26 
BULLETIN 1377, TJ. S. DEPARTMENT OF AGRICULTURE 
In Tables 23, 24, 25, and 26 are summarized from Tables 8 to 16, 
inclusive, those average yields of wheat, corn, oats, and timothy 
which show the average effects of crop rotation and the use of fertiliz- 
ers on the yield of wheat, corn, oats, and timothy when these two 
farm practices are conjoined. In the column to the right of the one 
containing the average yields are given the average increases, over 
check plots in continuous culture, due to the conjoint effects of rota- 
tion and the use of manure, and in case of wheat, the conjoint effects 
of rotation and the use of chemical fertilizer. 
Table 23. 
■Average effects of the conjoint action of crop rotation and the use of 
fertilizers on the yields of wheat, Missouri 
Plot No. 
Cultural conditions, rotation and check plot in continuous culture 
Average 
yield per 
acre 
Average 
increase 
over check 
plot in 
continuous 
culture, 
due to 
rotation 
and use 
of fertiliz- 
ers 
11, 12, 14, 20 
6-year rotation: 
Rotation and use of manure 
Bushels 
30.9 
30.0 
12.5 
Bushels 
18.4 
3 
Rotation and use of chemical fertilizer 
17.5 
9 
No rotation and no fertilizer 
34, 35, 37. 38 
4-year rotation: 
Rotation and use of manure 
28.8 
23.9 
9 
No rotation and no manure 
4.9 
28.3 
9.7 
24.9 
9.1 
28 
3-year rotation: 
Rotation and use of manure 
18.6 
9 
31 
2-year rotation: 
Rotation and use of manure 
15.8 
9 
Average yield and increase effected by rotation and use of 
28.2 
30.0 
19.1 
Yield and increase effected by rotation and use of chemical 
17.5 
Table 24. 
■Average effects of the conjoint action of crop rotation and the use of 
farm manure on the yields of corn 
Plot No. 
Cultural conditions, rotation and check plot in continuous 
culture 
Average 
yield per 
acre 
Average 
increase 
over check 
plot in 
continuous 
culture due 
to rotation 
and use of 
manure 
11, 14, 20 
17 
6-year rotation: 
Bushels 
44.6 
20.3 
47.7 
28.6 
51.0 
18.4 
Bushels 
24.2 
34, 35, 37, 38 
17 
4-year rotation: 
19.1 
28 
3-year rotation: 
32.6 
17 
Average yield and increase effected by rotation and use of 
47.7 
25. J 
