NOVELTY - Sustained-release fertilizer comprises 15-17 pts. wt. yellow phosphorus slag, 8-10 pts. wt. lime stone, 1-2 pts. wt. agar powder, 7-10 pts. wt. dry grass, 14-16 pts. wt. fly ash, 15-18 pts. wt. loess, 3-4 pts. wt. bio-fermentation agents, 3-5 pts. wt. epsilon -polylysine, 4-6 pts. wt. sodium carbonate, 6-8 pts. wt. potassium fulvate, 2-3 pts. wt. ammonium phosphate, 12-14 pts. wt. urea, 3-5 pts. wt. ammonium sulfate, 4-5 pts. wt. auxiliary agent and water (suitable amount). The auxiliary agent comprises e.g. leaf of Chinese Ilex oil, medicinal stone powder and ammonium persulfate.    USE - The fertilizer is useful for growing fruits and vegetables (claimed).    ADVANTAGE - The fertilizer comprising limestone maintains sandiness of the ground; facilitates sustained release of nutrients; prevents soil compaction, and nutrient loss; utilizes dry weeds, and straw as raw materials, and recyclable minerals; and meets the healthcare and environmental protection requirements.    DETAILED DESCRIPTION - Sustained-release fertilizer comprises 15-17 pts. wt. yellow phosphorus slag, 8-10 pts. wt. lime stone, 1-2 pts. wt. agar powder, 7-10 pts. wt. dry grass, 14-16 pts. wt. fly ash, 15-18 pts. wt. loess, 3-4 pts. wt. bio-fermentation agents,3-5 pts. wt. epsilon -polylysine, 4-6 pts. wt. sodium carbonate, 6-8 pts. wt. potassium fulvate, 2-3 pts. wt. ammonium phosphate, 12-14 pts. wt. urea, 3-5 pts. wt. ammonium sulfate, 4-5 pts. wt. auxiliary agent and water (suitable amount). The auxiliary agent comprises 1-2 pts. wt. zinc gluconate, 0.5-1.5 pts. wt. nano-carbon powder, 0.8-1.4 pts. wt. leaf of Chinese Ilex oil, 2-3 pts. wt. medicinal stone powder, 0.5-1 pts. wt. ammonium persulfate, 10-15 pts. wt. nano-iron ore tailings, 3-5 pts. wt. methyl methacrylate, 4-6 pts. wt. borax, 2-3 pts. wt. glycerol and water (suitable amount). The preparation comprises mixing glycerol with water in a ratio of 1:10 until the mixture gets dissolved, then adding zinc gluconate, nano-carbon powder, Chinese Ilex oil, methyl methacrylate and ammonium persulfate, and heating at 80-90 degrees C, and stirring for 20-30 minutes, mixing by adding nano-iron ore tailing and borax, into a paste form, drying, and crushing. An INDEPENDENT CLAIM is also included for preparing the fertilizer, comprising (i) crushing limestone into sand-type powder, adding agar powder and water in a ratio of 1:150, heating while stirring to dissolve, then pouring sand-type limestone powder, stopping the heating process, and stirring at normal temperature for 30-45 minutes, filtering, and cooling to room temperature to obtain powder; (ii) crushing agar powder by adding water, and drying, then mixing by adding yellow phosphorus slag, fly ash and loess, and simultaneously adding water and bio-fermentation agent in a ratio of 1:10, dissolving, spraying organic material onto the mixed material, uniformly mixing, adjusting the water content to 30-40%, and fermenting for 12-15 days at 35-40 degrees C; (iii) mixing epsilon -polylysine, sodium carbonate, potassium fulvate, ammonium phosphate, urea, ammonium sulfate, auxiliary agent and other remaining components, adding water in an amount of 1-14 times, and stirring to dissolve by adding water; (iv) mixing the extracts of the step (i) with limestone powder and the organic material, and stirring by turning over, and uniformly spraying the mixed materials, simultaneously, and drying, adjusting the water content to less than or equal to 20%, and carrying out ultra-micro crushing, granulating until the particle diameter is 4-5 mm, and adding the materials into a bag film.