1. A method for producing a fertilizer containing a trace element metal polyphosphate composition, the method comprising dissolving the metal-containing compound in phosphoric acid to form a reaction mixture containing phosphoric acid and cations (other than protons), the amount of phosphoric acid is less than the stoichiometric amount required for the complete conversion of cations in the corresponding dihydrogen phosphate, wherein the metal-containing compound includes a metal trace element selected from the group consisting of chromium, cobalt, di, iron, manganese and zinc, and the polymerization of phosphoric acid and dissolved trace metal at a temperature of from about 90 ° C to 165 ° C to obtain a trace metal polyphosphate composition. 2. The method according to claim 1, wherein the polymerization is stopped when the reaction mixture is dissolved in 2% (by weight) citric acid. The method according to any one of claims 1 and 2, further comprising cooling the polymerized reaction mixture, adding water to the cooled polymerized reaction mixture when the temperature of the cooled polymerized reaction mixture is less than about 90 ° C., neutralizing the cooled polymerized reaction mixture with a neutralizing base to obtain a neutralized product, drying the neutralized product and grinding the dried, neutralized product. 4. The method according to any one of claims 1 and 2, wherein the phosphoric acid and the dissolved metal microelement are polymerized at a temperature of from about 120 ° C to 140 ° C. 5. The method according to any one of claims 1 and 2, in which the reaction mixture includes zinc, and molar1. Способ получения удобрения, содержащего композицию полифосфата металла микроэлемента, причем способ включает растворение металлосодержащего соединения в фосфорной кислоте с образованием реакционной смеси, содержащей фосфорную кислоту и катионы (отличные от протонов), количество фосфорной кислоты меньше чем стехиометрическое количество, требуемое для полного
