THE BACTERIA OF NEBRASKA SOIL 



WITH SPECIAL REFERENCE 



TO THE FIXATION OF NITROGEN, AMMONIFICATION 



DENITRIFICATION IN NON-PROTEIN MEDIA, 



INCLUDING OBSERVATIONS ON THE 



REDUCTION OF NITRATES BY 



SOIL BACTERIA IN 



GENERAL 



BY 



JOHN J. PUTNAM 



SUBMITTED TO THE 



GRADUATE COLLEGE 



OF 



THE UNIVERSITY OF NEBRASKA 



IN CANDIDACY FOR THE DEGREE 

 DOCTOR OF PHILOSOPHY 



FEBRUARY 20. 1913 



1913 



THE WOODRUFF PRESS 

 LINCOLN, NEB. 



