Happy Earth Day!
Let's talk about dirt.
In particular:
Azotobacter, Rhizobia, N. europaea, nitrobacter winogradskyi, Actinobacteria (which could possibly be flushed out and about in a heavy rainfall -- just sayin'), Actinomycetales, Bifidobacteriales, Propionibacteriaceae, Ectomycorrhizae, Frankiaceae, Streptomyces, Achromobacter, Pseudomonas, Cyanophycease, the Chlorophycease, the Bacillariacease ...
Oh my goodness, the list could go on and on forever because we have not discovered and categorized all the little buggers yet -- and besides that they may be evolving and differentiating themselves faster than we mere humans can monitor them.
Them there is just a very, very brief list of soil microbes and I've tried to be fair to the little rascals by including something from the various sorts: bacteria, fungi, algae, I think I skipped out on the protozoa and God only knows that there may be other categories at this moment undiscovered that we don't know about.
And, that is a damnably stupid conclusion because if we haven't discovered them yet we can't possibly know about them.
But, these little critters are incredibly busy: they nitrify soil, they denitrify soil, they decompose, they serve as a telecommunications service for trees and stuff ... and other stuff that we don't even know about yet.
And, we mere humans could not possibly be around without their existence.
So there!