12 
BULLETIN 1310, U. S. DEPARTMENT OF AGRICULTURE 
RESULTS OF MANURING FALLOW 
The effect of an application of barnyard manure has been tested 
in two comparisons with winter wheat and one with oats. The 
manure is applied at the rate of approximately 10 tons per acre 
before the land is plowed for fallow. Rotation 38 is alternate 
winter wheat and fallow with manure, and plats C and D in the 
continuous-cropping series are alternate winter wheat and fallow 
without manure. Rotations Nos. 118 and 172 are 4-year rota- 
tions of fallow, winter wheat on fallow, corn on spring plowing, and 
oats on disked cornland. The difference between them is that the 
fallow in rotation No. 172 is manured and that in No. 118 not 
manured. Rotations Nos. 171 and 119 are similar 4-year rota- 
tions in which oats are on fallow, corn on spring plowing, and winter 
wheat on disked cornland. The difference in these rotations is that 
fallow is manured in rotation No. 171, while in No. 119 it is not 
manured. 
The annual and average yields of winter wheat and oats following 
manured and unmanured fallow in these rotations are shown in 
Table 8. No increase in the yield on manured fallow over that 
which was not manured has occurred. In rotation No. 38, which is 
alternate winter wheat and manured fallow, the yield was more 
than 3 bushels below that of plats C and D, which are alternate 
winter wheat and fallow without manure. This difference may be 
due in part to differences in winterkilling, as these rotations are 
located some distance apart in the field. In 1922 grasshoppers took 
the crop in rotation No. 38, so that year is not included in the aver- 
age of rotation 38 and of plats C and D with which it is compared. 
The winter-wheat yields in rotations Nos, 172 and 118 were about 
equal, showing practically no effect from the application of manure 
in No. 172. 
Table 8. — Annual and average yields of winter wheat and oats on manured and 
unmanured fallow, 1917 to 1923, inclusive 
Rotation 
Yields per acre (bushels) 
Crop and treatment 
1917 
1918 
1919 
19201 
1921 
19221 
19231 
Aver- 
age 
38 
MCCorD 
172 
118 
171 
119 
8.2 
10. 
12.5 
11.8 
21.6 
25.6 
7.2 
8.2 
8.3 
11.3 
9.7 
10.9 

3.5 
2.8 
1.8 
3.4 
3. 1 
4.0 
9. 3 
5.2 
6.0 
29.4 
28.4 
11.0 
19.0 
19.3 
14.8 
43.4 
35.3 

14.5 
9.8 
10.7 
19.7 
28.8 




35.0 
33.8 
2 5.1 
-it- *. !,„„+ Unmanured .. 
2 8.3 
Winter wheat Manured __ _ 
8.3 
lUnmanured 
q . /Manured 
8.1 
23.2 
\Unmanured .. 
23.7 
1 Winter wheat winterkilled in 1920 and 1922 and was reseeded to Marquis in the spring. In 1923 it 
partly winterkilled and was reseeded to Marquis, but the plats were too weedy to harvest. 
2 Average for six years, not including 1922, when the wheat in rotation 38 was destroyed by grasshoppers. 
The average yield of oats in rotation No. 171, which receives an 
application of manure, was slightly less than in No. 119, which is 
not manured. 
The application of manure before plowing the land has not in- 
creased the yields of small grains above those on fallow unmanured. 
In each case manuring has slightly decreased the yields. These 
results may change as the plats age or under more favorable climatic 
