High-efficiency slow-release type granular magnesium sulfate and preparation method thereof

The invention relates to a crop fertilizer, and in particular relates to high-efficiency slow-release type granular magnesium sulfate and a preparation method thereof. The high-efficiency slow-release type granular magnesium sulfate is a granular product which is prepared by mixing, pelleting, screening, drying and cooling magnesium sulfate monohydrate, magnesia powder and sulfur powder as raw materials together with a magnesium sulfate monohydrate solution as an adhesive of certain concentration according to a certain scientific ratio. According to the preparation method, quick-acting magnesium, slow-release magnesium, quick-acting sulfur and slow-release sulfur are reasonable combined, a prepared product has double effects of quick acting and slow release, the requirements of crops on nutrition such as magnesium and sulfur elements in different growth periods are met, the problem that a conventional magnesium fertilizer is not balance in nutrient supply to crops in the growth period is solved, and the granular magnesium sulfate is spherical granule shaped, is large in strength, easy to mix and use with a nitrogen-phosphorus-potassium fertilizer, and is easy in essential raw material acquisition, low in cost, simple in production cost and easy to implement.