350 
Journal of Agricultural Research 
Vol. VII, No. 8 
In the case of rather more than half of the samples the calculated 
values agree satisfactorily with the directly determined hygroscopic 
coefficients. In the case of the Lincoln and Weeping Water samples, 
which are richest in clay and silt, and correspondingly poorest in very fine 
sand (2, p. 407), the calculated values are much too low for all except 
those samples from the surface foot. As an index of texture the calcu¬ 
lated hygroscopic coefficients would be very misleading. For instance, 
the Wauneta samples, with an average of 9.6, would appear almost as 
fine-textured as the Weeping Water soils with an average of 10.2, whereas 
in fact actual mechanical analyses have shown the latter to contain 
nearly three times as much clay, more than half as much again silt, and 
only about one-fourth as much very fine sand (Table V). It is of interest 
that in the case of those members of this series with which satisfactory 
results are obtained by the Briggs-Shantz formula for the calculation of 
the hygroscopic coefficient from the mechanical analysis the formula of 
the same authors for the calculation of this value from the maximum 
water capacity fails, and vice versa. 
Table V Relation of calculated hygroscopic coefficients to the texture of Nebraska soils. a 
Item, 
Wauneta. 
McCook. 
Holdrege. 
Hastings. 
Lincoln. 
Weeping 
Water. 
Maximum water ca¬ 
Per cent. 
Per cent. 
Per cent. 
Per cent . 
Per cent. 
Per cent. 
pacity . 
Calculated hygroscopic 
61. 6 
60.8 
65.6 
69.8 
66 . I 
64.8 
coefficient... 
Determined hygroscopic 
9.6 
9.2 
IO. 4 
II. 4 
IO. 2 
coefficient. 
9.2 
9.9 
10.3 
II. 0 
J 3 * 1 
13.0 
Gravel, above 1.0 mm... 
Gsarse sand, 1.0—0.5 
. 0 
• 0 
.0 
. O 
. 1 
. O 
mm . 
Medium sand, 0.5—0.25 
. 1 
. I 
. 2 
. 2 
.4 
. 2 
mm . 
Fine sand, 0.25—0.10 
•3 
• 4 
•3 
•5 
* 7 
•3 
mm . 
Very fine sand, 0.10— 
1.9 
i -5 
i -3 
1.9 
2.4 
1. 2 
0.05 mm . 
49-3 
3 & 6 
27.9 
21. 6 
10.3 
12. 7 
Silt, 0.05-0.005 mm - 
42. 2 
5 i. 6 
62.6 
64- 5 
68.5 
68.5 
Clay, 0.005—0.000 mm. . 
6-3 
7.8 
7*7 
II. 3 
17. 6 
17*3 
a The mechanical analyses are from Alway and Rost (2, p. 407.) 
The series of samples reported in Table VI includes, in addition to loess 
soils from Nebraska, residual soils from the same State and a few samples 
from the Southwestern States. The data upon both the hygroscopic 
coefficient and the water capacity are the means of five or more, concordant 
determinations. The range in texture is much wider than that of those in 
Table IV and quite similar to that of the soils dealt with by Briggs and 
Shantz (4, p. 67). Except in a few cases, the calculated value agrees fairly 
weM with the directly determined value. The widest departures are shown 
by the eastern Nebraska loess subsoil, similar in texture to the Lincoln and 
Weeping Water subsoils reported in Table IV and by two surface soils, 
