sept. 9,1918 Deep Tilling and Dynamiting in the Great Plains 
495 
Table VII— Yields at the Archer (I Wyo .) Field Station of spring wheat, winter ■wheat, 
oats, barley, and corn each year from. 1914 to 1916, inclusive, on plot E, subsoiled, and 
plot B, not subsoiled but otherwise similarly treated , together with the average of 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 
[Yield of corn in pounds of stover; other crops in bushels of grain per acre] 
Yield or ratio. 
Crop and plot. 
1914 
3915 
1916 
Average. 
Probable 
error of 
mean 
ratio. 
Spring wheat: 
plot B . 
7 - 5 
5-8 
87 
23*7 
25.0 
103 
2.4 
1. 0 
59 
II. 2 
10. 6 
83 
± 9. 6 
Plot E . 
Ratio of E to mean. 
Winter wheat: 
Plot B. 
Plot E .. . 
O. O 
O. O 
24.7 
24. 2 
99 
7-4 
2.4 
49 
10. 7 
8.9 
74 
±21. I 
Ratio of E to mean. 
Oats: 
plot B . 
14. 5 
9-4 
79 
35-9 
34.7 
98 
3-7 
5*6 
120 
18. 0 
16. 6 
99 
± 8. 4 
PiotE . 
Ratio of E to mean . 
Barley; 
Plot B . 
29. 8 
35-8 
109 
5*2 
4.2 
89 
i 7*5 
20. 0 
99 
± 8. S 
PiotE . 
Ratio of E to mean . 
Com: 
Plot B . 
1, 090 
i, 130 
102 
3 j 900 
47 45 ° 
107 
(a) 
(°) 
2,495 
2,790 
105 
± 2. I 
Plot E . 
* Ratio of E to mean . 
a Weights lost. 
AKRON FIELD STATION 
The soil of the field station at Akron, Colo., is a clay loam locally known 
as “ hard land.” It is.characterized in the native vegetation by a growth 
of short grass. 
Table VIII presents an unbroken record of eight years’ results with 
spring wheat, oats, barley, and corn, and seven years’ results with winter 
wheat at this station. The E plots were subsoiled in the fall of 1908, 
1909, 1812, 1913, and 1914. Of the 39 comparisons presented in this 
table only 7 show the higher yields from the subsoiled plot. The only 
consistency in the distribution of these among the different crops or years 
is that in 1909 all four crops under trial that year showed the heavier 
yield on the subsoiled plot. In the average of the eight years the better 
yield of each crop has been obtained from the plot not subsoiled. The 
average decrease in yield as a result of subsoiling ranges from 1.7 bushels 
per acre with winter wheat to 3.4 bushels per acre with corn. The 
