enhance the availability of Zn in calcareous soil, potentially replacing conventional Zn fertilizers and simultaneously boosting crop yield and nutrient content.

Keywords