TECHNOLOGY FOCUS - BIOLOGY - Preferred Component: The nutritive soil is prepared by mixing peat, natural soil, diatomaceous earth, composting manure, blast furnace slag and sustained-release granules in a weight ratio of 5-8:0.5-1:4-6:3-5:2-3:1-2. The sustained-release granules are prepared by using 20-30 pts. wt. urea, 10-15 pts. wt. potassium dihydrogen phosphate, 8-12 pts. wt. light calcium powder, 2-3 pts. wt. magnesium sulfate, 1-2 pts. wt. trimethylolpropane triacrylate, 0.5-1 pts. wt. borax, 15-20 pts. wt. sucrose powder, 10-15 pts. wt. illite, 5-10 pts. wt. meerschaum, 5-10 pts. wt. coal gangue, 3-4 pts. wt. Rhododendron molle, 1.5-2.5 pts. wt. neem bark, 2-3 pts. wt. maple leaves, 1-2 pts. wt. Stemona sessilifolia, 2-3 pts. wt. Ailanthus leaves, 16-22 pts. wt. chitosan, 5-10 pts. wt. polysodium aspartate, 1.5-2.5 pts. wt. Tween-80 (RTM: Polysorbate 80) and 3-5 pts. wt. carboxymethyl cellulose, mixing the R.molle, neem bark, maple leaves, S.sessilifolia and Ailanthus leaves in the above-mentioned weight proportions, adding water to the raw materials in an amount 8-12 times with respect to total amount of the raw materials, extracting mixture for 1-2 hours, filtering obtained extract, adding water to residues in an amount 5-10 times with respect to total amount of the residues, performing extraction for 0.5-1 hour, filtering extract, mixing filtrate, adding illite, meerschaum and coal gangue to obtained mixed filtrate solution, placing obtained solution in water bath, heating the solution to 70-80 degrees C for 1-2 hours, homogenizing solution for 20-30 minutes, spray-drying homogenized solution to obtain powder, mixing the powder with urea, potassium dihydrogen phosphate, trimethylolpropane triacrylate acetate, magnesium sulfate, sucrose powder, light calcium powder and borax uniformly, granulating obtained mixture, drying obtained granules, dissolving 2% chitosan in acetic acid solution to obtain 15-20 g/l chitosan colloidal solution, adding polysodium aspartate, Tween-80 (RTM: Polysorbate 80) and carboxymethyl cellulose to the chitosan colloidal solution, placing obtained solution in water bath, heating the solution to 50-60 degrees C, stirring the solution for 5-10 minutes, slowly coating the solution on to the dried granules using atomizing nozzle to obtain uniformly coated sustained-release granules and drying the granules.