42 
Research Bulletin No. 5 
ture content of these two plats was sufficient to make the plat 
which had been disked plow in good shape while the other was 
too dry to plow. 
In summing up the data given in these two tables, it seems 
that moisture is conserved by disking following the binder if 
there is sufficient water in the soil after harvest to start weeds. 
In some cases we do not get a great deal of difference in the mois- 
ture content while in others we get a greater difference. But the 
disking will usually serve a twofold purpose. It will loosen the 
surface of the soil to catch and retain water and will kill most of 
the weeds. It is, however, frequently so dry after harvest that it 
is necessary to weight the disk in order to make it cut into the 
soil deeply enough to kill the weeds. 
In Table 14 are given some data obtained from three plats of 
soil in 1912. On one of these plats the soil was kept thoroly stirred 
with a disk and any weeds which escaped the disk were cut 
with a hoe. On another plat the surface was not cultivated, but 
the weeds were kept cut with a hoe. The third plat was not 
cultivated and the weeds were allowed to grow. At the close of 
the test it is shown that there was very little more water in the 
upper three feet of soil where it had been disked than where it 
had not been disked. There is a difference, however, in the mois- 
ture content of the 4th, 5th, and 6th feet, which indicates that 
more water was caught and retained on the surface which was 
disked than on the smooth surface. The soil on which weeds 
had been growing was dry all the way down except the first foot. 
The moisture shown in the first foot was acquired from a rain 
just previous to the last sampling. 
Table 15 gives the results from a test made to determine the 
relative effectiveness of plowing and disking to store water. The 
disking was done August 22 and the plowing August 25 and 29. 
The plowing was done to a depth of five to six inches. The disk 
was not weighted, but was set as deep as it would cut. Most of 
the weeds were killed by the disking and the surface soil was all 
stirred. During the interval in which the test was conducted, a 
total of 2.25 inches of rain fell. It will be noted from the table 
that during the period the plowed soil retained enough water to 
increase the moisture content of the second foot. In the disked 
soil there is no increase in moisture content in the second foot. 
The greater loss of water shown in the first foot in the disked 
soil than is shown in the first foot in the plowed land may be due 
to some weeds having escaped the disk and then having used the 
w^ater, or it may be due to the water being held closer to the sur- 
face in the disked soil and exposed to greater evaporation. 
