WINTER-WHEAT PRODUCTION AT FORT HAYS STATION. 13 
WHEAT IN ROTATIONS FOR 14 YEARS. 
Of the nine plats of wheat grown in rotations in this block, two 
follow immediately after peas as green manure, two follow rye as green 
manure, four are on disked corn ground, and one on fallow. 
The highest average yield has been from the one on fallow in 
rotation No. 57. This isa 4-year rotation of fallow, winter wheat, 
corn on spring-plowed wheat stubble, and barley on disked corn 
ground. The wheat has averaged 19 bushels per acre. This should 
be compared with the yield of 20.3 bushels on fallow in the alternately 
cropped plats C and D that have been considered. The two have 
followed each other very closely in yield except in 1918, when the 
alternately cropped plat was very high and rotation No. 57 very low. 
For the other 13 years there is an average difference of only 0.3 
bushel in favor of rotation No. 57. 
No one of the other eight plats in rotations has averaged as much 
as either plats E or F continuously cropped to wheat. 
Rotation No. 51 is the same as No. 57, except that in place of the 
bare fallow a crop of winter rye is turned under as green manure. 
This is plowed under on the average date of May 31. Thereafter 
until seeding, the ground is given the necessary cultivation, like the 
fallow, to keep it free from vegetation. Its average yield is only 
13.4 bushels per acre. 
Rotation No. 55 is the same as No. 51 except that it contains kafir 
instead of corn. It is rye for green manure, wheat, kafir, and barley. 
Its average yield of wheat is 16.5 bushels. It appears that the 
greater part, if not all, of the difference in the yield of wheat in this 
rotation and in rotation No. 51 is due to plat variation and experi- 
mental error rather than to the fact that one has kafir and the other 
corn two years before the wheat. Nearly 1 bushel of the difference 
is accounted for by the failure of the wheat in rotation No. 51 in 1912. 
This was caused by fall and winter soil blowing and was unquestion- 
ably due to location in the field. The average of the two plats fol- 
lowing rye for green manure, one in rotation No. 51 and one in rota- 
tion No. 55, is 15 bushels per acre. This is only 0.4 of a bushel more 
than wheat on early plowing, less than wheat on subsoiled or early- 
listed ground, and 4.7 bushels less than the average of the two 
plats on fallow. 
Rotation No. 92 is similar to No. 51, and rotation No. 56 is similar 
to No. 55, the difference being the replacement of the rye by a legume 
for green manure. Rotation No. 92 is peas for green manure, winter 
wheat, corn, and barley, and rotation No. 56 is peas for green manure, 
winter wheat, kafir, and barley. In the first four years, from 1906 
to 1909, inclusive, cowpeas were used, but beginning with 1910 a 
change was made to field peas. Cowpeas grow in late season and are 
