POTASSIUM PHOSPHATE ON RATE OF AMMONIFICATION 45 



Exercise ii 



Effect of Dibasic Potassium Phosphate on Rate of Am- 

 mo nification 



1. Prepare ten 50-gram portions of soil in tumblers. 



2. Add I per cent, dovet and hold the moisture at 

 two-thirds saturation. 



3. Arrange as follows: 



(a) I and 2, analyze at once. 



Q}) 3 and 4, control. 



(c) 5 and 6, plus o i per cent. K2HPO4. 



{d) 7 and 8, plus 0.2 per cent. K2HPO4. 



{e) 9 and 10, plus 0.5 per cent. K2HPO4. 



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. — Efeci of Dibasic Potassium Phosphate on Rate of Ammonification 



No 



Treatment. 



Ammonia nitrogen in 100 gm of soil. 



Nitrogen 



Total 



Blank 

 subtracted. 



Average. 



ammonified. 



I 



Per cent. 

 None. 



Mgm. 



Mgm 



MgHl. 



Per cent. 



2 



do. 











3 



0.1 K2HPO4 











4 



do. 











5 



0.2 K2HPO4 











6 



do. 











7 



o.S K2HPO4 











8 



do. 











