BIOLOGICAL SOIL PROCESSES 



599 



anaerobic conditions were obtained by adding one inch of sterile 

 paraffin oil. The materials were incubated a week at 30° C. 

 and the ammonia determined by distillation with MgO. 



Experiment I. Ammonification of blood meal and casein under aerobic and 

 anaerobic conditions in soils. Ammonia in milligrams per 100 grams of soil. 



Casein 



Experiment II. Ammonification in sterile soil by mass cultures under aerobic 

 and anaerobic conditions. Ammonia in milligrams per 100 grams of soil. 



Casein 



Greenhouse. 



Loam 



Clay 



96.39 

 82.96 

 91.29 



ANAEROBIC 



95.61 



81.26 

 81.94 



In experiment II the mass cultures were obtained by inocu- 

 lating Lipman's synthetic media (Lipman and Brown 1911) 

 with soils of the different types and growing one week at 30° C. 

 The soil was sterilized in the autoclave. Twenty cubic centi- 

 meters of this mass culture were added to each 100 grams of 

 soil. 



It is at once apparent that ammonification in soil proceeds 

 just as readily under anaerobic conditions as it does under 



