44 
Research Bulletin No. 5 
Table 16. — Effect of cultivation on soil moisture, 1910. 
PER CENT MOISTURE IN THE SOIL. 
Depth 
Disking 
Plowing 
May 22 
May 28 
Gain 
May 22 
May 28 
Gain 
Feet 
1 
13.1 
16.8 
3.7 
14.8 
17.1 
2.3 
2 
10.7 
10.9 
11.3 
14.7 
3.4 
3 
8.9 
8.8 
9.6 
9.3 
Average . 
10.9 
12.2 
11.9 
13.7 
In Table 16 are given additional data to show the difference 
between a plowed surface and a disked surface in retaining water 
from a rain.* During the interval a rain of .85 inch came. Prac- 
tically all of the water which fell was retained in the plowed 
land. The disked soil held 65 per cent of the rain, all of which 
was held in the first foot of soil. Tn the plowed soil the moisture 
content of the second foot was increased. 
All of the considerable number of tests that have been made 
during the past several years show an advantage of plowing over 
disking to store water. In many cases the difference is very 
small and depends largely on the weather conditions and the 
weeds that escape the disk. If the weather continues dry during 
a test of this kind or if the disking kills the weeds as thoroly as 
the plowing, little difference will be found. If the disking, how- 
ever, does not kill all the weeds the difference will be greater, 
depending upon the amount of water used by the weeds. Where 
heavy rains come during the test, the advantage of plowing over 
disking will be greater. The plowing puts the soil in better 
shape than does the disk to catch the heavy rains. 
* This rain is shown in the records as 1.44 inches. This amount fell in 
North Platte, as reported by the U. S. Weather Station. The precipita- 
tion tables are made from the Weather Bureau records, because they 
are kept at the Substation only during the growing season. 
