178 



Transformation of Nitrogen 



Table 38. 



Influence of Carbohydrates upon the Accumulation of Ammonia 

 FROM Nitrogenous Organic Materials (from Lipman) 



Total 



Ammonia Formed 



* Four grams of organic material added to 100 gm of soil. 



portions of soil; the moisture content was brought to an optimum, 

 and after the soils were incubated for 7 days, the ammonia was de- 

 termined by distilling with MgO. Rice flour and corn meal, with a 

 wide carbon-nitrogen ratio, allowed no accumulation of ammonia, 

 either with or without additional carbohydrate. The substances rich 

 in nitrogen allowed an accumulation of almost 50 per cent of the 

 nitrogen as ammonia, but this was considerably reduced when more 

 available energy in the form of carbohydrates was added ( Table 39 ) . 



Table 39. Influence of Added Nitrogen Salt upon the Decomposition of Rye 

 Straw * and Its Constituent Carbohydrates by Microorganisms 



Units in milligrams. 



* Five-gram portions. 



