I don't believe the philosophy of using no fertilizer at all.
But I lean 99% to the mycorrhizal fungi.
It's just that if soil is truly deficient in a needed nutrient, mycorrhizae cannot provide what does not exist.
My means is to apply fertilizer in minor doses over an extended period of time.
It can be the salts that hurt the microorganisms. But it's concentrations that kills things, not just any amount.
My concept is written in-full on this page...
Tree feeding the Mycorrhizae way
That and organic matter.