50 
BULLETIN 1377, U. S. DEPARTMENT OF AGRICULTURE 
Table 50. — Comparison of relative values of rotation (R) and of the additive effects- 
of conjoining rotation and the use of fertilizers on limed and unlimed soils — Con. 
Cultural conditions 
Values for 
.Rand F 
Rela- 
tive 
value 
of E 
Additive effects 
of rotation and 
use of fertilizers 
Crop 
Average 
yield 
per acre 
R 
F 
Sum of 1 
increase j 
effected Actual 
by rota- 1 increase 
tion and effected 
use of i by con- 
fertilizer joining 
when rotation 
prac- and use 
ticed of ferti- 
sepa- lizers 
rately 
(r+/) 
Oats (Wooster).. 
Unlimed— Continued. Bushels 
Rotation without chemical 32.3 
Bushels 
Bushels Percent 
Bushels 
Bushels 
fertilizer. 
Use of chemical fertilizer 
without rotation. 
Rotation and use of manure. 
Rotation without manure. . . 
Use of manure without rota- 
tion. 
Limed: 
Rotation and use of chemical 
fertilizer. 
Rotation without chemical 
fertilizer. 
Use of chemical fertilizer 
without rotation. 
Unlimed: 
Rotation and use of chemical 
fertilizer. 
Rotation without chemical 
fertilizer. 
Use of chemical fertilizer 
without rotation. 
37.9 
4i. y 
32.9 
28.4 
Pounds 
1,929 
1,584 
1.860 
1,925 
1,648 
1,877 
13.5 9.0 | 150.0 
22.7 
22.6 

Cotton (South 
Carolina). 
Pounds Pounds 
69 345 
20 
Pounds 
1,014 
Pounds 
714 
48 
277 
17.3 
947 
636 
f 
For the want of liming tests in the continuous-culture series at 
Wooster, the yields on the unlimed plots of the same series are used 
in evaluating rotation and the use of fertilizers on the limed plots' in 
rotation. In doing so it is assumed that direct applications of lime 
on wheat, corn, and oats when grown in continuous culture produce 
no positive results. In as much as these three crops are tolerant of 
soil acidity, and for this reason show but little or no response to lim- 
ing, the yields obtained on the unlimed plots in continuous culture 
can not deviate very much from the results if said plots were limed (5) . 
Because the comparable average yields are for different periods, the 
relative values for crop rotation in the Wooster experiments as given 
in Table 50 are higher than the corresponding values given in Table 35. 
In comparing the results obtained under limed and unlimed condi- 
tions, as summarized in Table 50, it is to be noted that when the soil 
reaction is altered or changed by liming both the average absolute 
and relative values for rotation (R) have been increased— the average 
increase in the relative value, including all crops and fertilizers, being 
23.0 per cent. These increases in the effectiveness of rotation due to 
liming are also reflected in the conjoint effects of rotation and the 
use of fertilizers, as indicated by the comparative values given in the 
last two subcolumns of the table. 
