Diazotrophs 'fix' atmospheric nitrogen into biologically available forms. In very general, non-technical terms, an over-abundance of these organic nitrogen forms within a soil beyond what biota in the soil metabolically require has been suggested to result in the increase of nitric acid in the soil. What I would be very interested in is if anyone has done work to help establish a rate of nitric acid production in response to this over abundance of organic nitrogen.

Cheers!

Eron