Sept. 9.1918 Deep Tilling and Dynamiting in the Great Plains 
507 
then seeded to durum wheat. The eight plots composing the two tiers 
on the south side of the block were replowed and the seed bed prepared 
with the disk and harrow. These eight plots were planted to com. 
The season proved very dry, and both crops were a failure on all plots. 
The late breaking was not considered a favorable preparation because 
of the lack of water in storage in the soil. Under favorable conditions 
of spring and summer rainfall it would have produced a crop, but under 
the conditions that actually obtained only failure was to be expected. 
No effect of the blasting could be observed in the crop. Where a 
charge of dynamite had been set, there was a slight depression and the 
wheat in this space was an inch or two taller than that surrounding it, 
but no taller than it was in other depressions not caused by blasting. 
The wheat plots were plowed 5 inches deep on September 23. The 
com plots were plowed 5 inches deep on July 15, when the corn was so 
badly damaged by drought that it was evident there would be no crop 
produced. The same plots were replanted to wheat and corn in 1914. 
The yields are given in Table XV. The difference between the average 
yield of wheat on the four plots dynamited and on the four plots not 
dynamited is well within the probable error of the series. The average 
yield of com on the plots not dynamited was T 4.1 bushels, with a prob¬ 
able error of 1.5 bushels, while on the dynamited plots the average 
yield was 18.6 bushels, with a probable error of 1.3 bushels. Even the 
apparent increase in‘yield, which the probable error shows is open to 
question that it may have been due to accidental causes, is in no way 
commensurate with the expense of dynamiting, even if the effect per¬ 
sisted for a number of years. 
TablS XV.— Yields of wheat and corn (bushels per acre) in 1914 at the Akron (Colo.) 
Field Station on land dynamited in I9i2 t and on control plots not dynamited 
Crop and treatment. 
Plot and yield. 
Average. 
Probable 
error. 
Wheat: 
Not dynamited. 
{ A « 
C 
K 
M 
±0.6 
Dynamited..... 
\ 17-8 
/ B 
S ' 7 
J 3 ° 
l 5 ' 3 
* 5-5 
l 14-4 
l6. I 
14.0 
15*6 
15.0 
±0.4 
Com: 
Not dynamited. 
{ \ 
G 
O 
11. 6 
N 
Q 
l6. 7 
P 
Dynamited... 
f J F 
10.4 
H 
14.1 
\ * 3-4 
20, 0 
18. 9 
22. 2 
18.6 
In 1915 the eight plots constituting the west half of the block were 
planted to com and the eight plots constituting the east half to wheat. 
The average yield of ear corn was 33.2 bushels per acre. The average 
yield of the four plots dynamited in the fall of 1912 was exactly the same 
