microorganisms present in the casts of earthworms were responsible for the release
of phosphorus (Prakash and Karmegam 2010) along with the mobilization, and
mineralization of phosphorus due to combined activity of earthworms and microbes
might be responsible for the increase of total available phosphorus (Goswami et al.
2013). Microorganisms also produce acids during the decomposition of organic
matter, which converts insoluble phosphorus into soluble forms which lead to
increase in total phosphorus content (Suthar 2010). The higher potassium content
in vermicompost indicates its potential in agronomy and its suitability for plant
growth (Suthar 2012).
The potassium content (K) of the compost was significantly affected by
P. hysterophorus treatment. The microflora present in the earthworm’s gut might
be responsible for the variation in potassium content during vermicomposting, and
these microorganisms played a significant role in vermicomposting process (Suthar
2007). They further stressed that the various acids produced by the worms during
vermicomposting may convert insoluble potassium to soluble potassium by increasing its concentration in the compost.
P. hysterophorus significantly affected the physicochemical properties of the
compost, but it enhances the nutrient content when mixed with the organic waste,
such as cow dung, and can be used as valuable manure. It has been proved that
vermicomposting could be introduced as an effective technology to convert the
P. hysterophorus into a nutrient-rich product for sustainable agriculture.
15.2.2 Concentration of Heavy Metals
Heavy metals are present in the form of complexes of humic or fulvic acids in the
soil. The metal toxicity is not caused by the presence of metals, but it depends on
many factors:
• Concentration of metal
• Metal toxicity and its mobility
• The route of uptake mechanism
• The bioavailability for the intake of plants
It is important to analyze the concentration of metals in the final product before
being applied to soil due to their high toxicity and risk (Jamali et al. 2009).
The heavy metals were present in both bedding materials and the intestine of
earthworms.
(a) Heavy metal concentration in bedding material: Heavy metals (cadmium,
chromium, nickel, and iron) were in higher concentration in the final
vermicompost than in the initial substrate. The increase in the metal content
may be due to the degradation of organic matter and mineralization followed by
reduction in volume of substrate material that led to the congregation of the
material and elevation in heavy metal content (Sharma and Garg 2017) followed
252
H. Kaur et al.
of phosphorus (Prakash and Karmegam 2010) along with the mobilization, and
mineralization of phosphorus due to combined activity of earthworms and microbes
might be responsible for the increase of total available phosphorus (Goswami et al.
2013). Microorganisms also produce acids during the decomposition of organic
matter, which converts insoluble phosphorus into soluble forms which lead to
increase in total phosphorus content (Suthar 2010). The higher potassium content
in vermicompost indicates its potential in agronomy and its suitability for plant
growth (Suthar 2012).
The potassium content (K) of the compost was significantly affected by
P. hysterophorus treatment. The microflora present in the earthworm’s gut might
be responsible for the variation in potassium content during vermicomposting, and
these microorganisms played a significant role in vermicomposting process (Suthar
2007). They further stressed that the various acids produced by the worms during
vermicomposting may convert insoluble potassium to soluble potassium by increasing its concentration in the compost.
P. hysterophorus significantly affected the physicochemical properties of the
compost, but it enhances the nutrient content when mixed with the organic waste,
such as cow dung, and can be used as valuable manure. It has been proved that
vermicomposting could be introduced as an effective technology to convert the
P. hysterophorus into a nutrient-rich product for sustainable agriculture.
15.2.2 Concentration of Heavy Metals
Heavy metals are present in the form of complexes of humic or fulvic acids in the
soil. The metal toxicity is not caused by the presence of metals, but it depends on
many factors:
• Concentration of metal
• Metal toxicity and its mobility
• The route of uptake mechanism
• The bioavailability for the intake of plants
It is important to analyze the concentration of metals in the final product before
being applied to soil due to their high toxicity and risk (Jamali et al. 2009).
The heavy metals were present in both bedding materials and the intestine of
earthworms.
(a) Heavy metal concentration in bedding material: Heavy metals (cadmium,
chromium, nickel, and iron) were in higher concentration in the final
vermicompost than in the initial substrate. The increase in the metal content
may be due to the degradation of organic matter and mineralization followed by
reduction in volume of substrate material that led to the congregation of the
material and elevation in heavy metal content (Sharma and Garg 2017) followed
252
H. Kaur et al.