DETERMINATION OF MESH SIZE FOR SIEVING OF VERMICOMPOST ...

Electronic Journal of Environmental Sciences Vol. 4, 25-30 (2011) Original Article
ISSN: 0973-9505 (Available online at www.tcrjournals.com)

Indexed in: ProQuest database Abstract, USA ( ProQuest Science journals, Techonology Research database, Illustrata
Technology, Environment Science collection and Health and Medical complete), EBSCO databases (USA), Indian
Science abstract.

DETERMINATION OF MESH SIZE FOR SIEVING OF
VERMICOMPOST WITHOUT COCOONS AND INCUBATION
MEDIUM FOR COCOONS PRODUCED BY THREE SPECIES OF

EARTHWORMS

?

MURALI, M. AND NEELANARAYANAN, P.

Centre for Eco-friendly Agro-Technologics (Vermibiotechnology), Research Department of Zoology, Nehru
Memorial College (Autonomous), Puthanampatti 621 007, Tamil Nadu. E mail: [email protected]

Received: February 27, 2011; Accepted:

Abstract: The processed mixed leave’s litter were mixed with cured cow dung at 50:50
concentrations and filled in three sets of plastic trays (each set had nine trays). Each tray
(45x15x30cm) had 4 kg of predigested waste i.e., 2 kg of cow dung and 2 kg of leaves’
litter. In each set of nine trays, individually, hundred healthy chosen three species of
adult earthworm (Eudrilus eugeniae, Perionyx excavatus and Lampito mauritii), were
introduced. The vermicompost produced by each species of these earthworms from nine
trays were sieved by using 2 mm (1-3 trays); 3mm (4-6 trays) and 4 mm (7-9 trays) mesh
size sieve. The vermicompost and residues were collected separately in containers. Later
they were weighed individually and both the vermicompost and residues were checked
for the presence / absence of cocoons separately and if they were found counted and
recorded. The mean conversion ratio of waste into vermicompost was found to be
marginally high in L. mauritii when compared to other two worms’ conversion. Further,
two sets of nine trays were taken and they were divided in to three subsets. The first,
second and third subsets of three trays each were used with the sieved out vermicompost
produced by these animals. Of the nine trays of second set, three trays each were filled
with sieved residues as incubation medium. Then 100 cocoons of each species of
earthworm were placed in first, second and third sets of trays (both vermicompost and
residues as incubation mediums) respectively. The results indicated that the VC obtained
by using 3 mm mesh size sieve had comparatively nil or less number of cocoons than the
other two mesh sizes. The residues were determined as the best medium for incubation of
cocoons as there were more numbers of hatchlings/young ones observed and their mean
body length were higher when compared to VC incubation medium.

Key words: Mesh size, Annelida, Cocoons, Vermicompost

INTRODUCTION way of vermistabilization [1-4]. Earthworms are
able to convert waste into fine mucus coated
Earthworms are soil inhabiting invertebrates well faecal pellets, popularly known as vermicompost.
known for their beneficial role in nutrient cycling This is a quality organic manure rich in beneficial
in various ecosystems and waste disposal by the micro flora and plant growth promoter substances

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Electronic Journal of Environmental Sciences

along with major and micro nutrients necessary May 2009 in Vermiculture unit of Nehru Memorial
for plant growth, in water soluble form so that College. Puthanampatti, Tiruchirappalli. The
they are immediately available for plants use [5,6]. mixed leaves’ litter consisted of leaves’ litter of
Thus, earthworms are the natural fertilizer Neem tree (Azadirachta indica), Asoka tree
factories which serve as bio-catalytic agents to (Polyalthiya longifolia) and Teak tree (Tectona
enhance the soil fertility through physical, grandis). The leaves were subjected to shredding
chemical and biological processes. Farmers in order to convert them into small pieces. Later,
consider earthworms as beneficial organisms it was cured both in the open to sun light area
because they play a significant role in organic and in a shade for 15 days. Water was sprinkled
matter decomposition and mineral cycling [7]. on the waste twice in a day in order to hasten
Vermicompost in recent years has gained the pre-digestion process. Similar method was
importance because of its higher economic value adopted for curing cow dung.
compared with compost derived from traditional
methods [8]. Bearing the beneficial role of After 15 days, the cured cow dung and mixed
vermicompost in mind now-a-days it is produced leaves’ litter (50:50 concentrations) were mixed
commercially by many local groups. In order to thoroughly and allowed them for pre-digestion
sustain the vermiculture practices by these for one week in a cool and shady place. Water
people, the composting earthworms are to be was sprinkled everyday on the cow dung and
produced continuously. For accomplishing this leaves’ litter mixture in order to maintain the
goal the vermicompost are to be sieved out moisture (50 -60 %) by using a sprinkler. Twenty
without cocoons and the residues with cocoons. seven plastic trays (45x15x30 cm each) were
The cocoons are to be retained by vermiculturists taken and washed thoroughly with tap water.
in order to produce the young worms i.e., the Then these trays sun dried for 30 minutes. The
recruiters. Further, it is believed that both prepared predigested foods were filled in these
vermicompost and residues are considered as trays. In each tray 4 kg of predigested waste
best incubation medium for the cocoons of was filled (i.e., 2 kg of cow dung and 2 kg of
earthworms. The review of literature indicate that mixed leaves’ litter).
there is no published information on the sieve size
suitable for sieving of vermicompost without Inoculation of Earthworm species: After
cocoons both under monoculture and polyculture ensuring that there was no heat in each tray, 10
conditions and to determine whether the adult healthy worms of E. eugeniae, (first nine
vermicompost or residue is the best medium for trays) P. excavatus (second nine trays) and L.
the incubation and hatching of earthworms’ mauritii (third nine trays) were inoculated. After
cocoons and hence the present study has been ensuring that all the inoculated worms entered in
carried to find out the best mesh size (2mm, 3mm to the trays, on the following day 90 more adult
and 4mm) to sieve the vermicompost without and healthy worms were introduced in to each
cocoons produced by three conventional species tray. Then these trays were maintained with a
of earthworms under monoculture conditions as temperature of around 25ºC-30ºC and moisture
well as to determine whether the vermicompost level around 50-60%. This was accomplished by
or residue is the best medium for cocoons’ sprinkling of water and also covering of each tray
incubation and hatching of young ones. with wet jute bags. The trays were kept
undisturbed for 15 days in a shady place. After
MATERIALS AND METHODS 15 days vermicompost were collected from each
tray separately and labeled with tray numbers 1-
It is understood that there are more than 3000 27 and used for sieving.
species of earthworms present worldwide,
however, of them only half a dozen are so Selection of best sieve size to sieve the
important in vermiculture [9,10]. The present vermicompost without cocoons: The
study was carried out between January 2009 and vermicompost produced by different species of

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Murali and Neelanarayanan

earthworms were sieved with different mesh and recorded. Appropriate Statistical tools were
sizes viz., 2mm (1-3 trays), 3mm (4-6 trays) and utilized for the analysis of data.
4mm (7-9 trays). The vermicompost and residues
were collected separately in containers. Later RESULTS AND DISCUSSION
they were weighed individually and both the
vermicompost and residues were checked for the The vermicompost produced by E.eugeniae, P.
presence / absence of cocoons separately and if excavatus and L. mauritii, individually, were
they were found counted and recorded. harvested after 15 days of their inoculation. The
mean weight of the vermicompost obtained were
Selection of best medium for incubation of 2161g (E. eugeniae); 1795g (P. excavatus) and
cocoons: Eighteen plastic trays were taken for 2196g (L. mauritii ). The percent conversion of
this study. Of them, the first nine trays were filled vermicompost was found to be 54% (E.
with cured cow dung and vermicompost; and eugeniae); 45% (P. excavatus) and 55% (L.
second set of nine trays with the sieved out mauritii ) (Table 1). The mean weight of the
residues as incubation medium for cocoons. The residues quantified after sieving were 1839 g for
first set of nine trays were filled and spread with E. eugeniae, 2204g for P. excavatus and 1803g
cured cow dung up to a height of 5 cm and these for L. mauritii. The percentage of residues
were divided into three sets. Above to this layer, observed were 46%, 55% and 45%, for E.
in each set with triplicates, the sieved eugeniae, P. excavatus and L. mauritii,
vermicompost produced by E. eugeniae, P. respectively (Table 1).
excavatus and L. mauritii were spread,
respectively up to height of 10 cm. Later, 100 The results of the present study reveal that the
cocoons of E. eugeniae, were placed in to each quantity of sieved vermicompost produced by
tray of first set for incubation. Simultaneously, in E.eugeniae, P. excavatus, and L. mauritii by
each of the second set of three trays 100 cocoons using 2 mm mesh size was found to be lower
of P. excavatus were placed. The third set of than residues. On the other hand, the harvested
trays, individually, had 100 cocoons of L. mauritii. vermicompost produced by the three species of
These trays were maintained with optimum earthworms was sieved with 3 mm and 4 mm
temperature (25ºC-300C) and moisture (50-60%) mesh sizes individually and it yielded more
for one month by sprinkling of water every day. quantity of vermicompost (X=2600 g; X=1783g
The cocoons for this study was obtained from and X=2550g for 3 mm; X=2208 g; X=2133g ;
the present study and vermiculture unit of our X= 2308g for 4 mm) than the residues
college as well. (X=1400g;X=2217 and X=1450g for 3mm;
X=1792 g ; X= 1867g and X= 1692g for 4 mm).
The second sets of nine trays were also divided It is obvious from the results that of the three
in to three groups. In first, second and third group mesh sizes chosen the 3 mm mesh size separated
of trays the sieved out residues produced by E. more quantity of vermicompost than the residues
eugeniae, P. excavatus and L. mauritii were except for P. excavatus (Table 2). Further, it was
filled and spread, individually, up to a height of 15 also observed that the final sieved vermicompost
cm. Then, 100 cocoons of E.eugeniae, P. with 3mm sieve appeared as more or less uniform
excavatus, and L. mauritii were placed inside in size and homogeneous (Personal observation).
each of the first, second and third sets of trays,
respectively and maintained. The sieved out vermicompost by using 2 mm
mesh size did not contain E.eugeniae, P.
After the cessation of one month, each tray was excavatus and L. mauritii worms’ cocoons while
emptied on a plastic sheet and the number of the same sieved out by using 3mm and 4 mm
young earthworms from each tray were counted mesh size contained cocoons. In contrast, all
and recorded. The length of randomly chosen 10 the residues obtained after sieving i.e., by using
young worms from these trays were measured 2 mm, 3 mm and 4 mm mesh sizes contained a

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Electronic Journal of Environmental Sciences

Table 1: Magnitude of Composition of predigested food and its bioconversion in to vermicompost by E.
eugeniae, P. excavatus and L. mauritii. *Experiments were conducted with nine trays for each species.

Particulars Experimental Trays in 50:50 concentrations*

Weight of leaves litter waste in each tray (g) E. eugeniae P. excavatus L. mauritii
Weight of cow dung in each tray (g)
Total weight of predigested mixture in each tray (g) 2000 2000 2000
Number of adult earthworms introduced in each tray
Mean weight of vermicompost obtained (g) 2000 2000 2000
Mean Percentage of bioconversion in to vermicompost
Mean weight of residues obtained (g) 4000 4000 4000
Mean percentage of residues
100 100 100

2161 1795 2196

54 45 55

1839 2204 1803

46 55 45

Table 2: Extent of vermicompost and residues obtained after sieving with different mesh size sieves and number
of cocoons enumerated from them. *Experiments were conducted with nine trays for each species and among
them vermicompost from three trays each were used for sieving with 2mm, 3mm and 4mm mesh size sieve.

Experimental Trays in Mesh size Mean weight Mean weight Total number Total number
50:50 concentrations* of sieve of vermicompost of residues of cocoons enumerated of cocoons counted

obtained ( g ) (g) in vermicompost in residues
Nil 224
2mm 1575 2425 5 354
93 43
E. eugeniae 3mm 2600 1400 Nil 11
1 6
4mm 2208 1792 9 6
Nil 13
2mm 1470 2530 Nil 15
5 9
P. excavatus 3mm 1783 2217

4mm 2133 1867

2mm 1653 2347

L. mauritii 3mm 2550 1450

4mm 2308 1692

Table 3: Quantity of hatched out young ones of E. eugeniae, P. excavatus and L. mauritii observed in vermicompost
and residues as cocoons’ incubation medium after 30 days. *Mean and standard deviation values were obtained
from 3 individual (triplicates) observations

Species of Number of Hatched out Mean No. Hatched out Mean No.
Earthworms cocoons introduced young ones of young ones Number of cocoons young ones of young
counted in hatch out from introduced in every enumerated ones hatch out
in every vermicompost one cocoon in
vermicompost tray (X ± SD)* Vermicompost residues tray in residues from one
X ± SD)* cocoon

E. eugeniae 100 173 ± 21.93 1.73 100 365 ± 24.37 3.65

P. excavatus 100 95 ±19.00 0.95 100 110 ± 11.00 1.10

L. mauritii 100 145 ± 7.48 1.45 100 190 ± 1.69 1.90

Table 4: Mean length of young ones of E. eugeniae, P. excavatus, and L. mauritii observed from vermicompost
and residues incubation medium after 30 days of incubation. *Mean and standard deviation values were
obtained from 10 individual observations.

Species of Earthworms Length of young worms Length of young
in vermicompost Worms in residues
E. eugeniae X ±SD* (mm)
P. excavatus X±SD* (mm)
L. mauritii 26.4±2.97
31.5±3.17
17.10±6.48
21.50± 4.82
25.1± 6.27
30.0± 3.49

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mean number of cocoons to the tune of 224, 354 produced >one juvenile per cocoon [11]. But
and 43 (E. eugeniae ); 11, 6 and 6 (P. excavatus), the subsequent studies have shown that A.
13, 15 and 9 (L. mauritii), respectively (Table caliginos, E. tetrahedral and O. lacteum coc-
2). oons produced one or two juveniles and those of
Dendrodilus rubidus up to four from each
It is apparent from the above results that the cocoon [12]. Similar results of this kind have
residues obtained by using 3 mm mesh size had been observed in the present investigation.
comparatively high number of cocoons than the
other two residues excepting for P. excavatus. All the three species of young ones observed in
Hence it may be concluded that the mesh size 3 residues were comparatively longer than the
mm is comparatively better for sieving the young ones observed in vermicompost (Table 4).
vermicompost produced by all the three species The highest number of juveniles and their growth
of earthworms because it separated large quantity seen in the residues medium may be attributed
of homogeneous vermicompost, vermicompost to congenial environment for cocoons’ incubation;
without or with negligible number of cocoons and adequate quantity of food (uneaten by
more number of cocoons were seen in the earthworms) for the juveniles to feed on them
residues than the vermicompost (Table 2). and consequently the juveniles would have grown
well.
The magnitude of hatched out young ones of E.
eugeniae, P. excavatus and L. mauritii observed Cocoons of earthworms are required for the
in vermicompost and residues as incubation vermiculturists to produce new young ones.
medium is given in Table 3. The mean number of These recruiters will replace the aged earthworms
young ones hatched out from 100 cocoons of E. in a population of earthworms which are used
eugeniae , P. excavatus and L. mauritii for vermicomposting. Our interest must be to
observed in the vermicompost as incubation retain the cocoons of earthworms with residues
medium were 173± 21.93, 95 ± 19 and 145 ± instead of vermicompost. If the majority of
7.48, respectively. It is inferred from these results cocoons had gone with the vermicompost to
that cocoons of E. eugeniae (1.73) and L. farmers through sales, then the vermiculturists
mauritii (1.45) produced more than one juveniles. will find it difficult to get young recruiters. Hence,
Contrary to this, cocoons of P. excavatus (0.95) utilization of suitable mesh size will help the
yielded approximately only one juvenile (Table vermiculturists to sieve the vermicompost without
3). cocoons.

The mean quantity of young ones enumerated in From overall data it is concluded that 3 mm mesh
the residues incubation medium were to the tune size is considered as the best one for sieving of
of 365±24.37 for E. eugeniae, 110±11 for P. vermicompost produced by E. eugeniae, P.
excavatus and 190±1.69 for L. mauritii. It is excavatus, and L. mauritii under monoculture
apparent from the results that on an average more conditions as well as for the separation of
than three young ones had hatched out from E. vermicompost. residues and vermicompost
eugeniae (3.65), one from P. excavatus(1.10), without cocoons and residues containing good
and nearly two from L. mauritii (1.90) cocoons. number of cocoons. Further, the residues is the
Of the two incubation mediums used in the best medium for incubation of E.eugeniae, P.
present study, the residues medium was found to excavatus and L. mauritii cocoons to get more
be comparatively better than the vermicompost numbers of juveniles/ young ones and to get their
medium (Table 3) in terms of producing more good growth. The importance of vermiwash has
number of juveniles. Of the fourteen Lumbricid been shown as an excellent source of nutrition
species kept in culture, E. foetida commonly for plant growth [13].

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Electronic Journal of Environmental Sciences

ACKNOWLEDGEMENTS [10] Nithya, S., Sathiskumar,N.,Vijayakumar, K.,
Senthilmurugan, S. and Ramaswamy, M.: J. Ecol.
We thank the Management and Principal of Res. Biocon., 7(1&2): 30-36 (2006).
Nehru Memorial College, Puthanampatti for their [11] Evans, A.C. and Guild, W.J.: Ann. Appl.
encouragement and help in various ways. We Biol., 34: 307-330 (1947).
are thankful to Ministry of Environment and
Forests, New Delhi for extending financial [12] Reinecke, A.J. and Visser, F.A.: Rev. Ecol. Biol.
assistance to do this work. Our special thanks Sol. 18: 473-485 (1981)..
are due to Mr. P. Karuppannan, Mr. S. Sivakumar
and Ms. S. Porkizhi, Post Graduate Students of [13] Rai, N. and Bansiwal, K.: Vermiwash: An excellent
Research Department of Zoology, Nehru source of nutrition for plant growth: Elect. J.
Memorial College (Autonomous) Puthanampatti Environ. Sci., 1:19-21 (2008)
for their help. We are indebted to Mr. M.
Kandasamy, Mrs. M. Sarasu, and Mrs. M.
Kamatchi, Vermiculture unit assistants, Nehru
Memorial College, Puthanampatti, for their help
during the study period.

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