WINTER-WHEAT PRODUCTION AT FORT HAYS STATION. 95 
sidered in the following pages, and it is also low in comparison with 
' wheat on alternate fallow in methods of fallow. These latter are in 
fairly good agreement. It has been shown that kafir has a very 
depressing effect upon the yield of wheat that follows it immediately, 
_ but the evidence as a whole indicates that this effect is eliminated 
_ by a fallow. No. 402 is an adjoining rotation of kafir listed, fallow, 
_ winter wheat on fallow, and kafir listed. The wheat on fallow in 
this rotation has averaged only 17.6 bushels. This seems to show 
that the growth of two crops of kafir in succession establishes a de- 
pressing effect that persists through a fallow. This possible con- 
clusion is subject to a reasonable doubt by the yields in 1914, when 
the rotations had not run long enough to differentiate the wheat on 
fallow in rotations Nos. 401 and 402, but when the yield of wheat in 
No. 402 was low. ~ 7 
The kafir following wheat in rotation No. 410 has averaged 22.6 
bushels per acre; following wheat in rotation No. 402 it has averaged 
20.4 bushels, and following kafir in the same rotation it has averaged 
only 14.7 bushels. While a potential difference of soil and location 
might be established between rotations Nos. 401 and 402, the two plats 
of kafir in No. 402, like the two plats of wheat in No. 401, are grown 
on the same ground, one following the other from year to year over the 
four plats that constitute the rotation. 
These 4-year rotations were started for comparisons with the 3-year 
rotations of kafir, fallow, and wheat that are considered in the fol- 
lowing pages to determine the effect of lengthening them by intro- 
ducing a second crop of wheat or a second crop of kafir. Their 
evidence is very positive. The second crop of wheat (wheat on early- 
plowed stubble of wheat raised on fallow) has an exceptionally 
favored position. The rotations should be lengthened by increasing 
the number of wheat crops. On the other hand, the second crop of 
kafir (kafir following kafir) is depressed to about two-thirds the 
yield of kafir following wheat. There is also indication, although 
the evidence is by no means conclusive, that this doubling of the 
_ kafir crop establishes a depressing effect that is not entirely eliminated 
by a year of fallow. 
In 1916 two 4-year rotations were started. Rotation No. 403 is 
corn on spring plowing, barley on disked corn ground, winter wheat 
on fall-plowed barley stubble, and winter wheat on fall-plowed wheat 
stubble. Rotation No. 404 is the same in all respects except that kafir 
takes the place of corn. 
The 4-year average yield of the wheat on fall-plowed barley stubble 
has been 17 bushels in each rotation. The wheat following wheat has 
averaged 17.2 bushels in rotation No. 403 and 16.1 bushels in No. 404. 
The barley has averaged 23.8 bushels following corn and 22.5 
bushels following kafir. These rotations show little or no depression 
