A high efficiency magnesium fertilizer and a method for applying the same to an agronomic carrier or directly to soil. 5-20 wt % of a mixture of flavonoids, 2-20 wt % of condensed tannins or proantocyanidins and 0. This device preferably includes two pads machined on the die at the same time as the imprint, and each including two notches in the form of a cross. The tool assembly also includes a passageway for directing a flow of coolant to the cutting end periphery. In an alternative embodiment, breaks 28 are provided in the fins.