NOVELTY - Fertilizer composition and preparation are claimed. The oilseed rape straw compound fertilizer composition comprises 1000 pts. wt. dry straw, 2500 pts. wt. biogas slurry, 400-500 pts. wt. urea, 60-90 pts. wt. monopotassium phosphate, 80-110 pts. wt. boric acid, 40-50 pts. wt. chromium trichloride, 40-50 pts. wt. manganese chloride, 100-120 pts. wt. zinc sulfate, 20-30 pts. wt. polyaspartic acid, 15-20 pts. wt. Trichoderma, 9-15 pts. wt. Micromonospora and 20-30 pts. wt. Polyangium cellulosum.    USE - The oilseed rape straw compound fertilizer is useful for slowly releasing drought stress (claimed).    DETAILED DESCRIPTION - Fertilizer composition and preparation are claimed. The oilseed rape straw compound fertilizer composition comprises 1000 pts. wt. dry straw, 2500 pts. wt. biogas slurry, 400-500 pts. wt. urea, 60-90 pts. wt. monopotassium phosphate, 80-110 pts. wt. boric acid, 40-50 pts. wt. chromium trichloride, 40-50 pts. wt. manganese chloride, 100-120 pts. wt. zinc sulfate, 20-30 pts. wt. polyaspartic acid, 15-20 pts. wt. Trichoderma, 9-15 pts. wt. Micromonospora and 20-30 pts. wt. Polyangium cellulosum. The preparation involves (a) selecting normal biogas production for not less than 2 months, (b) irradiating Co60 with Trichoderma and Micromonospora for 10 minutes, (c) mixing chopped dry straw with biogas, adding monopotassium phosphate to mixture, adding low amount of Micromonospora and P.cellulosum to the mixture, stirring the mixture, and performing aerobic fermentation at 35-45 degrees C for 30 days, (d) mixing Trichoderma and urea to the fermented mixture, stirring the mixture, performing anaerobic fermentation by closing fermentor at 45-50 degrees C for 2 days, increasing the temperature to 60-75 degrees C and maintaining for 3-5 days, and lowering the temperature to 50-55 degrees C, and maintaining the temperature of the mixture for 6-30 days, and (e) adding boric acid to the obtained mixture at room temperature, adding chromium trichloride, manganese chloride, zinc sulfate, and polyaspartic acid to the mixture, mixing and packing the mixture.