24 
BULLETIN 1377, U. S. DEPARTMENT OF AGRICULTURE 
Table 18. — Effects of crop rotation and of the use of farm manure on the yields 
of com 
[Rotation and the use of manure practiced independently of each other] 
Plot 
No. 
Cultural conditions 
Average 
yield 
per acre 
Average 
increase 
due to 
rotation 
Average 
increase 
due to 
use of 
manure 
13 
6-year rotation and continuous culture: 
Rotation without use of manure 
Bushels Bushels 
41.5 21.2 
Bushels 
18 
Use of manure without rotation 
27.8 
20.3 
38.6 
44.5 
28.6 
32.6 
39.0 
18.4 
7.5 
17 
39 
4-year rotation and continuous culture: 
Rotation without use of manure 
10.0 
18 
15.9 
17 
27 
3-year rotation and continuous culture: 
14.2 
18 
20.6 
17 
15.1 
14.7 
Table 19. — Effects of crop rotation and of the use of farm manure on the yields 
of oats 
IRotation and the use of manure practiced independently of each other] 
Plot 
No. 
Cultural conditions 
Average 
yield 
per acre 
Average 
increase 
due to 
rotation 
Average 
increase 
due to 
uso of 
manure 
13 
6-year rotation and continuous culture: 
Bushels 
27. 3 
33.6 
19.5 
27.9 
32.6 
23.4 
Bushels 
7.8 
Bushels 
15 
14. 1 
16 
39 
4-year rotation and continuous culture: 
4.5 
15 
9.2 
16 
Average increase from rotation and use of manure 

6.2 
11.7 
Table 20. — Effects of crop rotation and of the use of farm manure on the yields 
of timothy 
[Rotation and the use of manure practiced independently of each other] 
Plot 
No. 
Cultural conditions 
Average 
yield 
per acre 
6-year rotation and continuous culture: Pounds 
Rotation without use of manure 2,446 
Use of manure without rotation i 5,850 
No manure and no rotation. 2,894 
Average 
increase 
due to 
rotation 
Pounds 
-448 
Average 
increase 
due to 
use of 
manure 
Pounds 
2,956 
In Table 21 are summarized the data contained in the four fore- 
going tables. Timothy is not included, since results seem to show 
that this crop is not benefited by rotation under conditions of these 
experiments. 
