38 
BULLETIN 1180, U. S. DEPARTMENT OF AGRICULTURE. 
The yields from Section II show no marked differences between 
ammonium phosphate, ammoniated superphosphate, and ammonium 
sulphate. Cyanamid gave smaller increases than the other nitrogen 
carriers, due to the extremely poor and rocky soil. It will be noted 
that where ammonium nitrate was used under these conditions it 
also failed to give a good growth. We can not, therefore, say that 
cyanamid was not as good a source of nitrogen for corn as the other 
materials used. The early growth of corn with ammonium sulphate 
and ammonium phosphate is shown in Plate XIII, Figure 2, and 
the yields with ammonium nitrate and ammoniated superphosphate 
in Plate XIV, Figures 1 and 2. 
Field Xo. 5. 
Another area of approximately 5 acres was used for experimental 
purposes in 1920. The treatments and general plat arrangements 
were an exact duplicate of field No. 3. Unfortunately, the soil was 
so fertile that the fertilizers produced negligible increases in most 
cases. For this reason work was not continued on this area during 
1921. 
The yields mean very little except on those plats receiving am- 
monium chlorid and cyanamid and planted to corn. It happened 
that the soil on this portion of the field was rather poor and quite 
uniform. These figures are given in Table 20, but all others are 
omitted. 
Table 20. — Yields per acre of corn from Sections I and II of field No. 5. 
Plat. 
Yields of corn. 
Fertilizer ratio. 
Stalks 
(pounds). 
Grain (bushels). 
Actual. 
Average. 
Increase 
over 
check. 
Section I.— Ammonium chlorid: 
0-0-0 
{ i 
< i 
9 
10 
10 
12 
13 
14 
15 
2,140 
1,780 
2,200 
2,240 
2,800 
2,960 
2,580 
1,440 
1,688 
2,273 
2,790 
3,083 
24.3 
25.4 
24.0 
33.1 
32.6 
42.9 
41.1 
14.8 
16.1 
16.7 
28.6 
33.1 
J 24.9 
} 28.6 
32.6 
42.9 
41.1 
14.8 
16.1 
16.7 
28.6 
33.1 
0-4- 9 
1-4-2 
4.0 
2-4-2 
14.3 
4-4-2 
12.5 
Section II.— Cyanamid: 
O-O-O 
04 2 
1-4-2 
.6 
2-4-2 
12.5 
4-4-2 
17.0 
The increases in yields produced by ammonium chlorid were very 
good, but the material again shows indications of being slightly 
toxic when applied in high concentrations. Soon after germina- 
tion the plants showed a distinct burning and some yellowing of 
the leaves with the application of 40 pounds of ammonia per acre. 
A few plants died, but the others apparently recovered. The yields 
indicate that the bad effects were never completely overcome. 
Cyanamid gave excellent results on corn and showed a much higher 
yield with 40 pounds of the ammonia equivalent than with 20 pounds. 
