Humic acid composite fertilizer and preparation method thereof

The invention relates to the field of fertilizers, in particular to humic acid composite fertilizers and a preparation method thereof. The humic acid composite fertilizer comprises the following raw materials in parts by weight: urea, monoammonium phosphate, potassium chloride, ammonuim humate, attapulgite, glimmerton, borax, manganese sulfate and ammonium molybdate. The preparation method comprises the following steps: pulverizing the borax, the manganese sulfate and the ammonium molybdate according to the parts by weight to form powder, adding the powder into a stirring machine, stirring and mixing to form a mixture, and adding a proper amount of distilled water to dissolve the mixture; adding a complexing agent and performing stirring reaction to obtain a component A; mixing and stirring the ammonuim humate and the component A to obtain a component B; pulverizing the attapulgite, glimmerton, and the component A separately, adding the powder as well as the potassium chloride and the monoammonium phosphate a