5oo 
Journal of Agricultural Research 
Vol. XIV, No. XI 
TUCUMCARI FIELD STATION 
The soil of the field station at Tucumcari, N. Mex., is of a residual type 
and is classified by the Bureau of Soils as a fine sand. The sand extends 
down to a depth of from i to 3 feet, gradually blending into a clay which 
continues in many places to a depth of at least 135 feet. 
Table XII presents three years' results with kafir, milo, sorghum, 
broom com, and cotton at this station. Of the 15 comparisons afforded 
in this table only 2 are in favor of subsoiling. These are kafir in 1914 
and broom com in 1915. This evidence seems conclusive that subsoiling 
here is at least an unnecessary if not a detrimental practice. 
Table XII .—Yields at the Tucumcari (N. Mex.) Field Station of kafir , milo, sorghum , 
broom corn , and cotton each year from 1914 to 1916 , inclusive , on plot E t 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 
(Yields of kafir and milo in bushels; sorghum in pounds of forage; broom corn in pounds of brush; and cot¬ 
ton in pounds of seed cotton per acre] 
Yield or ratio. 
Crop and plot. 
1914 
1915 
X916 
Average. 
Probable 
error of 
mean 
ratio. 
Kafir: 
Plot B. 
34.9 
38.5 
I0 5 
- 5 Q. g 
18.0 
30-9 
32. I 
102 
Plot E. 
oy* v 
30. 8 
18. 0 
100 
Ratio of E to mean. 
0 y* 
100 
±1.4 
Milo: 
Plot B.. 
45-8 
36. 2 
88 
46.8 
4.1 1 
33-9 
28. 2 
90 
Plot E. 
y. 0 
Ratio of E to mean. 
J. 
94 
7. * 
89 
±1. 4 
Sorghum: 
Plot B. 
5,32° 
5,08° 
98 
5,020 
4,980 
100 
5 . 560 
4, 600 
9 i 
5,300 
4,887 
96 
Plot E. 
Ratio of E to mean.. 
±2. 2 
Broom com: 
Plot B. 
S «3 
4.00 
COO 
420 
190 
62 
5 oi 
487 
92 
Plot E. 
780 
122 
Ratio of E to mean. . ... 
01 
±12. 2 
Cotton: 
Plot B.... 
838 
tors 
380 
205 
70 
579 
439 
82 
Plot E... 
340 
79 
Ratio of E to mean. 
t to 
96 
± 5-8 
COMPARATIVE RESULTS WITH SUBSOILING DIFFERENT CROPS 
The comparative results with different crops as shown in Table XIII 
and figures 2 and 3 scarcely warrant any conclusion that one crop is 
affected differently than another by subsoiling. The average ratios with 
