44 



SOIL BACTERIOLOGY 



Exercise 10 

 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- 

 monincation. 



4. Arrange as follows: 



(a) i and 2, neutral field soil. 



(6) 3 and 4, neutral field soil plus i per cent, of CaCO 3 . 



(c) 5 and 6, acid field soil. 



(d) 7 and 8, acid field soil plus i per cent, of CaCO 3 . 



5. Determine the amount of ammonia after four or six 

 days. 



TABLE 15. Effect of Limestone on Rate of Ammonification 



