WHEAT PRODUCTION ON DRY LANDS. 19 
deep each year. Pacific Bluestem spring wheat was used until 1917: 
in 1918 and 1919 Baart spring wheat was used; and in 1920 and 1921 
Turkey winter wheat was used. In each series two check plats 
_ were plowed 8 to 10 inches deep, uniformly cultivated, and cropped to 
_ spring wheat from 1912 to 1919, inclusive, and to winter wheat in 
1920 and 1921. 
The plats of the tillage experiments were arranged in series of 10, 
with the third and eighth plats in each series used as uniformly cul- 
_ tivated check plats. The dimensions of the plats were 2 rods by 8 
- rods. Each series or block was surrounded by a road 16 feet wide, 
and the plats were divided by alleys 5 feet wide. In the spring- 
plowing experiments the check plats were all plowed in April and 
given uniform cultural treatment thereafter. In the fall-plowing 
experiments the check plats were plowed late in the fall during the 
first five years, but during the past three years they were plowed in 
the spring to make them uniform with the other check plats. 
YIELDS OF CHECK PLATS AT MORO. 
The average yields of the check plats in the date-of-plowing experi- 
ments at Moro are shown in Table 9. The yields from the check 
plats are average yields of two plats in each year. Average yields 
are shown in the table for the entire 9-year period from 1913 to 1921, 
- inclusive; for the years 1914 to 1921, inclusive; and for 1919 to 1921, 
inclusive. The yields of the check plats will be taken into considera- 
_ tion in interpreting the results obtained in the tillage experiments 
at Moro. 
_ Tasie 9.—Average yields of Turkey winter wheat on the uniformly cultivated check plats 
in the tillage experiments at Moro, Oreg., by periods in all or part of the 9-year period 
from.1913 to 1921, inclusive. 
Average yield per acre 
bushels). 
Series. | 
| 1913 to 1914 to 1919 to 
1921, 1921. 1921, 
SE: Se ee ee ee eee a ee 30.6 31.2 35. 1 
Ly. . 0 SESS ie ee ee ee eee 30. 9 31.9 | 36.3 
EH ee ee See ee ee 29.0 29.5 35.6 
eeetarty fall plowing (dry) ..........-...---.----- Zo PSR eee eee ae a e a 
ee ey ey a Seay Pee 
DATE-OF-PLOWING EXPERIMENTS. 
RESULTS AT MORO, 
The yields obtained in the date-of-plowing experiments in the 
years 1913 to 1921, inclusive, are shown in Table 10 for various 
methods of cultivating the summer fallow. For the spring plowing 
| the yields are from single tenth-acre plats. In the fall-plowing ex- 
» periments the yields are averages of duplicate tenth-acre plats for 
each year. For each date of plowing eight tenth-acre plats were 
used in addition to the check plats. Results are available in the 
spring-plowing experiments for the nine years from 1913 to 1921, 
‘Inclusive, a in the fall-plowing experiments for the eight years 
from 1914 to 1921, inclusive. Data from these experiments are 
shown graphically in Figures 14 and 15. 
