Apr. 9,1917 
Water-Retaining Capacity of Soil 
59 
to use the average values for all of the 12 inches in calculating the ratios. 
The nitrogen and organic carbon content reported in the same table 
show the typical character of the one as a surface soil and of the other as 
a subsoil. The average hygroscopic coefficient for the surface foot from 
the fallow field was 9.4 compared with 10.2 for the surface soil D, while 
that for the surface foot of the exposed subsoil is 12.7 compared with 13.3 
for the subsoil A. 
A Government rain gauge, maintained at the Experiment Station 
and within 400 yards of both sampled areas, furnished the data on the 
rainfall. The weather of the four months involved did not depart widely 
from the normal at Lincoln, except that the May rainfall, amounting to 
0.69 inch occurring in five showers (0.10 inch on the 1st, 0.32 on the 4th, 
0.15 on the 10th, 0.02 on the 20th and 0.10 on the 26th) was 3.64 inches 
below the normal. The rainfall for June, July, and August 1 to 26 
amounted to 4.03, 2.68, and 3.86 inches, respectively. Both areas were 
sufficiently far from trees and alfalfa plants to avoid any draft by roots 
upon the subsoil moisture. 
The compact, uncultivated, but weedless, and gently sloping surface of 
the exposed subsoil was unfavorable to the ready penetration of the rains 
and favorable to run-off, while the loose, almost level surface of the fallow 
field permitted ready penetration and prevented any serious lossby run-off. 
The ratios for the surface inch and the four 3-inch sections are reported 
in Table XXIII. While on both areas the ratio in the surface 3-inch 
section fell very low during dry weather, at depths below this in the 
exposed subsoil it remained very constant, varying only from 1.9 to 2.4; 
but in the fallow it ranged from 2.1 to 3.9, the former after dry weather 
and the latter very soon after a heavy rain. In the fallow field the lowest 
3-inch section showed a lower ratio than the overlying two sections, in 
this resembling the exposed subsoil. 
Table XXIII .—Ratio of water content to hygroscopic coefficient at different levels in the 
surface foot of two adjacent fields 
Date. 
Weather conditions. 
Bare subsoil. 
Fallow field. 
First 
inch. 
1 to 3 
inches. 
4 to 6 
inches. 
OsS 
*>.s 
IO tO 12 
inches. 
First 
inch. 
I to 3 
inches. 
4 to 6 
1 inches. 
o> <2 
s i 
t-.S 
U 
8.9 
May 25-27. 
Prolonged hot dry weather fol¬ 
lowed by 0.10 inch rain. 
0.8 
1.0 
2.0 
2.1 
2.0 
o -5 
1.1 
2.8 
2.9 
2.4 
June 1. 
Within 8 hours after 0.50 inch 
rain. 
2.4 
2. X 
2.0 
2.2 
2.2 
2.6 
2.0 
2.9 
2.9 
2.4 
June 14. 
Within 5 hours after 2.71 inches 
rain... 
2.3 
2.3 
2. ^ 
2.4 
3*6 
July 10. 
Prolonged hot dry weather fol¬ 
* 0 
O' T 
j ’ y 
3 * / 
lowed by 0.24 inch rain. 
1* 7 
1.6 
1.9 
2.0 
2-0 
1.8 
i*S 
2.8 
3 * 2 
2.5 
July 11. 
Within 4 hours after 0.81 inch 
*•9 
1 * 7 
1.9 
2- I 
2-3 
3*4 
3 * 2 
3 * * 
3 * * 
3 *5 
Aug. 3. 
After a week of dry weather. 
• 9 
i *3 
2.0 
2. I 
2-2 
2. 7 
2*5 
2.1 
3 * 1 
3 *5 
Aug. 6. 
Within 6 hours after 1.30 inches 
rain. 
1.8 
1.8 
1.9 
2. I 
2. 2 
3-6 
3*5 
3*4 
3 * 1 
3 *5 
Aug. 16. 
Within 8 hours after 2.11 inches 
rain. 
2.1 
2. I 
2.1 
2. 2 
2. I 
4.0 
4.0 
3*9 
3*4 
2.7 
Aug. 26. 
After 10 days of dry weather. 
1.2 
i -7 
2.0 
2. O 
2. I 
i *7 
2.3 
3 *i 
3 *o 
2*5 
78370°—17 - 3 
