NOVELTY - Sustained-release organic fertilizer comprises hydrochloric acid solution, dolomite, dried cow manure, corn straw, rice bran, effective microorganism (EM) microbial inoculants, potassium sulfate, ammonium dihydrogen phosphate, potassium permanganate, urea, fertilizer additive and suitable quantity of water, where the fertilizer additive comprises gypsum powder, linseed oil, styrene, sodium stearate, N-methylolacrylamide, ethanol and suitable quantity of water.    USE - The sustained-release organic fertilizer is useful for rice (claimed).    ADVANTAGE - The sustained-release organic fertilizer is easily absorbable, and soluble, and reduces water loss.    DETAILED DESCRIPTION - Sustained-release organic fertilizer comprises 40-50 pts. wt. 0.1 mol/l hydrochloric acid solution, 15-20 pts. wt. dolomite, 20-30 pts. wt. dried cow manure, 35-50 pts. wt. corn straw, 25-40 pts. wt. rice bran, 2-3 pts. wt. effective microorganism (EM) microbial inoculants, 8-15 pts. wt. potassium sulfate, 12-16 pts. wt. ammonium dihydrogen phosphate, 6-8 pts. wt. potassium permanganate, 20-25 pts. wt. urea, 4-5 pts. wt. fertilizer additive and suitable quantity of water, where the fertilizer additive comprises 10-15 pts. wt. gypsum powder, 4-6 pts. wt. linseed oil, 10-12 pts. wt. styrene, 1-2 pts. wt. sodium stearate, 2-3 pts. wt. N-methylolacrylamide, 8-10 pts. wt. ethanol and suitable quantity of water. The fertilizer additive is prepared using ethanol and water in a ratio of 1:10 in a reaction kettle, adding styrene and N- methylolacrylamide, heating the mixture at 70-80 degrees C, uniformly stirring the mixture to dissolve, mixing linseed oil and sodium stearate, adding 4-5 times water to linseed oil and sodium stearate mixture, stirring for 10 minutes, foaming the mixture, then adding the mixture to the reaction kettle, stirring and heating the mixture at the speed of 300-500 revolutions/minute (rpm) for 0.5-2 hours, grinding gypsum powder into fine powder, sieving the fine powder through 200 mesh size sieve, uniformly stirring the mixture into emulsion, and thermal insulating the product. An INDEPENDENT CLAIM is included for method for preparing sustained-release organic fertilizer, which involves (a) crushing dolomite, sieving the crushed dolomite through 40-60 mesh size sieve, adding hydrochloric acid solution, stirring for 5-10 minutes, and filtering and washing using water for 2-3 times, (b) crushing corn straw into residue, mixing dried cow manure, plant ash and rice bran, adding EM microbial inoculants and water, where 10 times water is added, diluting, adjusting water content to 40%, and fermenting the mixture for 30-35 degrees C for 20-25 days to obtain fermented material, (c) mixing and crushing potassium sulfate, ammonium dihydrogen phosphate, potassium permanganate and urea into powder using pulverizer, preheating fertilizer additive at 100-110 degrees C, and spraying and rolling the surface of the particle obtained in step (a) using rolling machine for 5-7 minutes, and (d) combining and mixing the resulting product obtained in step (b) and (c) and the remaining materials, adding water until the water content is 20%, and granulating the mixture.