June z6, X923 Azotobacter Flora and Nitrogen Fixing Ability of Soils 919 
Tabi.B VII.— Type of growth, nitrogen fixed, and reaction of soils of Series II —Continued 
Son 
No. 
153 
154 
155 
156 
157 
158 
159 
160 
Dupli¬ 
cate 
soil. 
Type of film. 
Nontypical Azoto- 
bacter. 
Typical Azotobacter. 
....do . 
None. 
Typical Azotobacter. 
Nontypical Azoto¬ 
bacter. 
Typical Azotobacter. 
_do. 
Microscopic picture. 
Azotobacter present. 
Typical Azotobacter. 
,...do . 
No Azotobacter. 
Typical Azotobacter. 
Azotobacter present. 
Typical Azotobacter. 
....do. 
Nitro¬ 
gen 
fixed. 
Azoto¬ 
bacter. 
Ph 
colori¬ 
metric. 
Ph 
electro¬ 
metric. 
Mgm. 
2.8 
— 
S-6 
S- 59 
8.3 
+ 
6. 0 
6. 17 
9 - 7 
+ 
6. I 
6. 34 
9.6 
— 
5 - 5 
5. 61 
8.0 
+ 
6. 0 
6. 27 
8. I 
+ 
6. 2 
6. 51 
8.3 
+ 
7.8 
7-77 
10. I 
-1- 
6. 2 
6. 89 
Tabi,B VIII.— Correlation between reaction and presence of Azotobacter in soils of Series II 
Ph determined electrometrically. 
Ph determined colorimctrically. 
Soil No. 
Ph. 
Azoto¬ 
bacter. 
Soil 
No. 
Ph. 
Azoto¬ 
bacter. 
Soil 
No. 
Ph. 
Azoto¬ 
bacter. 
Soil 
No. 
Ph. 
Azoto¬ 
bacter. 
143. 
8 . 77 
+ 
151.. 
6. 25 
+ 
143 - • 
8. I 
+ 
155-• 
6. I 
+ 
145. 
7-94 
154.. 
6. 17 
+ 
142. . 
7.8 
+ 
116. . 
6. 0 
+ 
159. 
7 - 77 
+ 
152. . 
5-96 
+ 
159 -• 
7.8 
+ 
151.. 
6. 0 
+ 
144. 
7. 72 
+ 
139- • 
5-90 
+ 
129.. 
7.6 
+ 
152.. 
6. 0 
+ 
107. 
7. 70 
+ 
I16. . 
5 - 90 
+ 
118.. 
7-5 
+ 
154.. 
6. 0 
+ 
148. 
7. 69 
+ ; 
I13. . 
5.85 
4 “ 
107.. 
7-4 
4 - 
157-• 
6. 0 
+ 
150. 
7 - 6$ 
+ 
128. . 
5.78 : 
— 
no.. 
7-4 
+ 
123. . 
5-9 
+ 
149. 
7. 62 
120. . 
5.68 
+ 
130.. 
7.4 
+ 
128.. 
5-9 
— 
no. 
7. 61 
+ 
123. . 
5 - 64 
+ 
133 * 
7-3 
+ 
132. . 
! 5*9 
+ 
142. 
7 - 59 
+ 
156.. 
5. 61 
— 
144. • 
7-3 
+ 
112 . . 
5.8 
+ 
130-. 
7 - 52 
+ 
153- • 
5 - 59 
-- 
148.. 
7*3 
+ 
114. . 
5.8 
4 - 
I4I. 
7.48 
+ 
II4. . 
5 - 59 
+ 
150.. 
7-3 
+ 
120. . 
5.8 
4 - 
133...... 
7-45 
+ 
137- • 
5 - 58 
— 
105.. 
7.2 
+ 
122 . . 
5.8 
4 - 
129. 
7 - 30 
+ 
132. . 
5 - 54 
+ 
135 -• 
7.2 
+ 
I3I.. 
5.8 
— 
140. 
7 - 30 
+ 
122 . . 
5 - 51 
+ 
141.. 
7. 2 
+ 
137- • 
5.8 
— 
II8. 
7. 28 
+ 
II5.. 
5-51 
+ 
145 -• 
7. 2 
+ 
106. . 
5-7 
— 
135. 
7. 20 
+ 
II 2 . . 
5 - 48 
+ 
104®. 
7 - I 
+ 
I 2 I. . 
5-7 
— 
146. 
7. 16 
+ 
108. . 
5* 48 
+ 
119.. 
7-1 
+ 
108. . 
5-6 
4 - 
105. 
7. 08 
+ 
I3I.. 
5 - 47 
— 
149.. 
7-1 
+ 
113.. 
5-6 
4 - 
124. 
7. 06 
+ 
103. . 
5 - 27 
— 
140.. 
7.0 
+ 
153- • 
5-6 
— 
147. 
7. 06 
+ 
106. . 
5-25 
— 
124.. 
6.9 
+ 
125.. 
5-5 
— 
II9. 
7. 00 
+ 
I 2 I . . 
5 - 24 
— 
146.. 
6.9 
+ 
126. . 
5 - 5 
— 
160. 
6.89 
126. . 
5 - 19 
— 
147.. 
6.8 
+ 
127. . 
5-5 
— 
lOI. 
6. 71 
+ 
125.. 
5 - 15 
— 
lOI . . 
6. 7 
+ 
156. . 
5 - 5 
— 
II7. 
6. 56 
+ 
127. . 
5. 10 
— 
109. . 
6.6 
+ 
103.. 
5-4 
— 
158. 
6. 51 
+ 
138.. 
5 - 05 
— 
in.. 
6.6 
+ 
115.. 
5-4 
4 - 
109. 
6. 47 
+ 
134.. 
4.88 
— 
117. . 
6.6 
+ 
134.. 
5‘4 
— 
Ill. 
6.39 
+ 
136. . 
4.88 
+ 
139 • 
6. 2 
+ 
136. . 
5-4 
4 - 
155. 
6. 34 
+ 
102 . . 
3 - 78 
— 
158. . 
6. 2 
+ 
138.. 
5-4 
— 
157 . 
6. 27 
+ 
160. . 
6. 2 
+ 
102 . . 
5-0 
fl Ph not determined electrometrically. 
