INDEX 



235 



Nitrification, causes of, 120 

 Nitrification, early ideas on, 119 

 Nitrification, early work on, 8, 9, 



118 

 Nitrification, factors influencing, 



Nitrification, in soil, 1 78-1 80 



Nitrification, influence of alkalies 

 on, 192 



Nitrification, influence of arsenic 

 on, 207 



Nitrification, influence of crops 

 on, 127, 128, 178-180 



Nitrification, influence of fallow 

 on, 127, 128 



Nitrification, influence of manure 

 on, 216, 217 



Nitrification, influence of mois- 

 ture on, 125, 220 



Nitrification, influence of oxygen 

 on, 124 



Nitrification, influence of tem- 

 perature on, 125 



Nitrifiers, distribution of, 122 



Nitrifiers, food requirements of, 

 126 



Nitrobacter, 122 



Nitrogen cycle, 99-102 



Nitrogen famine predicted, 99 



Nitrogen fixation, early ideas on, 

 156 



Nitrogen fixation, early work on, 

 10 



Nitrogen fixation, early knowl- 

 edge of, 139-142 



Nitrogen fixation, later work on, 

 156-159 



Nitrogen fixation, factors influenc- 

 ing, 143, 160, 161 



Nitrogen fixation, influence of al- 

 kalies on, 192 



Nitrogen fixation, influence of ar- 

 senic on, 207 



Nitrogen fixation, influence of 

 cellulose on, 187 



Nitrogen fixation, influence of 

 crops on, 146 



Nitrogen fixation, influence of 

 fertilizer on, 162 



Nitrogen fixation, influence of 

 Jieat on, 201 



Nitrogen fixation, influence of ir- 

 rigation water on, 220 



Nitrogen fixation, influence of 

 lime on, 142, 143 



Nitrogen fixation, influence of 

 manure on, 145 



Nitrogen fixation, influence of 

 moisture on, 161, 162 



Nitrogen fixation, influence of 

 nodules on, 160, 161 



Nitrogen fixation, influence of 

 non-legumes on, 162, 163 



Nitrogen fixation methods, 1 47 



Nitrogen fixation, non-symbiotic, 



138-155, 156, 170 

 Nitrogen fixed by bacteria, 20 

 Nitrogen fixed by legumes, 163- 



165 

 Nitrogen fixed in nodules, 158, 



159, 160, 161 

 Nitrogen fixed in Utah soils, 146 

 Nitrogen fixed, quantity, 139 

 Nitrogen fixers, discovered, 140, 



141 



