WINTER-WHEAT PRODUCTION AT FORT HAYS STATION. ash 
| and double-disked before seeding in 1916, 1918, and 1919. It has 
_ received no other cultivation or treatment except seeding and 
harvesting. Its average yield for the 7-year period from 1914 to 
1920, inclusive, as shown in Table 8, is 20.4 bushels per acre. This 
' may be properly compared with the yield of 21.4 bushels on early 
_ fall-plowed wheat stubble in rotation No. 401. 
Further evidence on this subject is furnished by an experiment 
as to the frequency of plowing for winter wheat, which was started. 
in 1916. This occupies six plats continuously cropped to winter 
wheat. Plat A is plowed each year, B is plowed one year and sown 
in stubble the next, C is plowed one year and sown in stubble two 
years, D is plowed one year and sown in stubble three years, E is to 
be sown in stubble continuously, and F, originally planned for 
another method, has been plowed each year except for the crop of 
1917. The tillage on these plats is early plowing, which is worked 
down immediately and given necessary cultivation until seeding 
time. The plats sown without plowing receive no other treatment 
than a double-disking. in preparation for the crop of 1917 this was 
done at the time of early plowing. Since then it has been done at 
the time of late plowing. The yields from these plats for the 5-year 
period from 1916 to 1920, inclusive, are given in Table 9. The land 
was fallowed in 1915 and seeded that fall as a solid field. The plats 
were blocked out from the field in the spring of 1916. Differences 
in yield that year are natural differences between plats of uniform 
treatment. For 1917 plat A was plowed and the others seeded in 
disked stubble. All except plat A were consequently of uniform 
treatment. For 1918 plats A, B, and F were plowed, and C, D, and E 
were again seeded on disked stubble and again given uniform treat- 
ment. For 1919 plats A, C, and F were plowed, and for the fourth 
year D and E were seeded on disked stubble continued uniform. For 
1920 plats A, B, D, and F were plowed, and uniformity between any 
of the plats disappeared. 
In Table 9 the yields on plowed ground in the 4-year period from 
1917 to 1920, inclusive, are printed in boldface type. Despite the 
plat variation, as shown by differences in yield when the treatment 
was uniform, the results are clear as to differences between plowing 
and not plowing in the years during which the experiment had been 
conducted, but they do not yet illuminate the question of how often 
plowing must be resorted to or how long it may be dispensed with. 
The average of each plat for the 4-year period from 1917 to 1920, 
inclusive, is given at the bottom of Table 9. In the present stage of 
the experiment perhaps a better comparison is afforded by deter- 
mining the average yield each year of the plowed plats and of those 
not plowed. Such averages are shown in the right-hand columns 
of the table. In 1917 the one plowed plat was a total failure, due to a. 
