Multilayer sustained-release potassium sulfate fertilizer and preparation method thereof

The invention belongs to the technical field of fertilizers, and relates to a multi-layer sustained-release potassium sulfate fertilizer and a preparation method thereof.The fertilizer is composed of a fertilizer core, an inner film layer and an outer cladding layer, and the fertilizer core is prepared from potassium sulfate and multiple microelements through granulation; the inner membrane layer is prepared from the following raw materials in parts by weight: 55-70 parts of potassium sulfate, 15-25 parts of talcum powder, 5-20 parts of urea, 3-5 parts of starch, 1-2 parts of urea sulfate, 0.5-1.5 parts of sodium carboxymethyl cellulose and 0.5-1 part of polyacrylamide. The multi-layer sustained-release potassium sulfate fertilizer has a good sustained-release effect, can give consideration to early-stage quick-acting instant-dissolving and middle-later-stage long-acting sustained-release effects of the fertilizer, and can ensure nutrient supply to plants in the early, middle and later stages. 本发明属于肥料技术领域，涉及一