Method and liquid compound that improves the efficiency of ammoniacal nitrogenated fertilisers and the ammonium present in the ground. The invention relates to a method for producing a liquid compound and to the compound used to improve the results of the application of ammoniacal nitrogenated fertilisers to crops requiring same and the ammonium present in the ground, said compound being a mixture consisting mainly of 3.5 DMPP as a nitrification inhibitor, phosphorus, the main function of which is to participate in all of the processes and energetic reactions of the crop, and amino acids winch are synthesised by the plants in enzymatic reactions generated by means of the animation, where absorbed ammonium salts and organic acids are produced.
