TIME OF PLOWING SMALL-GRAIN STUBBLE. 
9 
As already stated, the percentages are computed on the dry weight 
of the soil, and, as the weight of the soil in the first foot is less than 
in those below, the percentage of moisture must be higher to indicate 
an equal amount of water. For example, the percentage of moisture 
on April 9, 1912, on plat A in the first foot was higher than for the 
second, but the actual amount of water in each of the 2 feet was the 
same. The weight per cubic foot of the lower 5 feet is nearly the'same, 
so that a comparison of moisture percentages is also a direct compari- 
son of moisture content. 
DEPTH 1908 1909 1909 1910 1910 1911 1911 1911 *9« I9U 1912 1913 I9l3 1913 1914 1914 
INFCET fi«gxi *prl fiugZf M*H7 Jut'O /ffnB fiugO- 0cf30 tyr* fog.J Oct.2 9 ^rS Jv/24 Octz Afar.24 M.Z9 
<3 
I* 
5 
T 
in 
I 
•3 
! 
■ ■■ill 
Fig. 1. — Graphs showing the amounts of water available to wheat in each of the upper 6 feet of soil at 
certain dates of sampling at the Akron Field Station, for the years 1908 to 1914, inclusive. Plat A is 
spring plowed, plat B is fall plowed, and both are continuously cropped to spring wheat. 
A small percentage of moisture in any foot does not necessarily 
mean that the moisture was evenly distributed through that foot. It 
may have been contained in a few inches of one foot. The determina- 
tions of October 30, 1911, show 4.7 per cent in the first foot of plat A, 
all of which was probably in the upper 8- inches. The soil is usually 
exhausted of available moisture at the time the small grain is har- 
vested. One exception to this was plat A, on August 7, 1912. The 
summer precipitation had been so heavy that all the water in the 
soil on April 9, 1912, had not been needed in the production of the 
crop. The spring sampling of April 7, 1909, showed a little higher 
moisture content in plat B than in plat A. The difference was in the 
third and fourth feet. 
