June i6,1923 Azotobacter Flora and Nitrogen Fixing A bility of Soils 915 
Table V .—Type of growth, nitrogen Jioced, and reaction of soils of Series I —Continued 
Soil 
No. 
Type of jSlxn. 
Microscopic picture. 
Nitro¬ 
gen 
fixed. 
Azoto- 
bacter. 
Ph 
colori¬ 
metric. 
Ph 
electro¬ 
metric. 
58 
59 
60 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 
88 
89 
90 
None.. 
Typical Azotobacter 
None. 
....do . 
Typical Azotobacter, 
_do. 
_do. 
None. 
....do . 
_do. 
Nontypical. 
None. 
Typical Azotobacter. 
Nontypical. 
_do. 
None. 
Nontypical ^. 
Typical Azotobacter, 
Nontypical «. 
None... 
Nontypical. 
Typical Azotobacter, 
Nontypical. 
Typical Azotobacter. 
. ,do. 
.do 
. .do. 
.do 
. .do... 
.do 
. .do. 
.do 
. .do. 
.do 
. .do. 
.do 
. .do. 
.do 
. .do. 
.do 
. .do. 
.do, 
No Azotobacter. 
Typical Azotobacter.... 
No Azotobacter. 
.do. 
Typical Azotobacter.... 
.do. 
.do. 
No Azotobacter. 
.do. 
....do . 
Typical Azotobacter.... 
No Azotobacter. 
Typical Azotobacter.... 
....do . 
_do. 
No Azotobacter. 
Typical Azotobacter ^.. 
.do. 
_do o, . 
No Azotobacter. 
Typical Azotobacter.... 
-do. 
Azotobacter present.... 
Typical Azotobacter.... 
Mgm. 
4.0 
10.6 
4.6 
3- 7 
7-3 
II.o 
8.3 
, 5-2 
3.8 
4.1 
6.9 
4.1 
8.7 
6.9 
6.8 
4- 5 
8.1 
6.1 
3-4 
4.2 
5- 5 
7.6 
9.2 
9.6 
8.0 
9.9 
9-5 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
4 - 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
5-5 
7-4 
5.8 
5-5 
7-5 
7-4 
6.1 
5-7 
5-7 
5-5 
6.1 
5-6 
6.8 
5-6 
7.0 
5-9 
7*4 
7-5 
5-5 
5-6 
7-7 
7-7 
7.6 
7-4 
7-7 
7.6 
7-5 
7-5 
7-5 
7.8 
6.9 
7-5 
7-3 
5-46 
7-49 
5-73 
5-51 
7-55 
7-43 
6.35 
5-94 
5 .81 
5-32 
6.05 
5- 19 
6.93 
5.61 
6.72 
5.88 
7-25 
7*30 
5-63 
5-34 
7-54 
8.48 
7.84 
7-77 
7.60 
7.72 
7-47 
7.62 
7.60 
7-59 
6.88 
7.76 
7.06 
« Ph not determined electrometrically. 
