NOVELTY - Slow-release granular fertilizer comprises corn straw powder, leaf powder, root stimulating agent, pig manure, urea, bean straw powder, ammonium sulfate, calcium-magnesium phosphate fertilizer, sweet potato powder, potassium chloride, potassium sulfate, zinc sulfate, ferrous sulfate, borax, peanut shell powder, copper sulfate, slow release carrier, and microorganism strain.    USE - As slow-release granular fertilizer.    ADVANTAGE - The fertilizer improves nutrient content, pH of soil and growth speed of plant, is environmentally-friendly and cost-effective, and can be prepared simply.    DETAILED DESCRIPTION - Slow-release granular fertilizer comprises 60-80 pts. wt. corn straw powder, 70-90 pts. wt. leaf powder, 10-20 pts. wt. root stimulating agent, 30-50 pts. wt. pig manure, 10-20 pts. wt. urea, 5-10 pts. wt. bean straw powder, 50-60 pts. wt. ammonium sulfate, 1-3 pts. wt. calcium-magnesium phosphate fertilizer, 20-30 pts. wt. sweet potato powder, 15-30 pts. wt. potassium chloride, 5-8 pts. wt. potassium sulfate, 4-8 pts. wt. zinc sulfate, 2-5 pts. wt. ferrous sulfate, 1-3 pts. wt. borax, 20-30 pts. wt. peanut shell powder, 2-4 pts. wt. copper sulfate, 20-25 pts. wt. nano slow release carrier and 10-14 pts. wt. microorganism strain. The nano slow release carrier is prepared by (a) mixing silicon hydroxyapatite, attapulgite, hydrotalcite, montmorillonite, titanium pigment, calcite and kaolin in a weight ratio of 35-45:10-15:10-15:8-10:8-10:7-8:5-7, adding 230 pts. wt. dimethyl sulfoxide (DMSO) and 50 pts. wt. methanol, stirring mixture at 60 degrees C for 65 hours, filtering using hot ethanol of 60 degrees C, removing excess of DMSO, vacuum-drying mixture, drying at 60 degrees C for 24 hours, crushing and sieving to obtain modified compound, mixing 1 pts. wt. modified compound, 15 pts. wt. potassium acetate and 25 pts. wt. distilled water, heating mixture at 50 degrees C for 10 hours, dispersing for 3.5 hours under ultrasonic electric power of 250-350 W for 4 hours, filtering, washing filtrate using distilled water for 3 times, vacuum-drying at 80 degrees C for 24 hours, crushing and sieving to obtain second modified compound, adding 1 pts. wt. second modified compound, ultrasonically dispersing at 600 W for 60 minutes, heating at 90 degrees C, and stirring mixture at 1200 revolutions per minute (rpm) for 60 minutes by machinery stirrer. An INDEPENDENT CLAIM is included for method for preparing the fertilizer, which involves mixing the above-mentioned raw materials except microorganism strain, corn stalk powder and pig manure, stirring mixture for 45-55 minutes, crushing raw materials into 60 meshes sieve, fermenting the raw materials in fermentation tank, adding microorganism strain, adding water to fermentation tank, fermenting mixture at 30-40 degrees C for 5 days, mixing obtained fermented mixture with corn stalk powder and pig manure, naturally drying, storing mixture at 120-140 degrees C for 2 hours, sterilizing mixture at 120-140 degrees C, drying mixture at 120-140 degrees C for 10-15 minutes, and preparing into granule through pelletizer.