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CChhaapptteerr IIIIII

LITERATURE REVIEW

VERMIREMEDIATION SYSTEM

Edwards and Burrows (1988) studied the agronomic impacts of vermicompost

and found that it consistently improved seed germination, enhanced seedling growth

and development, and increased plant productivity much more than would be possible

from the mere conversion of mineral nutrients into plant-available forms. The growth

responses of plants from vermicompost appears more like hormone-induced activity

associated with the high levels of nutrients, humic acids and humates in vermicompost

rather than boosted by high levels of plant-available nutrients.

Studies made by Baker and Barrett (1994) at CSIRO Australia found that the

earthworms can increase growth of wheat crops by 39%, grain yield by 35%, lift

protein value of the grain by 12% and fight crop diseases. Palainsamy (1996) also

studied that earthworms and its vermicast improve the growth and yield of wheat by

more than 40%.

Bhawalker (1995) studied the agronomic impacts of vermi-compost on farm soil

and found that if 100 kg of organic waste with say, 2 kg of plant nutrients (NPK) are

processed through the earthworms in farm soil, there is a production of about 300 kg of

fresh living soil with 6% of NPK and several trace elements. This magnification of

plant nutrients is done from grinding rock particles with organics and by enhancing

atmospheric nitrogen fixation. Earthworms activate this ground mix in a short time of

just one hour.

Arancon et al. (2004) studied the agronomic impacts of vermicompost and

inorganic (chemical) fertilizers on strawberries when applied separately and also in

combination. Vermicompost was applied at 10 tons/ha while the inorganic fertilizers

(nitrogen, phosphorus, potassium) at 85 (N)-155 (P)-125 (K) kg/ha. While there was

not much difference in the dry shoot weight of strawberries, the yield of marketable

strawberries and the weight of the largest fruit was greater on plants in plots grown on

vermicompost as compared to inorganic fertilizers in 220 days after transplanting. In

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addition, there were more runners and flowers on plants grown on vermicompost. Also,

farm soils applied with vermicompost had significantly greater microbial biomass than

the one applied with inorganic fertilizers.

Webster et al., (2005) studied the agronomic impact of vermicompost on

cherries and found that it increased yield of cherries for three (3) years after single

application inferring that use of vermicompost in soil builds up fertility and restore its

vitality for long time and its further use can be reduced to a minimum after some years

of application in farms. Buckerfield and Webster (1998) found that worm-worked

waste (vermicompost) boosted grape yield by two-fold as compared to chemical

fertilizers.

VERMIREMEDIATION IN INDUSTRAL POLLUTION

Large tract of arable land is being chemically contaminated due to mining

activities, heavy use of agro-chemicals in farmlands, landfill disposal of toxic wastes

and other developmental activities like oil and gas drilling. No farmland of world

especially in the developing nations is free of toxic pesticides, mainly aldrin, chlordane,

dieldrin, endrin, heptachlor, mirex and toxaphene. According to National Environment

Protection Council, there are over 80,000 contaminated sites in Australia. There are

40,000 contaminated sites in US; 55,000 in just six European countries and 7,800 in

New Zealand. There are about 3 million contaminated sites in the Asia-Pacific. These

also include the abandoned mine sites along with the closed landfills. The contaminated

sites mostly contain heavy metals cadmium (Cd), lead (Pb), mercury (Hg), zinc (Zn)

etc., and chlorinated compounds like the PCBs and DDT. Cleaning them up

mechanically by excavating the huge mass of contaminated soils and disposing them in

secured landfills will require billions of dollars. There is also great risk of their leaching

underground (aggravated by heavy rains) and contaminating the groundwater.

Contaminated soils and waters pose major environmental, agricultural, and human

health problems worldwide (UNEP, 1996; Eswaran, 2001).

Traditionally, remediation of chemically contaminated soils involves off-site

management by excavating and subsequent disposal by burial in secured landfills. This

method of remediation is very costly affair and merely shifts the contamination

problem elsewhere. Additionally, this involves great risk of environmental hazard while

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the contaminated soils are being transported and migration of contaminants from

landfills into adjacent lands and water bodies by leaching. Soil washing for removing

inorganic contaminants from soil is another alternative to landfill burial, but this

technique produce a residue with very high metal contents that requires further

treatment or burial (Baker and Herson, 1994; Schaffner, 2004).

Since the late 1980s, after the chemical and mechanical treatments of lands and

water bodies and thermal treatment (incineration) of hazardous wastes proved

economically and environmentally unsustainable, focus shifted towards the biological

methods which are cost-effective as well as environmentally sustainable and also

socially acceptable (BIO-WISE 2000; Schaffner, 2004).

Kaushik and Garg (2004) studied the ability of epigeic earthworm E. fetida to

transform textile mill sludge mixed with cow dung and/or agricultural residues into

value added product, i.e., vermicompost. The growth, maturation, mortality, cocoon

production, hatching success and the number of hatchlings were monitored in a range

of different feed mixtures for 11 weeks in the laboratory under controlled

environmental conditions. The maximum growth and reproduction was obtained in

100% cow dung, but worms grew and reproduced favorably in 80% cow dung + 20%

solid textile mill sludge and 70% cow dung + 30% solid textile mill sludge also.

Addition of agricultural residues had adverse effects on growth and reproduction of

worms. Vermicomposting resulted in significant reduction in C:N ratio and increase in

TKN, TP, TK and TCa after 77 days of worm activity in all the feeds.

Garg and Kaushik (2005) made investigations to explore the potential of an

epigeic earthworm E. fetida to transform textile mill sludge spiked with poultry

droppings into value added product, i.e., vermicompost. The growth and reproduction

of E. fetida was monitored in a range of different feed mixtures for 77 days in the

laboratory under controlled experimental conditions. The maximum growth was

recorded in 100% cow dung (CD). Replacement of poultry droppings by cow dung in

feed mixtures and vice versa had little or no effect on worm growth rate and

reproduction potential. Worms grew and reproduced favourably in 70% poultry

droppings (PD) +30% solid textile mill sludge (STMS) and 60% PD+40% STMS feed

mixtures. Greater percentage of STMS in the feed mixture significantly affected the

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biomass gain and cocoon production. Net weight gain by earthworms in 100% CD was

2.9-18.2 fold higher than different STMS containing feed mixtures. The mean number

of cocoon production was between 23.4+/-4.65 (in 100% CD) and 3.6+/-1.04 (in 50%

PD+50% STMS) cocoons earthworm for different feed mixtures tested.

Vermicomposting resulted in significant reduction in C: N ratio and increase in

nitrogen and phosphorus contents. Total potassium, total calcium and heavy metals (Fe,

Zn, Pb and Cd) contents were lower in the final product than initial feed mixtures.

Vermiremediation (using chemical tolerant earthworm species) is emerging as a

low-cost and convenient technology for cleaning up the chemically polluted/

contaminated sites / lands in world. Earthworms in general (especially E. fetida) are

highly resistant to many chemical contaminants including heavy metals and organic

pollutants in soil and have been reported to bio-accumulate them in their tissues.

Earthworms have been used for land recovery, reclamation and rehabilitation of sub-

optimal soils such as poor mineral soils, polder soils, open cast mining sites, closed

landfill sites and cutover peat (Lowe and Butt, 2003; Butt et al., 2004). Within the soil

environment, an earthworm’s sphere of influence is known as the drilosphere system.

This incorporates the burrow system; surface and belowground earthworm casts,

internal earthworm gut and process, the earthworm surface in contact with the soil, and

associated biological, chemical and physical interactions, in addition to the soil

microorganisms (Brown and Doube, 2004).

Earthworms in general are highly resistant to many chemical contaminants

including heavy metals and organic pollutants in soil and have been reported to bio-

accumulate them in their tissues. After the Seveso chemical plant explosion in 1976 in

Italy, when vast inhabited area was contaminated with certain chemicals including the

extremely toxic TCDD (2, 3, 7, 8–tetrachlorodibenzo-p-dioxin) several fauna perished

but for the earthworms that were alone able to survive. Earthworms, which ingested

TCDD contaminated soils were shown to bio-accumulate dioxin in their tissues and

concentrate it on average 14.5 fold (Satchell, 1983).

Experiments have established that it is possible to generate an earthworm

population of 0.2-1.0 million per hectare of land within a short period of three months

for vermiremediation task (Bhawalkar, 1995). Given the optimal conditions of

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moisture, temperature and feeding materials earthworms can multiply rapidly to

produce a huge army of worms in a short time.

Earthworm species suitable for land remediation (soil decontamination)

Certain species of earthworms such as E. fetida, Aporrectodea tuberculata,

A. giardi, Lumbricus terrestris, L. rubellus, Dendrobaena rubida, D. veneta, Eiseniella

tetraedra and Allobophora chlorotica have been found to tolerate and remove wide

range of chemicals from soil (Satchell, 1983; Schaefer, 2005; Alekseeva, 2006).

Further study also indicates that E. fetida is most versatile chemical bio-accumulator.

Earthworms have been tested and found to bio accumulate heavy metals, pesticides and

lipophilic organic micro pollutants like the polycyclic aromatic hydrocarbons (PAH)

from the soil (OECD 2000; Contreras-Ramos, 2006).

E. fetida was used as the test organisms for different soil contaminants and

several reports indicated that E. fetida tolerated 1.5% crude oil (containing several toxic

organic pollutants) and survived in this environment (Safawat et al., 2002; Tomoko et

al., 2005).

FACTORS AFFECTING VERMIREMEDIATION

Same climatic factors of temperature, moisture and pH that are critical to the

survival and function of earthworms during vermicomposting and vermifiltration of

wastes, and wastewaters also effects vermiremediation of contaminated soils by worms

(Sinha et al., 2008b).

MECHANISM OF WORM ACTION IN VERMIREMEDIATION

Earthworms have both abiotic and biotic effects on contaminated soils in the

remediation process. Abiotic effects are burrowing actions and the resulting burrows

acts as inputs points and preferred pathways for water and particle movement, nutrient

flow and aeration. This also results into mechanical breakdown of soil particles

exposing greater surface areas for biotic action (Brown and Doube, 2004). Earthworm’s

uptake chemicals from the soil through passive absorption of the dissolved fraction,

through the moist body wall in the interstitial water and by mouth and intestinal uptake

while the soil passes through the gut. The passive diffusion is driven by the difference

between the pore water in soil and within the earthworm’s tissues (Jatger et al., 2003).

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Hydrophobic organic contaminants are taken up by the earthworms in two

ways-1) By passive diffusion from the soil solution through the worms outer

membrane; 2) By intestinal re-sorption of the compounds from the soil while it passes

through the gut (by digestion) and then their degradation by enzymatic activity called

Cytochrome P 450 system. This enzymatic activity have been found to operate

particularly in Eisenia fetida which survive the benzo(a)pyrene concentration of 1,008

mg/kg of soil (Achazi et al, 1998).

Earthworms apparently possess a number of mechanisms for uptake,

immobilization and excretion of heavy metals and other chemicals, they either bio-

transform or biodegrade the chemical contaminants rendering them harmless in their

bodies. Some metals are bound by a protein called metallothioneins found in

earthworms which has very high capacity to bind metals. The chloragogen cells in

earthworms appear to mainly accumulate heavy metals absorbed by the gut and their

immobilization in the small spheroidal chloragosomes and debris vesicles that the cells

contain (Ireland, 1983). Ma et al. (1995) found that earth worms biodegrade organic

contaminants like phthalate, phenanthrene, and fluoranthene.

VERMIREMEDIATION TECHNOLOGY versus MECHANICAL AND

CHEMICAL TREATMENT OF CONTAMINATED SITES

There are several advantages in using earthworms for bioremediation of

chemically contaminated soils. They have been shown to both retard the binding of

chemical compounds with soil particles and also increase compound availability for

microbial action while also enhancing the population of degrader microbes within the

system. Earthworms have the potential to be employed not only in the recovery of

contaminated soils as a part of bioremediation strategy, but also in the subsequent

improvement of that soil and the land as a whole, for other beneficial use (Brown and

Doube, 2004).

1) On-site treatment: The greatest advantage of the vermiremediation technology

is that it is on-site treatment and there are no additional problems of earth-cutting,

excavation and transportation of contaminated soils to the landfills or to the treatment

sites incurring additional economic and environmental cost. Vermiremediation would

cost about $ 500-1000 per hectare of land as compared to $ 10,000-15,000 per hectare

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by mechanical excavation of contaminated soil and its landfill disposal (Brown and

Doube, 2004).

2) Simultaneously reuse and recycles organic wastes: Of considerable economic

and environmental significance is that the worm feed used in vermiremediation process

is necessarily an organic waste product. This means that it would also lead to reuse and

recycling of vast amount of organic wastes which otherwise end up in landfills for

disposal at high cost.

3) Improves total quality of land and soil: Significantly, vermiremediation leads

to total improvement in the quality of soil and land where the worms

inhabit.Earthworms significantly contribute as soil conditioner to improve the physical,

chemical as well as the biological properties of the soil and its nutritive value. They

swallow large amount of soil every day, grind them in their gizzard, and digest them in

their intestine with aid of enzymes. Only 5-10 percent of the digested and ingested

material is absorbed into the body and the rest is excreted out in soil in the form of fine

mucus coated granular aggregates called vermicastings which are rich in NKP,

micronutrients and beneficial soil microbes including the nitrogen fixers and

mycorrhizal fungus (Bhawalkar, 1995; Butt, 1999).

Moreover, what is of still greater economic and environmental significance is

that the polluted land is not only cleaned-up but also improved in quality. The soil

becomes lighter and porous rich in biological activities and the productivity is increased

to several times. During the vermi-remediation process of soil, the population of

earthworms increases significantly benefiting the soil in several ways. A wasteland is

transformed into wonderland. Earthworms are in fact regarded as biological indicator of

good fertile soil and land (Brown and Doube, 2004; Sinha et al., 2008b).

VERMIREMEDIATION TECHNOLOGY DESTINED TO BECOME A

GLOBAL MOVEMENT

Vermiremediation by commercial vermiculture in U.K. Land Reclamation and

Improvements Programs has become an established technology for long-term soil

decontamination, improvement and maintenance, without earth-cutting, soil excavation

and use of chemicals (Butt, 1999; Lowe and Butt, 2003; Butt et al., 2004). U.S.,

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Australia, and other developed nations are also using vermiculture technology for clean

up of contaminated lands at mine sites, oil-drilling sites and landfills (Bogdanov, 1996;

Lotzof, 2000; Dynes, 2003).

Removal of heavy metals

Hartenstein et al. (1980) studied that earthworms can bio-accumulate high

concentrations of heavy metals like cadmium (Cd), mercury (Hg), lead (Pb) copper

(Cu), manganese (Mn), calcium (Ca), iron (Fe) and zinc (Zn) in their tissues without

affecting their physiology and this particularly when the metals are mostly non-

bioavailable. They can particularly ingest and accumulate extremely high amounts of

zinc (Zn), lead (Pb) and cadmium (Cd). Cadmium levels up to 100 mg per kg dry

weight have been found in tissues. Ireland (1983) reported that the earthworms species

L. terrestris can bio-accumulate in their tissues 90-80 mg lead (Pb)/gm of dry weight,

while L. rubellus and D. rubida it was 2600 mg/gm and 7600 mg/gm of dry weight,

respectively. Zinc (Zn), manganese (Mn), and iron (Fe) were shown to be excreted

through the calciferous glands of earthworms. Contreras-Ramos et al. (2005) also

confirmed that the earthworms reduced the concentrations of chromium (Cr), copper

(Cu), zinc (Zn) and lead (Pb) in the vermicomposted sludge (biosolids) below the limits

set by the USEPA in 60 days.

Removal of polycyclic aromatic hydrocarbons (PAHs)

PAHs are priority pollutants and cause great concern with respect to human

health and environment. They are inherently recalcitrant hydrocarbons, and the higher

molecular weight PAHs are very difficult to remediate. Ma et al. (1995) studied the

influence of earthworm species L. rubellus on the disappearance of spiked PAHs

phananthrene and fluoranthene (100 μg/kg of soil) and found that the losses of both

PAHs occurred at a faster rate in soils with earthworms, than the soil without worms.

After 56 days (8 weeks), 86% of the phenanthrene was removed. Eijsackers et al.

(2001) reported that the concentration of phenanthrene decrease steadily when the

worms are added. After 50 days, only very low concentration of phenanthrene was

detected (<0.5 mg/kg of soil), and after 11 weeks no phenanthrene was detected as it

was <0.03 mg/kg of soil. Contreras-Ramos et al. (2006) studied the uptake of three

PAHs viz. phenanthrene, anthracene and benzo (a) pyrene at different concentrations by

E. fetida and measured the PAHs concentrations in the soil and in the tissues of

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earthworms exposed to the PAHs for 11 weeks. 10 earthworms per 50 g of soil

(equivalent to 200 worms per kg of soil) were added and sufficient moisture was

maintained. The concentration of anthracene decreased by 2-fold after addition of

earthworms and the average removal was 51% which was only 23% by microbes alone

when the earthworms were not added to the soil. On an average the concentration of

benzo (a) pyrene decreased by 1.4- fold and the average removal was 47% which was

only 13% by microbes when earthworms were not present. Phenanthrene was

completely removed (100%) by earthworms when the amount of the chemical was

<100 mg/kg of soil, while only 77% was removed by microbes in absence of

earthworms.

Removal of petroleum and crude oil hydrocarbons

Schaefer (2005) studied that increased microbial catabolic activity due to the

presence of E. fetida was responsible for the loss of 91% (1074 mg/kg of soil to 96

mg/kg) of crude oil contamination in 56 days of treatment. Tomoko et al. (2005) added

earthworm species, E. fetida with varying organic wastes to an oil contaminated soil

and found that worms significantly decreased oil contents in comparison to the control.

Martin-Gil et al. (2007) also studied the use of E. fetida and vermicomposting in the

treatment of high molecular weight hydrocarbons asphaltens from the Prestige Oil

Spill. About 80% vegetable waste (potato peelings etc.) was added to 20% heavily fuel

oil contaminated soil and then vermicomposted in treatment vessel. Earthworms were

added at the density of 330 gm/sq. meter of treatment vessel for 6 months. Earthworms

mineralized the asphaltens thus eliminating it from the system.

Removal of agrochemicals

Several studies have found definite relationship between organochlorine

pesticide residues in the soil and their amount in earthworms, with an average

concentration factor (in earthworm tissues) of about 9 for all compounds and doses

tested. Studies indicated that the earthworms bio-accumulate or biodegrade

organochlorine pesticide and PAHs residues in the medium in which it lives (Davis,

1971; Ireland, 1983; Haimi et al., 1992). Ramteke and Hans (1992) isolated microbes

from the gut of earthworm Pheretima posthuma treated with hexachlorocyclohexane

(HCH) and noted significant subsequent HCH degradation. The HCH degrader

microorganisms in the worms gut gradually increased over a 5-week period, replacing

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other gut microflora, indicating the potential for specialized gut growth by earthworms

in order to degrade organic chemicals. Bolan and Baskaran (1996) studied the effect of

earthworm species L. rubellus and A. callignosa vermicast on the sorption and

movement of herbicides C14 -metsulforon methyl, C14 -atrazine, C14-2,4

dichlorophenoxyacetic acid (2,4-D) in soil. Worm vermicasts sorbed higher amount of

herbicides from the contaminated soil than the control soil due to the higher levels of

organic carbon and more fine size of fractions in worm worked contaminated soils.

Gevao et al. (2001) applied earthworms (Aporrectodea longa) at 5 worms per 2 kg of

soil contaminated with non-extractable pesticides (C14-isoproturon, C14-dicamba and

C14-atrazine) residues in soil for 28 days. They found that due to earthworm burrowing

actions, a greater degree of bound pesticides residues in soil was released as compared

to those without worms. When the study was applied to freshly added pesticides in soil,

the non-extractable residues of C14-isoproturon, C14-dicamba and C14-atrazine were

higher by factors 2, 2, and 4, respectively in the soil without worms. Thus, not only the

earthworms restricted the formation of bound fraction of pesticides, but also enhanced

the release and mineralization of bound pesticides residues.

Removal of polychlorinated biphenyls (PCBs)

PCBs are a group of oily, colorless, organic fluids belonging to the same

chemical family as the pesticide DDT. They constitute a family of chemicals with over

200 types, and used in transformers and power capacitors, electrical insulators, as

hydraulic fluids and diffusion pump oil, in heat transfer applications, as plasticizers for

many products. PCBs are categorized as unusually toxic and persistent organic

pollutant (POPs). They were produced at about 100 million pounds per year during the

1960s and 70s but now severely curtailed due to its potential adverse effects on the

human health and the environment. Singer et al. (2001) studied the role of earthworm

specie P. hawayana in mixing and distribution of PCB-degrader microorganisms when

added to Aroclor 1242 contaminated soil (100 mg/kg of soil) over 18 weeks period.

Ten (10) earthworms per 0.6 kg of contaminated soil were added. The contaminated

soil treated with earthworms resulted in significantly greater PCB losses (average 52%)

when compared to the soil without earthworm treatment which was 41%. The authors

concluded that PCB losses from contaminated soils were partly due to burrowing

activities of worms, thus allowing more infiltration of microorganisms and about 10-

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fold greater gas exchange and diffusion. Also, the deposition of nutrient rich vermicast

in the burrows maintained a more metabolically active degrader microbial community.

Vermiremediation of PAHs contaminated soil

Sinha et al. (2008b) studied the remedial action of earthworms on PAHs

contaminated soils obtained from a former gas works site in Brisbane where gas was

being produced from coal. The initial concentration of total PAHs compounds in the

soil at site was greater than 11,820 mg/kg of soil. The legislative requirements for

PAHs concentration in soil in Australia is only 100 mg/kg for industrial sites and 20

mg/kg for residential sites. 10 kg each of PAHs contaminated soil was subjected to

three treatments and studied for 12 weeks. In treatments 1 and 2, 500 earthworms

(mixed species of E. fetida, E. eugeniae and P. excavatus) were added to the soil with

5kg each of feed materials (semi-dried cow dung and food wastes). The treatment 3

was kept as control in which only 5 kg of conventional compost was added and no

worms. Compost provided the necessary degrader microbes for PAHs degradation and

hence that could determine the precise role of earthworms in PAHs removal as

earthworms also proliferate degrader microbes in any system and act synergistically.

Soils were kept moist (about 60-70% moisture content) by regular sprinkling of water.

Sinha et al. (2008b) showed that the worms could remove nearly 80% of the

PAHs (or above 60% after considering the dilution factors) as compared to just 47%

and 21% where earthworms were not applied, In addition they found that only

microbial degradation have occurred. This was just in 12 weeks study period. It could

have removed by 100% in another few weeks. More significant was that the worm

added soil became odor-free of chemicals in few days and were more soft and porous in

texture.

VERMICOMPOSTING OF DIFFERENT ORGANIC SUBSTRATES

In recent years, Clitellate earthworms E. eugeniae, E. fetida and P. excavatus

were cultured for 21 days (at room temperature of 28°C - 30°C) in individual troughs

with partitioned four culture beds of blackgram pod husk, redgram pod husk, redgram

grain husk and bengalgram grain husk mixed with cow manure in 1:1 ratio to find out

their selective preference for wastes under multiple choice as their food. Preference as

judged by number of cocoons in each waste (Reinecke and Kriel, 1981).

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Experiment has been carried out with different types of organic wastes such as

cow dung, biogas slurry, kitchen wastes and the dietary influence on the biomass and

reproduction rate of the tropical earthworm, L.mauritii and the tropical endemic

species, P. excavatus in the biogas slurry recorded higher than the other two organic

wastes (Ponnuraj et al., 1998).

Sugar factory waste i.e., filters or agricultural residues were composted by two

exotic and epigeic species of earthworm’s E. fetida a Chinese species, E. eugeniae an

African species and with one fungal species Trichoderma harzianum. After days of

composting, the physical and chemical parameters increased significantly. The pH

value was nearly neutral in all experiments whereas Eudrilus worked compost showed

maximum amount of macro and micronutrients as 2.6% N, 6.64% P, 0.73% K, 6.85%

C, 1.30% Mg, 0.23% Na, 0.44% I, 214 ppm Co, 391 ppm Mn and 1.1% S. The

bacterial load was maximum Eudrilus worked compost (843 CFU x 105). Micrococci,

Bacillus and Acromobactor, were the three bacterial species found in the all-

experimental compost. The gut of the exotic species of earthworms consists of bacterial

colony of Acromobactor, Micrococci, Vibrio and Bacillus. Hence Eudrilus eugeniae

can be used for composting sugar factory waste agricultural residues and the compost

may be used as an organic fertilizer since it has appropriate macronutrients,

micronutrients and microorganisms that may support the plant growth (Balamurugan et

al., 1999).

Bansal and Kapoor (2000) studied vermicomposting with E. fetida of mustard

residues and sugarcane trash mixed with cattle dung in a 90-day composting

experiment. Vermicomposting resulted in significant reduction in C:N ratio and

increase in mineral N, after 90 days of composting, over treatments uninoculated with

earthworms. Microbial activity, as measured by dehydrogenase assay, increased up to

60 days and declined on further incubation. There was total N in the compost prepared

by earthworm inoculation. However, the differences were not significant. Total P, K,

and Cu contents did not differ in compost prepared with earthworm inoculation from

the uninoculated treatments.

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Paper mills have severe problem in disposing effluent or semisolid sludge

despite repeated recycling. It requires treatment prior to disposal of sludge. In recent

years biological treatment method received much attention and is considered an

efficient low-cost treatment, to dispose the paper mill sludge biologically using 2

exotic species (E. eugeniae and E. fetida) and an indigenous species (L. mauritii) of

earthworm. The agricultural residues in various concentration 25%, 50% and 75%

were subjected to vermitub treatment for a period of 60 days. During the period of

study, data were collected on reproductive strategies of earthworm and chemical

analysis of wastes before and after treatment. Results obtained indicate that 25%

concentration of sludge was ideal and of the three worms, used E. fetida proved the best

worm for biomanagement (Banu et al., 2001).

The vermicomposting with E.andrei of dry olive cake, a lignocellulosic waste

produced during the extraction of olive oil, either alone or mixed with municipal

biosolids, was studied in a nine-month pilot scale experiment. The increase in

hydrolytic enzymes and overall microbial activity during the vermicomposting process

indicated the biodegradation of the olive cake and resulted in the disappearance of the

initial phytotoxicity of the substrate. However, the recalcitrant lignocellulosic nature of

the dry olive cake prevented suitable humification during the vermicomposting process.

For this reason, in addition to organic amendments, other management procedures

should be considered (Benitez et al., 2002).

A vermicomposting system using E. fetida for composting household biowaste

discarded daily was studied in comparison with a flowerpot-using solid-biowaste

composting (FUSBIC) process in terms of waste reduction efficiency and microbial

population structure. Both systems were operated at ambient temperature and at a waste

loading rate of 0.10-0.12 kg (wet wt) day-1. The rate of waste reduction in the

vermicomposter strongly depended upon air temperature, and varied seasonally

between 24 and 83%, the average reduction rate 49%. It was concluded that the

vermicomposting system investigated is less effective in reducing household biowaste

than the process (Hiraishi, 2002).

Adult E. fetida were used to vermicompost woodchips (WC) and sewage sludge

(SS) that are produced as waste product by platinum mines. Results revealed that there

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were no effects on growth (P>0.05), reproductive success decreased (P<0.05), and

aluminum (Al), copper (Cu), and nickel (Ni) were bioconcentrated P<0.05) in the

treatment groups without an inoculate. Earthworms in the treatment group with the

microorganism inoculate manifested no effects on growth or reproductive success and

did not accumulate Al, Cu, and Ni. It is concluded that the only economically feasible

way to bioconvert WC and SS to a potential ameliorant of platinummine tailings would

be with the addition of a microorganism inoculate (Maboeta and Rensburg, 2003).

An epigeic (surface dweller) earthworm species E. fetida and an anecic (deep

burrower) earthworm species L. mauritii have been tested for decomposition of kitchen

waste plus cow dung. However, organic carbon matter showed reduction in their

amounts for 3-4 months and afterwards slightly increased up to 150 days. E. fetida

produced 0.27%, 156%, 41% and 38% increases in organic carbon, nitrogen,

phosphorus, and potassium as well as 61% and 29% decreases in C/N and C/P ratios as

compared to control after 150 days of earthworm inoculation.. The average numbers of

cocoons and adults produced were greater by E. fetida than by L. mauritii after 150

days. These results indicate E. fetida may be a better adapted species for decomposition

of kitchen waste plus cow dung under tropical conditions. (Tripathi and Bhardwaj,

2004)

Comparative studies were performed to evaluate composting potential, biomass

growth and biology of a non-native (E. fetida) and an endemic (L. mauritii) species of

earthworm in the semiarid environment of Jodhpur district of Rajasthan in India.

Earthworms were reared in a mixed bedding material comprised of biogas slurry, cow

dung, wheat straw, leaf litter and sawdust and kitchen waste. A comparative

assessment of biomass growth of E. fetida and L. mauritii was done under controlled

laboratory conditions. The optimum temperature, moisture content, and pH for E. fetida

were 25 degrees C, 70% and 6.5, respectively. The net reproductive rate was 9 per

month in the case of E. fetida and 1 per month for L. mauritii. These observations

indicate E. fetida may be a more efficient breeder than L. mauritii in the desert region

of Rajasthan (Tripathi and Bhardwaj, 2004a).

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The performance of four species of earthworm E. eugeniae, Kinberg, Drawida

willsi Michaelsen, Lampito mauritii, Kinberg and P. excavatus, Perrier--born and

grown in vermireactors fed with paper waste was studied over six months, in terms of

vermicast output per unit feed, production of offspring, and increase in worm zoomass.

The results indicated that cowdung-spiked paper waste can be an adequate food for

successive generations of earthworms and that reactor can be operated indefinitely on

this feed. The results also indicated that the earthworm generations born and raised in

vermireactors operated on this feed become better vermiconverters of this feed than the

parent earthworms (Gajalakshmi and Abbasi, 2004).

Garg et al. (2005) studied the effect of various animal wastes on growth and

reproduction of an epigeic earthworm E. fetida in identical laboratory conditions. For

each waste, viz., cow, buffalo, horse, donkey, sheep, goat, and camel, five hatchlings

per 10g of waste were inoculated and monitored for biomass gain, mortality, sexual

maturity, cocoons production periodically for 15 weeks. No mortality was observed in

any waste.Net biomass earthworm in different animal wastes was in the order of

sheep>donkey>buffalo>goat= cow=horse>camel.

Ahmad and Bhargava (2005) have studied the feasibility of vermicomposting of

agricultural residues in detail and the nutrient properties of the final vermicompost were

analyzed for its use as an agricultural soil enhancer. Four components of soil, viz,

carbon content, nitrogen content, phosphorous content, and the potassium content were

analysed on a periodic basis to assess the trend of nutrient variation in the

vermicompost sample. The experiment was carried out simultaneously in four bins

with varying ratios of agricultural residues and food waste contents to assess the

vermicomposting potential in each case. The results showed a decrease in the total C/N

ratio and increments in the P and K values as the vermicomposting period progressed

and the end product was quite high in soil nutrients and could safely be used as a soil

fertilizer.

The bioconversion potential of two epigeic species (E. fetida Sav.and

E.eugeniae Kinberg) of earthworms was assessed in terms of efficiency and

sustainability of vermicomposting of Taro (Colocasia esculenta (Linn) Schott in Schott

and Endl). In different vermireactors, each runs in triplicates with one of the two

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species of earthworms, and 60 g of 6:1 Colocasia: cowdung as feed, vermicasts were

produced with steadily increasing output in all the reactors. E. eugeniae was found to

be more efficient producer of vermicasts than E. fetida. In all reactors, the earthworms

grew well, increasing their weights and number (Kurien and Ramasamy, 2005).

Loh et al. (2005) used two types of livestock manure for culturing of the

earthworm, E. fetida. The concentrations of total C, P and K in goat manure vermicasts

were higher than those in cattle manure vermicasts. Cattle vermicasts had a higher N

content than goat vermicasts but the C:N ratio of fresh manure was higher than that of

vermicasts for both materials. The cocoon production per worm in cattle manure was

higher than in goat manure. However, the hatchability of cocoons was not affected by

manure treatments. In conclusion, cattle manure provided a more nutritious and

friendly environment to the earthworms than goat manure.

Deolalikar et al. (2005) studied the change in metal content on vermicomposting

of paper mill solid waste. On vermicomposting, quantity of iron, zinc and chromium

was found to be increased where as quantity of aluminum, copper, manganese, nickel

and lead was found comparatively low. The bioaccumulation of any metal was not

observed in the body of the earthworm, hence after vermicomposting, there is no harm

to fishes to utilize earthworm biomass as theirs.

Garg et al. (2005) investigated the potential of an epigeic earthworm, E. fetida,

to transform solid textile mill sludge (STMS) spiked with anaerobically digested biogas

plant slurry (BPS) into vermicompost to evaluate the feasibility of vermicomposting in

industries for waste management. Vermicomposting resulted in pH shift toward acidic,

significant reduction in C:N ratio and increase in nitrogen, phosphorus, and potassium

contents. Microbial activity measured as dehydrogenase activity increased with time up

to day 75 but decreased on day 90, indicating the exhaustion of feed and decrease in

microbial activity. These experiments demonstrate that vermicomposting can be an

alternate technology for the recycling and environmentally safe disposal/management

of textile mill sludge using an epigeic earthworm, E. fetida, if mixed with anaerobically

digested BPS in appropriate ratios.

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Garg et al. (2006) conducted a study (100 days duration) to evaluate the

efficiency of an exotic earthworm species (epigeic-E. fetida) for decomposition of

different types of organic substrates (kitchen waste, agro-residues, institutional and

industrial wastes including textile industry sludge and fibres) into valuable

vermicompost. The percentage of, nitrogen, phosphorous and potassium in

vermicompost was found to increase while pH and total organic carbon declined as a

function of the vermicomposting period. 4. 4-5.8-fold increases in TKN were observed

in different feed mixtures at the end of vermicomposting period. The increase in TKN

for different feed substrates was found in the order: textile sludge>textile

fibre=institutional waste > agro-residues > kitchen waste. The data reveals that

vermicomposting (using E. fetida) is a suitable technology for the decomposition of

different types of organic wastes (domestic as well as industrial) into value-added

material.

Gajalakshmi et al. (2005) reported litter of the mango (Mangifera indica) tree

leaves was composted and then converted into vermicast by the action of the

earthworm E. eugeniae Kinberg. After over nine months of continuous operation the

vermireactors with 62.5 animals generated approximately 13.6g vermicast per litre of

reactor volume (l) per day (d) whereas the reactors with 75 animals produced

approximately 14.9 g vermicast. The ability of the earthworms to survive, grow and

breed in the vermireactors fed with composted mango tree leaves, and a rising trend in

vermicast output inspite of the death of a few worms after four months of reactor

operation, indicate the sustainability of this type of vermireactors. It also indicates that

even better vermireactor efficiency may be possible by modifying the reactor geometry.

Gajalakshmi and Abbasi (2004) reported that vermicomposting of neem

(Azadirachta indica A. Juss) was accomplished in high-rate reactors operated at the

earthworm (E.eugeniae) densities of 62.5 and 75 animals per litre of reactor volume.

Contrary to the fears that neem--a powerful nematicide--might not be palatable to the

annelids, the earthworms fed voraciously on the neem compost, converting upto 7% of

the feed into vermicompost per day. Indeed the worms grew faster and reproduced

more rapidly in the neem-fed vermireactors than in the reactors fed with mango leaf

litter earlier studied by the authors (Gajalakshmi et al., 2003). Another set of

experiments on the growth, flowering, and fruition of brinjal (Solanum melongena)

CHAPTER-I Introduction

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plants with and without fertilization with vermicompost, revealed that the

vermicompost had a significantly beneficial impact.

During vermicomposting of coconut leaves by the earthworm Eudrilus sp.,

Oryctes rhinoceros L. (rhinoceros beetle), an insect pest of palms, was found to breed

in the decomposing organic material. Metarhizium anisopliae var. major was tried as a

biocontrol agent for the management of this pest. The effect of pathogen at spore loads

of 103, 104 and 105 per 10 g of substrate was tested in laboratory on Eudrilus sp. kept

with O. rhinoceros grubs and on Eudrilus sp. alone for the pathogenic capability of the

fungus on the pest and its possible toxicity towards the vermin. The efficacy of the

entomopathogen was also tested in the field in vermicomposting tanks. In laboratory

bioassay, 100% mycosis of O. rhinoceros grubs could be obtained while the

entomopathogen had no toxic effect on the earthworms. There was a positive change in

the number and weight of the earthworms on treatment with M.anisopliae. In

conclusion, M. anisopliae could effectively control O. rhinoceros in vermicomposting

sites and was non-hazardous to the vermicomposting process as well as the Eudrilus

spp (Gopal et al., 2006).

Suthar (2006) recycled the guar gum industrial waste through vermitechnology

under laboratory conditions by using composting earthworm P. excavatus (Perrier).

Three different combinations of guar gum industrial wastes namely guar gum industrial

waste:cow dung:saw dust in 40:30:30 ratio (T1), guar gum industrial waste:cow

dung:saw dust in 60:20:20 ratio (T2), and guar gum industrial waste: cow dung:saw

dust in 75:15:10 ratio (T3) were used for vermicomposting experiments. Chemical

changes during vermicomposting were measured and comparatively T2 showed greater

increase (from its initial level) for total N (25.4%), phosphorus (72.8%) and potassium

(20.9%) than the other treatments. T2 also showed higher vermicomposting coefficient

(VC), higher mean biomass for P. excavatus (146.68 mg) and higher cocoon production

(about 21.9% and 645.5% more than the T1 and T3, respectively). Maximum

earthworm mortality during vermicomposting was recorded with T3 treatment while

zero mortality was recorded for T2 treatment after 150 days. Overall, T2 treatment

appeared to be an ideal combination for enhancing maximum biopotential of

earthworms to management guar gum industrial waste as well as for earthworm

biomass and cocoon production.

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The decomposition efficiency of P. sansibaricus (Perrier) for vermicomposting

was evaluated by using a variety of wastes such as agriculture waste, farm yard manure

and urban solid waste. Vermicomposting resulted in significant increase in total N

(80.8–142.3%), phosphorous (33.1–114.6%) and potassium (26.3–125.2%), whereas

decrease in organic C (14.0–37.0%) as well as C:N ratio (52.4–69.8%) in different

experimental beddings. P. sansibaricus showed maximum biomass production, growth

rate (mg day-1), mean cocoon numbers, and reproduction rate (cocoon worm-1) in VLL

(vegetable waste + leaf litter) as compared to other substrate materials. There was a

consistent trend for earthworms growth and reproduction rate, related to initial N-

content of the substrate (P < 0.05), but there was no clear effect of C:N ratio of the

composted material on earthworm cocoon numbers and weight gain. Earthworm

showed minimum total population mortality in VLL and maximum in HHCD

(household waste + cow dung), after 150 days of experimentation. The increased level

of plant metabolites in end product (vermicompost) and growth patterns of

P. sansibaricus in different organic waste resources demonstrated the candidature of

this species for wastes recycle operations at low-input basis (Suthar, 2007).

With the industrial growth, changing life style and consumeristic attitude paper

consumption had increased significantly in yesteryears. The authors have observed that

waste paper obtained from consumable items and used paper products are disposed in

open by the consumers as these are not accepted by the salvaging industry. Non-

recyclable post consumer paper waste (PW) has been amended with cowdung (CD)

employing E. fetida earthworm in order to transform it into a value added product, i.e.,

vermicompost. Vermicomposting of paper waste resulted in net reduction in ash

content and total organic carbon (42.5–56.8%) but increment in total Kjeldhal nitrogen

(2.0–2.4-fold), total potassium (2.0-fold), and total phosphorous (1.4–1.8-fold) was

achieved after 91 days of worm’s activity. The C:N ratio decreased with time in all the

worm-worked vermireactors in the range of 71.9–82.0%, depicting advanced degree of

organic matter stabilization. The FT-IR spectroscopy of the vermicomposts showed

reduction in aliphatic compounds during the vermicomposting process. The results also

demonstrated the worm growth and reproduction are not significantly affected if PW

content is up to 30% in the vermireactor (Gupta and Garg, 2008a).

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The potential of vermicomposting technology in the management of horse dung

(HD) spiked sugar mill filter cake (SMFC) using an epigeic earthworm E. fetida under

laboratory conditions has been studied. A total of six vermicomposters filled with

different ratios of HD and SMFC were maintained. The growth and fecundity of

E. fetida was monitored for 12 weeks. Maximum growth was recorded in 90% HD +

10% SMFC feed mixture containing vermicomposter. Earthworms biomass gain and

reproduction was favorably up to 50% HD + 50% SMFC feed composition. Maximum

cocoons were also recorded in 90% HD + 10% SMFC feed mixtures, however

increasing proportions of SMFC in different vermicomposters affected the growth and

fecundity of worms. A significant decrease in C:N ratio and increase in total kjeldahl

nitrogen, total available phosphorus and calcium contents was recorded. The heavy

metals, content were higher in the vermicompost obtained in all the reactors than initial

feed substrates. Based on investigations it is concluded that vermicomposting could be

an alternative technology for the management of filter cake if it is mixed in 1:1 ratio

with horse dung (Sangwan et al., 2008a).

Vermitechnology was investigated by Padmavathiamma et al. (2008) as a

means of reducing organic waste materials. Vermicomposting conditions were

optimized to convert the biowastes to nutritious composts for amending agricultural

soil. Studies were undertaken to select the most suitable earthworm species for

vermicomposting, to enrich vermicompost by inoculation with beneficial microbes, to

standardize an economically feasible method of vermicomposting, to achieve nutrient

economy through vermicompost application in acid soils (pH 4.5), and to assess the

performance of vermicompost as a bioinoculant in cow-pea, banana, and cassava.

Earthworm species E. eugeniae, E. fetida, P. sansibaricus, P. corethrurus and

M. chinensis were compared for their efficiencies in biodegrading organic wastes,

E. eugeniae was found to be a superb agent. As a bioinoculant, vermicompost increased

nitrogen and phosphorous availability by enhancing biological nitrogen fixation and

phosphorous solubilisation. Vermicompost-amended acid-agriculture-soil significantly

improved the yield, biometric character, and quality of banana, cassava, and cow-pea.

Vermicompost application stimulated root growth, facilitating nutrient absorption and

thereby favouring higher yield.

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The post-harvest residues of some local crops, e.g. wheat (Triticum aestivum),

millets (Penniseum typhoides and Sorghum vulgare), and a pulse (Vigna radiata) were

subjected to recycling through vermicomposting by using the epigeic earthworm

E. eugeniae Kinberg, under laboratory conditions. The crop residues were amended

with animal dung; and three types of vermibeds were prepared: (i) millet straw

(S. vulgare + P. typhoides in equal quantity) + sheep manure (1:2 ratio) (MS), (ii) pulse

bran (V. radiata) + wheat straw (T. aestivum) + cow dung (1:1:2 ratio) (PWC), and

(iii) mixed crop residues (mixing of all types crop residues, used in this study) + cow

dung in 1:1 ratio (MCR + CD). The fourth treatment was cattle shed manure (CSM). At

the end, ready vermicompost showed lower organic C content and higher

concentrations of other important plant nutrients. Organic C content decreased in the

order: MCR+CD (27.6%) > PWC (22.8%) >CMS (22.6%) >MS (19.4%). The ready

vermicompost obtained from MCR+CD vermibed showed the maximum increase (% of

initial level) in content of total N (143.4%), available P (111.1%) and exchangeable K

(100.0%). The end product showed reduction in C:N ratio between the ranges of 60.7%

(CSM) and 70.3% (MCR + CD), at the end. The composting earthworm E. eugeniae

exhibited the highest values of biological parameters: maximum mean individual

biomass (1261.25±7.0 mg), biomass gain (955.84±11.03 mg), growth rate

(10.62±0.10mgwt.worm−1 day−1), cocoon numbers (87.67±6.51), and reproduction rate

(0.66±0.01 cocoonsworm−1 day−1) in CSM container, while MS vermibeds showed the

lowest values of these parameters. During experimentation, the maximum mortality for

E. eugeniae was recorded in MS (16.67±7.63%) followed by CSM> PWC>MCR+CD.

Results indicated that the C:N ratio of the substrate drastically influenced the growth

parameters of E. eugeniae, and it showed the close relations with maximum individual

biomass gain (R2 = 0.96), individual growth rate (R2 = 0.82), and reproduction rate

(cocoonworm−1 day−1) (R2 = 0.72), in different treatments. This study clearly indicates

that vermicomposting of crop residues and cattle shed wastes can not only produce a

value added product (vermicomposting) but at the same time acts as best culture

medium for large-scale production of earthworms (Suthar, 2008).

Freshly-shredded green waste (yard waste) was composted for 16 weeks using a

mechanically-tumed windrow system. The rate of organic matter stabilisation was

determined by measuring the reduction in the volatile solids content of the waste.

Samples of the fresh material were also vermicomposted using E.andrei (Bouche) and

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the rates of growth and reproduction obtained were comparable to published rates for

other wastes. Vermicomposting for 8 weeks produced a material with a significantly

lower volatile solids content compared to composting for a similar period (P< 0.01). A

combined composting and vermicomposting system was investigated by extracting

partially composted samples from the compost windrow every 2 weeks and feeding

these to E. andrei. Growth and reproduction were found to be positively correlated to

the volatile solids content of the waste (P<0.01). Vermicomposting partially composted

waste (2 weeks), for a further 6 weeks, reduced volatile solids content significantly

more than for composting fresh waste for 8 weeks (P<0.001). It is concluded that E.

andrei is capable of attaining good rates of growth and reproduction in fresh green

waste and that vermicomposting can result in a more stable material (lower volatile

solids content) compared to composting. Combining vermicomposting with existing

composting operations can also accelerate stabilisation compared to composting alone.

The duration of pre-composting will, determine the subsequent rate of growth and

reproduction of E.andrei (Frederickson et al., 1997).

An experiment was conducted during 1998–1999, in a deciduous forest located

in the semi-arid tropics of central India, to evaluate the suitability of different forest

litters as food material for the tropical epigeic earthworms i.e. E. fetida (Savigny),

P. excavatus (Perrier) and D. bolaui (Michaelsen). The aim was to examine the

influence of these earthworms on the decomposition processes of three types of forest

litters i.e. T. grandis (teak), Madhuca indica (mahua) and Butea monosperma (palas),

on the maintenance of quality in a vermicomposting system, and to assess the effect of

applications of insitu prepared vermicomposts on the growth of forest trees. The results

indicated that T. grandis litter was the most suitable food material for the earthworms

possibly because it contained high reserves of mineral nutrients. Comparisons of the

survival and reproduction rates of the three epigeic earthworm species indicated that a

higher reproduction rate was maintained for E. fetida compared to P. excavatus and

D. bolaui in the decomposition of these forest litters. The rates of growth and

population increases of E. fetida approximately doubled after 12 weeks of litter

decomposition. The litter decomposition process was associated strongly with the

quality of the materials and their chemical composition. Irrespective of earthworm

inoculations, the levels of available nutrient such as NH4-N, NO3-N, available P and K

increased significantly (p60:05) in the order T. grandis litter compost>M. indica litter

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compost>B. monosperma litter compost. The mature decomposed litter had lower C/N

ratios (11.3–24.8:1), water-soluble carbon (0.30–0.58%), water-soluble carbohydrates

(0.35–0.71%) and larger cation exchange capacity/total organic carbon ratios than the

values in the parent forest litter. The lignin content increased with maturation with a

concomitant decrease in cellulose resulting in higher lignin/ cellulose ratios (Manna et

al., 2003). The vermicomposting of pulp mill sludge mixed with sewage sludge, pig

slurry and poultry slurry at different ratios was studied. E. andrei (Bouche and Ferriere,

1986) showed high growth rates and high mortalities in al1 the mixtures considered

(Elvira et al., 1997).

Gupta et al. (2007) have investigated the potential of water hyacinth (WH)

spiked with cow dung (CD) into vermicompost. Five vermireactors containing WH and

CD in different ratios, were run under laboratory conditions for 147 days. The

maximum worm growth was recorded in CD alone. Worms grew and reproduced

favourably in 25% WH+ 75% CD feed mixture. Greater proportion of WH in feed

mixture significantly affected the biomass gain, hatchling numbers and numbers of

cocoons produced during experiments. In all the vermireactors, there was significant

decrease in pH, TOC and C:N ratio, but increase in TKN, TK and TAP at the end. The

heavy metals content in the vermicomposts was lower than initial feed mixtures. The

results indicated that WH could be potentially useful as raw substrate in

vermicomposting if mixed with up to 25% in cow dung (on dry weight basis). Sludges

are stabilized to reduce pathogens, eliminate offensive odors and inhibit, reduce or

eliminate the potential for putrification. Stabilization of municipal wastewater sludge

with and without earthworms (E. fetida) was studied. The earthworms were fed at the

optimum level of 0.75 kg-feed/kg-worm/day. Decomposition and stabilization of

wastewater sludge occurred both in the presence and in the absence of earthworms

during 9 weeks but the process was accelerated in their presence. Phosphorus content

increased in the sludge with earthworms but decreased in it without them. Nitrogen

content in the resulting vermicompost showed no difference with its quantity in the

original substrate while it increased in the control treatment.

Nair et al. (2006) conducted a study to test combination of the

thermocomposting and vermicomposting to improve the treatment efficiency and assess

the optimum period required in each method to produce good quality compost. The

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results showed that pre-thermocomposting improved vermicomposting of kitchen

waste. A 9-day thermocomposting prior to vermicomposting helped in mass reduction,

moisture management and pathogen reduction.

VERMI-COMPOSTING TECHNOLOGY versus CONVENTIONAL

TECHNOLOGIES

a) Earthworms enrich composts by nutrients and make them bio-available

Earthworms induce several beneficial changes in the biochemical properties of

the composting wastes. They mineralize the nitrogen (N), phosphorus (P), potassium

(K) and all other nutrients in the waste organics to increase their value in the

vermicompost and also make them bio-available to plants (Buchanan et al., 1988).

They ingest nitrogen from the waste and excrete it in the mineral form as nitrates,

ammonium, and muco-proteins. The nitrogenous waste excreted by the nephridia of the

worms is plant-available as it is mostly urea and ammonia.

b) Earthworms propagate beneficial soil microbes in the compost

Worms have been found to propagate Actinomycetes, Azotobacter, Rhizobium,

Nitrobacter, and phosphate solubilizing bacteria significantly in their products. Singh

(2009) also indicated higher values of Azotobacter (the nitrogen fixing bacteria) and the

Actinomycetes (the bacteria that increase biological resistance in plants against pests

and diseases) in vermicompost as compared to the conventional aerobic and anaerobic

composts.

c) Earthworms destroy harmful microbes in compost and make it more hygienic

The earthworms release coelomic fluids that have anti-bacterial properties and

destroy all pathogens in the waste biomass (Pierre et al., 1982). They also devour the

harmful protozoa, bacteria and fungus as food. They seem to realise instinctively those

anaerobic bacteria and fungi are undesirable and so feed upon them preferentially, thus

arresting their proliferation. Eastman et al. (2001) and Bajsa et al. (2004) reported

significant pathogen reduction by vermicomposting. Hence, vermicompost is more safe

and hygienic to handle.

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d) Low greenhouse gas (GHG) emissions by vermicomposting of waste

High volumes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)

is emitted from the conventional composting process especially in anaerobic

conditions. CH4 and N2O are 21 and 310 times more powerful than CO2 as GHG.

Worms significantly increase the proportion of aerobic to anaerobic decomposition in

the compost pile by burrowing and aerating action leaving very few anaerobic areas in

the pile, and thus significantly reducing emission these gases and also volatile sulfur

compounds. Analysis of vermicompost samples has shown generally higher levels of

available nitrogen (N) as compared to the conventional compost samples made from

similar feedstock. This implies that the vermicomposting process by worms is more

efficient at retaining nitrogen (N) rather than releasing it as nitrous oxide (N2O).

Sinha et al., (2009d) found that on average the anaerobic composting systems

emitted the highest amount of CO2 (2950 mg /m2/hour) and CH4 (9.54 mg/m2/hour),

while the vermicomposting system with worms emitted the least amount of CO2 (880

mg/m2/hour) and CH4 (2.17 mg/m2/hour). Vermicomposting systems had the lowest

emission of N2O, which is most powerful GHG.

e) No or low energy use in vermi-composting process

Normal microbial composting requires energy for aeration (constant turning of

waste biomass and even for mechanical airflow) and sometimes for mechanical

crushing of waste to achieve uniform particle size. Vermi-composting does not involve

such use of energy. Earthworms aerate the system constantly by burrowing actions.

f) Homogenous end- products

The greatest advantage over the conventional composting system is that the end

product is more homogenous, richer in plant-available nutrients and humus and

significantly low contaminants. They are soft, highly porous with greater water holding

capacity (Hartenstein, 1981; Appelhof, 1997; Lotzof, 2000).

g) Earthworms remove toxic chemicals from end- products

Several studies have found that earthworms effectively bio-accumulate or

biodegrade several organic and inorganic chemicals including heavy metals,

organochlorine pesticide and polycyclic aromatic hydrocarbons (PAHs) residues in the

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medium in which it feeds and detoxify the end-products (Hartenstein et al., 1980;

Nelson et al., 1982; Ireland, 1983; Sinha et al., 2008b).

h) Earthworm biomass comes as valuable by-product of waste vermicomposting

Huge population of earthworms results from vermicomposting of wastes.

Worms are finding new uses for production of some life-saving medicines and nutritive

feed materials besides their traditional uses in farms for improving soil fertility and

enhancing crop productivity.

VERMICULTURE: A GLOBAL MOVEMENT AND BOOMING BUSINESS

Although farmers have been practicing vermicomposting of farm wastes

throughout the world for centuries large scale vermicomposting of MSW including the

sewage sludge on commercial scale is a recent development to divert them from ending

up in the landfills, and has become a global movement (Sherman, 2000). First serious

experiments for management of municipal/industrial organic wastes were established

in Holland in 1970, and subsequently in England, and Canada. Later vermiculture were

followed in USA, India, Italy, Philippines, Thailand, China, Korea, China, Japan,

Brazil, France, Australia, Israel and Russia.

1) USA: U.S. has some largest vermicomposting companies and plants in world and

States are encouraging people for backyard vermicomposting to divert wastes from

landfills (Bogdanov 1996, 2004). The American Earthworm Company started a vermi-

composting farm in 1978-79 with 500 t/month of vermicompost production (Edwards,

2000). A farm in LA rears 1,000,000 worms to treat 7.5 tons of garbage each month.

Nearly 300 large-scale vermiculturist formed an International Worms Growers

Associationin1997 and is having booming business.Vermicycle Organics produced 7.5

million pounds of vermicompost every year in high-tech greenhouses. Its sale of

vermicompost grew by 500 % in 2005. Vermitechnology has doubled its business

every year since 1991 (NCSU, 1997; Kangmin, 1998). US scientists are also searching

for life saving vermi-medicines from the bioactive compounds in earthworms (Mihara

et al., 1990).

2) India: India had launched vermicomposting program of MSW in the 1990s and and

Bhawalkar Earthworms Research Institute (BERI) in Pune were among the pioneer

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institutions. Tata Energy Research Institute (TERI) in Delhi is also doing commendable

works. In recent years, it is growing as a part of sustainable non-chemical agriculture

program combined with poverty eradication program. Farmers are using vermicompost

on large scale and a revolution is going on. Vermicomposting business has enhanced

the lives of poor in India and generated self-employment opportunities for the

unemployed. In several Indian villages, NGOs are freely distributing cement tanks and

1000 worms and encouraging men and women to collect waste from villages and

farmers, vermicompost them and sell both worms and vermicompost to the farmers.

People are earning, rupees 5 to 6 lakhs every year from sale of both worms and their

vermicompost to the farmers. Mostly they use farm waste and MSWs collected from

streets and waste dumpsites (Bhawalkar, 1995; Haiti, 2001).

Bihar, Karnataka, Tamil Nadu, Gujarat and Mahrashtra are leading states in

vermiculture revolution. The Karnataka Compost Development Corporation established

a first vermicomposting unit in the country to handle all municipal urban solid wastes

and is producing 150 to 200 tons of vermicompost every day from city garbage (Kale,

2005). Several farmers whose life has been changed from a poor farm labourer to a rich

farmer who embraced vermiculture had been documented.

3) Canada: Canada is also ahead in vermicomposting business on commercial scale

for both vermicompost and vermimeal production. Large-scale vermicomposting plants

have been installed at several places to vermicompost municipal, farm wastes, and their

use in agriculture (GEORG, 2004). An Organic Agriculture Centre of Canada has been

established whose objective is to replace Chemical Agriculture by Vermiculture

(Munroe, 2007).

4) UK: UK is also following US and Canada in promoting vermiculture mainly for

waste management and to reduce the needs of waste landfills. Large 1000 metric ton

vermi-composting plants have been erected in Wales to compost diverse organic

wastes (Frederickson, 2000).

5) France: France is also promoting vermiculture on commercial scale to manage all

its MSW and reduce the needs of landfills. About 20 tons of mixed household wastes

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are being vermi-composted everyday using 1000 to 2000 million red tiger worms (E.

andrei) (Visvanathan et al., 2005).

6) New Zealand: It is also a leading nation in vermiculture. The Envirofert Company

of New Zealand is vermicomposting thousands of tons of green waste every year. They

put the green waste first to a lengthy thermophilic cooking, and then to

vermicomposting by worms after cooling. Cooking of green waste help destroy the

weeds and pathogens which may come from the feces of pets in grasses. They claim

that each worm eat the cooked green waste at least 8 times leaving an end product rich

in key minerals, plant growth hormones, enzymes, and beneficial soil microbes.

Envirofert is also planning to vermicompost approximately 40,000 tones of food

wastes from homes, restaurants and food processing industries every year

(Frederickson, 2000; Gary, 2009).

7) Australia: Vermicomposting is being done on large scale in Australia as a part of

the Urban Agriculture Development Program utilizing the urban solid wastes (Lotzof,

2000). The Sydney Waters in New South Wales have set up a vermiculture plant of 40

million worms to degrade up to 200 ton of urban wastes a week. The Gayndah Shire

Council in Queensland, Australia, is vermi-composting over 600 tons of organic waste

into valuable organic fertilizer (vermi-compost) and selling to the local farmers.

Vermicomposting of sludge from the sewage and water treatment plants is being

increasingly practiced in Australia and as a result, it is saving over 13,000 cum of

landfill space every year in Australia (Komarowski, 2001). The Hobart City Council in

Tasmania, vermicompost and stabilize about 66 cum of sewage sludge every week.

8) Philippines: Vermiculture and vermicomposting were introduced in the Philippines in the

1970s. Vermicompost is being used by farmers on large scale replacing the chemical fertilizers.

Recently, commercial production of vermimeal from earthworm’s biomass has been started as

a substitute to fishmeal for promoting fishery industries (Guerrero, 2005).

9) Argentina: Vermiculture is an expanding business in Argentina especially for the

development of countrysides. Worms Argentina is a growing company which reports to

be exporting composting worms on large scales to European, South American,

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Caribbean and Middle East nations. They are in high demands from Middle East

countries for recycling of polluting dairy effluents (Pajon, 2009).

10) China: Vermiculture is a fast growing industry in China for the development of

rural communities. It is in fact revival of the traditional culture practiced by ancient

medicinemen who used earthworms for treatment of several diseases. Earthworms are

now being used for vermicomposting of waste, promoting organic farming and for the

development of vermi-medicines and nutritive vermimeals. A dietary supplement in the

name of PLASMIN is being marketed in China (Sun, 2003; Lopez, 2003).

11) Russia: Vermiculture is being promoted on large scale in Russia especially for the

development of life-saving vermi-medicines for treatment of human diseases for which

conventional medicine do not have an answer. Scientists have developed a special

breed of the versatile species E. fetida which can tolerate and survive in cold climates

(Titov and Anokhin, 2005).

12) Japan: Japan is promoting vermiculture since 1970s mainly for production of

vermi-medicines from the bioactive compounds isolated from earthworms (Tanaka and

Nakata, 1974; Wang, 2000).

VERMICULTURE BASED AGRICULTURE versus CHEMICAL BASED

AGRICULTURE

1) Safe food for society: The biggest advantage of great social significance is that the

food produced is completely organic safe and chemical-free.

2) Highly nutritive crop fertilizer with bio-available nutrients: Studies indicate that

vermicompost is at least 4 times more nutritive than the conventional composts and

gives 30-40% higher yield of crops over chemical fertilizers. In Argentina, farmers

consider it to be seven (7) times richer than conventional composts in nutrients and

growth promoting values (Pajon - Undated). The humic acid in vermicompost

stimulates plant growth even in small amount (Canellas et al., 2002). Vermicompost

retains nutrients for long time than the conventional compost and while the latter fails

to deliver the required amount of macro and micronutrients to plants in shorter time, the

vermicompost does. Of greater agronomic significance is that the minerals in the

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vermicompost are readily and immediately bio-available to the plants (Arancon and

Edwards, 2006). Chemical fertilizers (and also manures) have to be broken down in the

soil before the plants can absorb.

3) Reduces water for crop irrigation: Vermicompost has very high porosity, aeration,

drainage and water holding capacity than the conventional compost (Nighawan and

Kanwar, 1952) and hence, the use of vermicompost reduces the requirement of water

for irrigation by about 30%-40%. On the contrary, use of chemical fertilizers require

high amount of water for irrigation.

4) Benefits economy and ecology of nations: Another big advantage of great

economic and environmental significance is that production of vermicompost locally

(on farm) from municipal solid wastes (MSW) (which constitute about 75 % organic

components) divert a large volume of MSW from landfills which are proving to be an

economic and environmental burden on human societies. Its production is also

significantly cheaper than the chemical fertilizers, which are produced in factories from

vanishing petroleum products generating huge waste and pollution.

5) Regenerate farm soil and reduces use of fertilizers: Over successive years of

application, vermicompost build-up the soils natural fertility improving its total

physical (porous), chemical (rich in nutrients) and biological (beneficial soil microbes)

properties. It also regenerates a rich population of worms in the farm soil from the

cocoons which further help improve soil fertility and subsequently lesser amount of

vermicompost is required to maintain a good yield and productivity (Bhawalkar, 1995;

Chaoui et al., 2003; Sinha et al., 2009b). On the contrary, with the continued application

of chemical fertilizers over the years the natural fertility of soil is destroyed and it

becomes addict. Subsequently greater amount of chemicals are required to maintain the

same yield and productivity of previous years. There is also significant loss of chemical

fertilizer from the farm soil due to oxidation in sunlight. Study reveal that upon

application of 100 kg urea (N) in farm soil, 40-50 kg gets oxidised and escapes as

ammonia (NH3) into the air, about 20-25 kg leaches underground polluting the

groundwater, while only 20-25 kg is available to plants.(Suhane, 2007).

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6) Protects crops and reduces use of chemical pesticides: Another advantage of great

environmental significance is that vermicompost repel and also suppress plant pests and

disease in crops and inhibits the soil-born fungal diseases (Anonymous, 2001). In field

trials with pepper, tomatoes, strawberries, and grapes significant suppression of plant-

parasitic nematodes has been found. There is also significant decrease in arthropods

(aphids, buds, mealy bug, and spider mite) populations with addition of 20% and 40%

vermicompost in soil (Edwards and Arancon, 2004). Humus in vermicast extracts

toxins, harmful fungi and bacteria from soil and protects plants. Actinomycetes in

vermicast induce biological resistance in plants against pests and diseases (Suhane,

2007). As such, use of vermicompost significantly reduces the need for chemical

pesticides.

THE GLOBAL MOVEMENT FOR ECOLOGICAL AGRICULTURE BY

VERMICULTURE

Worldwide farmers are desperate to get rid of the vicious circle of the use of

chemical fertilizers as their cost have been constantly rising and also the amount of

chemicals used per hectare has been steadily increasing over the years to maintain the

yield and productivity of previous years. Nearly 3-4 times of agro-chemicals are now

being used per hectare what was used in the 1960s (Suhane, 2007). In Australia, the

cost of MAP fertilizer has risen from AU $ 530.00 to AU $ 1500.00 per ton since 2006

(Sinha et al., 2009b). So is the story everywhere in world because the chemical

fertilizers are produced from vanishing resources of earth. Farmers urgently need a

sustainable alternative, which is both economical and productive while also

maintaining soil health and fertility. The new concept is Ecological agriculture, which

is by definition different from Organic Farming that was focused mainly on production

of chemical-free foods. Ecological agriculture emphasize on total protection of food,

farm and human ecosystems while improving soil fertility and development of

secondary source of income for the farmers. UN has also endorsed it. Vermiculture

provides the best answer for ecological agriculture, which is synonymous with

sustainable agriculture (Sinha et al., 2009b).

In India, a movement is going on to motivate farmers to embrace vermiculture.

A number of villages in the districts of Samastipur, Hazipur and Nalanda in state of

Bihar have been designated as Bio-Village where the farmers have completely switched

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over to organic farming by vermicompost and have given up the use of chemical

fertilizers for the last four years since 2005 (Suhane, 2007; Sinha et al., 2009 b). In the

state of Karnataka in India, a vermiculture revolution is going on under the guidance of

Prof. Radha Kale since the 1990s (Kale, 2005) more than 50 % farmers in the state has

switched over to vermiculture in farming and given up chemical agriculture.

Microorganisms and Vermicomposting

Cattle manure is produced in large quantities in industrial breeding facilities and

the storage and/or spreading of this waste on land may cause contamination of the

atmosphere, soil and water. For this, the degree of decomposition as well as the

microbial activity and microbial composition of the resulting products after the active

phase of composting and vermicomposting were analysed. Nevertheless, the lowest

values of microbial biomass and activity corresponded to the earthworm-worked

substrates, in which fungal growth was also promoted; the combined treatment

(composting + vermicomposting) was the most effective in terms of stabilizing the

cattle manure. Moreover, earthworms promoted the retention of nitrogen and gradual

release of P, as well as a reduction in electrical conductivity, thereby producing

improved substrates for agricultural use (Lazcano et al., 2008).

Epigeic earthworms are detritivorous organisms that live and feed in the soil

litter layer. These earthworms exert important effects on the presence of decomposer

micro-organisms and their microbial grazers, which lead to changes in the rate of

decomposition of the organic matter. To assess the effect of the transit through the gut

of epigeic earthworms on the decomposer organisms, the gut contents analysed four

epigeic species reared under laboratory conditions, with pig slurry as food source. The

numbers of nematodes, protozoa (flagellates, testate and naked amoebae) and total

coliforms in the hindgut of the earthworm species, E. fetida, E. andrei, L. rubellus and

E. eugeniae, were compared with the numbers of the same organisms in the pig slurry.

No nematodes were found after transit through the gut of the earthworms and there was

a decrease between 85% and 98% in the numbers of total coliforms of the pig slurry.

The effect on the numbers of protozoa depended on both groups of protozoa and

species of earthworm considered. The numbers of flagellates were greater in the gut

samples of E. fetida and E. andrei than in the ones of L. rubellus and E.eugeniae. The

density of testate amoebae was not affected by the transit through the gut of

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earthworms, and the numbers of naked amoebae were greater in the gut samples of

L. rubellus than in the fresh pig slurry. The results indicate that short-time effects

associated with the digestive activity in the earthworm gut play an important role in the

changes that epigeic species exert on the decomposer community (Monroy et al., 2008).

Manure heaps and vermicomposting systems are hotspots of heterotrophic

activity supporting a high-detritivore biomass where epigeic earthworms interact

intensively with bacteria, fungi and other soil fauna. Tissues of earthworms were

significantly 15N-enriched (by 4–8%) relative to fresh and mature manures in both

vermicomposting systems. The d13C values of adult earthworms were not different

from those of the fresh animal wastes in both vermicomposting systems, suggesting

that adult worms preferred fresh manure than worked materials as carbon source. The

little but significant enrichment in 15 N observed in hatchlings living in the pig slurry

vermicomposting bins relative to adult tissues likely reflect different feeding strategies,

not observed in the cattle manure heap. Besides, hatchlings in the cattle manure heap

appeared markedly depleted in 13C relative to the adult earthworms, suggesting the use

of a different source of carbon in the early stage. In the cattle manure heap three trophic

levels may be also identified, with larvae of Diptera and Coleoptera as the less

15Nenriched level, a general detritivore group in intermediate position, and finally a

predatory taxa with a +9% shift comprised by Staphylinidae (Sampedro and

Domınguez, 2008).

Aira et al. (2007) studied the relationships between earthworm activity,

microbial biomass and the activation and dynamics of several enzyme activities. In an

experiment ion with low and high rates (1.5 and 3 kg respectively) of pig slurry were

applied to small scale reactors with and without earthworms. In both rates of pig slurry

applied, the presence of earthworms in young layers stimulated microbial growth,

which decreased once earthworms left the slurry and the layers aged. This increase was

related to the initial activation of the microbial enzymes studied as correlations between

microbial biomass and enzymes showed, which indicated an increase of intracellular

enzyme activity. In the aged slurry, the pattern of activity of the four enzymes assayed

depended on the rate of pig slurry applied. Thus, in low rate reactors, enzymatic

activity through layers appeared to be related to microbial biomass, but in high rate

reactors, the activity of enzymes was more or less continuous.

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The introduction of vermicomposting as a cost effective method of managing

organic waste in Ghana depends on the suitability of local earthworms. At nine

locations across Accra, the capital of Ghana, the soil-litter layer was sampled to

evaluate the occurrence and abundance of surface dwelling earthworms (0 - 10 cm

depth) and to investigate the relationship between earthworm abundance and soil

properties (physicochemical and microbial). E.eugeniae (Kinberg), a rapidly growing

large worm (adults reach 14 cm long), was the only earthworm collected from seven of

the nine locations. Small unpigmented holonephric worms were collected at the other

two locations. Earthworm densities ranged between 35 and 2175 individuals m-2.

Significant (P< 0.05) negative correlations existed between earthworm abundance and

organic C and exchangeable Na. All locations tested positive for the microbial

indicators; Total coliforms, Escherichia coli, Staphylococcus, Yeast and Moulds and

Aspergillus. There was a significant (P< 0.01) positive correlation between earthworm

abundance and all the bacterial indicators tested. Earthworm abundance was also

weakly correlated (P < 0.1) with the yeast and mould loads (Mainoo et al., 2008).

Aira and Dominguez (2008) studied how the transit through the gut of the

earthworm E. fetida affects the microbial and nutrient stabilization of pig and cow

manure, by analyzing fresh casts. Earthworms reduced the pools of dissolved organic C

and N in casts from both types of manure, as wells as mineral N. Microbial biomass

was enhanced only in casts from pig manure and did not change in casts from cow

manure, and fungal populations only rose in casts from cow manure. Earthworms

reduced microbial activity in casts from cow manure and did not modify in casts from

pig slurry. Enzyme activities in casts also depended on the manure ingested; there were

no changes in dehydrogenase and -glucosidase activities, whereas acid and alkaline

phosphatases increased. The results indicate that the first stage in vermicomposting of

pig and cow manure by E. fetida, i.e. casting, produced a microbial stabilization

decreasing the activity of microorganisms; this stabilization occurred despite of the

increase in microbial biomass.

A laboratory experiment was carried out to study soil quality amelioration

through in situ vermicomposting of biological sludges. The experiment dealt with the

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stabilization, through the action of worms (E. fetida). The results showed that by

increasing the percentage of anaerobic sludge in the mixtures, the number of worms,

which left the sludge and chose the soil as their habitat increased. The chemico-

structural changes of the sludges left on the soil surface by worms were evaluated

through the technique of pyrolysis-gas chromatography, which showed that the degrees

of mineralization and humification of organic matter were dependent on the

composition of the sludge mixtures. When the amount of aerobic sludge in the mixtures

was higher than 50%, a stimulation of soil microbial metabolism occurred, as

demonstrated by the index of metabolic potential. All treatments increased the

percentage of soil total shrinkage area, mostly due to the formation of cracks of

small±medium size (<1000 mm), which represent a favourable site for microbiological

and biochemical processes in the soil. A positive statistical correlation between soil

dehydrogenase activity, C and N substrates, and cracks of small±medium size was

found (Masciandaro et al., 2000).

Ashraf et al. (2007) studied the agricultural and kitchen wastes viz., potato

peels, sugar cane waste, tree bark, used microbiological media, news paper, saw dust,

fruit peels, grass, leaves, guar, used tea, spinach twigs, wood chips, fruit and vegetable

wastes were used alone and in combinations as compost feed-stocks. Microorganisms

isolated and characterized from the above composts include the species of fungi viz.,

Aspergillus, Trichoderma, Mucor, Penicillium, Alternaria, Cladosporium, Monilia,

Helminthosporium, Coccidioides, Scedosporium, actinomycete viz., Nocardia and

bacteria viz., Bacillus, Lactobacilli, Micrococcus, Pseudomonas, Clostridium. Of these

isolates, members of the genus Aspergillus were most prevalent (38%) followed by

Bacillus comprising of 20% of the total microbial isolates. The study supports the idea

that composting can be useful to treat wide range of organic materials such as yard

trimmings, kitchen wastes and food processing discards. In addition, the knowledge

regarding species composition of the microorganisms of different composts can help to

optimize compost quality standards.

Studies were performed to appreciate the presence of micro-organisms able to

degrade OLA, in earthworm casts or in the surroundings. Worms were grown in

biosynthesol, an artificial soil. The counting of bacteria and fungi in earthworm’s casts

and in biosynthesol without earthworms suggested that earthworms ate some of the

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microorganisms. The main filamentous fungi genera found were Aspergillus,

Trichoderma, Fusarium and Penicillium. Previous results in the literature have shown

that some species from the Aspergillus and Fusarium genera were able to degrade OLA

and other aliphatic esters. It could be suggested that these two genera and some bacteria

were responsible for the pre-degradation of OLA, and that earthworms might eat them

(Alauzet et al., 2001).

Vermicomposting and Plant Growth

Vermicomposts have been shown to promote the germination, growth, and

yields of plants. This paper aims at demonstrating the effects of vermicomposts

produced from three types of wastes on growth and flowering of petunias, which are

important U.S. flowering crop. Vermicomposts, produced commercially from cattle

manure, food wastes and paper wastes, were substituted at a range of different

concentrations with a soilless commercial bedding plant container medium, Metro-Mix

360 (MM360), to evaluate their effects on the growth and flowering of petunias

(Petunia sp.) in the greenhouse. Seeds of petunia (var. Dreams Neon Rose F1) were

sown into 100, 90, 80, 70, 60, 50, 40, 30, 20 or 10% MM360 substituted with 0, 10, 20,

30, 40, 50, 60, 70, 80, 90 or 100% cattle manure, food waste or paper waste

vermicompost. Each type of vermicompost constituted a separate sub-experiment. All

plants were watered three times weekly with 200 ppm Peter’s nutrient solution,

containing all nutrients required, from sowing up to 79 days. Substitutions with all of

the vermicomposts into MM360 increased germination significantly on almost all

sampling dates. Shoot dry weights increased significantly after substituting MM360

with 10–60% cattle manure vermicompost and 10–100% of both food waste and paper

waste vermicomposts. Numbers of flowers increased significantly after MM360

substitutions with 20–40% of both cattle manure and food waste vermicomposts, and

by only 40% of paper waste vermicompost. There were no positive correlations

between the increases in numbers of flowers, and the amounts of mineral-N and

microbial biomass-N in the potting mixtures, or the concentrations of N in the shoot

tissues of petunias. Factors such as improvement of the physical structure of the potting

medium, increases in populations of beneficial microorganisms, and most probably, the

availability of plant growth-influencing-substances such as hormones and humates

produced by microorganisms during vermicomposting, probably contributed to the

increased petunia germination, growth and flowering (Arancon et al., 2008).

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Vermicompost was produced from a green waste compost feedstock and

assessed for its potential use in a high value horticultural market. Replicated plant

growth trials were undertaken with lettuce using pure worm cast (vermicompost), green

waste derived compost and mixtures of the two, i.e. 50/50 (v/v) and 20/80 (v/v) of

worm casts and green waste feedstock. Results showed that plant biomass production

was optimal with a 20/80 (v/v) compost blend, whilst pure worm cast and green waste

compost yielded poor growth. Leaf chlorophyll content indicated that pure worm cast

inhibited plant growth and depressed N content, whereas plant grown with the other

treatments contained similar amounts of chlorophyll. In general, the vermicomposting

process did not result in an increased availability of nutrients or potentially toxic

elements, the only exception being Zn (Muhammad Ali et al., 2007).

An experiment was designed to characterize the physical, chemical and

microbial properties of a standard commercial horticultural, greenhouse container,

bedding plant medium (Metro-Mix 360), that had been substituted with a range of

increasing concentrations (0%, 5%, 10%, 25%, 50% and 100% by volume) of pig

manure vermicompost and to relate these properties to plant growth responses. The

growth trials used tomatoes (Lycopersicon esculentum Mill.), grown in the substituted

media for 31 days under glasshouse conditions, with seedling growth recorded in 20

pots for each treatment. Half of the tomato seedlings (10 pots per treatment) were

watered daily with liquid inorganic fertilizer while the other half received water only.

The percentage total porosity, percentage air space, pH and ammonium concentrations

of the container medium all decreased significantly, after substitution of Metro-Mix

360 with equivalent amounts of pig manure vermicompost; whereas bulk density,

container capacity, electrical conductivity, overall microbial activity and nitrate

concentrations, all increased with increasing substitutions of vermicompost. The

growth of tomato seedlings in the potting mixtures containing 100% pig manure

vermicompost was reduced, possibly as a result of high soluble salt concentrations in

the vermicompost and poorer porosity and aeration. The growth of tomato seedlings

was greatest after substitution of Metro-Mix 360 with between 25% and 50% pig

manure vermicompost, with more growth occurring in combinations of pig manure

vermicompost treated regularly with a liquid fertilizer solution than in those with no

fertilizer applied. When the tomato seedlings were watered daily with liquid inorganic

fertilizer, substitution of Metro-Mix 360 with a very small amount (5%) of pig manure

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vermicompost resulted in a significant increase in the growth of tomato seedlings. Such

effects could not be attributed solely to the nutritional or physical properties of the pig

manure vermicompost. Therefore, it seems likely that the pig manure vermicompost

provided other biological inputs, such as plant growth regulators into the container

medium, that still need to be identified fully (Atiyeh et al., 2001).

Field trials conducted by Karmegam and Daniel (2008b) with Lablab purpureus

(L.) Sweet, showed that growth and yield parameters were significantly higher in the

plots which received vermicompost, chemical fertilizer and vermicompost + chemical

fertilizer mixture than in the control plots (p<0.05). The highest fruit yield (fresh

weight) of 109 tonnes ha-1 was recorded in the treatment which received 2.5 tonnes of

vermicompost [prepared with a weed, Rottboellia exaltata + cowdung, (1:1) using P.

ceylanensis] + ½ dose of recommended NPK ha-1, while it was 61.9 tonnes ha-1 in

control plots without vermicompost and/or chemical fertilizer.

Growth influences of worms and vermicompost on crop plant

Sinha et al. (2009b) studied the growth impacts of earthworms and their

vermicompost on potted egg and okra plants. Egg-plants grown on vermicompost with

live worms in soil bored on average 20 fruits / plant with average weight being 675 g.

Those grown on chemical fertilizers (NPK) bored only 14 fruits/plant with average

weight being only 500 g. Total numbers of fruits obtained from vermicompost (with

worms) applied plants were 100 with maximum weight being 900 g while those on

chemicals were 70 fruits and 625 gm as maximum weight of a fruit. Okra plants grown

on vermicompost with live worms in soil bored on average 45 fruits/ plant with average

weight being 48 gm. Those grown on chemical fertilizers (NPK) bored only 24

fruits/plant with average weight being only 40 g. Total numbers of fruits obtained from

vermicompost (with worms) applied plants were 225 with maximum weight being 70 g

while those on chemicals were 125 fruits and 48 g as maximum weight of a fruit.

Presence of live worms with vermicompost in soil made significant difference in total

growth promotion (height of plants; number, size and weight of fruits) of both

vegetable crops.

In another study by Sinha et al. (2009) on the growth impacts of earthworms

and their vermicompost on potted corn plants compared with chemical fertilizers (NPK

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+ Mg + S + Fe + B+ Zn). Vermicompost with earthworms in soil achieved excellent

growth over chemical fertilizers. While the plants on chemicals grew only 5 cm (87 to

92 cm) in 7 weeks (week 7-19), those on vermicompost with worms grew by 15 cm (90

to 105 cm) within the same period. Corn plants with worms and vermicompost also

attained maturity (appearance of male and female reproductive organs, very fast. Plants

with worms only although did not achieve good growth in height, but also matured

faster than the control group and the male reproductive organs appeared. Another

significant finding was that plants on vermicompost demanded less water for irrigation.

Sinha et al. (2009b) studied the growth impacts of earthworms with vermicompost

on potted wheat plants and compared with chemical fertilizers (NPK + Mg + S + Fe +

B + Zn) and conventional compost (cow manure). It had three treatments with two

replicas of each and a control. Wheat crops on vermicompost with worms maintained

very good growth from the very beginning and achieved maturity very fast. The

striking rates of seed germination were very high, nearly 48 hours (2 days) ahead of

others and the numbers of seed germinated were also high by nearly 20%. Plants were

greener and healthier over others, with large numbers of tillers and long seed ears at

maturity. Seeds were healthy and nearly 35-40% more as compared to plants on

chemical fertilizers. What they achieved in just 5 weeks, was achieved by others in 10

weeks. More significant was that the pot soil with vermicompost was very soft and

porous and retained more moisture. Pot soil with chemicals was hard and demanded

more water frequently.

Sinha et al. (2009b) also studied the growth impacts of vermicompost on wheat

crops in farms in India and compared it with conventional cattle dung compost and

chemical fertilizers. Vermicompost supported yield better than chemical fertilizers.

And when same amount of agrochemicals were supplemented with vermicompost at 25

quintal (Q)/ha the yield increased to about 44 Q/ha which is over 28% and nearly 3

times over control. On cattle dung compost applied at 100 Q/ha (4 times of

vermicompost) the yield was just over 33 Q/ha. Application of vermicompost had other

agronomic benefits. It significantly reduced the demand for irrigation by nearly 30-

40%. Test results indicated better availability of essential micronutrients and useful

microbes in vermicompost applied soils. Most remarkable observation was significantly

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less incidence of pests and disease attacks in vermicompost applied crops which

reduced use of chemical pesticides by over 75%.

Earthworm activity and vermicomposting

A laboratory experiment was carried out to determine the effect of earthworm

(Lampito mauritii) activity on mobility of Pb2+ and Zn2+ in the soil (DTPA-extractable)

and its composting potential in presence of these metals. Well clitellate earthworms

collected from an uncontaminated site were exposed to different concentrations (75,

150, 300 mg kg_1) of Pb2+ and Zn2+ separately for 30 days. It was observed that the

metal burden in the earthworm tissue increased with the increase in metal treatment.

L. mauritii elevated the soil pH of all the metal treated beds and lowered the soil C/N

ratio in the cast by reducing the organic carbon and fixing additional nitrogen.

Earthworm activity significantly increased the availability of phosphorous, potassium

and decreased the amount of DTPA-extractable Pb2+ and Zn2+ in the cast, which

implies the immobilization of metals in soils. These findings suggest the use of

L. mauritii in amelioration of metal contaminated soil (Maity et al., 2008).

Efforts were made to evaluate the decomposition potentials of traditional

monoculture and some novel polyculture vermireactors. Three earthworm species, i.e.

E. fetida (E. f.), P. excavatus (P. ex.) and L. mauritii (L. m.), representing two different

ecological categories: epigeic (E. fetida and P. excavatus) and anecic (L. mauritii),

were used to design seven different vermireactors, i.e. Mono-(E. f.), Mono-(P. ex.),

Mono-(L. m.), Poly-(E. f. + P. ex.), Poly-(P. ex. + L. m.), Poly-(E. f. + L. m.) and Poly-

(E. f. + P. ex. + L. m.). The microbial load of vermireactors was evaluated through

measuring dehydrogenases activities (DH-ase) and microbial biomass-N, while

mineralization rate was measured in respect to changed level of some important

nutrients in vermicomposted substrate. The vermicomposting caused decrease in pH

(67.0–15.0%), organic C (46.1–28.4%) and C:N ratio (72.2–57.1%) and increase in

total N (137.7–67.8%) as well as available P (107.9–16.9%) contents, at the end. The

carbon and nitrogen mineralization rate showed the order: Poly-(E. f. + P. ex. + L. m.) >

Poly-(E. f. + L. m.) > Poly-(P. ex. + L. m.) > Poly-(E. f. + P. ex.) > Mono-(E. f.) >

Mono-(P. ex.) > Mono-(L. m.) for this study. The Poly-(E. f. + P. ex. + L. m.)

vermireactor showed the maximum level of DH-ase activity 1926±245gg−1 substrate

24h as well as microbial biomass-N 3059.1±242.3mgNg−1 substrate, during

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experimentation. This study clearly suggests that burrowing earthworms in

vermireactor not only promote the microbial colonization, but at the same time also

accelerate the mineralization rate in decomposing waste. The polyculture

vermicomposting, using burrowing earthworms with epigeics, could be more efficient

than traditional monoculture vermireactors to decompose organic waste resources

(Suthar and Singh, 2008b).

Cattle feedlots face serious environmental challenges associated with manure

management, including greenhouse gas, odor, NH3, and dust emissions. Earthworms

offer the potential for alleviation of many of these adverse characteristics. Most of the

vermicomposting process of cattle manure is carried out using only single species of

earthworm for different cattle wastes. Sparse literature is available on research works

carried out on cattle manure using a combination of earthworms. The main objective of

the present work was to find out the potential of the different epigeic earthworms

E. fetida, E. eugeniae and local species e.g. P. excavatus as well as their combinations

in cattle wastes. The biochemical changes in fresh cattle manure caused by the three

earthworms and their combinations were measured over a period of 45 days. The

earthworm biomass increased in the range of 20-30 % for all the earthworm

combinations. Three and half fold increase in ash content from 11.82% to 40.714% was

observed proving a high rate of volatilization. BOD/COD ratio decreased up to a

minimum of 0.06 which confirms that the compost became non-biodegradable, or

stable in terms of no further biodegradation. The study gained more significance in the

light of the fact that the methodology can be easily used on a rural scale and that the

cattle manure can be treated at or near to its site of generation, without having the threat

of losing local earthworms at many places as local worms have been found to be lost in

ground (Khwairakpam and Bhargava, 2007).

Three different earthworm species E. fetida, E. eugeniae, P. excavatus in

individual and combinations were utilized by Khwairakpam and Bhargava (2009) to

compare the suitability of worm species for composting of sewage sludge as well as the

quality of the end product. The sewage sludge without blending can be directly

converted into good quality fertilizer (vermicompost). Vermicomposting resulted in

reduction in C/N ratio 25.6 to 6–9, TOC (25%) but increase in electrical conductivity

(EC) (47–51%), total nitrogen (TN) (2.4–2.8 times), potassium (45–71%), calcium (49–

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62%), sodium (62–82%) and total phosphorous (TP) (1.5–1.8 times), which indicated

that sewage sludge can be recycled as a good quality fertilizer. The present study also

inferred that the application of sewage sludge in the agricultural fields after

vermicomposting would not have any adverse effect as the heavy metals (Cu, Mn, Pb

and Zn) are now within the permissible limits.

Vermicomposting with E. andrei of sludges from a paper mill mixed with cattle

manure in a six-month pilot-scale experiment. Initially, a small scale laboratory

experiment was carried out to determine the growth and reproduction rates of

earthworms in the different substrates tested. In the pilot-scale experiment, the number

of earthworms increased between 22- and 36-fold and total biomass increased between

2.2- and 3.9-fold. The vermicomposts were rich in nitrogen and phosphorus and had

good structure, low levels of heavy metals, low conductivity, high humic acid contents

and good stability and maturity. These sludges could be potentially useful raw

substrates in larger commercial vermicomposting systems, and would reduce the costs

related to the exclusive use of different types of farm wastes as feed for earthworms

(Elvira et al., 1998)

Karmegam and Daniel (2008a,b) and John Paul et al. (2008) undoubtedly

confirm that the earthworm species, P. ceylanensis is a potential vermicomposting

species and the vermicompost produced by using this worm had very good effect on

plant growth and yield. While investigating the efficiency of L. mauritii and P.

ceylanensis for vermicomposting different organic substrates, Karmegam and Daniel

(2008a) suggested that both the earthworm species can be used for vermicomposting;

however, duration of vermicomposting with P. ceylanensis is not as much of L.mauritii.

The standardization of P. ceylanensis, a locally available species, for vermicomposting

of different organic substrates is a new finding and the species could be useful for

vermiconversion of organic substrates under local conditions.

Nutrient Dynamics during Vermicomposting

Singh et al. (2005) reported that the growing awareness about vermicomposting

technology in recycling different types of organic wastes, this study was conducted to

investigate the effect of initial substrate pH on vermicomposting. The substrate pH and

ash content were evaluated as a function of time. The data showed an exponential

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relationship between substrate pH and time of vermicomposting while a phase Bode

plot of a single zero system relationship between the ash content and time of

vermicomposting. The model parameters of these relationships also had very good

correlation with the initial substrate pH. Based on obtained correlation between model

parameters and initial substrate pH, generalized predictive models for the substrate pH

and ash content have been evolved in terms of the duration of vermicomposting and the

initial substrate pH. Plots of the predictive and experimentally observed values

indicated a high robustness of predictive models.

The quality of compost made from the organic fraction of municipal organic

waste (MOW), in terms of organic matter and nutrient concentrations, is inferior to that

of compost from other feedstocks. The aim of this work was to improve the quality of

MOW compost by means of cocomposting with biosolids (at ratios of 1:1, 2:1, and 3:1

MOW/biosolids) and vermicomposting. Vermicomposting (ground beds with worms)

treatments were prepared from traditional pile material after 40 composting days;

ground beds without worms were also included. Several parameters, including pH,

electrical conductivity, carbon dioxide production, organic matter, total nitrogen, water-

soluble carbon, nitrate, ammonium, and extractable phosphorus, were measured

throughout the process. Organic matter in the products at 120 days ranged between 39

and 45%, whereas total nitrogen was between 1.7 and 2%. Extractable phosphorus was

also greatly increased from 128 mg/kg in MOW compost to 542–722 mg/kg in the

cocompost. Of the three MOW/biosolids ratios employed, only the 2:1 and 3:1 mixtures

were adequate for composting and produced similar product qualities. However, the 2:1

mixture required more turnings and exhibited higher N losses. The improvement of

quality by vermicomposting was limited. Compared to traditional piles, it did not affect

concentrations of organic matter or total nitrogen. The direct action of worms measured

by comparing ground beds with and without worms, increased nitrate concentrations

for mixtures 2:1 and 3:1 and extractable phosphorus concentrations for mixture 3:1

(Tognetti et al., 2007b).

The effects of different MOW management practices (shredding, addition of

carbon-rich materials and inoculation with earthworms) on organic matter stabilization

and compost quality were studied. Four static piles were prepared with: (i) shredded

MOW; (ii) shredded MOW + woodshavings; (iii) non-shredded MOW; and (iv) non-

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shredded MOW + woodshavings. After 50 days, a part of each pile was separated for

vermistabilization, while the rest continued as traditional thermophilic composting

piles. At different sampling dates, and in the finished products, the following

parameters were measured: pH, electrical conductivity, carbon dioxide evolution, and

concentrations of organic matter, total nitrogen, water-soluble carbon, nitrate nitrogen,

ammonium nitrogen, and extractable phosphorus. Shredded treatments exhibited faster

organic matter stabilization than non-shredded treatments, evidenced specially by

earlier stabilization of carbon dioxide production and shorter thermophilic phases.

Wood shavings addition greatly increased quality of final products in terms of organic

matter concentration, and pH and electrical conductivity values, but decreased total

nitrogen and available nutrient concentrations. Vermicomposting of previously

composted material led to products richer in organic matter, total nitrogen, and

available nutrient concentrations than composting only, probably due to the coupled

effect of earthworm activity and a shorter thermophilic phase (Tognetti et al., 2007b).

Leachate from vermicomposting contains large amounts of plant nutrients and

can be used as liquid fertilizer, but normally diluted to avoid plant damage. The amount

of nutrients applied is thus reduced so that an additional fertilizer is required. It was

found that vermicompost leachate stimulated plant development, but fertilization with

NPK was required for maximum growth (Antonio et al., 2008).

Tejada et al. (2008) investigated the possible agricultural use of the

vermicomposting process leachates. Treatments were applied 30, 60 and 90 days after

planting (DAP). The obtained results showed that foliar fertilization with SCD and SGF

increased the morphological and chemical parameters on tomato crop with respect to

the plants receiving foliar treatment with SH and C, possibly due to the humic

substances content in SCD and SGF. The higher content of humic substances in SGF

with respect to the SCD is possibly responsible the higher chlorophyll contents

observed in the plants receiving the former treatment. This aspect possibly promoted an

increase in plant photosynthesis and therefore an increase in fruit quality.

The chemical changes occurring in cattle manure (CM) and a mixture of two-

phase olive pomace and CM (OP + CM) after vermicomposting with E. andrei for eight

months were evaluated. Further, humic acid (HA)-like fractions were isolated from the

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two substrates before and after the vermicomposting process, and analyzed for

elemental and acidic functional group composition, and by ultraviolet/visible, Fourier

transform infrared and fluorescence spectroscopies. Before vermicomposting, the HA-

like fractions featured a prevalent aliphatic character, large C contents, small O and

acidic functional group contents, a marked presence of proteinaceous materials and

polysaccharide-like structures, extended molecular heterogeneity and small degrees of

aromatic ring polycondensation, polymerisation and humification. After

vermicomposting, the total extractable C and HA-C contents in the bulk substrates

increased, and the C and H contents, aliphatic structures, polypeptidic components and

carbohydrates decreased in the HA-like fractions, whereas O and acidic functional

group contents increased. Further, an adequate degree of maturity and stability was

achieved after vermicomposting, and the HA-like fractions, especially that from

OP+CM, approached the characteristics typical of native soil HA. Vermicomposting

was thus able to promote organic matter humification in both CM alone and in the

mixture OP + CM, thus enhancing the quality of these materials as soil organic

amendments (Plaza et al., 2008).

The indicators of degradability and nutrient release capacity were measured net

N and C mineralization, extractable-P release, N retained in microbial biomass, and

dehydrogenase activity in 16-week laboratory incubations, using soil amended at a rate

of 40 g kg_1. All products increased soil N and P availability, and the size and activity

of soil microbial populations. Carbon and N mineralization, and extractable-P release

were influenced by amendment chemical characteristics, especially organic matter,

total N, total P, C to N ratio, extractable-P and water soluble C. Cocomposting MOW

and biosolids is an important alternative for MOW management, because it was the

most effective strategy at increasing product degradability and nutrient release capacity

(highest net N and C mineralization, extractable-P release and microbial biomass-N).

Shredding MOW increased C mineralization, while the addition of wood shavings

decreased net N mineralization, but generally did not affect C mineralization. Thus,

these two practices should be used when these specific product characteristics wish to

be achieved. Vermicomposting did not prove to be an efficient strategy when MOW

was mixed with biosolids (Tognetti et al., 2008b).

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Sangwan et al. (2008b) investigated that the transformation of sugar mill sludge

(PM) amended with biogas plant slurry (BPS) into vermicompost employing an epigeic

earthworm Eisenia fetida. To achieve the objectives experiments were conducted for 13

weeks under controlled environmental conditions. In all the waste mixtures, a decrease

in pH, TOC, TK and C:N ratio, but increase in TKN and TP was recorded. Maximum

worm biomass and growth rate was attained in 20% PM containing waste mixture. It

was inferred from the study that addition of 30–50% of PM with BPS had no adverse

effect on the fertilizer value of the vermicompost as well as growth of E. fetida. The

results indicated that vermicomposting can be an alternate technology for the

management and nutrient recovery from press mud if mixed with bulking agent in

appropriate quantities.

The feasibility of vermicomposting technology to stabilize the distillery

industry sludge mixed with a bulking agent (cow dung) in different proportions viz.

20% (T1), 40% (T2), 60% (T3) and 80% (T4), was tested using composting earthworm

P. excavatus for 90 days. The vermitreated sludge was evaluated for different physico-

chemical parameters and all vermibeds expressed a significant decrease in pH (10.5–

19.5%) organic C contents (12.8–27.2%), and an increase in total N (128.8–151.9%),

available P (19.5–78.3%) as well as exchangeable K (95.4–182.5%), Ca (45.9–

115.6%), and Mg contents (13.2–58.6%). Data suggested that inoculated earthworms

could maximize the decomposition and mineralization rate, if sludge is used with

appropriate bulking material for earthworm feed. Vermicomposting also caused

significant reduction in total concentration of metals: Zn (15.1–39.6%), Fe (5.2–

29.8%), Mn (2.6–36.5%) and Cu (8.6–39.6%) in sludge. Bioconcentration factors

(BCFs) for metals in different treatments were also calculated and the greater values of

BCFs indicate the capability of earthworms to accumulate a considerable amount of

metals in their tissues from substrate. The feasibility of earthworms to mitigate the

metal toxicity and to enhance the nutrient profile in sludge might be useful in

sustainable land restoration practices at low-input basis (Suthar and Singh, 2008b).

Venkatesh and Eevera (2008) reported that the environmental problems

generated by large-scale production of fly ash, increasing attention are now being paid

to the recycling of fly ash as a good source of nutrients. Because availability of many

nutrients is very low in fly ash, available ranges of such nutrients must be improved to

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increase the effectiveness of fly ash as a soil amendment. Fly ash was mixed with cow

dung at 1:3, 1:1, and 3:1 ratios and incubated with E. eugeniae for 60 days. The

concentration of above said macro and micronutrient was found to increase in the

earthworm-treated series of fly ash and cow dung combinations compared with the fly

ash alone. This helped to transform considerable amounts of total nitrogen, total

phosphorus, total potassium and micronutrients from fly ash into more soluble forms

and thus resulted in increased bioavailability of the nutrients in the vermicomposted

series. Among different combinations of fly ash and cow dung, nutrient availability was

significantly higher in the 1:3 fly ashs to cow dung treatment compared with the other

treatments.

In India, over the last few decades, there has been a remarkable increase in

sewage sludge production due to population increase and unplanned urbanization.

Gupta and Garg (2008a) was investigated the ability of an epigeic earthworm E. fetida

to transform primary sewage sludge (PSS) amended with cow dung (CD) into value

added product, i.e., vermicompost in laboratory scale experiments. In all the PSS and

CD mixtures, a decrease in pH, TOC and C:N ratio, but increase in EC, TKN, TK and

TP was recorded. The heavy metals content in the vermicomposts was higher than

initial mixtures. Maximum worm biomass was attained in 10% PSS + 90% CD mixture

while, the worm growth rate was highest in 30% PSS + 70% CD feed mixture. It was

inferred from the study that addition of 30–40% of PSS with CD had no adverse effect

on the fertilizer value of the vermicompost as well as growth of E. fetida. The results

indicated that PSS could be converted into good quality manure by vermicomposting if

mixed in appropriate ratio (30–40%) with cow dung.

Nutritive values of cast of E. eugeniae, prepared on six different diets has been

studied in detail and reported by (Kale and Bano, 1986) Nutritive qualities ranged, (pH

6.65 to 7.20; EC (mambos/cm), 0.950 to 1.800; per cent OC, 3.84 to 5.04; per cent N,

0.455 to 0.560; per cent P2O5, 0.716 to 1.215 and percent K2O, 0.075 to 0.115. These

values on comparison with other organic manures like decomposed FYM, Organic

matter, cow dung and pig manure showed higher per cent of N (0.52)’ P2O5 (0.94) and

K2O (0.999) excepting N in pig manure by only 0.03%. The Eudrilus cast has since

then been released as Vie Camp E 83 UAS, by Karnataka

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Composting and vermicomposting processes are useful methods for producing a

stabilized and mature organic material; rich in humic substances, which may change

some properties in the soil solution. Humic acid (HA) samples used were isolated from

composted, vermicomposted materials and from soil. Their chemical and

physicochemical properties were studied through different analytical techniques,

elemental and functional group composition, FT-IR and potentiometric titrations. HA

derived from the less evolved organic materials (compost and vermicompost) showed

different humification levels (higher in composting than in vermicomposting process),

higher aliphatic nature, higher nitrogen compounds content, lower oxidation degree,

lower charge development, differences in the acidity strength of the acidic functional

groups and differences in the heterogeneity than those extracted from more evolved

materials (soil). The acidic functional groups of the HA from composted materials are

stronger than those of the HA from vermicomposted materials and the former have

similar acidic strength in comparison with soil HA. These data are very important from

chemical and physicochemical point of view of HA isolated from mature organic

matter obtained through different technologies, which can be an instrument for

predicting the biological maturity, chemical stability and their contribution to some

important soil properties (CEC, buffer capacity, among others) of the organic

amendment, and in this way, it could be considered as an indicator for a successful

agronomic performance of compost and vermicompost in soil (Campitelli and

Ceppi,2008a).

Frederickson et al. (2007) studied to determine the effect of thermophilic pre-

composting followed by vermicomposting on compost characteristics compared with

thermophilic pre-composting and windrow composting. Source segregated household

waste was thermophilically composted (14 days) to sanitise the waste. Organic matter

and nitrogen losses were 9% and 5%, respectively. The waste was then matured (84

days) using either vermicomposting beds or composting windrows. At the end of the 98

days processing there was a significantly greater mass (P<0.01) of fine particles (<10

mm) in the vermicomposting beds (65.3% m:m) compared with the compost windrows

(36.9% m:m) suggesting enhanced fragmentation of the paper-based feedstock

components by the earthworms. The vermicompost NO3 concentration (2660 mg kg_1)

was significantly higher (P<0.05) than for the windrow compost (1531 mg kg_1). In a

programme of plant response tests based on B.S.I. PAS 100 (2005), the screened (<10

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mm) vermicompost and windrow compost performed comparably when formulated

into growing media based on equalising EC levels.

The high variability of some important compost and vermicompost parameters

suggests an urgent need for establishing quality assurance procedures in order to

classify the available materials. The organic amendments prepared from different

organic wastes (raw material), with different kind (composting or vermicomposting)

and time of process, produce a final product which differs in its quality. A set of

twenty-eight different compost and vermicompost were analyzed through nineteen

chemical, physical and biological parameters. The chemometric evaluation was

performed by the following multivariate techniques: principal component analysis

(PCA) and linear discriminant analysis (LDA). The aim of this paper was to

characterize and classify composted and vermicomposted materials by means of

multivariate statistical analysis methods, such as PCA and typical classification

techniques, LDA, by determining parameters related to their physical, chemical and

biological characteristics in order to obtain useful information for both producers and

consumers. Results showed a wide variation in some parameters such as total organic

carbon (TOC), germination index (GI), pH, total nitrogen (TN), and water soluble

carbon (WSC), which depends on the characteristics of each process. Through the use

of statistical techniques, PCA, LDA, it was possible to classify all the organic

amendments analyzed in the following categories: A, B1, B2, B3 and C, and to give to

each one the characteristics from the point of view of their quality (Campitelli and

Ceppi, 2008b).

The literature clearly shows that study on the efficiency of the earthworm in

waste decomposition is very limited. In addition, there exists a lacuna in the knowledge

of physico-chemical and microbiological characteristics of vermicasts and

vermicompost and a complete characterisation have not done so far i.e starting from the

earthworm culture progressing with improvement of soil fertility and its effect on plant

growth parameters. Hence, there is need for this complete characterisation study for

future agro and Industrial applications.