NOVELTY - Slow-release fertilizer comprises quartz sand, wood pulp, pomelo leaves, Fimbristylis miliacea, rice bran, clay, agar, microbial inoculum, urea, EDTA, ammonium sulfate, potassium nitrate, fulvic acid, additives and water. The additive comprises zinc gluconate, nanocarbon powder, wintergreen oil, maifan stone powder, ammonium persulfate, iron ore tailing, methyl methacrylate, borax, glycerol and water.    USE - The slow-release fertilizer is useful for apple (claimed).    ADVANTAGE - The slow-release fertilizer improves fertility of soil, and reduces nutritional loss in crops.    DETAILED DESCRIPTION - Slow-release fertilizer comprises 10-12 pts. wt. quartz sand, 12-14 pts. wt. wood pulp, 6-8 pts. wt. pomelo leaves, 8-10 pts. wt. Fimbristylis miliacea, 8-10 pts. wt. rice bran, 15-17 pts. wt. clay, 1-2 pts. wt. agar, 2-3 pts. wt. microbial inoculum, 12-14 pts. wt. urea, 2-4 pts. wt. EDTA, 4-6 pts. wt. ammonium sulfate, 5-7 pts. wt. potassium nitrate, 2-3 pts. wt. fulvic acid, 4-5 pts. wt. additives and water (remainder). The additive comprises 1-2 pts. wt. zinc gluconate, 0.5-1.5 pts. wt. nanocarbon powder, 0.8-1.4 pts. wt. wintergreen oil, 2-3 pts. wt. maifan stone powder, 0.5-1 pt. wt. ammonium persulfate, 10-15 pts. wt. iron ore tailing, 3-5 pts. wt. methyl methacrylate, 4-6 pts. wt. borax, 2-3 pts. wt. glycerol and water (remainder). The additive is prepared by dissolving glycerol in water in a weight ratio of 1:8, adding zinc gluconate, nanocarbon powder, wintergreen oil, maifan stone powder, ammonium persulfate, and methyl methacrylate to dissolved mixture, and heating mixture at 80-90 degrees C for 20-30 minutes, mixing heated mixture with remaining raw materials, and drying and crushing product. An INDEPENDENT CLAIM is included for method for preparing the fertilizer, which involves (a) adding agar to water in a ratio of 1:150, dissolving mixture and adding quartz sand, stirring mixture for 30-40 minutes, cooling stirred mixture to room temperature, and filtering stirred mixture, (b) crushing pomelo leaves and adding water, adding rice bran, clay, and microbial inoculum to mixture, adding water to mixture in a ratio of 1:10, and fermenting mixture at 35-40 degrees C for 12-15 days, (c) mixing urea, EDTA, ammonium persulfate, potassium nitrate, fulvic acid, and additives, adding 12-15 times water to mixture, heating mixture, and adding products obtained in the steps (a) and (b), and (d) drying and crushing obtained mixture.