POTASSIUM PHOSPHATE ON RATE OF AMMONIFICATION 45 



Exercise 1 1 



Effect of Dibasic Potassium Phosphate on Rate of Am- 

 monification 



1. Prepare ten 5o-gram portions of soil in tumblers. 



2. Add i per cent, clover and hold the moisture at 

 two-thirds saturation. 



3. Arrange as follows: 



(a) i and 2, analyze at once. 

 (6) 3 and 4, control. 



(c) 5 and 6, plus o.i per cent. K 2 HPO 4 . 



(d) 7 and 8, plus 0.2 per cent. K 2 HPO 4 . 



(e) 9 and 10, plus 0.5 per cent. K 2 HPO 4 . 



Note. The dibasic potassium phosphate is readily added from a solution. 

 For this purpose prepare a stock solution. 



4. Incubate at room temperature for four days. 



5. Determine the amount of ammonia. 



TABLE 16. Effect of Dibasic Potassium Phosphate on Rate of Ammonification 



