10 
The foregoing data show that when equal amounts ox nitrogen 
were added, the amounts of ammonia formed still varied considerably. 
Casein was far more readily decomposed during the early stages of 
the action than the other materials. At the end of 2 days 58.3 milli- 
grams of casein nitrogen had been ammonified, as contrasted with 4 
milligrams in dried blood, 14.9 milligrams in soy bean cake meal, 
17.3 milligrams in cottonseed meal, and 3.5 milligrams in linseed 
meal. Later the yields became more nearly equal and showed much 
less variation than when equal weights of the materials were added 
(see Series II). The maximum percentages of ammonia formed 
from the different materials, not allowing for evaporation and nitri- 
fication, the latter of which was small, ranged from 56.9 per cent 
from casein to 32 per cent from cottonseed meal. 
SERIES IV — AMMONIFICATION IN SOIL UNDER ANAEROBIC CONDITIONS. 
In order to measure the rates of ammonification under anaerobic 
conditions the same soil was used and sufficient sterile water added 
to insure complete submergence. Equal amounts of nitrogen (132.9 
milligrams) and 1 gram of calcium carbonate were mixed with 100- 
gram portions of soil as in the preceding series. 
Amount of ammonia in soil under anaerobic conditions. 
[Average of 2 samples.] 
Nitrogen as ammonia from — 
Period of incubation. 
Casein 
1.072 gm. 
Dried 
blood 
lgm. 
Soy bean 
cake meal 
1.606 gm. 
Cotton- 
seed meal 
2.605 gm. 
Linseed 
meal 
2.658 gm. 
Mg. 
8.5 
47.3 
62.4 
70.7 
Mg. 
2.0 
6.6 
13.7 
16.3 
Mg. 
3.5 
9.1 
14.2 
18.6 
Mg. 
6.3 
8.2 
9.4 
11.4 
Mg. 
2.0 
3.5 
7.3 
9 days 
9.2 
Per cent of total N converted into NH 3 
53.2 
12.3 
14.0 
8.5 
6.9 
The above data show that under anaerobic conditions active 
ammonification of casein did not begin until after two days' stand- 
ing, but it then was approximately as rapid as under aerobic condi- 
tions. With dried blood, soy bean cake meal, cottonseed meal, and 
linseed meal ammonification took place at greatly reduced rates 
throughout the experimental period. The percentages of the total 
nitrogen converted into ammonia were as follows: Casein 53.2 per 
cent, dried blood 12.3 per cent, soy bean cake meal 14 per cent, 
cottonseed meal 8.5 per cent, and linseed meal 6.9 per cent. By 
comparing these data with the preceding it will be seen that anaerobic 
conditions greatly retarded the formation of ammonia from all the 
