BACTERIA IN THE SOIL 



145 



A SCHEME SHOWING THE PLACE AND FUNCTION OF THE 

 ECONOMIC MICRO-ORGANISMS FOUND IN SOIL 



Water Chemical Substances Gases 



[Nitrates, etc.] [CO 2 ,H,N,O] 



\ / 



PLANT LIFE 



I 



T 



Carbohydrates Fats Proteids Vegetable Mineral Water 



[albumoses, sugar, [bodies containing Acids Salts 



starch, etc.] Nitrogen] 



ANIMAL LIFE 



Gases [CO 2 , etc.] Water Urea, Albuminoids, Nitrogen in many 



Ammonia compounds, etc. forms locked up 



in the body 



PUTREFACTIVE AND DENITRIFYING BACTERIA 



r ~T~ 



Free Nitrogen Gases [CO 2 ] 



NITROGEN-FIXING 

 BACTERIA 



[In^oil and in the nodules 

 le rootlets of Legu- 



Water Ammonia [Nitrites] 

 and other elements 

 of broken-down 

 complex bodies. 



NITRIFYING BACTERIA 

 I 



Nitrites[= Nitrous organism 



| (Nitrosomans)] 



Nitrates[ = Nitric organism 

 (Nitrosomonas)J 

 [In soil and 

 available for 

 plant life] 



