Apr. 5, 1924 
Studies with Cyanamid 
47 
Table IV .—Ammoniftcation and nitrification of varying quantities of treated and 
untreated cyanamid —Continued 
NITROGEN ADDED—52.2 MOM. PER 250 GM. SOIL 
Incu¬ 
bation 
period 
Cyan¬ 
amid 
Am¬ 
monia 
mgm.N 
Ni¬ 
trates 
mgm.N 
Recovery of N 
Treatment 
and di- 
cyan- 
amid 
mgm.N 
Test for 
cyanamid 
Urea 
mgm.N 
Am¬ 
monia 
mgm.N 
Ni¬ 
trates 
mgm.N 
Total 
mgm.N 
Cyanamid treated.. 
Days 
2 
24. 76 
Present. 
1. 73 
13.86 
2.38 
13.06 
—1.01 
38. 54 
Do... 
5 
8.23 
Tracfi 
Trace. 
Nono 
22.12 
2.53 
3.94 
21.05 
—2.02 
27. 26 
Do___ . 
10 
3.75 
None 
24. 42 
23.58 
—2.42 
24.91 
Do. ____. 
19 
2.49 
do. 
...do _ 
14.10 
9. 59 
12.90 
2.87 
18. 26 
Do.... 
31 
2. 77 
_ do 
do_ 
4.96 
21.43 
49.07 
3.63 
12.90 
19.30 
Do.... 
50 
.75 
_do_ 
_do ._ 
1. 21 
.56 
37.71 
39.02 
Do... 
100 
.00 
do 
do 
1. 22 
64.35 
63. 75 
.01 
48.34 
48.35 
Do... 
150 
.00 
*do 
do. . 
1.00 
. 21 
44 46 
44. 67 
Cyanamid untreated ___ 
2 
23.14 
Present. 
1. 59... 
14.28 
2.43 
13.48 
- .96 
37.25 
Do.... 
5 
6. 48 
None 
Trace. 
25.75 
2.36 
24 68 
-2.19 
28.97 
Do.... 
10 
3.13 
do.. . 
None . 
27.40 
3.70 
26.56 
—2.66 
27.03 
Do... 
19 
.62 
_do 
do_ 
12.63 
12.41 
11.43 
5.69 
17.74 
Do._... 
31 
1. 28 
do.... 
.. do 
11.03 
21.10 
9.70 
12.57 
23.55 
Do... 
50 
. 72 
.do 
do . 
.70 
54. 65 
.05 
43.29 
44 06 
Do.. 
100 
.00 
do__ 
_do 
1. 23 
64 52 
-.02 
48.51 
48.53 
Do... 
150 
.00 
...do_ 
...do... 
1.26 
66.69 
.47 
47.40 
47.87 
NITROGEN ADDED—104.4 MGM. PER 250 GM. SOIL 
Cyanamid treated_ 
2 
57.92 
Present - 
5.59 
17.68 
2.95 
16.88 
-0.44 
79.95 
Do.... 
5 
32.77 
...do. 
1.47 
31.63 
2.80 
30.56 
-1.75 
63.05 
Do.. 
10 
14 53 
None_ 
1.11 
45.62 
3.02 
44 78 
-3.34 
57.08 
Do. 
19 
9.84 
_..do. 
1.20 
46.35 
4.21 
45.15 
-2.51 
53.68 
Do. 
31 
9.37 
...do_ 
None— 
56.60 
5.58 
55.27 
-2.95 
61.69 
Do... 
50 
9.04 
___do_ 
...do— 
68.43 
13.17 
67.78 
1.81 
78.63 
Do... 
100 
3.61 
_do. 
- do... 
48.44 
49.94 
47.25 
33.93 
84 77 
Do... 
150 
4.20 
-..do- 
...do— 
41.87 
56.78 
41.08 
37.49 
82.77 
Do.. 
200 
2.65 
_do. 
—do— 
39.52 
69.47 
39.26 
48.69 
90.60 
Cyanamid untreated_ 
10 
51.08 
3.62 
50.24 
-2.74 
47.50 
Do__ 
19 
39.25 
7.67 
38.05 
.95 
39.00 
Do. 
31 
60.20 
11.36 
58.87 
2.83 
61.70 
Do... 
50 
41.78 
28.48 
41.13 
17.12 
58.25 
Do... 
100 
25.07 
59.92 
23.86 
43.91 
67.77 
Do__ 
150 
/ 
42.93 
54 91 
42.14 
35.62 
77.76 
Do. 
200 
17.68 
85.78 
17.42 
65.00 
82.42 
i 
The test for cyanamid showed none present at the end of 10 days and with the 
smaller concentrations of cyanamid none could be found after 5 days. The 
figures for the determination of combined cyanamid and dicyanodiamid nitrogen 
showed a considerable amount present in these two forms even after 10 days 
with the larger applications. Since qualitative tests showed cyanamid absent 
after this length of time we would naturally assume that all of the nitrogen 
precipitated by the method of Brioux was dicyanodiamid. However, silver 
nitrate precipitates guanylurea, guanidin and other decomposition products of 
cyanamid which may possibly have been present. Whether such compounds are 
formed in appreciable amounts in normal soils still remains to be shown. 
Urea determinations showed only very small quantities present at any time 
although it is undoubtedly an intermediate product in the decomposition of cyan, 
amid in the soil. Ammonia formation from urea in the presence of a mixed flora 
of microorganisms takes place so rapidly that no accumulation can occur. 
The two samples of cyanamid, one oiled and hydrated and the other untreated, 
nitrified at about the same rates, where used in the smaller concentrations. At 
the heavier rates the latter appeared to be somewhat better than the former. 
Shortly after these experiments were started the hydrate^ and oiled cyanamid 
used in the mixtures was again analyzed for its various forms of nitrogen. It 
was found that the dicyanodiamid nitrogen had increased considerably over that 
found at the previous analysis, which was made about two months before the 
