Organic Soil / Manure - Give plant food or not?

Someone posted in a thread that the chemical plant food kills the microbacteria in the soil, which makes the mollasses in the feedings useless because they're dead...

is this true? should I just let her grow without the extra npk?

It will still help, there is lots of good stuff in it that will not need to be broken down by mycho fungi. go for it