May 14, 1917 
Soil Nitrogen and Nutrition of Citrus Plants 
187 
TablR I.— Nitrification of dried bloody barley hay , horse manure , and green manures 
in Citrus Experiment Station soils , Riverside , Cal. April 8 , 
[Results expressed as milligrams of nitrogen per 100 gm. of soil] 
PLOT S 
Material added. 
Constituent. 
Incubation period. 
7 days. 
14 days. 
21 days. 
28 days. 
35 days. 
42 days. 
Dried blood (1 per cent).. 
Ammonia,. 
35 - 28 
33- 20 
25. 66 
25. 48 
25. 76 
25.48 
Do. 
Nitrates ... 
3 * 04 
3 °- 94 
47-31 
46.37 
49. 6l 
47.29 
Oats (1 per cent). 
Ammonia., 
.56 
1.28 
1. 12 
- .28 
.46 
.84 
Do. 
Nitrates ... 
.09 
•57 
•74 
.46 
.38 
• 33 
Barley (1 per cent). 
Ammonia.. 
•56 
. 16 
- .09 
- .28 
. QO 
. 21 
Do. 
Nitrates.... 
• 5 1 
.42 
• 53 
- .03 
2. 57 
I. 38 
Melilotus (1 per cent).... 
Ammonia,. 
2.24 
• 7 2 . 
• 56 
I. 40 
1. 68 
I. 40 
Do. 
Nitrates.... 
3 - 6S 
5 - 23 
8. 70 
II. 40 
10. 22 
8- 73 
Alfilaria (1 per cent)_ 
Ammonia.. 
I. 12 
. 16 
. 14 
.28 
.68 
.28 
Do. 
Nitrates.... 
• 73 
.84 
.98 
I. 28 
1. 32 
2. 02 
Water only. 
Ammonia.. 
1.12 
.96 
1. 12 
I. 40 
1. 12 
.84 
Do... 
Nitrates.... 
.96 
1.40 
1. 68 
2. 40 
2. 24 
2.80 
PLOT D 
Dried blood (1 per cent). 
Ammonia.. 
47.92 
54 - 24 
58.44 
46.36 
47.96 
45. 02 
Do. 
Nitrates ,.. 
.99 
— 1. 40 
- .99 
6. 27 
13.69 
15- 75 
Oats (1 per cent).— 
Ammonia.. 
. 00 
• 56 
. 00 
.44 
. 00 
.28 
Do. 
Nitrates..... 
. 01 
-1. 77 
— . 01 
1. 21 
1. 57 
2. 83 
Barley (1 per cent)--- 
Ammonia,. 
. 00 
1.12 
• 56 
.58 
•56 
.44 
Do. 
Nitrates.... 
1, 48 
-1. 77 
- -77 
2. 81 
3 - 45 
3 -83 
Melilotus (1 per cent). 
Ammonia.. 
1. 68 
1. 68 
. 00 
. 00 
. 00 
. 00 
Do.. 
Nitrates.... 
2. 07 
2. 58 
3- 06 
5 * 90 
6. 01 
7 - 77 
Alfilaria (1 per cent) 
Ammonia.. 
• 56 
.56 
. 00 
• 44 
.56 
.40 
Do. 
Nitrates.... 
1. 81 
•33 
1. 01 
2. 85 
2. 87 
3 - 45 
Water only. 
Ammonia.. 
1. 68 
1. 12 
1.12 
1. 24 
1.12 
. 96 
Do.... 
Nitrates.... 
1-25 
3 - 54 
3 -09 
i- 95 
2. 22 
y 
2.18 
PLOT C 
Dried blood (1 per cent). 
Ammonia.. 
33 - 44 
34 - 72 
31- 36 
24. 64 
25. 20 
24. 08 
Do.... 
Nitrates.... 
3. 10 
7 - 39 
iS- 3 1 
17. 46 
28. 99 
29. 41 
Barley hay (1 per cent).. 
Ammonia.. 
- . 16 
- .44 
. OO 
. 00 
. 00 
. 00 
Do. 
Nitrates.... 
-1. 31 
-I. 18 
- .66 
- .72 
- .63 
- .42 
Barley (1 per cent). 
Ammonia.. 
.40 
.80 
. 00 
• 56 
•55 
. 00 
Do. 
Nitrates.... 
1. 56 
3 - 73 
3-98 
3. 28 
2. 89 
2-37 
Melilotus (1 per cent) ... 
Ammonia.. 
1. 96 
•S 6 
.. 00 
- .42 
. 00 
. 00 
Do. 
Nitrates.... 
2. 62 
3 - 90 
3 - 76 
7. 29 
7 - 39 
8.37 
Horse manure (1 per cent) 
Ammonia.. 
. 00 
- • 56 
. OO 
. 00 
. 00 
. 00 
Do. 
Nitrates.,.. 
- .42 
• 45 
- .66 
.86 
1. 07 
1. 20 
Water only .. 
Ammonia.. 
1. 84 
1. 68 
1.68 
1. 68 
i. 12 
1. 12 
Do.. 
Nitrates.... 
*■ 73 
1. 70 
2. 65 
2.88 
2. 36 
2. 83 
In studying the figures presented in Table I it is seen that the increase 
in ammonia resulting from the application of 1 per cent of blood reaches 
the maximum in soil E after 7 days, in soil C after 14 days, and in soil D 
not until after 21 days. It is observed that the ammonia is uniformly 
higher in soil D than in soil E or C. Some increase in nitrates is observed 
