470 
Journal of Agricultural Research 
Vo!. XIV, No. ii 
its hygroscopic coefficient, its finer texture (Table II), and its almost 
negligible content of organic matter (Table I), behaved quite differently 
from the three others. 
upper umit 
At the time of the first sampling the frost was out of the plowed land 
and almost gone from the grass fields. Not more than a trace of rain 
had fallen within a 24-hour period during the 16 days preceding this, but 
still the ratios in both the grass field and the fallow were found almost 
as high as at any time later in the season, except immediately after very 
heavy rains, as on June 14 and August 16. In the two fields mentioned 
the ratios were similar, except for the drier condition of the surface inch 
in the fallow, and averaged alike, 3.1, for the 11-inch section (2 to 12 
inches), and almost alike, 3.2 and 3.1, respectively, for the whole 12-inch 
section. At the second sampling, 19 days later, the ratios were almost 
the same, with an average of 3.3 in both fields. A rain of 1.71 inches 
had fallen three days before. 
The heaviest rain of the season, 2.81 inches in 48 hours, fell on June 
12 and 13. Samples were taken from all three fields within less than 
12 hours after the cessation of this, and the highest ratios of the season 
found, averaging 3.7 and 3.9 for the surface 6 inches and 3.5 for the 
surface 12 inches of the grass field and fallow. The surface inch in the 
former showed the exceptionally high value of 4.7.. In laboratory experi¬ 
ments such high ratios have been found to be common where the down¬ 
ward movement of the water is delayed (2, p . 40). 
The second heaviest rain, 2.11 inches, fell during the night of August 
15-16. Early in the following forenoon the uppermost 9 inches in the 
fallow was found as moist as on June 14, and that in the grass field almost 
as moist, but the lower part of the foot was distinctly drier. 
In the cornfield ratios practically as high as those in the fallow were 
found near the surface when the sampling followed soon after a rain, as 
on August 5, 7, and 16, but the high ratios did not extend so far from the 
surface, and this for the simple reason that the corn kept withdrawing 
water from all levels, while in the fallow the loss was confined to evapora¬ 
tion through the surface, and during the month of August the rains were 
not sufficient to restore the moisture content of the lower sections in the 
cornfield to their water-retaining capacity. 
On the exposed subsoil the maximum ratios were found on June 14; 
but even then, when the samples had been taken only a few hours after 
the cessation of a heavy rain, the highest ratio was 2.4 or 2.5, and the 
average for the 12 inches 2.3, compared with 3.5 in both fallow and grass 
field. While the compact, smooth, weedless surface with a gentle slope 
increased the run-off and prevented the ready penetration of water, this 
relatively low maximum, found also in laboratory experiments with 
similar soil (soil A, 3, p. 402 ), must be attributed to the character of the 
soil itself rather than to the surface conditions. 
