Agriculture Reference
In-Depth Information
1.0
x
x
25
°
C
x
20
C
°
15
°
C
0.8
Wt
(mg)
x
0.6
0.4
x
+
10
C
°
+
+
0.2
+
x
+
+
20 40 60 80
Days
FIGURE 18.2
Growth of
Eisenia fetida
at different temperatures.
x
+
x
0.75
30
°
C
x
+
25
°
C
+
20
°
C
x
Wt
(mg)
x
15
°
C
0.50
+
+
x
+
0.25
90 80 70 60
Moisture content of waste (%)
FIGURE 18.3
Growth of
Eisenia fetida
at different moisture contents.
ammonia and salts were washed out of the waste. Earthworms were relatively tolerant regarding
pH, but when given a choice in a pH gradient, they moved toward the more acid material, with an
apparent pH preference of 5.0. The optimal conditions for breeding
E. fetida
are summarized in
Table 18.3
.
These do not differ much from those suitable for the other species.
F
OOD
AND
E
NVIRONMENTAL
R
EQUIREMENTS
OF
D
IFFERENT
E
ARTHWORM
S
PECIES
THAT
P
ROCESS
O
RGANIC
W
ASTES
Different earthworm species have quite different environmental requirements for optimal develop-
ment, growth, and productivity in organic wastes. The characteristics of the more commonly used
earthworm species are summarized in this section.
