4^0 
Journal of Agricultural Research vd. xiv, no. « 
MANDAN FIELD STATION 
The record for the Mandan (N. Dak.) Field Station covers only two 
years, but spring wheat has been replicated four times each year and all 
other crops, except flax, three times each year. On the main field the 
soil is a light, sandy loam with a more sandy subsoil. On this field spring 
wheat appears twice and the other crops once. The soil of the south 
field is a heavy clay loam with a heavier subsoil. All crops except flax 
are grown in duplicate on the south field. 
Table III.— Yields at the Mandan (N. Dak.) Field Station of spring wheat , oats, 
barley, corn t and flax for 1915 and 1916 on plot E , subsoiled , and plot B , not subsoiled 
but otherwise similarly treated , together with the average of each method for the two years; 
the ratio of the yield on E to the mean of the yield on B and E each year and replication t 
the mean ratio , and the probable error of the mean ratio 
[Yields in bushels per acre. Flax one, spring wheat four, and other crops three replications each yearj 
Yield or ratio. 
South field. 
Prob- 
Crop and plot. 
main neia. 
Aver¬ 
age. 
able 
11 
!V 
error of 
mean 
ratio. 
1915 
1916 
1915 
1916 
1915 
1916 
*915 
1916 
Spring wheat: 
17.8 
21. 8 
18.7 
Plot B. 
32. I 
18. s 
3 °* 4 
31*3 
17. 0 
23*5 
Plot E. 
Ratio of E 
3^7 
18.8 
24. 8 
iS -5 
25. 6 
16. 0 
27.1 
18.2 
22. 2 
98 
±1. 6 
to mean.. 
99 
IOI 
90 
93 
90 
97 
in 
99 
Oats: 
Plot B .... 
59-8 
S 7 -S 
57-5 
57 - 2 
81.3 
68.4 
63-4 
59 -* 
74-7 
69.1 
52.2 
60.3 
64.9 
61. 9 
Plot E • - - 
Ratio of E 
to mean.. 
±i *3 
98 
IOO 
9 i 
96 
96 
107 
98 
Barley: 
Plot B .... 
S 7 -o 
49-7 
26. 7 
29. 2 
58.3 
50.8 
28.5 
26. 5 
52.7 
54-3 
24. 0 
27-3 
41.2 
39-6 
Plot E. 
±2. 0 
Ratio of E 
to mean.. 
93 
104 
93 
96 
IOI 
109 
99 
Com: 
Plot B. 
26. 7 
49.1 
28.6 
28. 9 
29. 2 
35 -o 
32.9 
Plot E . . 
24. 8 
44 - S 
20. 0 
33 - 8 
26. 3 
34 -i 
30. 6 
Ratio of E 
to mean.. 
±2. 0 
96 
95 
82 
I08 
95 
99 
96 
Flax: 
Plot B. 
13 - 1 
14. 8 
5-2 
6.9 
0. 2 
Plot E. 
IO. 9 
Ratio of E 
to mean.. 
± 3-4 
106 
114 
no 
The results are presented in detail in Table III. Of the 28 com¬ 
parisons afforded, only 9 appear to be in favor of subsoiling. These are 
not confined to particular crops, to either year, or to either type of soil. 
