17.4.3 Total Organic Carbon (TOC)
TOC indicates the total carbon contained by the sample mixtures. Its high concentration can make the sample highly toxic for the soil biota (plants and microorganisms). So to manage the TOC content, most of the scientists have used the
earthworms with the sample and incubate them for few (two) months
(vermicomposting). It has found that the earthworms are capable of decreasing the
TOC form the initial to final fly ash mixtures (Usmani et al. 2017; Singh et al. 2016).
The earthworms help to encourage the microbial growth and their actions along with
microbes bring the mineralization and decomposition of organic carbon that leads to
carbon loss in the form of CO 2 in the feed mixtures during vermicomposting
(Domínguez 2004; Suthar and Sharma 2013).
17.5 Impacts of Earthworms on NPK (Nitrogen,
Phosphorus, and Potassium) Contents
17.5.1 Nitrogen Content
Nitrogen is an essential element for plant growth, and it is a basic structural
component of the amino acids, which are further important components of proteins.
It is available in the environment (air) in free form (N 2 ) and is not able to consume by
plants. To make it consumable to plants, some microorganisms like bacteria are
involved, which convert it into soluble forms like ammonia, nitrates, and nitrites. It is
found that the earthworms are very useful in increasing the level of nitrogen in the
post compost samples by mineralization and decomposition of the organic nitrogenous compound. It was found that the earthworms are helpful to make the nitrogen
level high by the production of vermicast. Bhattacharya and Chattopadhyay (2004)
also found the increasing trends of nitrogen during vermicomposting of fly ash. It is a
rich source of nitrogen and also capable of producing the other stable products like
ammonia, urea, and uric acid (Suthar 2009; Waseem et al. 2013). It was found that
the nature and type of organic matter (cattle dung) used in vermicomposting is fully
responsible for the number of nutrient contents of the vermicompost (Atiyeh et al.
2002; Bhat et al. 2015b; Kawaguchi and Nishi 2007).
17.5.2 Phosphorus Content
Phosphorus content was found to increase in the samples treated with earthworms
during vermicomposting. It may be due to mineralization and decomposition of the
organo-phosphorus compound by the earthworms (Hartenstein 1981; Hamilton and
Mitchell 1997). The increasing content of phosphorus was reported in the water
17 Earthworm-Assisted Amelioration of Thermal Ash
289
TOC indicates the total carbon contained by the sample mixtures. Its high concentration can make the sample highly toxic for the soil biota (plants and microorganisms). So to manage the TOC content, most of the scientists have used the
earthworms with the sample and incubate them for few (two) months
(vermicomposting). It has found that the earthworms are capable of decreasing the
TOC form the initial to final fly ash mixtures (Usmani et al. 2017; Singh et al. 2016).
The earthworms help to encourage the microbial growth and their actions along with
microbes bring the mineralization and decomposition of organic carbon that leads to
carbon loss in the form of CO 2 in the feed mixtures during vermicomposting
(Domínguez 2004; Suthar and Sharma 2013).
17.5 Impacts of Earthworms on NPK (Nitrogen,
Phosphorus, and Potassium) Contents
17.5.1 Nitrogen Content
Nitrogen is an essential element for plant growth, and it is a basic structural
component of the amino acids, which are further important components of proteins.
It is available in the environment (air) in free form (N 2 ) and is not able to consume by
plants. To make it consumable to plants, some microorganisms like bacteria are
involved, which convert it into soluble forms like ammonia, nitrates, and nitrites. It is
found that the earthworms are very useful in increasing the level of nitrogen in the
post compost samples by mineralization and decomposition of the organic nitrogenous compound. It was found that the earthworms are helpful to make the nitrogen
level high by the production of vermicast. Bhattacharya and Chattopadhyay (2004)
also found the increasing trends of nitrogen during vermicomposting of fly ash. It is a
rich source of nitrogen and also capable of producing the other stable products like
ammonia, urea, and uric acid (Suthar 2009; Waseem et al. 2013). It was found that
the nature and type of organic matter (cattle dung) used in vermicomposting is fully
responsible for the number of nutrient contents of the vermicompost (Atiyeh et al.
2002; Bhat et al. 2015b; Kawaguchi and Nishi 2007).
17.5.2 Phosphorus Content
Phosphorus content was found to increase in the samples treated with earthworms
during vermicomposting. It may be due to mineralization and decomposition of the
organo-phosphorus compound by the earthworms (Hartenstein 1981; Hamilton and
Mitchell 1997). The increasing content of phosphorus was reported in the water
17 Earthworm-Assisted Amelioration of Thermal Ash
289