SUBSOILING, DEEP TILLING, AND SOIL DYNAMITING 
IN THE GREAT PLAINS 1 
By E. C. ChilcoTT, Agriculturist in Charge , and John S. Cole, Agriculturist , Dry- 
Land Agriculture Investigations , Bureau of Plant Industry , United States Depart¬ 
ment of Agriculture 
GENERAL DISCUSSION OF SUBSOILING, DEEP TILLING, AND SOIL 
DYNAMITING 
There is perhaps no agricultural operation that is so often and enthusi¬ 
astically advocated and at the same time so little practiced as that of 
loosening or tilling the soil below the depth reached by the ordinary plow. 
The supposed necessity or desirability of such an operation appears 
to be based on a widespread belief that only that part of the soil loosened 
and moved by man with his implements of tillage is utilized by nature in 
the production of crops; that this part of the soil is the only part that 
participates in the storage of water to be recovered by the crop; that 
the development and growth of the roots of crop plants is limited to 
this portion of the soil, and that this is the only portion of the soil from 
which plant food may be obtained by the crop. 
A less extreme belief recognizes that these things are not entirely 
limited to the portion of the soil that man loosens, stirs, pulverizes, or 
inverts, but holds that the soil so treated provides a more effective medium 
for their action than does the undisturbed soil. 
Such beliefs apparently either overlook the luxuriant vegetation 
produced on land that has never known the tillage implements of man or 
assume that the roots of crop plants are essentially different in their 
relation to the soil than those of other plants or of the same plants 
growing wild. 
Studies of the root systems of agricultural crops have shown that in 
the deep soils and subsoils of the prairies and plains the roots of annual 
crops are well distributed through the soil to a depth of 3 feet or more. 
1 The experimental work of this investigation was carried out at 12 field stations of the Office of Dry¬ 
land Agriculture Investigations. The following members of the scientific staff of the office assisted in the 
experiments at their stations: J. M. Stephens, superintendent, Judith Basin Substation, Moccasin, Mont., 
in charge of northern district; O. J. Grace, superintendent, Akron (Colo.) Field Station, in charge of 
central district; E. F. Chilcott, superintendent, Woodward (Okla.) Field Station, in charge of southern 
district; W. P. Baird, assistant, Judith Basin Substation; A. E. Seamans, assistant, Huntley (Mont.) 
Field Station; W. A. Peterson, superintendent, F. E. Cobb and N. O. Henchel, assistant arboriculturists, 
Max Pfaender, assistant in horticulture, J. T. Sarvis, physiologist, and R. S. Towle, assistant, Mandan 
(N. Dak.) Field Station; O. R. Mathews, assistant. Bellefourche (S. Dak.) Field Station; F. E. Kelso, 
superintendent, Ardmore (S. Dak.) Field Station; Albert Osenbrug, assistant, Scottsbluff (Nebr.) Field 
Station; W. E. Lyness, assistant^ Archer (Wyo.) Field Station; J. F. Brandon, assistant, Akron (Colo.) 
Field Station; A. E. Hallsted, assistant, Hays (Kans.) Substation; C. B. Brown, assistant. Garden City 
(Kans.) Substation; E. N. Jensen, assistant, Amarillo (Tex.) Field Station; H. G. Smith, superintendent, 
Tucumcari (N. Mex.) Field Station. 
Journal of Agricultural Research, 
Washington, D. C. 
pf 
Vol. XIV, No. 11 
Sept. 9, 1918 
Key No. G-153 
