Don't bother. If micronutrients are needed, that is because there are issues with the soil causing them to be tied up. I hate seeing micronutrients added in amounts only sufficient to stain pools and concrete. Take iron, for example. Effective rates of iron sulfate applied dry are more like 10 lbs per 1000 sq ft. That would mean 5 lb of the NPK and 10 lb of iron. Ironite works because you are applying 10 or more lbs per 1000 and it is in the form of sulfates and sulfides.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738