Nitrogen transformations

Hello! I'm hoping to match up my understanding about nitrogen transformations from lecture and from the relevant content on Soil Food Web. Would it be accurate to say that N transformations include: immobilization, mineralization (which incorporates aminization, ammonification, and nitrification), ammonium fixation, ammonium volatilization, and denitrification? All of these seem to involve a transformation of the chemical form of nitrogen in question, except, perhaps, for ammonium fixation, where the NH4+ appears to just get trapped in the phyllosilicate or humus complex. Thank you.

Amy, considering Inputs, Transformations and Losses....
volatilization and denitrification would be losses (i.e. losses of N from the soil).