What are all the ways that nitrogen can be maintained in soil?

Answer 1

ALL the ways?! There are probably some odd ones that don't matter. I can think of a few.

In humus, and other organic matter.

Chemically bound to soil particles as nitrates and nitrites, and such...Ammonium ions...

In the living tissues of plants. In the root nodules of legumes, and in all root tissues. And in mycelia of the fungi.

Its there in gaseous form too, in the air spaces of the soil.

And there are minerals which contain nitrogen too. Ya know the rocks. Can't thnk of what rocks have nitrogen makeup tho. (Not much in my garden's parent material.)

Answer 2

I don't know about all of the ways , but the most commonly effective is to plant peas or beans as legumes fix nitrogen into the soil as part of their life function.