a ~ al 7=- 
WHEAT PRODUCTION ON DRY LANDS. 25 
with the moldboard plow. The 8-year average yields obtained from 
_ the plats plowed early (dry) in the fall were 2.5 bushels less than those 
obtained from the plats plowed on April 1 and 0.7 bushel less than 
the yield from the plats plowed on May 1. The yields obtained from 
the late (wet) fall plowing were 2.1 bushels less per acre than those 
~ obtained from the plats plowed on May 1, and 1.5 bushels more per 
acre than the yield of the plats plowed on June 1. 
RESULTS AT LIND. 
The summer-fallow experiments at Lind were conducted on two 
series of twentieth-acre plats, one series being in fallow and one in 
crop each year. These series of plats are widely separated, being on 
opposite sides of the station farm. Check plats were not used, and 
because the experiments were somewhat extensive and in their 
resent form were considered somewhat temporary they have not 
as replicated each season. 
In the Washington portion of the Columbia Basin the greater part 
of the fallow is plowed in the spring, only a very little being plowed 
in the fall. Two dates of fall plowmg, two of spring plowing, and 
one of early summer plowing are included in these experiments. The 
_ two fall dates represent dry and wet plowing and the three spring 
and summer dates early, intermediate, and late work, the first being 
done at a time when the soil is wettest, the third when the soil is 
practically dry, and the second intermediate between the other two. 
All of these dates vary with the season and are considered as more or 
less relative, depending on prevailing conditions during any one year. 
Experiments to determine the best date of plowing have been com- 
_ bined with those covering other factors as well, and the yields given 
_ for dates of plowing are the averages obtained from 3 to 12 plats 
plowed on each date in each year. The data are presented in Table 
12 and are shown graphically in Figures 14 and 15. 
_ Taste 12.—Annual and average yields of wheat on fallow land plowed on different dates, 
at Lind, Wash., during the 4-year period 1918 to 1921, inclusive. 
Annual and average yields per acre (bushels). 
Time of plowing and condition of soil. | i 
1918 1919 1920 1921 | Betis 
Fall plowing 
we es. - 22 ee 3.9 9.2 7.0 8.9 7.2 
oO" SS ES SS ee a eee 4.1 9.6 75 11.7 8,2 
Spring plowing: 
March Va ga ae ae 6.9 12.3 8.4 13.4 10. 0 
ll aD So ee ee eee 5.9 12.6 8.3 13.8 10.1 
Summer plowing: 
DEILG  y % See ee eee eee 5.8 10.3 6.0 10.8 | 8.2 
! 
1 Average of 3 plats variously cultivated. 3 Average of 7 plats variously cultivated. 
2 Average of 12 plats variously cultivated. 4 Average of 6 plats variously cultivated. 
_& In planning the experiments it was intended to crop entirely to 
_ winter wheat, but seasonal conditions prevented adherence to this 
plan. The crops of 1918, 1920, and 1921 were Early Baart spring 
_ wheat, and the crop of 1919 was Turkey winter wheat. This varia- 
_ tion, however, apparently did not affect the results. 
48605—23——-4 
