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

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1 Electronic Journal of Environmental Sciences Vol. 4, (2011) ISSN: (Available online at Original Article 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 , Tamil Nadu. E mail: srialyyam@rocketmail.com 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 Earthworms are soil inhabiting invertebrates well known for their beneficial role in nutrient cycling in various ecosystems and waste disposal by the 25 way of vermistabilization [1-4]. Earthworms are able to convert waste into fine mucus coated faecal pellets, popularly known as vermicompost. This is a quality organic manure rich in beneficial micro flora and plant growth promoter substances

2 along with major and micro nutrients necessary for plant growth, in water soluble form so that they are immediately available for plants use [5,6]. Thus, earthworms are the natural fertilizer factories which serve as bio-catalytic agents to enhance the soil fertility through physical, chemical and biological processes. Farmers consider earthworms as beneficial organisms because they play a significant role in organic matter decomposition and mineral cycling [7]. Vermicompost in recent years has gained importance because of its higher economic value compared with compost derived from traditional methods [8]. Bearing the beneficial role of vermicompost in mind now-a-days it is produced commercially by many local groups. In order to sustain the vermiculture practices by these people, the composting earthworms are to be produced continuously. For accomplishing this goal the vermicompost are to be sieved out without cocoons and the residues with cocoons. The cocoons are to be retained by vermiculturists in order to produce the young worms i.e., the recruiters. Further, it is believed that both vermicompost and residues are considered as best incubation medium for the cocoons of earthworms. The review of literature indicate that there is no published information on the sieve size suitable for sieving of vermicompost without cocoons both under monoculture and polyculture conditions and to determine whether the vermicompost or residue is the best medium for the incubation and hatching of earthworms cocoons and hence the present study has been carried to find out the best mesh size (2mm, 3mm and 4mm) to sieve the vermicompost without cocoons produced by three conventional species of earthworms under monoculture conditions as well as to determine whether the vermicompost or residue is the best medium for cocoons incubation and hatching of young ones. MATERIALS AND METHODS It is understood that there are more than 3000 species of earthworms present worldwide, however, of them only half a dozen are so important in vermiculture [9,10]. The present study was carried out between January 2009 and Electronic Journal of Environmental Sciences 26 May 2009 in Vermiculture unit of Nehru Memorial College. Puthanampatti, Tiruchirappalli. The mixed leaves litter consisted of leaves litter of Neem tree (Azadirachta indica), Asoka tree (Polyalthiya longifolia) and Teak tree (Tectona grandis). The leaves were subjected to shredding in order to convert them into small pieces. Later, it was cured both in the open to sun light area and in a shade for 15 days. Water was sprinkled on the waste twice in a day in order to hasten the pre-digestion process. Similar method was adopted for curing cow dung. After 15 days, the cured cow dung and mixed leaves litter (50:50 concentrations) were mixed thoroughly and allowed them for pre-digestion for one week in a cool and shady place. Water was sprinkled everyday on the cow dung and leaves litter mixture in order to maintain the moisture (50-60 %) by using a sprinkler. Twenty seven plastic trays (45x15x30 cm each) were taken and washed thoroughly with tap water. Then these trays sun dried for 30 minutes. The prepared predigested foods were filled in these trays. In each tray 4 kg of predigested waste was filled (i.e., 2 kg of cow dung and 2 kg of mixed leaves litter). Inoculation of Earthworm species: After ensuring that there was no heat in each tray, 10 adult healthy worms of E. eugeniae, (first nine trays) P. excavatus (second nine trays) and L. mauritii (third nine trays) were inoculated. After ensuring that all the inoculated worms entered in to the trays, on the following day 90 more adult and healthy worms were introduced in to each tray. Then these trays were maintained with a temperature of around 25ºC-30ºC and moisture level around 50-60%. This was accomplished by sprinkling of water and also covering of each tray with wet jute bags. The trays were kept undisturbed for 15 days in a shady place. After 15 days vermicompost were collected from each tray separately and labeled with tray numbers 1-27 and used for sieving. Selection of best sieve size to sieve the vermicompost without cocoons: The vermicompost produced by different species of

3 Murali and Neelanarayanan earthworms were sieved with different mesh sizes viz., 2mm (1-3 trays), 3mm (4-6 trays) and 4mm (7-9 trays). 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. Selection of best medium for incubation of cocoons: Eighteen plastic trays were taken for this study. Of them, the first nine trays were filled with cured cow dung and vermicompost; and second set of nine trays with the sieved out residues as incubation medium for cocoons. The first set of nine trays were filled and spread with cured cow dung up to a height of 5 cm and these were divided into three sets. Above to this layer, in each set with triplicates, the sieved vermicompost produced by E. eugeniae, P. excavatus and L. mauritii were spread, respectively up to height of 10 cm. Later, 100 cocoons of E. eugeniae, were placed in to each tray of first set for incubation. Simultaneously, in each of the second set of three trays 100 cocoons of P. excavatus were placed. The third set of trays, individually, had 100 cocoons of L. mauritii. These trays were maintained with optimum temperature (25ºC-30 0 C) and moisture (50-60%) for one month by sprinkling of water every day. The cocoons for this study was obtained from the present study and vermiculture unit of our college as well. The second sets of nine trays were also divided in to three groups. In first, second and third group of trays the sieved out residues produced by E. eugeniae, P. excavatus and L. mauritii were filled and spread, individually, up to a height of 15 cm. Then, 100 cocoons of E.eugeniae, P. excavatus, and L. mauritii were placed inside each of the first, second and third sets of trays, respectively and maintained. After the cessation of one month, each tray was emptied on a plastic sheet and the number of young earthworms from each tray were counted and recorded. The length of randomly chosen 10 young worms from these trays were measured and recorded. Appropriate Statistical tools were utilized for the analysis of data. RESULTS AND DISCUSSION The vermicompost produced by E.eugeniae, P. excavatus and L. mauritii, individually, were harvested after 15 days of their inoculation. The mean weight of the vermicompost obtained were 2161g (E. eugeniae); 1795g (P. excavatus) and 2196g (L. mauritii ). The percent conversion of vermicompost was found to be 54% (E. eugeniae); 45% (P. excavatus) and 55% (L. mauritii ) (Table 1). The mean weight of the residues quantified after sieving were 1839 g for E. eugeniae, 2204g for P. excavatus and 1803g for L. mauritii. The percentage of residues observed were 46%, 55% and 45%, for E. eugeniae, P. excavatus and L. mauritii, respectively (Table 1). The results of the present study reveal that the quantity of sieved vermicompost produced by E.eugeniae, P. excavatus, and L. mauritii by using 2 mm mesh size was found to be lower than residues. On the other hand, the harvested vermicompost produced by the three species of earthworms was sieved with 3 mm and 4 mm mesh sizes individually and it yielded more quantity of vermicompost (X=2600 g; X=1783g and X=2550g for 3 mm; X=2208 g; X=2133g ; X= 2308g for 4 mm) than the residues (X=1400g;X=2217 and X=1450g for 3mm; X=1792 g ; X= 1867g and X= 1692g for 4 mm). It is obvious from the results that of the three mesh sizes chosen the 3 mm mesh size separated more quantity of vermicompost than the residues except for P. excavatus (Table 2). Further, it was also observed that the final sieved vermicompost with 3mm sieve appeared as more or less uniform in size and homogeneous (Personal observation). The sieved out vermicompost by using 2 mm mesh size did not contain E.eugeniae, P. excavatus and L. mauritii worms cocoons while the same sieved out by using 3mm and 4 mm mesh size contained cocoons. In contrast, all the residues obtained after sieving i.e., by using 2 mm, 3 mm and 4 mm mesh sizes contained a 27

4 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* E. eugeniae P. excavatus L. mauritii Weight of leaves litter waste in each tray (g) Weight of cow dung in each tray (g) Total weight of predigested mixture in each tray (g) Number of adult earthworms introduced in each tray Mean weight of vermicompost obtained (g) Mean Percentage of bioconversion in to vermicompost Mean weight of residues obtained (g) Mean percentage of residues 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 50:50 concentrations* E. eugeniae P. excavatus L. mauritii Mesh size of sieve Mean weight of vermicompost obtained ( g ) Mean weight of residues ( g ) Total number of cocoons enumerated in vermicompost Total number of cocoons counted in residues 2mm Nil 224 3mm mm mm Nil 11 3mm mm mm Nil 13 3mm Nil 15 4mm 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 Earthworms Number of cocoons introduced in every vermicompost tray Hatched out young ones counted in vermicompost (X ± SD)* Mean No. of young ones hatch out from one cocoon in Vermicompost Number of cocoons introduced in every residues tray Hatched out young ones enumerated in residues X ± SD)* Mean No. of young ones hatch out from one cocoon E. eugeniae ± ± P. excavatus ± ± L. mauritii ± ± 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 in vermicompost X ±SD* (mm) Length of young Worms in residues X±SD* (mm) E. eugeniae 26.4± ±3.17 P. excavatus 17.10± ± 4.82 L. mauritii 25.1± ±

5 Murali and Neelanarayanan mean number of cocoons to the tune of 224, 354 and 43 (E. eugeniae ); 11, 6 and 6 (P. excavatus), 13, 15 and 9 (L. mauritii), respectively (Table 2). It is apparent from the above results that the residues obtained by using 3 mm mesh size had comparatively high number of cocoons than the other two residues excepting for P. excavatus. Hence it may be concluded that the mesh size 3 mm is comparatively better for sieving the vermicompost produced by all the three species of earthworms because it separated large quantity of homogeneous vermicompost, vermicompost without or with negligible number of cocoons and more number of cocoons were seen in the residues than the vermicompost (Table 2). The magnitude of hatched out young ones of E. eugeniae, P. excavatus and L. mauritii observed in vermicompost and residues as incubation medium is given in Table 3. The mean number of young ones hatched out from 100 cocoons of E. eugeniae, P. excavatus and L. mauritii observed in the vermicompost as incubation medium were 173± 21.93, 95 ± 19 and 145 ± 7.48, respectively. It is inferred from these results that cocoons of E. eugeniae (1.73) and L. mauritii (1.45) produced more than one juveniles. Contrary to this, cocoons of P. excavatus (0.95) yielded approximately only one juvenile (Table 3). The mean quantity of young ones enumerated in the residues incubation medium were to the tune of 365±24.37 for E. eugeniae, 110±11 for P. excavatus and 190±1.69 for L. mauritii. It is apparent from the results that on an average more than three young ones had hatched out from E. eugeniae (3.65), one from P. excavatus(1.10), and nearly two from L. mauritii (1.90) cocoons. Of the two incubation mediums used in the present study, the residues medium was found to be comparatively better than the vermicompost medium (Table 3) in terms of producing more number of juveniles. Of the fourteen Lumbricid species kept in culture, E. foetida commonly produced >one juvenile per cocoon [11]. But the subsequent studies have shown that A. caliginos, E. tetrahedral and O. lacteum cocoons produced one or two juveniles and those of Dendrodilus rubidus up to four from each cocoon [12]. Similar results of this kind have been observed in the present investigation. All the three species of young ones observed in residues were comparatively longer than the young ones observed in vermicompost (Table 4). The highest number of juveniles and their growth seen in the residues medium may be attributed to congenial environment for cocoons incubation; adequate quantity of food (uneaten by earthworms) for the juveniles to feed on them and consequently the juveniles would have grown well. Cocoons of earthworms are required for the vermiculturists to produce new young ones. These recruiters will replace the aged earthworms in a population of earthworms which are used for vermicomposting. Our interest must be to retain the cocoons of earthworms with residues instead of vermicompost. If the majority of cocoons had gone with the vermicompost to farmers through sales, then the vermiculturists will find it difficult to get young recruiters. Hence, utilization of suitable mesh size will help the vermiculturists to sieve the vermicompost without cocoons. From overall data it is concluded that 3 mm mesh size is considered as the best one for sieving of vermicompost produced by E. eugeniae, P. excavatus, and L. mauritii under monoculture conditions as well as for the separation of vermicompost. residues and vermicompost without cocoons and residues containing good number of cocoons. Further, the residues is the best medium for incubation of E.eugeniae, P. excavatus and L. mauritii cocoons to get more numbers of juveniles/ young ones and to get their good growth. The importance of vermiwash has been shown as an excellent source of nutrition for plant growth [13]. 29

6 ACKNOWLEDGEMENTS We thank the Management and Principal of Nehru Memorial College, Puthanampatti for their encouragement and help in various ways. We are thankful to Ministry of Environment and Forests, New Delhi for extending financial assistance to do this work. Our special thanks are due to Mr. P. Karuppannan, Mr. S. Sivakumar and Ms. S. Porkizhi, Post Graduate Students of Research Department of Zoology, Nehru Memorial College (Autonomous) Puthanampatti 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. Electronic Journal of Environmental Sciences [10] Nithya, S., Sathiskumar,N.,Vijayakumar, K., Senthilmurugan, S. and Ramaswamy, M.: J. Ecol. Res. Biocon., 7(1&2): (2006). [11] Evans, A.C. and Guild, W.J.: Ann. Appl. Biol., 34: (1947). [12] Reinecke, A.J. and Visser, F.A.: Rev. Ecol. Biol. Sol. 18: (1981).. [13] Rai, N. and Bansiwal, K.: Vermiwash: An excellent source of nutrition for plant growth: Elect. J. Environ. Sci., 1:19-21 (2008) REFERENCES [1 Lee, K.E: Earthworms: Their Ecology and Relationship with Soil and Land use. Acad. Press, Australia, pp 411 (1985). [2] Edwards, C.A., Bohlen, P.J.: Biology and Ecologyof Earthworms. Chapman & Hall, London, pp 426 (1966). [3] Daniel, T. and Karmegam, N.: Ecol. Environ. Cons. 5: (1999). [4] Karmegam, N. and Daniel, T.: Indian J. Environ. Ecoplan., 3, (2000). [5] Bano, K., Kale, R.D. and Gajanan, G.N.: J. Soil Biol. Ecol., 7: (1987). [6] Bhawalkar, V.U. and Bhawalkar, U.S.: Organic Farming, National Seminar, Pune, 18-19, April (1992). [7] Edwards, C.A. and Lofty, J.R.: Biology of Earthworms. Chapman and Hall, New York (1977). [8] Buchanam, M.A., Rusell, E. and Block, S.D.: Chemical characterization and nitrogen mineralization potentials of vermicomposte derived from differing organic wastes. In: Earthworms on Environmental and Waste management (Edwards, C.A., Neuhauser, E.F. eds.), SPB Acad. Publ. The Netherlands, pp (1988). [9] Gupta, P.K.: Vermicomposting for sustainable Agriculture. Agrobios, India (2006). 30