dedicated slow-release potash fertilizer for tobacco and preparation method

The invention discloses a dedicated slow-release potash fertilizer for tobacco and a preparation method. The conventional potash fertilizer as a slow-release fertilizer center is wrapped by the compound of inorganic membrane material and organic materials as coating material to form micro-capsules, the product becomes grain after being dried, and the grain size is 3mm to 5mm; the weight of the coating material accounts for 30 to 50 percent of the total weight of the fertilizer; the weight of the inorganic membrane material accounts for 80 to 90 percent of the weight of the coating material, and the weight of the organic materials (including organic membrane material, binder and sealing agent) accounts for 10 to 20 percent of the weight of the coating material; the inorganic membrane material and the organic membrane material are first mixed at high speed, the conventional potash fertilizer and the mixture are then sequentially added into a rotary pelleting machine, pelleted and coated, meanwhile, the corresponding binding solution is sprayed in good time, and finally, the sealing agent is sprayed. Under the condition of little applied dose, the dedicated slow-release potash fertilizer for tobacco can increase the content of potassium element in the upper and the middle leaves of flue-cured tobacco by more than 30 percent; and meanwhile, in comparison with other slow-release potash fertilizers, the dedicated slow-release potash fertilizer for tobacco greatly simplifies the production process, and reduces the production cost.