

SOIL BACTERIOLOGY 



Exercise 6 



Effect of Moisture on Number of Bacteria 



I. Weigh out I kilogram of air-dry field soil and mix 

 thoroughly. 



Table 3 — Efed of Moisture on Number of Bacteria 



Time 



Moisture 



Dilution 



Bacteria per plate. 



Bacteria in 

 I gm of dry soil 



Days 



7 



Per cent 

 Air dry. 



do. 



do. 





Total 



Average 



Average. 



7 



15 



15 











7 



30 



30 

 30 











7 



45 

 45 

 45 











21 



Air dry. 

 do. 

 do. 











21 



15 



^ 15 



15 











21 



30 

 30 

 30 











21 



45 

 45 

 45 











