ATMOSPHERIC-XITROGEN FERTILIZERS. 
33 
The comparisons between acid phosphate and calcined phosphate 
as sources of phosphorus showed a small difference in favor of the 
former. This difference was in evidence to a slight extent during 
growth, the calcined phosphate being somewhat slower to stimulate 
growth. 
Table 17. — Yields per acre of com from Sections land II of field Xo. 3 in 1920 and 1921. 
Treatment. 
Ferti- 
lizer 
ratio. 
Plat 
Yields of corn. 
1920 
1921 
Stalks 
(pounds) 
Grain (bushels). 
Actual 
In- 
crease 
over 
check. 
Stalks 
(pounds) 
Grain (bushels). 
Actual. 
Aver- 
In- 
crease 
over 
check. 
Section I: 
No fertilizer. 
No nitrogen. 
Ammonium sul- 
phate 
No fertilizer 
No nitrogen 
Ammonium 
chlorid 
No fertilizer. 
No nitrogen. 
Double salt . 
Section n: 
No nitrogen 
Ammonium sul- 
phate. 
Ammoniated su- 
perphosphate. 
No nitrogen — 
Ammonium 
phosphate. 
Ammoniated su- 
perphosphate. 
No fertilizer 
No nitrogen 
Ammonium 
phosphate. 
Ammonium sul- 
phate. 
No fertilizer 
No nitrogen 
(acid phos- 
phate). 
No nitrogen 
(calcined phos- 
phate). 1 
No fertilizer. 
0-0-0 
0-4-2 
1-4-2 
2-4-2 
4-4-2 
0-0-0 
0-4-2 
1-4-2 
2-4-2 
4-4-2 
04M) 
0-1-2 
1-4-2 
2-4-2 
4-4-2 
0-5-2 
2-5-2 
2-5-2 
0-10-2 
2-7-2 
4-10-2 
0-0-0 
0-13-2 
4-13-2 
4-13-2 
0-0-0 
0-4-2 
0-4-2 
0-0-0 
No nitrogen (cal- 
cined phos- !• 0-4-2 
phate) 1 
Cyanamid (with ]'( 1-4-2 
calcined phos- \< 2-4-2 
phate).i I 4-4-2 
7 
L2 
6 
11 
8 
9 
10 
12 
17 
J U 
116 
13 
14 
15 
1 
2 
12 
2,950 
2,550 
2,300 
2,750 
2,950 
3,175 
3,600 
2,550 
1,500 
2,750 
1.800 
3.150 
3,100 
2,975 
1,500 
2.425 
1,800 
1,975 
2,400 
2,825 
3,075 
2,925 
3,100 
3, 125 
2,725 
2,950 
3,225 
2,250 
2,975 
3,700 
3,6.50 
2,250 
2,275 
1,925 
2,250 
1,925 
1,925 
2,425 
2,525 
2,975 
3,250 
45.7 
40.4 
33.9 
39.6 
43.2 
48.2 
54.6 
40.4 
16.3 
39.6 
19.6 
42.5 
44.6 
38.2 
16.3 
19.6 
19.6 
19.6 
17.5 
24.3 
33.9 
46.1 
47.1 
43.2 
40.4 
33.2 
37.5 
37.9 
43.9 
46.8 
45.7 
37.9 
37.9 
30.7 
37.9 
33.6 
30.7 
40.4 
36.4 
41.1 
48.6 
43.1 
36.8 
43.2 
48.2 
54.6 
28.4 
29.6 
42.5 
44.6 
38.2 
18.0 
19.6 
17.5 
24.3 
33.9 
46.1 
47.1 
43.2 
40.4 
33.2 
37.5 
37.9 
43.9 
46.8 
45.7 
37.9 
37.9 
30.7 
35.8 
35.6 
36.4 
41.1 
48.6 
6.4 
11.4 
17.8 
12.9 
15.0 
-2.1 
4.7 
14.3 
1.0 
-2.9 
-7.2 
-2.9 
2.9 
1.8 

■7.2 
5.5 
13.0 
1,950 
2,000 
2,200 
2,300 
2,300 
2,625 
2,725 
2,000 
1,325 
2,300 
1,700 
2,175 
2,200 
2,500 
1,325 
1,250 
1,700 
1,750 
1,700 
1,900 
2,075 
2.900 ' 
2,750 
2,525 
2,075 
2,050 
2,800 
1,800 
2,200 
2,225 
2,450 
1,800 
1,950 
2,000 
1,800 
1,825 
2,000 
2,200 
2,100 
2,025 
2,575 
30.7 
32.5 
31.4 
32.5 
32.1 
40.7 
43.6 
32.5 
9.3 
32.5 
12.1 
28.6 
32.9 
36.1 
9.3 
13.6 
12.0 
11.8 
12.1 
17.9 
26.1 
50.7 
45.4 
28.2 
31.8 
36.1 
33.6 
38.2 
35.0 
36.1 
32.9 
27.5 
36.1 
31.1 
27.5 
35.7 
35.0 
37.1 
45.0 
32.0 
32.1 
40.7 
43.6 
20.9 
22.3 
28.6 
32.9 
36.1 
11.5 
11.9 
12.1 
17.9 
26.1 
50.7 
45.4 
28.2 
31.8 
40.0 
36.1 
33.6 
38.2 
35.0 
36.1 
32.9 
27.5 
33.6 
31.6 
35.0 
37.1 
45.0 
0.1 
8.7 
11.6 
6.3 
10.6 
13.8 
.2 
6.0 
14.2 
-5.3 
-12.1 
3.6 
11.8 
4.6 
1.4 
-3.2 
-8.6 
3.4 
5.5 
13.4 
1 Basic slag was substituted for calcined phosphate in 1921. 
52765°— 24— Bull. 1180 3 
