NOVELTY - A slow release compound fertilizer comprises 10-15 pts. wt. 1250-2000 meshes diatomite, 23-25 pts. wt. urea, 4-6 pts. wt. quicklime, 5-6 pts. wt. slaked lime, 4-7 pts. wt. magnesite, 1-3 pts. wt. ammonium citrate, 6-8 pts. wt. polyaspartic acid, 12-15 pts. wt. sodium alginate, 3-5 pts. wt. livestock plasma, 6-8 pts. wt. dried Enteromorpha powder, 15-18 pts. wt. rotten cattle manure, 12-13 pts. wt. potato slag, 1-3 pts. wt. silicon dioxide, 0.1-0.2 pt. wt. zinc oxide, 0.001-0.002 pt. wt. cerium oxide, 5-8 pts. wt. sodium oleate, and 4-5 additive.    USE - Slow release compound fertilizer used for improving soil and promoting growth of crop.    ADVANTAGE - The fertilizer has wide source of raw materials, has high organic matter fertilizer effect, is easily absorbed by crops, protects soil environment, has double nutrient effect and good slow release control lasting ability, and increases crop production.    DETAILED DESCRIPTION - A slow release compound fertilizer comprises 10-15 pts. wt. 1250-2000 meshes diatomite, 23-25 pts. wt. urea, 4-6 pts. wt. quicklime, 5-6 pts. wt. slaked lime, 4-7 pts. wt. magnesite, 1-3 pts. wt. ammonium citrate, 6-8 pts. wt. polyaspartic acid, 12-15 pts. wt. sodium alginate, 3-5 pts. wt. livestock plasma, 6-8 pts. wt. dried Enteromorpha powder, 15-18 pts. wt. rotten cattle manure, 12-13 pts. wt. potato slag, 1-3 pts. wt. silicon dioxide, 0.1-0.2 pt. wt. zinc oxide, 0.001-0.002 pt. wt. cerium oxide, 5-8 pts. wt. sodium oleate, and 4-5 additive. The additive comprises 12-15 pts. wt. poultry feather, 30-40% 30-35 pts. wt. sulfuric acid solution, sodium hydroxide, 0.15-0.2 pt. wt. keratinase, 1-2 pts. wt. copper citrate, 1-2 pts. wt. manganese citrate, 1-2 pts. wt. zinc citrate, 20-22 pts. wt. medical stone powder, and 5-6 pts. wt. sodium silicate. The additive is prepared by washing poultry feather with water, high temperature sterilizing, crushing, adding sulfuric acid solution, hydrolyzing for 15-18 hours, adding sodium hydroxide solution, regulating pH value to 6.5-7.0, heating to 50-60 degrees C, adding keratinase, enzymolyzing for 12-15 hours, adding copper citrate, manganese citrate, and zinc citrate, stirring, reacting for 2-3 hours, adding sodium silicate, continuously stirring for 30-40 minutes, adding medical stone powder, stirring, drying, and grinding for 40-50 minutes. An INDEPENDENT CLAIM is included for the preparation of fertilizer comprising mixing quicklime, magnesite, livestock plasma, dried Enteromorpha powder, and potato pulp; mixing equal parts of water and diatomite, grinding for 20-30 minutes, adding ammonium citrate, cerium oxide, and zinc oxide, stirring, and drying to prepare coating material; dissolving sodium alginate and sodium oleate in deionized water, heating to 40-60 degrees C, stirring, adding polyaspartic acid and silicon dioxide, and dispersing to obtain sustained-released agent; and mixing product in first and second steps, granulating, adding sustained release coating agent, hot air drying, and cooling to room temperature.