Special long-acting slow release fertilizer for sugarcane

The invention discloses a special long-acting slow release fertilizer for sugarcane. The slow release fertilizer contains nitrogen, phosphorus and potassium according to a ratio of 20:12:5. The slow release fertilizer comprises the following raw materials by mass ratio: 96-190 of ammonium dihydrogen phosphate containing 49% of P2O5 and 9% of N, 149-405 of a calcium magnesium phosphate fertilizer containing 18% of P2O5, 398-416 of urea containing 46% of N, 83 of potassium chloride containing 60% of K2O and 0-180 of a packing material. The packing material is a mixture of clay and dry lime sludge in a mass ratio of (3-7):(7-3); and the water content of the dry lime sludge is controlled to be 5%-10%. By utilizing the fertilizer, the emergence rate, tillering rate and plant height of the sugarcane can be effectively increased, the agricultural yield and sugar yield of the sugarcane are obviously improved, and tests prove that the yield per unit and the sugar yield of the sugarcane are improved; and the quality of the sugarcane is obviously improved, and the fertilizer is applicable to soil with the medium fertility in the sugarcane areas of southern tropics and subtropics in China.