Oct. 9, 1916 
Nitrifying Powers of Humid and Arid Soils 
59 
soil accomplishes a 17 per cent transformation in this series, and three 
other soils transform more than 12 per cent of the nitrogen present into 
nitrate. The other soils are considerably inferior in the direction noted. 
PASADENA AREA SOIES 
The soil types of the Pasadena area number 33, and data are here 
given either for the whole number or for one or two less, in accordance 
with the circumstances attending the experimental work. Table IV 
sets forth the results obtained with the Pasadena area soils with the 
different forms of nitrogen as above described. 
Table IV .—Nitrification in Pasadena area soil type 
Name of type. 
Soil nitrogen 
(Group I). 
Soil nitrogen and 
sulphate of am¬ 
monia 
(Group II). 
Soil nitrogen and 
dried blood 
(Group III). 
Soil nitrogen and 
cotton-seed meal 
(Group IV). 
Ni¬ 
trate 
pro¬ 
duced. 
Total 
ni¬ 
tro¬ 
gen 
pres¬ 
ent in 
soil. 
Ni¬ 
tro¬ 
gen 
nitri¬ 
fied. 
Ni¬ 
trate 
pro¬ 
duced. 
Total 
ni¬ 
tro¬ 
gen 
pres¬ 
ent in 
soil. 
Ni¬ 
tro¬ 
gen 
nitri¬ 
fied. 
Ni¬ 
trate 
pro¬ 
duced. 
Total 
ni¬ 
tro¬ 
gen 
pres¬ 
ent in 
soil. 
Ni¬ 
tro¬ 
gen 
nitri¬ 
fied. 
Ni¬ 
trate 
pro¬ 
duced. 
Total 
ni¬ 
tro¬ 
gen 
pres¬ 
ent in 
soil. 
Ni¬ 
tro¬ 
gen 
nitri¬ 
fied. 
Mgm. 
Mgm 
P.ct. 
Mgm. 
Mgm. 
P.ct . 
Mgm. 
Mgm. 
P. cf. 
Mgm 
Mgm. 
P.ct. 
Dublin clay adobe...... 
7.60 
109. 20 
6 + 
39.60 
149.20 
26+ 
2* 60 
241. 20 
1+ 
50.60 
156. 20 
32+ 
TYiahln clay. 
5.68 
10+ 
15.88 
94.60 
16+ 
— • 32 
186.60 
7.68 
101.60 
7+ 
Zeinab li ght loam. 
20.30 
ft. 80 
IT'S. OO 
7 + 
— . 20 
209.00 
5.80 
124.00 
Altamont clay. 
9.80 
154-00 
6+ 
47.80 194.00 
24+ 
39 -80 
286.00 
13+ 
27.80 
201.00 
13+ 
Zelzah gravelly loam... 
9.44 
61.60 
15 + 
15.44 101.60 
15 + 
— • 56 
193- 60 
20.44 
108. 60 
18+ 
TTnllatiH Inam . 
67.20 
7 + 
— .08 
114. 20 
24-b 
Hanford coarse sandy 
loam.. 
4.28 
54- 60 
7+ 
9 - 38 
94.60 
9 + 
— .13 
186.60 
.68 
101.60 
Trace 
Hanford gravelly sandy 
loam. 
5. 59 
68.60 
8+ 
17.10 
108.60 
15+ 
- .81 
200.60 
- .81 
115. 60 
Hanford sandy loam... 
3 - 70 
40.60 
9 + 
5.90 
80. 60 
7 + 
— .30 
172.60 
3.90 
87-60 
4 + 
Hanford fine sandy 
]nam . 
15. 57 
— . 4^ 
13. 58 
Hanford loam. 
100.80 
14 - 79 
140.80 
10-f 
9 - 79 
232.80 
4 + 
39 - 79 
147.80 
26+ 
18.20 
58.20 
4-t- 
150. 20 
65. 20 
Zelzah stony loam. 
6. 00 
64.40 
9 + 
7. 00 
104.40 
6+ 
196.40 
24. OO 
in. 40 
21 + 
Hanford stony loam.... 
3-88 
28.00 
13 + 
6. 28 
68.00 
9 + 
- - 13 
160.00 
- -13 
75 -oo 
. 
Placentia loam. 
5. 50 
68.60 
8+ 
3- 00 
108.60 
2 + 
— I- 50 
170.60 
28. 50 
115. 60 
24 4 - 
Holland sandy loam.. . 
5 * 39 
46.20 
11 + 
3-39 
86.20 
3 + 
— . 61 
178.20 
. 
5 - 39 
93- 20 
5 + 
Hanford stony sandy 
loam . 
3- 80 
67. 20 
5+ 
0. 30 
107.20 
8+ 
— 2. 20 
199.20 
11. 80 
114. 20 
10+ 
Antioch clay loam. 
8. 00 
182.00 
4 + 
38. 00 
222.00 
17 + 
122. 00 
314.00 
38+ 
36. 00 
229. 00 
15 + 
Chino silty clay loam... 
14-40 
151. 20 
•9 + 
42.40 
191. 20 
22 + 
79-40 
283. 20 
27+ 
30.40 
198. 20 
15 + 
Chino clay adobe. 
II. 00 
382. 20 
2 -j- 
61. 00 
422. 20 
14+ 
119. 00 
514- 20 
23 + 
33 -oo 
429. 20 
7 + 
Chinn loam . 
— 9. 00 
187.60 
10. 00 
227.60 
4 + 
36. 00 3iq. 60 
11 + 
68. 00 
234. 60 
28+ 
Hanford fine sandy 
loam. 
13- 20 
88. 20 
14+ 
45- 20 
128. 20 
35 + 
8. 70 220. 20 
3 + 
77. 20 
135- 20 
57 + 
Chino silty clay loam.., 
7. 00 
219. 80 
3 + 
55- 00 
259.80 
21 + 
81. 00351. 80 
23 + 
31. 00:266. 80 
n + 
Hanford fine sand. 
1. 20 
35 -oo 
3 + 
4. 20 
75.00 
5 + 
— 1. 80 167. 00 
IO. 20 
82. 00 
12 + 
24+ 
55.40 
5 + 
— . 20 
IA' 7 . AO 
— . 20 
62. 40 
Yolo loam... 
— 2. 00 
123* 20 
13. 60 
163. 20 
8+ 
42. 00.255. 20 
16+ 
8. 30 
170. 20 
4 + 
Dublin clay loam. 
7.80 
105.00 
7 + 
11. 80 
145-00 
8+ 
19. 8o]237- 00 
8+ 
75 -So 
152. 00 
49 + 
Dtihlin clay . 
Q. <K 
131.60 
7 + 
64. q«: 
171. 60 
37 + 
47. Q5 263. 60 
18+ 
31. 95 
178. 60 
17+ 
Hanford sand. 
4. IO 
25.20 
16+ 
3- 80 
65. 20 
5 + 
157. 20 
. 20 
72. 20 
Trace 
Zelzah clay loam. 
9. OO 
109.20 
8 + 
21. 00 
149. 20 
14+ 
3. 00 241. 20 
1 + 
53 -oo 
156. 20 
33 + 
Altamont loam. 
7 - 67 
74- 20 
10+ 
14.67 
114. 20 
12 + 
17. 70 206. 20 
8+ 
23. 67:121. 20 
19+ 
Diablo clay adobe. 
7 - 95 
100. 80 
7 + 
16.15 
140. 80 
11 + 
35.95 232 . 80 
15 + 
19 - 95 I47-8o 
13+ 
Altamont clay loam.... 
■ 50 
93- 80 
Trace 
13- 00 
133- 80 
9 + 
17. OOj 225 * 80 
7 + 
13. 80^140. 80 
9 + 
The Pasadena area contains a larger percentage of soils having more 
than 0.1 per cent of nitrogen than does the Bay area. In the latter, 
for example, 26 per cent of the soils contained more than 0.1 per cent 
of nitrogen, while in the former more than 40 per cent of the soils belong 
in that class. Nevertheless it must still be observed that even the 
