sept. 9.1918 Deep Tilling and Dynamiting in the Great Plains 497 
every year from the subsoiled plot. Winter wheat, com, and kafir show 
inorpasps amounting to more than three times the probable error. With 
the other crops the differences are less than the probable error. This 
is the only station at which the averages of all crops show a ratio of 100 
or more on the subsoiled plot. With some of the crops the average 
yields have been so small as to be unprofitable from either method. It 
should be noted that this station has the highest annual precipitation 
of any station under study. As noted later in discussing the use of 
dynamite and deep plowing, the results of those practices do not support 
those obtained from subsoiling. 
Table IX — Yields at the Hays ( Kans .) Field Station .of spring wheat, winter wheat, oats, 
barley, corn, kafir, and milo each year from ipof to igi6, inclusive, on plot E, subsoiled, 
and plot B, not subsoiled but otherwise similarly treated , together with the average oj 
each method for the entire period of years ; the ratio of the yield on E to the mean of the 
yield on B and E each year; the mean ratio; and the probable error of the mean ratio 
[Yields of all crops in bushels per acre] 
Crop and plot. 
Yield or ratio. 
1907 
1908 
1909 
1910 
1911 
1912 
1913 
1914 
1915 
1916 
Aver¬ 
age. 
Prob¬ 
able 
error of 
mean 
ratio. 
Spring wheat: 
Plot B. 
Plot E. 
Ratio of E to mean... 
* 4-5 
5-2 
107 
8 
9-6 
12 .6 
114 
o- 0 
0.0 
15-2 
12 . 7 
91 
o -5 
1-3 
144 
w 
( 6 > 
7.0 
3-3 
108 
0.7 
•3 
60 
5-4 
5-8 
104 
± 7 -a 
Winter wheat: 
Plot B. 
Plot E. 
Ratio of E to mean... 
Oats: 
Plot B. 
Plot E . 
Ratio of E to mean... 
18.2 
13-6 
86 
23. 2 
30-5 
114 
8 
27.8 
39-8 
118 
•3 
■3 
100 
13-8 
20.1 
119 
2-3 
4-1 
128 
24.8 
25-3 
101 
13 - 1 
14 - 9 
106 
22.7 
27.6 
no 
16. 2 
19-6 
109 
±2.9 
3-7 
17-9 
166 
S 
16.6 
24*5 
119 
0.0 
0.0 
37-7 
45-1 
109 
10.6 
21.8 
135 
27.0 
26.6 
99 
25.1 
29. 2 
108 
6.0 
x.o 
29 
IS-8 
20. 8 
109 
± 9-1 
Barley: 
Plot B. 
Plot E. 
Ratio of E to mean... 
ia. 4 
14.8 
109 
8 
19-7 
19-3 
99 
0.0 
0.0 
28.8 
33 -& 
108 
4.0 
4.6 
107 
16. 7 
15-2 
95 
26.8 
22.4 
9 i 
10.1 
8.2 
90 
14-8 
14. 8 
100 
±2.4 
Com: 
Plot B. 
Plot E. 
Ratio of E to mean... 
Kafir: 
Plot B . 
12. 2 
13-6 
105 
3 -i 
8.8 
148 
7-9 
8.0 
101 
6.8 
7-4 
104 
1.8 
5-5 
151 
<«) 
( c ) 
5-5 
6.4 
108 
14-9 
16.5 
105 
3 - 6 
4 - 3 
109 
7 -o 
8.8 
116 
± 5-2 
.6 
1.0 
125 
12.8 
26.1 
134 
8 
16.3 
23*0 
117 
67.4 
66-6 
99 
•4 
• 7 
127 
19-5 
23-5 
120 
± 4-3 
Plot R 
Ratio of E to mean. . . 
Milo: 
Plot B . 
(<0 
( c ) 
16. 2 
17 - 5 
104 
a 
IS-2 
17.6 
107 
53-5 
48.8 
95 
1.4 
1-3 
96 
21.6 
21.3 
101 
±2.4 
Plot E . 
o Destroyed by hail. b Destroyed by soil blowing. c Destroyed by insects. 
GARDEN CITY EIEED STATION 
The work at the field station at Garden City, Kans., is on a high up¬ 
land. The soil is a light silt loam. With the exception of the accumu¬ 
lated humus near the surface it is practically uniform to a depth of at 
