Preparation of multi-trace element fertilizers

Abstract

A multi-trace element fertilizer which contains magnesium as a further nutrient and in which the complex-forming trace elements are present in the form of anionic chelates with one or more N-carboxyalkylaminoacids is prepared by a process wherein the N-carboxyalkylaminoacids are reacted, in the presence of water, with the trace elements or trace element compounds in a molar ratio of N-carboxyalkylaminoacids to trace elements or trace element compounds of not less than 0.8:1, at least 20% by weight of the trace element compounds being oxides, hydroxides and/or carbonates. At the same time, or subsequently, the pH of the solution is brought to 3.5-6 by adding a member selected from the group consisting of magnesium oxide, hydroxide and carbonate. A maximum of 50 equivalent percent of the magnesium compound may however be replaced by a member selected from the group consisting of alkali metal oxides, hydroxides and carbonates and ammonia.

Dependencies are inferred from the claim text.