952 
Journal of Agricultural Research 
Vol. XXXI, No. 10 
Table III. — Student’s method applied to corn yields in five-year rotation at Wooster , 
Ohio 
Year 
Actual yields 
Differ¬ 
ence in 
Devia¬ 
tion 
from 
.78 
(D) 
D2 
Gains effected 
Differ¬ 
ence in 
gains 
No. 17 
over 
No. 26 
Devia¬ 
tion 
from 
4.31 
(D) 
D2 
Plot 
No. 17“ 
Plot 
No. 26 6 
yields 
No. 17 
over 
No. 26 
Plot 
No. 17 
Plot 
No. 26 
Bush. 
Bush. 
Bush. 
Bush. 
Bush. 
Bush. 
1894__ 
20.50 
18.32 
2.18 
1.40 
1.96 
-0.62 
1.80 
-2.42 
6.73 
45.29 
1895. 
1896... 
56.89 
59.43 
-2.54 
3.32 
11.02 
5.80 
8. 74 
-2.94 
7.25 
52.56 
1897__ 
31.79 
42.86 
-11. 07 
11.85 
140.42 
13.11 
9.48 
3.63 
.68 
.46 
1898.... 
33.93 
38. 75 
-4.82 
5.60 
31.36 
8.06 
7.24 
.82 
3.49 
12.18 
1899_ 
40.50 
34.50 
6.00 
5.22 
27.25 
18.81 
10.36 
8.45 
4.14 
17.14 
1900..... 
48.68 
41.32 
7.36 
6.58 
43.30 
21.35 
10.75 
10.60 
6.29 
39.56 
1901__ 
60.64 
63.14 
-2.50 
3.28 
10.76 
19.35 
28.64 
-9.29 
13.60 
184.96 
1902...... 
75. 57 
89.18 
-13. 61 
14.39 
207.07 
23.25 
22.92 
.33 
3.98 
15.84 
1903__ 
22.32 
23.43 
-1.11 
1.89 
3.57 
19.67 
13.83 
5.84 
1.53 
2.34 
1904... 
40.04 
34. 46 
5.58 
4.80 
23.04 
22.95 
19.40 
3.55 
.76 
.57 
1905__ 
58.64 
49.18 
9.46 
8.68 
75.34 
20.86 
18.25 
2.61 
1.70 
2.89 
1906_ 
63.32 
64. 54 
-1.22 
2.00 
4.00 
28.12 
29.33 
-1.21 
5.52 
30.47 
1907...... 
48.29 
64. 57 
-16.28 
17.06 
291.04 
12.98 
17.56 
-4.58 
8.89 
79.03 
1908.__ 
44.96 
43.64 
1.32 
.54 
.29 
20.16 
10.51 
9.65 
5.34 
28. 52 
1909_ 
45. 07 
33. 67 
11.40 
10.62 
112.78 
25.29 
14.11 
11.18 
6.87 
47.20 
1910....__ 
17.07 
12.03 
5.04 
4.26 
18.15 
13.09 
3.19 
9.90 
5.59 
31.25 
1911.__ 
71. 75 
69.10 
2.65 
1.87 
3.50 
35.28 
25.02 
10.26 
5.95 
35.40 
1912_ _ 
1913...... 
42.50 
26. 25 
16.25 
15.47 
239.32 
29.87 
8.58 
21.29 
16.98 
288.32 
Mean__ 
45.70 
44.90 
+0.78 
69.12 
14.43 
+4.31 
M=50. 78 
<r=8.31 
18.74 j 
«r=7.12 
£=0.0939. £=0.61. 
P=less than ±0.6575. P= ±0.9886. 
Odds=less than 2 to 1. Odds=87 to 1. 
• Fertilizer treatment consists of 60 pounds of nitrate of soda, 25 pounds of dried blood, 160 pounds of 
acid phosphate, 100 pounds of muriate of potash, applied to wheat; and 80 pounds of nitrate of soda, 160 
pounds of acid phosphate, and 80 pounds of muriate of potash, applied to corn and oats. 
b Fertilizer treatment consists of 50 pounds of dried blood on wheat; 120 pounds, 240 pounds, and 240 
pounds of nitrate of soda, applied on wheat, corn, and oats, respectively; bone meal equivalent to 160 
pounds, 80 pounds, and 80 pounds of acid phosphate, applied to wheat, corn, and oats, respectively; and 
100 pounds, 80 pounds, and 80 pounds of muriate of potash, applied to wheat, corn, and oats, respectively. 
In this case a parallelistic analysis of the yields shows that the one 
fertilizer is practically as efficient as the other, but when Student's 
method is applied to the gains obtained, the odds are 87 to 1 that the 
fertilizer applied to plot No. 17 is more effective than that applied 
to plot No. 26. 
It may be of interest to cite four other cases to illustrate how a 
conclusion reached by applying Student's method to paired yields 
may be reversed when the parallelisms of the corresponding gains 
are studied (Table IV). 
