60 
J ournal of Agricultural Research 
Vol. XXVIII, No. 1 
Table X .—Amrnonification and nitrification of varying quantities of dicyano - 
diamid a 
Soil alone 
250 gm 
Dicyanodiamid 12.72 mgm. N per 
250 gm. soil 
Dicyanodiamid 25.45 mgm. N per 
250 gm. soil 
- 
Recovery of 
N 
Recovery of 
N 
Incubation 
period 
Am¬ 
mo¬ 
nia 
mgm. 
N 
Ni¬ 
trates 
mgm. 
N 
Dicy- 
ano- 
dia- 
mid 
mgm. 
N 
Am¬ 
mo¬ 
nia 
mgm. 
N 
Ni¬ 
trates 
mgm. 
N 
Am¬ 
mo¬ 
nia 
and 
ni¬ 
trates 
mgm. 
N 
Total, 
in¬ 
clud¬ 
ing 
dicy- 
ano- 
dia- 
mid 
mgm. 
N 
Dicy- 
ano- 
dia 
mid 
mgm. 
N 
Am¬ 
mo¬ 
nia 
mgm. 
N 
Ni¬ 
trates 
mgm. 
N. 
Am¬ 
mo¬ 
nia 
and 
ni¬ 
trates 
mgm. 
N 
Total, 
in¬ 
clud¬ 
ing 
diey- 
ano- 
dia- 
mid 
mgm. 
N 
Weeks 
4.. 
8&... 
0.43 
10.61 
16.16 
7.77 
5.20 
9.38 
4.56 
7.20 
2.90 
10.67 
16.65 
12.18 
10.47 
3.25 
4.73 
2.68 
19.33 
12. 
.83 
19.14 
4.73 
17.63 
10.48 
8.14 
12.87 
11.04 
23.72 
5.99 
9.74 
20.78 
20. 
1.35 
23.91 
3.54 
18.96 
18.02 
11.72 
15.26 
9.30 
29.18 
8.11 
12.03 
21.33 
24... 
1.30 
25.91 
2.40 
18.26 
22.14 
13.10 
15.59 
7.58 
31.80 
8.38 
12.97 
20.5 a 
28. 
1.52 
28.43 
1.36 
16.41 
25.50 
11.96 
13.32 
7.80 
33.21 
8.92 
12.18 
19.93 
36. 
.00 
29.26 
1.86 
5.04 
31.51 
7.29 
9.15 
7.24 
33.16 
10.45 
14.35 
21.59 
40. 
.39 
30.07 
2.51 
5.22 
34.98 
9.74 
12.25 
6.83 
36.58 
12.80 
18.92 
25.71 
«At the beginning of the experiment 250 gm. of the soil contained 1.88 mgm. of nitrogen as ammonia 
and 1.63 mgm. as nitrate. 
* The ammonia determinations were lost at this period of analysis. 
Table XI .—The effect of dicyanodiamid upon the rate of nitrification of ammonium 
sulphate ° 
Soil 
alone 
Ammonium sulphate 
(20.9 mgm. N) 
Dicyanodiamid 0.1 
mgm. (0.066 mgm. N) 
and ammonium 
sulphate 
Dicyanodiamid 0.5 
mgm. (0.331 mgm. N) 
and ammonium 
sulphate 
. Incubation period 
100 gm. 
nitrates 
mgm. 
N 
Ni¬ 
trates 
mgm. 
N 
Recov¬ 
ery 
as ni¬ 
trates 
mgm. 
N 
Con¬ 
ver¬ 
sion 
Ni¬ 
trates 
mgm. 
N 
Recov¬ 
ery 
as ni¬ 
trates 
mgm. 
N 
Con¬ 
ver¬ 
sion 
(per 
cent) 
Ni¬ 
trates 
mgm. 
N 
Recov¬ 
ery 
as ni¬ 
trates 
mgm. 
N 
Con¬ 
ver¬ 
sion 
(per 
cent) 
Days 
ft _ 
0.65 
0.65 
Per cent 
0.65 
* 
0.65 
i« 
4.98 
21.64 
16.66 
79.71 
14.63 
9.65 
46.17 
4.18 
“0.80 
0.00 
28... 
6.01 
23.48 
17.47 
83.59 
22.82 
16.81 
80.43 
10.66 
4.65 
22.25 
42. 
6.45 
24.05 
17.60 
84.21 
22.38 
15.93 
76.22 
14.53 
8.08 
38.60 
70. 
8.24 
26.64 
18.40 
88.04 
25.39 
17.15 
82.06 
24.89 
16.65 
79.66 
112.. 
11.03 
28.50 
17.47 
83.59 
27.22 
16.19 
77.46 
26.99 
15.96 
76.36 
168... 
12.34 
29.83 
17.49 
83.68 
29.35 
17.01 
81.39 
28.69 
16.35 
78.23 
Ammonium sulphate 
(20.9 mgm. N) 
Dicyanodiamid 2 
mgm. (1.33 mgm. N) 
and ammonium 
sulphate 
Dicyanodiamid 10.5 
mgm. (6.96 mgm. N) 
and ammonium 
sulphate 
16. 
4.31 
10.64 
6.33 
30.28 
1.05 
-3.26 
0.00 
0.94 
—3.37 
0.00 
42 .. 
6.91 
25.26 
18.35 
87.80 
1.73 
“5.18 
.00 
1.25 
—5.66 
.00 
112. 
9.83 
27.39 
17.56 
84.02 
3.94 
—5.89 
.00 
1.44 
—8.39 
.00 
210.__. 
13.75 
30.27 
16.52 
79.04 
26.41 
12.66 
60.57 
2.36 
“11.39 
.00 
280.. 
15.00 
28.58 
13.58 
64.97 
20.46 
5.46 
26.12 
Ammonium sulphate was used in all cases at the rate of 20.0 mgm. N per 100 gm. of soil. 
