1912] Kelley : Biological Transformations of Nitrogen in Soils 45 



NITRIFICATION 



Having failed to observe any antagonism between calcium and 

 magnesium in the complex process of ammonification in the soil 

 under investigation, attention was directed to a study of nitrifiea- 

 tion under similar conditions. A sandy soil from Anaheim, Cali- 

 fornia, that contained a vigorous nitrifying flora, was employed 

 in these studies. The following table of analyses furnished by 

 the kindness of Dr. Lipman shows the chemical composition of 

 this soil. 



Table V. Compositiox of Soil Used in Nitrification Experiments 



Per cent 



Insoluble matter 73.59 



Soluble Silica 11.17 



Potash (K3O) 64 



Soda (Na,0) l.j 



Lime (Ca O) 1.39 



Magnesia (Mg O) 93 



Br. Ox. Manganese (Mn.OJ 04 



Ferric Oxide (FeA) 5-10 



Alumina (ALO,) 3.92 



Phosphoric Acid (PA) 12 



Sulphuric Acid (SO,) 02 



Volatile matter ") j, „„ 



ILO at 110° C I '^' 



Total 99.95 



The nitrification experiments were carried out in tumblers, 

 tM^o grams of dried blood being mixed with each 100 gram portion 

 of soil. The amounts of calcium and magnesium carbonates added 

 are shown in the table. Optimum moisture conditions w^ere main- 

 tained throughout the 21 day incubation period during which 

 time a temperature of 27 to 28 degrees was maintained. The 

 results are shown in the following table. 



