Apr. 30, 1917 
Fixation of Ammonia in Soils 
151 
Table XIV .—Effect of adding potassium salts on the fixation of ammonia in soils from 
Riverside , Cal . 
Time potassium 
salt was allowed 
to act before the 
addition of am¬ 
monia. 
Quantity and 
strength of 
potassium salt 
added. 
Nitro¬ 
gen in 
ammo¬ 
nium 
.sulphate 
added 
per 100 
gm. of 
soil. 
Nitrogen recovered. 
Potassium 
sulphate. 
Potassium 
chlorid. 
Potassium 
nitrate. 
Hours. 
Mgm. 
Mgm . 
Per cent. 
Mgm. 
Percent. 
Mgm . 
Percent. 
x . 
10 c. c. Njx .. 
50. 00 
47. 09 
94. 18 
47.48 
94 - 96 
47-09 
94. 18 
x . 
10 C. C. N/ 2 . . 
50. OO 
42. 56 
85. 12 
42.56 
85. 12 
42. 74 
85. 48 
x . 
10 c. c. N/4. . 
50.00 
34 - 72 
69.44 
34 - 72 
69. 44 
34-72 
69.44 
X . 
10 c. c. Nj8 .. 
50. OO 
30. 80 
6l. 60 
30. 80 
61. 60 
30.80 
61. 60 
X . 
10 c. c. N/i6. 
50. 00 
28. OO 
56. OO 
28 . OO 
56.00 
28. 00 
56. OO 
X . 
10 C. C. NI32, 
50. 00 
26. 60 
53- 20 
26. 60 
53- 20 
26. 60 
53- 20 
24. 
10 c. c. N/z .. 
50. OO 
47-32 
94. 64 
47 - 25 
94 - 5 ° 
47.40 
94. 80 
24. 
10 C. C. N/ 2 . . 
50. OO 
42. 56 
85. 12 
43.00 
86. 00 
42. 60 
85. 20 
24. 
10 c. c. N/4 .. 
50. OO 
38. 64 
77.28 
38.60 
77. 20 
38. 50 
77. 00 
24 . 
10 c. c. N/8 .. 
50. OO 
32. 48 
64. 96 
32- 5 ° 
65.00 
32. 60 
65. 20 
24 . 
10 c. c. N/i6 . 
50. OO 
29. 12 
58.24 
29. 10 
58. 20 
29. 10 
58. 20 
24 . 
10 c. c. NI32. 
50. OO 
27. 72 
55-44 
27. 60 
55* 20 
27. 80 
55* 60 
The action of sodium salts on the fixation of ammonia is quite different 
from the action of potassium salts, as can be readily seen by comparing 
Tables XIV and XV. The addition of sodium salts seems to have 
slightly reduced the ammonia-fixing power of the soil. When the sodium 
salts were added 24 hours prior to the addition of the ammonia, the 
reduction in the fixing power of the soil was no greater than when the 
sodium , salt was allowed to act only one-half hour. The addition of 
magnesium and calcium salts, like the sodium salts, caused very little 
change in the ammonia-fixing power of the soil, even when the salts 
were added in considerable amounts (Tables XVI and XVII). 
It appears that the anions have little or no effect in determining the 
action of a salt on the ammonia-lixing power of a soil. The three cations 
which had a marked influence on the ammonia-fixing power of a soil 
were equally effective, regardless of the anion with which they were 
combined; and the action of the three cations which had little effect was 
apparently not influenced by the anions with which they were combined. 
