498 
Journal of Agricultural Research 
Vol. XIV, No. ii 
least 15 feet. The development of roots is limited only by the depth 
to which water is available and the physiological character of the plant. 
Table X presents the results of seven years’ work at this station, ex¬ 
clusive of 1913, when the crops were destroyed by hail. In 1911, which 
is included in the averages, all small-grain crops failed from drought so 
extreme that it was not overcome by any method under trial. In 1914 
the higher yield of all five crops under trial was on the subsoiled plot. 
This was the only year, however, when there was a consistent, marked 
difference in the results from the two methods. With none of the five 
crops has the average departure in either direction from the mean been 
greater than 4 per cent. Only in the case of wheat, which has a mean 
ratio of 103, with a probable error of 2.5, is the departure from the 
mean greater than the probable error. The results are conclusive in 
showing that subsoiling is without significant effect at this station. 
Table X. —Yields at the Garden City ( Kans.) Field Station of spring wheat, winter 
wheat, oats , barley, and corn each year from IQOQ to IQ16, inclusive, on plot E, sub¬ 
soiled, 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 com in total pounds; other crops in bushels per acre] 
Yield or ratio. 
Crop and plot. 
1909 
1910 
1911 
1912 
1913 
1914 
1915 
19x6 
Aver¬ 
age. 
Prob¬ 
able 
error 
of mean 
ratio. 
Spring wheat: 
Plot B. 
3*2 
5-2 
0. 0 
6.3 
(°) 
4*3 
12. 6 
0. 0 
4*5 
Plot E. 
2.9 
5-2 
0. 0 
7*7 
(°) 
5-3 
12. 0 
0. 0 
4*7 
Ratio of E 
to mean.. 
95 
IOO 
no 
no 
98 
103 
±2. 5 
Winter wheat: 
Plot B. 
0. 0 
0. 0 
0. 0 
0. 0 
(°) 
6*3 
10. 0 
0. 0 
2*3 
Plot E. 
0. 0 
0. 0 
0.0 
0. 0 
(°) 
6. 7 
9.9 
0. 0 
2.4 
Ratio of E 
to mean 
103 
99 
101 
dbi. 7 
Oats: 
Plot B. 
3-2 
10.3 
0. 0 
23 * 1 
( a ) 
8. 1 
32 - 7 
3 * 0 
XI * 5 
Plot E. 
2. 6 
IQ. O 
0. 0 
15*9 
(°) 
x 7 * 3 
3 °* 9 
3-0 
11. 4 
Ratio of E 
to mean.. 
90 
99 
82 
136 
97 
100 
101 
± 4 - 5 
Barley: 
Plot B. 
4. 8 
5-4 
0. 0 
9 * 0 
(°) 
15 * 2 
24. 2 
8.8 
Plot E. 
3 - 7 
5*2 
0. 0 
8*5 
( a ) 
17*3 
2 i *5 
4.0 
8. 6 
Ratio of E 
to mean.. 
87 
98 
97 
106 
94 
114 
99 
±2. 6 
Gom: 
Plot B. 
m 
(*) 
1,400 
4, 620 
( a \ 
3>°40 
1, 900 
1, 200 
2,440 
Plot E. 
W 
75 ° 
4, 500 
l a ) 
4,840 
1,80 :j 
2, 260 
2,830 
Ratio of E 
to mean.. 
70 
99 
123 
97 
131 
104 
± 7*8 
» Crop destroyed by hail. & Weights lost. 
