NOVELTY - Liquid fertilizer film comprises 12-14 pts. wt. coffee beans, 28-32 pts. wt. fish meal, 4-6 pts. wt. boric acid, 3-6 pts. wt. complex microbial inoculants, 13-16 pts. wt. modified starch solution, 20-24 pts. wt. boron humate, 32-36 pts. wt. edible mushroom residue and water. The complex microbial inoculant is made of silicate microbial inoculant, Bacillus subtilis and photosynthetic bacteria microbial inoculant at ratio of 2:1:1.    USE - Liquid fertilizer film used for reducing soil bulk density, increasing soil temperature and soil moisture, promoting growth and development of maize and increasing yield.    ADVANTAGE - The product has strong adsorption and heat insulation performance.    DETAILED DESCRIPTION - Liquid fertilizer film comprises 12-14 pts. wt. coffee beans, 28-32 pts. wt. fish meal, 4-6 pts. wt. boric acid, 3-6 pts. wt. complex microbial inoculants, 13-16 pts. wt. modified starch solution, 20-24 pts. wt. boron humate, 32-36 pts. wt. edible mushroom residue and water. The complex microbial inoculant is made of silicate microbial inoculant, Bacillus subtilis and photosynthetic bacteria microbial inoculant at ratio of 2:1:1. The modified starch solution prepared by taking 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, dissolving potato starch in 2 times the mass of water, heating at 70-90 degrees C for 30-60 minutes, adding solution of potassium permanganate, oxidizing for 50-70 minutes, stirring, adding acrylic acid, sodium hydroxide and N,N'-methylenebisacrylamide, crosslinking for 20-30 minutes, adding calcium acetate, stirring, heating, adding ferrous sulfate, chelating at 50-60 degrees C for 15 minutes, stirring, adding zinc sulfate, chelating for 15 minutes, adding manganese sulfate and chelating at 60-80 degrees C for 20-30 minutes. An INDEPENDENT CLAIM is included for preparation of liquid fertilizer film comprising mixing boron humate, edible mushroom residue and fish meal into the fermentation tank, adding 45-55% water, fermenting for 3-4 weeks to obtain fermented liquid, drying coffee beans at 60-80 degrees C, grinding into fine powder, adding water, heating at 80-90 degrees C, stirring for 5-10 minutes, cooling to 30 degrees C, adding silicate microbial inoculant, Bacillus subtilis and photosynthetic bacteria microbial inoculant to coffee liquid, stirring, filtering, drying filtrate, milling at 25-35 degrees C to obtain fixed microbial agents soluble coffee powder, mixing fermentation broth and modified starch solution, adding into the oven, drying at 100-120 degrees C for 30-40 minutes, cooling, sieving into 200 mesh, mixing the resulting powder, boric acid and residual materials, drying at 60-70 degrees C, mixing powder and water at mass ratio of 1:9 and spraying on the surface of the soil where amount of dilution per acre is 15-25 kg.