NOVELTY - Polymer-coated fertilizer comprises fishpond sludge, oxyfluorfen, cactus, methionine, corn bran, castor oil, fresh chicken manure, rapeseed cake, fish meal, humic acid, vermicompost, straw ash, effective microorganism (EM) bacterial agent, modified bamboo fiber, polyvinyl alcohol, urea, potassium nitrate, superphosphate, diatomitenanocarbon, zinc sulfate, butyl acrylate, 2-ethylhexyl acrylate, acrylonitrile, fatty alcohol ethoxylate, sodium persulfate and suitable amount of water.    USE - The fertilizer is useful for controlling weeds (claimed).    ADVANTAGE - The fertilizer improves soil quality, promotes soil aggregating, and protects soil.    DETAILED DESCRIPTION - Polymer-coated fertilizer comprises 42-48 pts. wt. fishpond sludge, 0.01-0.02 pt. wt. oxyfluorfen, 23-26 pts. wt. cactus, 2-3 pts. wt. methionine, 40-45 pts. wt. corn bran, 0.4-0.9 pt. wt. castor oil, 34-38 pts. wt. fresh chicken manure, 38-44 pts. wt. rapeseed cake, 14-18 pts. wt. fish meal, 4-7 pts. wt. humic acid, 32-37 pts. wt. vermicompost, 21-25 pts. wt. straw ash, 7-9 pts. wt. effective microorganism (EM) bacterial agent, 12-13 pts. wt. modified bamboo fiber, 3-5 pts. wt. polyvinyl alcohol, 23-27 pts. wt. urea, 13-17 pts. wt. potassium nitrate, 16-25 pts. wt. superphosphate, 3-4 pts. wt. diatomite, 2-4 pts. wt. nanocarbon, 2-3 pts. wt. zinc sulfate, 0.1-0.3 pt. wt. butyl acrylate, 1-3 pts. wt. 2-ethylhexyl acrylate, 3-5 pts. wt. acrylonitrile, 0.2-0.4 pt. wt. fatty alcohol ethoxylate, 0.2-0.4 pt. wt. sodium persulfate and suitable amount of water. The modified bamboo fiber comprises 2-4 pts. wt. nano calcium carbonate, 3-5 pts. wt. nano iron ore tailings, 6-8 pts. wt. nano attapulgite, 73-80 pts. wt. bamboo fiber, 18-23 pts. wt. acrylic acid, 0.2-0.4 pt. wt. ammonium persulfate, 0.02-0.03 pts. wt. N,N-methylene-bis-acrylamide, 12-14 pts. wt. tung oil, and suitable amount of water. An INDEPENDENT CLAIM is included for method for preparing the fertilizer which involves (a) mixing fishpond sludge, cactus, corn bran, chicken manure, rapeseed cake, fish meal, vermicompost, straw ash and EM agents until moisture content reaches 43-46%, performing aerobic fermentation of mixture for 15-20 days, turning the mixture once in every 14-20 hours, and granulating the mixture using a granulator to obtain granules, (b) dissolving fatty alcohol ethoxylate using water, adding diatomite to dissolved fatty alcohol ethoxylate, stirring the mixture at 1000-1200 rotations per minute (rpm) to obtain suspension, adding zinc sulfate, nanocarbon, polyvinyl alcohol and modified bamboo fiber, grinding the mixture uniformly, and dispersing the ground mixture to obtain viscous coating layer, and (c) mixing the products obtained in steps (a), and (b), adding the remaining materials to the mixture, heating the mixture at 70 degrees C, cooling the heated mixture, and granulating the mixture.