NOVELTY - Liquid fertilizer comprises cottonseed hull, coffee beans, smoke residue, modified starch solution, dried cow dung, urea, complex microbial inoculum, and water, where the microbial inoculum comprises silicate dissolving fungus, Bacillus subtilis and photosynthetic bacteria, and the modified starch solution comprises potato starch, calcium acetate, potassium permanganate solution, acrylic acid, sodium hydroxide, N,N-methylenebisacrylamide, ferrous sulfate, zinc sulfate, and manganese sulfate.    USE - The liquid fertilizer is useful for promoting growth of corn (claimed).    ADVANTAGE - The liquid fertilizer increases soil nutrient content, has excellent quality, improves stress resistance, early maturity and quality, and is environmentally-friendly.    DETAILED DESCRIPTION - Liquid fertilizer comprises 17-19 pts. wt. cottonseed hull, 6-9 pts. wt. coffee beans, 24-25 pts. wt. smoke residue, 11-13 pts. wt. modified starch solution, 30-32 pts. wt. dried cow dung, 8-10 pts. wt. urea, 2-3 pts. wt. complex microbial inoculum, and water (remainder), where the microbial inoculum comprises silicate dissolving fungus, Bacillus subtilis and photosynthetic bacteria microbial inoculum in a ratio of 2:2:1, the modified starch solution comprises 45-55 pts. wt. potato starch, 2-4 pts. wt. calcium acetate, 2-3 pts. wt. potassium permanganate solution, 15-20 pts. wt. acrylic acid, 3-4 pts. wt. sodium hydroxide, 0.1-0.3 pt. wt. N,N-methylenebisacrylamide, 8-10 pts. wt. ferrous sulfate, 6-8 pts. wt. zinc sulfate, and 7-9 pts. wt. manganese sulfate, and the modified starch solution is prepared by dissolving potato starch in 2 times water, heating the mixture at 70-90 degrees C, gelatinizing the mixture for 30-60 minutes, adding potassium permanganate solution to the mixture, subjecting the mixture to oxidation for 50-70 minutes, continuously stirring the mixture, adding acrylic acid, sodium hydroxide and N,N-methylenebisacrylamide to the mixture, cross-linking the mixture for 20-30 minutes, again adding calcium acetate, uniformly stirring the mixture, heating the mixture at 50-60 degrees C, adding ferrous sulfate to the mixture, chelating the mixture for 15 minutes, uniformly stirring the mixture, adding zinc sulfate, stirring the mixture for 15 minutes, adding manganese sulfate, reacting the mixture at 60-80 degrees C for 20-30 minutes, and adding remaining materials to the mixture. An INDEPENDENT CLAIM is included for method for preparing the above-mentioned liquid fertilizer, which involves (a) mixing diatomaceous earth, biogas residue and asphalt in fermentation tank, maintaining water content of the mixture to 40-60% and fermenting the mixture for 3-4 weeks, (b) drying coffee bean at 50-60 degrees C, grinding dried coffee bean, adding water, heating the mixture at 80-90 degrees C, stirring the heated mixture for 15-30 minutes, cooling the mixture to 30 degrees C, inoculating microbial inoculum, uniformly stirring the mixture, filtering the mixture, drying the filtrate at 40-60 degrees C and grinding the filtrate, (c) taking the product obtained in the step (a), adding modified starch solution, uniformly stirring the mixture, drying the mixture at 100-120 degrees C for 20-40 minutes, cooling the mixture and crushing the mixture to mesh size of 200, (d) mixing the products obtained in the steps (b) and (c), adding remaining materials to the mixture, processing the mixture at 40-50 degrees C and packing the obtained mixture in plastic film, and (e) mixing the obtained packed film and water in a mass ratio of 1:9, dissolving the mixture, spray drying the mixture, and diluting the obtained powder using 15-25 kg diluent.