i88 
Journal of Agricultural Research 
Vol. IX, No. 7 
in all of the soils after the first 7 days, and in soil C the amount increases 
somewhat uniformly until the end of the experiment. In soil E a rapid 
increase in nitrates is noted from 7 to 21 days; but during the last 3 weeks 
the gain is irregular and very slow. In soil D a loss of nitrates occurs 
between 7 to 21 days. It is interesting to note that during this period 
the ammonia is very highland there is a possibility of the action of the 
nitrifying organism being inhibited by the presence of so much am¬ 
monia. 
By referring to Table II it is seen that the percentage of nitrogen 
recovered as ammonia varies from 17.55 i* 1 soil C to 32.81 in soil D, while 
the percentage of the nitrogen recovered as nitrates varies from 11.48 
in soil D to 34.47 in soil E. The average loss of nitrogen from the three 
soils following the addition of 1 per cent of blood is 29.25 per cent of the 
nitrogen added. 
Table: II .-—Percentage of nitrogen added to soils in dried blood , barley hay , horse manure , 
and green manures recovered as ammonia and nitrates after six weeks ’ incubation; also 
percentage gain or loss of nitrogen added. April 8, IQ14 
[Results expressed as milligrams of nitrogen per ioo gm. of soil) 
PLOT E 
Material added 
Nitrogen 
inma- 
terial 
added. 
Nitro¬ 
gen as 
ammo¬ 
nia re¬ 
covered 
in 6 
weeks. 
Per¬ 
centage 
of nitro¬ 
gen as 
ammo¬ 
nia re¬ 
covered. 
Nitro¬ 
gen as 
nitrate 
recov¬ 
ered in 
6 weeks. 
Per¬ 
centage 
of nitro¬ 
gen as 
nitrate 
recov¬ 
ered. 
Nitro¬ 
gen re- 
main- 
ing in 
soil 
after 6 
weeks. 
Gain or 
loss. 
Percent¬ 
age of 
of nitro¬ 
gen 
gained 
or lost. 
Dried blood (i per cent). 
137 * 20 
25*48 
18. 57 
47.29 
34*47 
92.80 
— 44*40 
—32.36 
Oats, green (i per cent). 
Barley, green (i per cent). 
Melilotus, green (i per cent)... 
16.90 
.84 
4-97 
*33 
i *95 
33 *oo 
16.10 
95*27 
14*20 
. 21 
1.48 
1.38 
9.72 
24.50 
10.30 
72*53 
21. 20 
1.40 
6.60 
8*73 
,41.18 
34*00 
12.80 
60.38 
Alfilaria, green (i per cent)- 
x8.80 
.28 
1.49 
2.02 
10. 74 
26.60 
7.80 
41*49 
PLOT D 
Dried blood (1 per cent). 
137* 20 
45. 02 
32.81 
15*75 
xi. 48 
95. 20 
42.00 
— 30 . 6l 
Oats, green (1 per cent). 
Barley, green (1 per cent). 
Melilotus, green (1 percent)- 
16.90 
.28 
1.66 
2.83 
16. 74 
29. 20 
12.30 
72. 78 
14* 20 
•44 
3.10 
3.83 
26.97 
28.10 
13.90 
97*89 
21. 20 
,00 
.00 
7*77 
36*65 
35*30 
14* 10 
66. 51 
Alfilaria, green (1 per cent)... 
18.80 
.40 
2.13 
3*45 
18*35 
28.00 
9. 20 
48.94 
PLOT C 
Dried blood (1 per cent. 
137* 20 
24.08 
17* 55 
29*41 
21.44 
103. 20 
—34* OO 
—24. 78 
Barley hay (1 per cent). 
Barley, green (1 per cent). 
Melilotus, gxeen (1 per cent) ... 
13*60 
.00 
.00 
—.42 
—3.09 
16.10 
2- 50 
18.38 
14.20 
.00 
.00 
2*37 
16.69 
19.60 
5*40 
38.03 
21.20 
.00 
.00 
8*39 
39* 58 
3 ** 40 
10. 20 
48.11 
Horse manure (1 per cent). 
13*60 
.00 
.00 
I. 29 
9.49 
21.00 
7.40 
54*41 
The addition of 1 per cent of oats caused a moderate increase in 
ammonia in soil E, but very little increase in soil D. However, after 42 
days' incubation the ammonia content of both soils was somewhat higher 
than in the controls. It would seem that very little increase in nitrates 
resulted from the addition of the oats to soil E, and the increase in soil D 
amounts to only 2.83 mgm. The percentage of nitrogen recovered as 
ammonia was 4.97 in soil E and 1.66 in soil D. The percentage of 
