1919] 



Petiillt ton : A Study of Soil Types 



415 



g 40 



Q 



30 



Z 



3 20 













5. 



Soi Is. 



Fig. 19-A 



Fig. 19a. Graph showing ammonification in the four samples of Diablo clay 

 adobe. The quantities are expressed in terms of nitrogen produced per 100 

 grams of soil with 2% of dried blood. 



TJ 



21 



\0 



15 



5.0 



£5 







5 



Soils 



Fiq. 13 -B 



Fig. 19b. Graph showing nitrogen fixation in the three horizons of the four 

 samples of Diablo clay adobe. The quantities are ex]>n-<r.| in terms of milli- 

 grams of nitrogen fixed per gram of mannite in 50 grains of soil. 



