EFFECT OF LIMESTONE ON NUMBER OF BACTERIA 27 



Exercise 8 

 Effect of Limestone on Number of Bacteria 



1. Fill three tumblers with loo grams each of field soil. 



2. Arrange as follows: 



(a) Control. 



(b) Treat with 0.5 per cent of calcium carbonate or one-half enough 



calcium carbonate to neutralize the soil acidity. 



(c) Treat with i per cent, of calcium carbonate or enough calcium 



carbonate to neutralize all soil acidity. 



Table 5 — Effect of Limestojie on Number of Bacteria 



Time 



Treatment 



Dilution 



Bactena per plate. 



Bactena m i gm. 

 of dry soil 



Days 



7 



Per cent 



None. 

 do 

 do 





Total 



1 

 Average ! 



Total. 



7 



i lime, 

 do 

 do. 











7 



I lime, 

 do. 

 do. 











21 



None, 

 do. 

 do. 











21 



J lime 

 do. 

 do. 











21 



I lime 

 do 

 do. 











