ATMOSPHERIC-NITROGEN FERTILIZERS. 37 
Table 19. — Yields per acre of corn from Sections land II of field Xo. 4 in 1920 and 1921. 
Treatment. 
Ferti- 
lizer 
ratio. 
Yields of corn. 
1920 
1921 
Plat. 
Stalks 
(pounds) 
Grain (bushels). 
Grain (bushels). 
Actual 
Stalks 
^ ver _ Increase (pounds). 
■»■ cS. 
Actual. 
Aver- 
age. 
In- 
crease 
over 
check. 
Section I: 
Xo fertilizer. 
No nitrogen. 
Ammonium sul- 
phate 
No fertilizer. 
No nitrogen. 
Urea 
No fertilizer. 
No nitrogen. 
Double salt 1 . 
0- 0-0 
0- 4-2 
II- 4-2 
2-4-2 
4-4-2 
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 
14- 4-2 
No fertilizer -. 0-0-0 
_:rogen 
Ammonium nit ra~ 
Sectionll: 
No nitrogen 
Ammonium sul- 
phate 2-5-2 
Ammoniated su- 
perphosphate . . . 
W\ 
No nitrogen 
Ammonium phos- 
phate 
Am m oniated su- 
perphosphate . . . 
2- 5-2 
0-10-2 
2- 7-2 
4-10-2 
0-0-0 
0-13-2 
4-13-2 
No fertilizer 
No nitrogen 
Ammonium phos- 
phate 
Ammonium sul- 
phate 4-13-2 
0- 0-0 
0- 4-2 
0-4-2 
0- 0-0 
No fertilizer 
No nitrogen (acid 
phosphate) 
No nitrogen (cal- 
cined phos- 
phate; 2 
No fertilizer 
No iiitrogen (cal- 
cined phos- 
phate] 2 
Cyanamid (with 
"calcined phos- 
phate; 2 
0- 4-2 
1- 4-2 
2- 4-2 
4- 4-2 
No fertilizer 0-0-0 
No nitrogen , 0- 4-2 
Ammonium nitrate 1- 4-2 
2.020 
2,320 
2,400 
3.000 
2.S20 
2,960 
3,620 
2,320 
2,320 
3,000 
2,400 
3,180 
3,580 
2,320 
2,400 
3.120 
2,540 
3,040 
3,500 
3,020 
3,120 
3,440 
4,180 
2,980 
3,100 
2. 980 
2,360 
2,9S0 
3,280 
1,920 
2,240 
3,360 
3,140 
1,920 
2,640 
2,580 
1,920 
2,580 
1,920 
2,580 
2,800 
2,740 
1,540 
1,900 
2,220 
18.6 
20.9 
17.1 
23.4 
1>.6 
24.9 
36.3 
20.9 
20.9 
23.4 
22.9 
28. 6 
29.1 
37.4 
20.9 
22.9 
32.6 
24.0 
26.9 
40.0 
43.1 
32.6 
50.6 
54.0 
30.0 
29.4 
26.9 
18.6 
20.6 
17.4 
12.9 
26.0 
24.9 
17.4 
22.0 
23.4 
17.4 
23.4 
9.1 
18.3 
17.1 
18.9 
12.9 
16.0 
43.1 
32.6 
50.6 
54.0 
30.0 
29.4 
26.9 
18.6 
20.6 
33.4 
17.4 
12.9 
26.0 
24.9 
17.4 
22.0 
23.4 
17.4 
16.3 
18.3 
17.1 
18.9 
8.9 
12.9 
16.0 
1S.0 
21.4 
-3.1 
2.0 
14.8 
13.1 
12.0 
4.6 
6.0 
2.0 
.8 
2.6 
3.1 
1,460 
1,680 
2,280 
1,960 
2,300 
2,560 
2,640 
2,280 
3,080 
1,580 
1,600 
1,560 
1,180 
1,560 
1,760 
1,040 
1,180 
1,740 
1,680 
1,040 
1,360 
1,340 
1,040 
1,340 
580 
1,300 
1,400 
1,440 
640 
1,120 
1,300 
17.7 
24.9 
16.3 
26.0 
18.6 
23.1 
31.1 
24.9 
25.1 
26.0 
25.1 
32.6 
34.3 
37.1 
25.1 
25.1 
32. 3 
27.1 
33.1 
37.4 
42.0 
32.3 
39.7 
46.0 
27.1 
27.1 
25.1 
18.0 
23.7 
30.6 
15.7 
14.9 
29.1 
28.9 
15.7 
19.4 
19.1 
15.7 I 
19.1 ) 
8.3 j 
18. 6 
17.4 
21.7 
6.9 ! 
9.7 
13.4 
■2.6 
1.9 
21.3 
21.2 
IS. 6 
23.1 
31.1 
25.0 
25.6 
32.6 
34.3 
37.1 
25.1 
- ] 
27.1 
33.1 
37.4 
42.0 
32.3 
39. 7 
46. 13. 7 
-1.6 
4.4 
5.7 
27.1 
27.1 

25.1 
-2.0 
18.0 
23.7 
30.6 
12.6 
15.7 
14.9 

29.1 
14.2 
2S.9 
14.0 
15.7 
19.4 
3.7 
19.1 
15.7 
13.7 
18.6 
17.4 
21.7 
6.9 
9.7 
13.4 
3.4 
4.9 
3.7 
8.0 
3.7 
1 Ammonium chlorid was substituted for double salt in 1921. 
3 Basic slag was substituted for calcined phosphate in 1921. 
