Mar. a©, 1916 Relation of Green Manures to Failure of Seedlings 1165 
From the data of this experiment it is very evident that the serious 
injury caused by green manures is only temporary. Two weeks after 
the green manure was turned under, the conditions that affect seed ger¬ 
mination disappeared. Aside from the temporary nature of the inju¬ 
rious agent, it will be seen that the percentage of injury is fairly propor¬ 
tionate to the amount of green clover used. In the presence of 0.25 per 
cent, the rate of germination was decreased 34 per cent, while more than 
1 per cent of green manure entirely prevented germination. A compar¬ 
ison of the effect of green manures in different stages of decomposition 
on cotton germination is shown in Plate LXXXIII, figures 2 and 3. 
FIELD EXPERIMENTS WITH GREEN MANURES 
Early in the spring of 1914 a series of plot experiments with various 
seeds was made. For this purpose a good clover sod from the Experi¬ 
ment Station farm, near Madison, Wis., was chosen. This sod was 
divided into three equal sections: A, Clover; B , oats; and C, unplanted. 
The sections were subdivided into six plots, as shown in Table VI. 
Section A was allowed to remain in clover, while B and C were plowed, 
section B planted to oats, and C left without any crop. When the oats 
in section B and the clover in section A were partly in bloom, the soil 
was plowed and prepared for planting. One half of each section was 
planted immediately, the other half 25 days later. It was arranged to 
study the effect of clover and oat tissue on the germination of cotton, 
com, hemp, oats, and soybeans. The same weight of seed was planted 
in each plot. The results of this series of tests are given in Tables VI 
and VII. 
Table VI. — Effect of green clover on the germination of various seeds 
Planted immediately after turning under. 
Germination of seed 
planted 25 days af¬ 
ter turning under. 
No. 
Seed. 
With clover. 
Unplanted. 
Seed ger¬ 
mination. 
Weight. 
Seed ger¬ 
mination. 
Weight. 
With 
clover. 
Un¬ 
planted. 
1 Cotton.., 
2 .do . . 
3 Com. 
4 Hemp. . 
5 Oats...., 
6 Soybean 
60 
7i 
_ 76 
Few. 
505 
58 
Pounds . 
21 
8 
4 
9i 
129 
79 
Many. 
474 
83 
Pounds . 
190 
210 
202 
2lS 
27 
68 
75 ' 
27 
1,050 
x 3 ° 
Fme. 
Fine. 
5-5 
33 
88 
