These available forms of metals are then further absorbed by the epithelial layer of
gut during the waste transition (Suthar 2007). The chloragosomes in earthworms
function as the cation-exchange system having a capability to take up and retain the
heavy metals (Morgan and Morgan 1998), which is further excreted as chloragocyte
fraction (Fischer 1976). Richardson et al. (2015) stated that the bioaccumulation
process of heavy metals in earthworms appears to be site and species dependent, but
it also depends on body mass and abundance of metals present in the substrate. Tang
et al. (2017) revealed that the gut condition of earthworm may decrease the number
of ligands or metal-binding sites due to excretion of digestive enzymes (Wallwork
1983) and chemical composition of gut liquid, which may alter the bioavailability of
metals in the soil.
P. hysterophorus effected the heavy metal concentrations in both final substrates
and the intestine of earthworm. These heavy metals are responsible for the toxic
effects on the health of earthworms. The economic utilization of P. hysterophorus
can be introduced in the vermicomposting technology and also a model for ecological engineering and for the current agricultural needs. These weed amendments up
to 25% along with cow dung may help in its eradication and utilization.
15.2.3 Growth and Reproduction of Earthworms
The growth rate, survival, and reproduction capability of earthworms are highly
affected by type, quality, and palatability of the food (Gajalakshmi et al. 2005). The
rate of productivity of inoculated earthworms is a significant aspect in the waste
decomposing system of the vermiomposting process. Population buildup in the form
biomass and growth rate is a significant indicator of earthworm productivity in
different feed mixtures, as the biomass of earthworms was higher on the final day
than on the initial day of the study because the feedstock availability per unit of
earthworm body mass in waste substrate also affected the rate of biomass gain in
vermicomposting earthworms (Suthar 2011). It has been suggested that during
vermicomposting process, the presence of fungi in substrate becomes additional
food for the worms, which further contributes to the weight gain of the earthworms
(Pramanik and Chung 2011). Suthar et al. (2017) documented that the development
and growth of earthworms during vermicomposting process depend on:
1. Environmental conditions and quality
2. Growth-supporting nutrients present in feed mixture
The growth and development of earthworms were reported during
vermicomposting of almost all the wastes. Lesser weight gain in earthworm appears
to be a valuable indicator of physiological stress, which is related to the degree of
intoxication and exposure time (Frampton et al. 2006). Lesser gain in earthworm
biomass may also be due to the food deficiency and toxic nature of the waste
mixture. Loh et al. (2005) reported that biomass gain was more in cattle dung as
compared to goat dung as cattle dung provided more nutrition and suitable
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H. Kaur et al.
gut during the waste transition (Suthar 2007). The chloragosomes in earthworms
function as the cation-exchange system having a capability to take up and retain the
heavy metals (Morgan and Morgan 1998), which is further excreted as chloragocyte
fraction (Fischer 1976). Richardson et al. (2015) stated that the bioaccumulation
process of heavy metals in earthworms appears to be site and species dependent, but
it also depends on body mass and abundance of metals present in the substrate. Tang
et al. (2017) revealed that the gut condition of earthworm may decrease the number
of ligands or metal-binding sites due to excretion of digestive enzymes (Wallwork
1983) and chemical composition of gut liquid, which may alter the bioavailability of
metals in the soil.
P. hysterophorus effected the heavy metal concentrations in both final substrates
and the intestine of earthworm. These heavy metals are responsible for the toxic
effects on the health of earthworms. The economic utilization of P. hysterophorus
can be introduced in the vermicomposting technology and also a model for ecological engineering and for the current agricultural needs. These weed amendments up
to 25% along with cow dung may help in its eradication and utilization.
15.2.3 Growth and Reproduction of Earthworms
The growth rate, survival, and reproduction capability of earthworms are highly
affected by type, quality, and palatability of the food (Gajalakshmi et al. 2005). The
rate of productivity of inoculated earthworms is a significant aspect in the waste
decomposing system of the vermiomposting process. Population buildup in the form
biomass and growth rate is a significant indicator of earthworm productivity in
different feed mixtures, as the biomass of earthworms was higher on the final day
than on the initial day of the study because the feedstock availability per unit of
earthworm body mass in waste substrate also affected the rate of biomass gain in
vermicomposting earthworms (Suthar 2011). It has been suggested that during
vermicomposting process, the presence of fungi in substrate becomes additional
food for the worms, which further contributes to the weight gain of the earthworms
(Pramanik and Chung 2011). Suthar et al. (2017) documented that the development
and growth of earthworms during vermicomposting process depend on:
1. Environmental conditions and quality
2. Growth-supporting nutrients present in feed mixture
The growth and development of earthworms were reported during
vermicomposting of almost all the wastes. Lesser weight gain in earthworm appears
to be a valuable indicator of physiological stress, which is related to the degree of
intoxication and exposure time (Frampton et al. 2006). Lesser gain in earthworm
biomass may also be due to the food deficiency and toxic nature of the waste
mixture. Loh et al. (2005) reported that biomass gain was more in cattle dung as
compared to goat dung as cattle dung provided more nutrition and suitable
254
H. Kaur et al.