44- 



SOIL BACTERIOLOGY 



Exercise lo 

 Effect of Limestone on Rate of Ammonification 



1. Prepare eight tumblers with 50 grams each of soil. 

 Use two types, a neutral and an acid soil. 



2. Add to each soil i per cent, of clover or casein. 



3. Bring the moisture content up to optimum for am- 

 monification. 



4. Arrange as follows : 



(a) I and 2, neutral field soil. 



(b) 3 and 4, neutral field soil plus 1 per cent, of CaCOs. 



(c) 5 and 6, acid field soil. 



{d) 7 and 8, acid field soil plus i per cent, of CaCOs. 



5. Determine the amount of ammonia after four or six 

 days. 



Table 15. — Effect of Limestone on Rate of Ammonification 



No. 



Soil type 



Calcium 

 carbonate 



Ammonia nitrogen m loo gm of soil. 



Total 



Average 



Gain or loss 

 from limestone. 



I 



2 



3 



4 



5 

 6 



7 

 8 





Per cent. 



None. 



do. 



I CaCOs 



do. 

 None. 



do. 



I CaCOa 



do. 



Mgm. 



Mgm. 



Mgm 



