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.] [C02,H,N,0] 



\ i / 



r 



Carbohydrates 



[albumoses, sugar, 



starch, etc.] 



Plant Life 



I 



n \ \ 



Fats Proteids Vegetable 



[bodies containing Acids 

 Nitrogen] 



♦ 



Mineral 

 Salts 



Water 



Animal Life 



\ 



I \ 1 n 



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



Ammonia compounds, etc. forms locked up 



in the body 



PUTREFACTIVE AND DENITRIFYING BACTERIA 



I 



Free Nitrogen Gases [COg] Water Ammonia [Nitrites] 



and other elements 

 of broken-down 

 complex bodies. 



NITROGEN-FIXING 

 BACTERIA 



[In soil and in the nodules 

 on the rootlets of Legu- 

 minosa] 



NITRIFYING BACTERIA 



I 



Nitrites[=Nitrous organism 



I (Nitrosomans)] 



Nitrates[=Nitric organism 

 (Nitrosomonas)J 

 [In soil and 

 available for 

 plant life] 



