10 BULLETIN 595, U. S. DEPARTMENT OF AGRICULTURE. 
In conformity with the foregoing explanation, Table IV gives in 
detail the cost of producing winter wheat in the shock, expressed in 
dollars and cents and in bushels per acre at 70 cents per bushel. 
These prices are used as a working basis and are not offered as being 
exact. It is fully realized that the price of any or all factors used in 
obtaining them may vary locally from the fixed price assumed. 
RESULTS AT THE SEVERAL STATIONS. 
Accompanying the discussion of each station is a very brief descrip- 
tion of the soil, with particular reference to its depth and its water- 
holding capacity. Only such information is given as is necessary to 
understand fully the interpretation of the results. 
JUDITH BASIN FIELD STATION. 
The field station at Moccasin, Mont., in the Judith Basin, is located 
on a heavy clay soil of limestone origin. The soil is apparently very 
rich in available fertility. It is underlain at a depth of approxi- 
mately 3 feet by a limestone gravel that is closely cemented with 
lime materials. The gravel subsoil, which extends to a depth of about 
30 feet, is practically free from soil. While it is so closely cemented 
that it does not unduly drain the soil, it is not of a character that 
allows the storage of available water or the development of roots 
within it. Gravel in the surface soil interferes with the taking of 
samples satisfactory for the study of soil moisture. Enough has 
been done, however, to make it certain that the supply of water that 
can be stored in this soil is limited. This shallowness of the soil and 
consequent limitation of the quantity of water that can be stored in 
it and recovered by the crop makes the crop dependent in large part 
upon the rains that fall while it is growing. 
The first winter wheat raised at the station was the crop of 1909, 
which was all on summer-tilled land. The first crop which shows 
results from different methods of preparation is that of 1910. 
In the period under study, there has been one failure of winter 
wheat, the crop of 1916 being lost by winterkilling. In 1912 the crop 
was badly damaged by a hailstorm that entirely destroyed the 
Spring-sown grains. 
The highest average yield, 25.7 bushels per acre, has been obtained 
from summer tillage. The yields from summer tillage have been 
the highest every year except in 1910. The next highest average 
yield, 24.4 bushels, was secured after green-manure crops. The 
yields after green manure have been higher than from any other 
method, except summer tillage, every year except in 1912. Since 
1914, when the practice of seeding on disked corn ground was begun, 
this method has outyielded all others except green manuring and 
summer tillage. During this period, the yields after summer tillage 
have averaged 5.5 bushels greater than on disked corn ground. 
