Composition with a long-acting depot composition and preparation method of water-soluble long-acting fertilizer

The present invention discloses a method of long-acting depot composition and an aqueous composition was prepared long-acting fertilizer. Composition depot composition of the present invention is a poly amino acid is 5 to 25%, polyphosphate is 10 to 30% polyacrylate is 0.5 to 5%, long-acting agent is 25 to 45%, of humic substances 5 to 15% of the mass percentage of the components equal to 100%. Fertilizer of the invention can be manufactured by conventional processes into granules, powder, liquid or paste, and having the advantage of improved long-term crop of nitrogen, phosphorus and potassium utilization, is a very desirable irrigation fertilizers.