Slow-release brick fertilizer and preparation method thereof

The invention discloses a slow-release brick fertilizer and a preparation method thereof. The slow-release brick fertilizer is prepared from the following raw materials: agricultural and forestry wastes, engineering spoil, biochar, a nitrogen fertilizer, a phosphate fertilizer, a potassium fertilizer and desulfurized gypsum. According to the slow-release brick fertilizer provided by the invention, various waste resources such as agricultural and forestry wastes and engineering spoil are comprehensively utilized, the commercial value of recycling of the wastes is improved, the popularization feasibility of the wastes is improved, in addition, the slow-release brick fertilizer has the advantages of lasting slow-release effect and synergistic interaction of organic and inorganic nutrients besides a large amount of various wastes, and the slow-release brick fertilizer is worthy of popularization and application. The application prospect is wide. 本发明公开一种缓释砖肥及其制备方法，所述缓释砖肥包括以下原料：农林废弃物、工程弃土、生物炭、氮肥、磷肥、钾肥以及脱硫石膏。本发明提供的缓