sept. 9,1918 Deep Tilling and Dynamiting in the Great Plains 
499 
AMARILLO FIELD STATION 
The soil at the field station at Amarillo, Tex., is a heavy clay silt. 
The storage of water and the development of the feeding roots of the 
crop are apparently interfered with by comparatively impervious soil in 
the third foot. 
Eight years' results with spring wheat, winter wheat, oats, and barley, 
and nine years' with corn are presented in Table XI. The year 1910 is 
not included, as the location of the station was changed, and the prepara¬ 
tion of the land was uniform for that year. Of the 41 comparisons 
afforded in this table less than one-third show the higher yield to have 
been from the subsoiled plot. There is no consistency in the distribution 
of these either by years or by crops. In the average of the entire period 
the results with all crops are against subsoiling. The average decrease 
in yields as a result of subsoiling ranges from 1 bushel per acre with 
spring wheat to 3.2 bushels with oats. With all crops except corn the 
decrease due to subsoiling is more than twice the probable error. 
Table XI .—Yields at the Amarillo (Tex.) Field Station of spring wheat, winter wheat, 
oats, barley, and corn each year from igof 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 all crops in bushels per acre] 
Yield or ratio. 
Crop and plot. 
1907 
1908 
1909a 
1911 
19x2 
X 9 i 3 
1914 
19 X 5 
1916 
Aver¬ 
age. 
Prob¬ 
able 
error 
of mean 
ratio. 
Spring wheat: 
Plot B. 
14.0 
16. 2 
2.8 
xo-0 
8-5 
4. 2 
1.8 
12.8 
IX.0 
7.0 
x. 2 
8.5 
7 - 5 
Plot E. 
4. 0 
XX.3 
.8 
12.3 
10.3 
97 
Ratio of E to mean 
107 
xx8 
xo6 
66 
62 
98 
29 
85 
± 7*9 
Winter wheat: 
Plot B. 
14-3 
16. s 
107 
0.0 
3.5 
7.2 
3-3 
63 
x -3 
1*3 
23.0 
19-3 
91 
24.4 
19.7 
89 
3*6 
9 * 7 
Plot E. 
0.0 
x. 2 
4. $ 
8.2 
Ratio of E to mean 
51 
xoo 
in 
87 
±6.1 
Oats: 
Plot B. 
32-2 
28. X 
0.0 
27*5 
19. 2 
82 
14. X 
2. 5 
30-9 
31.7 
X2- 2 
18.9 
Plot E. 
0.0 
8.8 
4. X 
30.6 
100 
34-2 
X04 
17*3 
•9 
15. 7 
Ratio of E to mean 
Barley: 
Plot B. 
93 
13-2 
II. 9 
95 
77 
i -7 
x. 5 
X24 
0.0 
14 
3-8 
85 
8.8 
±8. 0 
5-8 
xi. 7 
10.3 
94 
16. 7 
Plot E.... 
0.0 
0. 0 
17.1 
x6-o 
. 2 
7- x 
Ratio of E to mean 
0.0 
94 
IOI 
96 
10 
70 
±12.0 
_ 
Com: 
Plot B. 
1.4 
22.9 
25-7 
106 
2. 7 
9. 2 
• 7 
0. 0 
3-6 
54 -o 
7. 2 
ix.3 
Plot E. 
x. 1 
I. 7 
7 - 1 
r-o 
0. 0 
5 - x 
46.4 
3 - 7 
10. 2 
Ratio of E to mean 
88 
77 
87 
118 
“7 
92 
68 
94 
± 4*7 
a No record for 19x0 on account of change in location of station. 
