12 BULLETIN 253, U. S. DEPARTMENT OF AGRICULTURE. 
plowing. The corn was given clean cultivation. The spring-plowed 
wheat plats averaged 3.8 bushels and the spring-plowed oat plats 1.3 
bushels per acre more than the fall-plowed plats. 
The heavy rains in August and early September in 1909 prevented 
thrashing and delayed fall plowing until the latter part of September. 
By that time the heavy growth of weeds had used the soil moisture 
resulting from the precipitation of August and September, and plat 
B plowed up dry and lumpy. No moisture determinations were 
made at this time, but it is only fair to assume that plat A was equally 
dry, as it also had produced a heavy growth of weeds. In the spring 
of 1910 the moisture content of plat A was decidedly greater in the 
first and second feet and slightly greater in the third foot than it was 
in plat B. This increase in moisture content was due to the snow 
held by the stubble on plat A. At harvest time the moisture was 
exhausted in both plats, but plat A gave a yield of 11.3 bushels and 
plat B yielded 6.2 bushels. 
The small difference in moisture content in the spring could not 
account directly for the difference in yields, but the slightly larger 
amount of moisture in plat A may have caused a quicker growth, 
which crowded out the weeds. All three crops were better on spring 
than on fall plowing. The corn, in which weeds were not a factor in 
determining the yield, showed a difference in favor of spring plowing. 
As the moisture in both plats A and B was exhausted at harvest 
time, their moisture content was probably the same when plat B was 
plowed, August 12, 1910. 
The early plowing of plat B prevented weed growth on it, and the 
greater part of the heavy rains of August and September was stored 
until the following season. Practically all the water from these rains 
was used in the fall by a heavy growth of weeds that occupied the 
plats which were to be spring plowed. Light precipitation during 
the winter of 1910-11 added very little water to the soil; conse- 
quently the spring-plowed plats had much less moisture in the spring 
than the fall-plowed plats. The yield was 4.1 bushels of wheat from 
plat A and 15.9 bushels from plat B. All the moisture had been used 
from both plats. Every fall-plowed plat gave a better yield than was 
obtained from any spring-plowed plat. 
Plat B was plowed on August 16, 1911, immediately after a rain 
of 1 inch. There were only light rains during August and September, 
which slightly increased the moisture content of the first foot in plat 
B but made no change in plat A. The heavy snows of February and 
March were held by the stubble on plat A. In melting they filled its 
soil to a depth of at least 5 feet. There was no change below the 
third foot in the water content of plat B. 
The precipitation of the growing season was so heavy that none of 
the crops suffered from lack of moisture. The yields from fall plow- 
