0
10
20
30
40
50
60
70
0
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
Nitrogen %
pH
Soil Samples
Population of Azotobacter sp × 10,000/g soil
pH
Total N%
Fig. 7.22 The relationship
between pH, Azotobacter
population 10
4 g
−1 soil and total
nitrogen content (N %) in soil
samples. (modified from Ben
Mahmoud and Ferjani 2018)
0
2
4
6
8
10
12
14
16
18
10
20
30
40
50
N (g/kg) dry compost
Incubation Time (Day)
Azotobacter
Burkholderia
Azospirillum
Uninoculated
Mixed inoculants
Fig. 7.23 Overall gain in N 2
content of compost from N 2
fixation process. (modified
from Ben Mahmoud et al. 2018)
0
5
10
15
20
25
30
35
10
20
30
40
50
P %
Incubation Time (day)
Azotobacter Burkholderia Azospirillum Uninoculated Mixed inoculants
Fig. 7.24 P (%) content of
compost with time following
inoculation of 40 days old
compost with N-fixing bacteria
singly and mixed inoculants
(modified from Ben Mahmoud
and Ferjani 2018)
114
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