CEOP ROTATION IN RELATION TO SOIL PRODUCTIVITY 
31 
In Table 29 is shown the similarity in the fertilizer treatments 
given to the five plots selected, as based on the quantities of the three 
major nutrient elements applied per acre. 
Table 29. — Quantities of the major nutrient elements applied in the form of chem- 
ical fertilizers and manure to five of the selected Wooster plots 
[12, p. 585] 
Plot 
Crop 
Quantity of material applied per acre 
Nutrient elements (per acre) 
Nitrogen 
Phosphorus 
Potassium 
12,3 
2 
Corn 
Oats 
Wheat 
Corn 
Oats 
Wheat .. 
Chemical fertilizer in continuous culture: 
335 pounds annually 
Pounds 
25 
25 
25 
25 
25 
25 
33 
33 
22 
35.2 
(*) 
35.2 
Pounds 
7.7 
7.5 
11.2 
5.6 
5.6 
11.2 
6.9 
6.9 
4.5 
7.4 
(') 
7.4 
Pounds 
26.5 
342.5 pounds annually 
430 pounds annually 
30.7 
41.0 
11 
Chemical fertilizer in rotation: 
320 pounds annually.. 
32.8 
15,6 
do 
430 pounds annually... 
Manure in continuous culture: 
3.75 tons annually 
do 
32.8 
41.0 
21 
Wheat 
21 
5 
Oats 
2.5 tons annually 
14 
20 
Corn 
Manure in rotation: 
4 tons 
22.4 
Oats 
(') 
Wheat 
4 tons 
22.4 
1 Average. 2 Residual effect. 
In Tables 30, 31, 32, and 33 are given in detail the yields of corn, 
oats, and wheat on the plots which have been selected for study, 
both in continuous culture and in rotation for each year from 1894 
to 1913, and the average yields for the fifth 5-year period, 1914- 
1918. The gains per acre are also given. The gain in each case 
has been determined by taking the difference between the yield on 
the fertilized plot and the calculated yield on the same plot if it were 
not fertilized — the latter yield being determined by the " progressive 
method," assuming any variations in the soil between two successive 
check plots to be uniformly progressive. 
