http://extension.missouri.edu/p/WQ252
http://apps.cmsfq.edu.ec/campbellbiology/media/objects/2560/2621894/quiz/haq3708q.jpg
Nitrogen fixation (nitrogen fixing bacteria)Ammonification- Nitrogen compounds(from organism waste or decomposition)
form ammonium
Nitrification (nitrifying bacteria)Denitrifying (denitrifying bacteria)-