Volume 3 Special Issue 2 2009
How to reference: Sharma S, Kumar A, Singh AP, Vasudevan P (2009) Earthworms and Vermitechnology – A Review. In: Karmegam N (Ed) Vermitechnology I. Dynamic Soil, Dynamic Plant 3 (Special Issue 2), 1-12
Vinayaka Missions University, India
CONTENTS AND ABSTRACTS
Satyawati Sharma, Ashwani Kumar, Anil Pratap Singh, Padma Vasudevan (India) Earthworms and Vermitechnology – A Review (pp 1-12)
Invited Review: Vermicomposting is a suitable means for waste remediation and organic manure (vermicompost) production. Earthworms occur in diverse habitats, vary greatly in size and feed upon a variety of organic materials. Most earthworms are terrestrial but may be estuarine. They are omnivorous but mostly feed on dead organic matter, living bacteria, rotifers, nematodes, fungi, and other microorganisms. Out of about 3000 species of earthworms found worldwide, in India about 500 species have been reported. Earthworms eject humus-rich castings and form water-stable aggregates, which improve soil physical and chemical properties. Casting also contains enzymes like protease, amylase, lipase, cellulase and chitinase to decompose organic matter. Vermiculture is feasible in suitable containers and can be done indoors or outdoors depending on local climatic conditions. A tremendous amount of work has been done worldwide on solid waste management employing different epigeic and anecic earthworm species. Use of earthworms as a source of human protein has also been advocated. They can also be utilized to feed fish, pigs and poultry. The action of earthworms in vermicomposting is by physical and biochemical processes. Physical processes include substrate aeration, mixing and grinding while biochemical processes involve decomposition of waste by various enzymes present in the gut of earthworms and is influenced by microbes present in their intestine. Earthworms have several medicinal properties and are also known to accumulate toxic residues from soil/substrates. The role of earthworms in sustainable farming is immense. The present paper reviews the information on various aspects of earthworms and vermitechnology.
Asha Aalok, Prafulla Soni, Ashutosh Kumar Tripathi (India) Role of Earthworms in Breakdown of Different Organic Wastes into Manure: A Review (pp 13-20)
Invited Review: Vermicomposting and composting are efficient methods of converting solid wastes into products richer in nutrients. Certain species of earthworms can consume organic residuals very rapidly and fragment them into much finer particles by passing them through a grinding gizzard, an organ that all earthworms’ possess. Vermicast contain microorganisms, hormones, enzymes, inorganic minerals and organic matter in a form available to plants. Based on the physical, chemical and biological characteristics, vermicomposts have considerable commercial potential in the horticultural industry as container media for growing vegetable and bedding plants. The aim of this review is to compare the nutritive value of compost and vermicompost produced from different organic wastes including composting-vermicomposting of different tree leaf litters mixed with municipal solid waste (MSW) using Eisenia foetida under glasshouse conditions.
Renée-Claire Le Bayon, Roxane Milleret (Switzerland) Effects of Earthworms on Phosphorus Dynamics – A Review (pp 21-27)
Invited Mini-Review: Belowground biotic interactions are known to influence soil fertility and plant growth by changing the physical environment and the soil nutrient cycles. Among the great diversity of soil biota, earthworms are keystone soil organisms in regulating nutrient cycling through: (i) their own metabolism that leads to high availability of carbon (C) and nitrogen (N) from metabolic wastes such as urine, mucus and tissue, (ii) the dispersal and the stimulation of soil microorganism activity associated with passage through the intestinal tract and (iii) the distribution and the mixing of organic matter and soil mineral particles. While many studies have examined impacts of earthworm on C and N fluxes in soils, less attention has been paid to the impact of earthworms on soil phosphorus (P). This paper reviews the current state of knowledge of the global earthworm’s impact on soil P dynamics in order to evaluate further involvements: i) on plant production and ii) on P transfer by runoff waters at the plot scale. This mini-review aims at considering research issues at several ecological levels, from individual earthworms (P distribution during food assimilation and excretion; gut microbial activities) to earthworm populations and communities (ecological categories and their influence on P dynamics) and, to the full extent, to the ecosystem scale (storage and/or loss of P). Interacting effects with other organisms (plants, microorganisms) are taken into account as well as the role of earthworms on physicochemical parameters (casting and burrowing activities, soil stability). Such a synthesis highlights the necessity to conduct interdisciplinary studies on biological, chemical and physical processes to better understand the effects of earthworms on P cycling at the ecosystem and landscape levels.
Rafael D. Guerrero III (Philippines) Earthworm Culture for Vermicompost and Vermimeal Production and for Vermiceutical Application in the Philippines (1978-2008) – A Review (pp 28-31)
Invited Mini-Review: The culturing of earthworms or vermiculture began in the Philippines around 1970s. The epigeic species, Perionyx excavatus and Eudrilus eugeniae, were found to be suitable for vermicompost (earthworm manure and other organic material) and vermimeal (earthworm meal) production using biodegradable farm wastes as culture material. Studies conducted on the use of vermicompost for fertilizing vegetable crops, corn and upland rice have clearly indicated the feasibility of reducing the application of the recommended chemical fertilizers up to l00% for the cultured plants. Vermimeal produced from cultured P. excavatus and E. eugeniae has been found to be an efficient and cost-effective replacement for fishmeal in the diets of the cage-cultured freshwater fish (Oreochromis niloticus) and poultry (chicken and quail). Feeding of dried earthworms (E. eugeniae) to the freshwater shrimp (Macrobrachium idella) also gave better results compared to feeding with dried fish (Therapon plumbeus) in ponds. The presence of a blood clot delaying factor, important saturated and unsaturated fatty acids and a fibrinolytic enzyme was demonstrated in the extracts of E. eugeniae which could be potential vermiceuticals (pharmaceuticals) for human medicine application.
Marta C. Rivera, Eduardo R. Wright (Argentina) Research on Vermicompost as Plant Growth Promoter and Disease Suppressive Substrate in Latin America (pp 32-40)
Invited Review: Composted organic materials have been used worldwide since ancient times. An increasing body of experimental evidence indicates that they stimulate plant growth and constitute a means to suppress crop diseases. Specially related to vermicomposts, many Latin American researchers have focused their work on chemical and microbiological analyses, crop production, plant health promotion and social benefits derived from their production and utilisation. This review summarizes published data on these subjects. In spite of the achievement of many interesting results, research needs to be intensified so as to improve the knowledge on these substrates, and favour a more generalized use of vermicomposts in the field.
D. Chakrabarty, S. K. Das, M. K. Das, P. Biswas (India) Application of Vermitechnology in Aquaculture (pp 41-44)
Invited Mini-Review: Sustainable aquaculture is one in which the goal is permanence, achieved through the utilization of renewable resources. This leads to development of concept of organic and natural farming. Among various components of organic and natural farming, vermicomposting is a key component for making compost through earthworms. Organic aquaculture is a production system, which avoids or largely excludes the use of synthetically compound fertilizers, pesticides, growth regulators and feed additives. The low cost organic aquaculture system mainly depends on the use of vermicompost and vermiproducts (vermiwash, earthworm, cocoon, etc.) which are produced naturally. There is urgent need to enhance the culture of earthworms since they are utilized as live fish food, bait and fishmeal supplement. Earthworms are unique as fish food as they contain many essential amino acids along with hemoglobin in their blood serum, which provide the required iron for developing fish. Adult earthworm, cocoons and vermiwash can serve the purpose of fish feed in different ways. So, the application of vermitechnology is required for the development of organic aquaculture.
Adele Muscolo, Maria Sidari, Diego Pizzeghello, Serenella Nardi (Italy) Effects of Humic Substances Isolated from Earthworm Faeces (pp 45-52)
Invited Mini-Review: Earthworm biomass and activity in soil are highly related to the nature of vegetable organic wastes and are controlled by climatic conditions, food composition, physical and chemical soil characteristics. Earthworms strongly affect soil fertility by increasing the availability of nutrients, improving soil structure and water-holding capacity, but the main effect of earthworms in soil concerns the control of the humification process. It has been suggested that earthworms can increase the velocity of organic residue decomposition and also produce faeces rich in bioactive humus. While the role played by earthworms in the growth and productivity of plants was previously related to their effects on soil structure, recent work has suggested that these effects may be due to the production of faeces that contain more than 40% of humic substances endowed with hormone-like activity. This mini-review summarizes the progress made in recent years on the effects of humic substances isolated from earthworm faeces. Some specific issues will focus on the effects of earthworms on humification processes, plant growth and physiological processes in plant tissues.
Biswarup Sen, Kalyani Mahapatra (India) Functional and Genetic Profiling Tools: Insight to the Black Box of Vermicomposting Process (pp 53-60)
Invited Review: The process of vermicomposting is highly dynamic, as it involves a complex interaction of earthworms with diverse microbial species. Over the last two decades, the focus of research has been mainly on the conversion of various types of organic wastes and pollutants such as agricultural, municipal and industrial wastes into vermicompost and on the development of parameters to assess maturity. There is however a lack of knowledge on the process dynamics and the complex interactions that occur between the microbes and earthworms during vermicomposting. A plethora of techniques such as biomass measurement, respiration rate, and enzyme activities are in routine use for assessment of vermicomposting dynamics at process level. However, less attention has been paid to the techniques useful in revealing community-level changes, which can give a significant insight into the microbe-earthworm interactions that finally affects the quality of vermicompost. Methods to study community-level changes such as community-level physiological profiling (CLPP), phospholipid fatty acid analysis (PLFA) and genetic fingerprinting have been commonly used in research on microbial ecology of soil, sediments, gut, and aerobic and anaerobic reactors, but not applied widely in vermicomposting ecosystems. In this review, we discuss the inventory of techniques relevant to vermicomposting process and which can provide significant knowledge on organic matter transformations and community-level changes. Furthermore, this review also brings to light the role of multivariate statistical analysis in predicting the possible relationship between the process-level and the community-level changes. A polyphasic approach to vermicomposting research is thus suggested which will facilitate in opening the blackbox of this complex and dynamic process.
Mira Grdiša, Ana-Matea Mikecin, Natalija Knežević (Croatia) Fibrinolytic Enzymes from Earthworms (pp 61-63)
Invited Mini-Review: The fibrinolytic system is responsible for the proteolytic degradation of fibrin and therefore plays a role in haemostasis and thrombosis. Intravascular thrombosis, a consequence of fibrin aggregation in the arteries, is one of the main causes of cardiovascular disease. Fibrin is the primary protein component of blood clots, which are formed from fibrinogen by thrombin. Formation of fibrin clot and fibrinolysis are normally well balanced in biological systems. However, if fibrin is not hydrolyzed due to some disorder, thrombosis can occur. The most common consequence of such thrombosis is myocardial infarction. Fibrinolytic enzymes are agents which dissolve fibrin clot. Today available agents are mostly plasminogen activator (t-PA), urokinase and streptokinase, which exhibit low specificity for fibrin, have undesired side effect and are also relatively expensive. Therefore, the search for other fibrinolytic agent from various sources continues. The presence of fibrinolytic activity in ceolomic fluid or tissue homogenate from earthworm has been reported previously. Because of that, earthworm tissue homogenate is an attractive source of various physiologically active compounds.
Nancy B. Iannucci, Silvia A. Camperi, Osvaldo Cascone (Argentina) Purification of Enzymes from Earthworms (pp 64-68)
Invited Mini-Review: Earthworms are a very rich source of enzymes useful for bioremediation of contaminated soils, in animal feeds for improving the digestion of proteins, lipids and carbohydrates, in detergents, in the saccharification of starch, and in human and animal therapeutics. Powdered earthworms are very popular in the Orient due to their properties as antipyretic, diuretic and fibrinolytic. However, in order to improve the applicability of these enzymes, purification at different levels is necessary. Among them, proteins such as fibrinolytic enzymes are being used in therapeutic nowadays. This article reviews the methods used for purification of fibrinolytic enzymes (useful for clotting disorders treatment), ceramide glycanase (useful for structural elucidation of glycosphingolipids), xylanolytic enzyme (useful for waste treatment), alpha amylase (useful for starch saccharification), lipase (useful for detergents formulation), glutathione transferase (useful as a potential antioxidant agent) and succinic semialdehyde dehydrogenase (useful for pesticide detoxification), in addition to lombricine kinase. All these enzymes were obtained by earthworm homogenization and further subjecting the earthworms extract to several chromatographic steps. All types of chromatography were applied: size exclusion, ion exchange, hydrophobic interaction and affinity. Moreover, an integrative technique such as aqueous two-phase partition was utilized for obtaining a clear extract containing the earthworm enzymatic pool.
Mariappan Balamurugan, Kasi Parthasarathi (India), Edwin L. Cooper (USA), Lalpet Sauri Ranganathan (India) Curative Effect of Earthworm Extract, Lampito mauritii (Kinberg) on Inflammation, Oxidation and Blood Profiles in Rats (pp 69-72)
Original Research Paper: Information is available on the therapeutic properties of different natural herbal products and formulations and very few studies have been made on the sources from animal origin, especially earthworms. Therefore our aim was to investigate, in vivo, the potential of Lampito mauritii asanti-inflammatory, anti-oxidative agent and further its positive influence on blood profiles of inflamed rats. Male albino Wistar rats were used for the study. The inflammation of subcutaneous dorsal granuloma pouch was induced by injecting 25 ml of sterile air, followed by injection of 0.5 ml of turpentine oil for 7 days. Rats were treated with earthworm extract (EE) at three different doses (50, 100 and 200 mg/kg body weight) orally. The anti-inflammatory property of EE was studied by weighing the granuloma pouch and the anti-oxidant property of EE was studied by assessing levels of reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) and thio barbituric acid reactive substances (TBARS). The haematological studies included differential cell counts and haemoglobin content along with measurements of serum protein albumin, cholesterol and alkaline phosphatase in inflamed rats. The administration of indomethacin (10 mg/kg) or different doses of earthworm extract (50, 100 and 200 mg/kg), reduced inflammation, normalized activity of glutathione peroxidase, catalase, superoxide dismutase, reduced glutathione and thio barbituric acid reactive substances in liver and normalized the blood cell count and haemoglobin content. The serum protein, albumin, cholesterol and alkaline phosphatases (ALP) reached the normal level in inflamed rats after treatment. Significant results were obtained in 200 mg/kg of earthworm extract /kg body weight administered rats. The potential of anti-inflammatory and anti-oxidant nature of earthworm extract can be attributed to the presence of phenolic substances in the earthworm tissue.
Tunira Bhadauria, K. G. Saxena, Pradeep Kumar, Rohit Kumar, V. K. Chaturvedi (India) Influence of Land Use and Land Cover Change on Diversity of Earthworms in Raebareli District of Indogangetic Plains, India (pp 73-81)
Original Research Paper: Land use-land cover change and management practices influence earthworm species composition and abundance. The natural and agro-ecosystems under study in the Indogangetic region have a depauperate earthworm fauna. This study provides evidence that agriculture intensification and soil sodicity can severely influence earthworm diversity, in which natural and less disturbed ecosystems had lower earthworm diversity. Predominance of endemic earthworms at all sites under study could probably be explained by barriers in dispersal of exotic species and a wider distribution of native species. The change in functional guild with the change in land use could be attributed to the change in the input rates and chemical characteristic of organic matter associated with varied land management practices. The ecological group studies revealed that earthworm communities of agro-ecosystems have lower species richness, fewer ecological groups and predominance of endogeics. Epigeic and anecic species are not widespread in the agriculture systems and their dependence on litter layer for survival implies that litter management practices must be implemented for their role of soil function to be important.
Sudhir D. Ghatnekar, Mahavash F. Kavian, Darshana S. Ghalsasi (India) Activities of Lumbricus rubellus and Eudrilus eugeniae and the Fate of Acacia auriculiformis, Casurina equisetifolia and Dalbergia sissoo Seeds (pp 82-86)
Original Research Paper: Seeds at the soil surface are more vulnerable to predation. Seed burial is a potent factor in prolonging the survival of seeds. In the present study, the ability of Lumbricus rubellus and Eudrilus eugeniae to ingest seeds of Acacia auriculiformis, Casurina equisetifolia and Dalbergia sissoo selectively and the effect of passage through the gut on subsequent seed germination were investigated. Both E. eugeniae and L. rubellus ingested highest percentage of A. auriculiformis seeds (66.5% ± 1.71 and 49.6% ± 1.98, respectively) when offered alone and in mixture (46.0% ± 1.85 and 34.0% ± 1.83, respectively) with C. equisetifolia. Both earthworm species ingested significantly (at 0.05 level of significance) fewer seeds when offered in mixture with other seed species than when offered alone. The ability of both earthworms to distinguish between species was exhibited when seed mixture was offered. In laboratory trials, more seeds were lost in the presence of L. rubellus than of E. eugeniae and no losses in control. In field trials, losses of A. auriculiformis and C. equisetifolia from the surface of the soil containing earthworms were greater in the first five weeks after sowing. Recovery of ingested seeds was highest with C. equisetifolia by L. rubellus (92.0% ± 0.32) and E. eugeniae (87.88% ± 0.49). Germination of seeds lost from soil surface was higher in relation to seeds still on soil surface. Percentage increase in seed germination was highest in D. sissoo in the presence of L. rubellus (9.7times). Seed viability was slightly affected by ingestion; the reduced germination of selected plant species egested by L. rubellus and E. eugeniae were probably due to scarification and enzyme activity or delayed germination.
Nik Nor Izyan, Adi Ainurzaman Jamaludin, Noor Zalina Mahmood (Malaysia) Potential of Spent Mushroom Substrate in Vermicomposting (pp 87-90)
Short Communication: The potential of spent mushroom substrate from saw dust in vermicomposting was investigated through the growth and reproduction of earthworms, including the nutrient elements of vermicompost produced at the end of vermicomposting. Five treatments in different ratios of cow dung: spent mushroom substrates were prepared as feed materials with four replicates for each treatment: 80: 20 (T1), 60: 40 (T2), 50: 50 (T3), 40: 60 (T4) and 20: 80 (T5). After 3 weeks of pre-composting followed by 7 weeks of vermicomposting, T4 showed the highest percentage of growth and reproduction where the mean number of earthworms increased (M = 295.00, SD = 17.32, n = 4) as did their weight (M = 28.86, SD = 5.97, n = 4). Furthermore, when a higher ratio of cow dung to spent mushroom was used in substrate T1, the resulting vermicompost showed highest percentage of macronutrient elements: N (1.90%), P (0.57%), and K (2.74%) compared to other treatments. Overall, spent mushroom substrate can be decomposed through vermicomposting by using Lumbricus rubellus with an optimal ratio of cow dung.
Chhotu D. Jadia, Madhusudan H. Fulekar (India) Phytoremediation: The Application of Vermicompost to Remove Heavy Metals by Green Plants (Alfalfa, Sunflower and Sorghum) (pp 91-96)
Original Research Paper: Vermicompost – a natural fertilizer – was developed by vermiculture biotechnology using market vegetable wastes. The collected vegetable waste was decomposed for a period of two weeks following mesophilic, thermophlic and cooling down stages which then subjected to subsequent vermicomposting for a period of two months. The developed vermicompost was characterized for its chemical and nutrient status. It was found to have high concentrations of the nutrient elements (Zn, Cu, Mg, Fe and Mn) and thus was used as an organic amendment in the soil (at the 3: 1 ratio) for enhancing the uptake capabilities of plant species in the phytoremediation studies. Glasshouse pot culture experiments were then conducted to investigate the phytoremediation potential of three plants- alfalfa, sunflower and fibrous root grass (sorghum) for the removal of heavy metals from the contaminated soil-vermicompost media. The soil-vermicompost media used in pot experiment were dosed separately at varying concentrations (0 to 50 ppm) of heavy metals; Cd, Ni, Cu, Pb and Zn to study the effect of heavy metals on seed germination and root and shoot growth of the plants. The uptake of metals by the three plants was also assessed. The results indicated that seed germination and root and shoot growth were significantly affected by these metals at higher concentrations (P<0.05). Zinc being an essential trace nutrient, it was found to be the only metal that caused significantly positive effect on plants at concentrations 20 to 50 ppm (P<0.05). All the three plants were observed to be significantly effective in uptake of heavy metals at all the evaluated concentrations. However, the findings of these phytoremediation studies demonstrate that accumulation potential of sunflower was found be greater than that of sorghum and alfalfa in the soil-vermicompost media.
Sasikala Kannan, Kaliaperumal Rajendran, Eevera Tamilmani, Senthamari Selvi Venugopalan, Kumaran Shanmugam (India) Waste Reduction, Nutrient Recovery from Solid Sludge Waste Materials by Vermicomposting (pp 97-99)
Original Research Paper: New ideas in sludge treatment are necessary for the today’s world where land filling and land dumping of solid wastes have not offered an eco-friendly solution to the solid waste management problem. Consumption of organic wastes by earthworms is an ecologically safe and economically viable process to get beneficial products. In this study, a cost effective experimental treatment using cow-dung mix with four different types of solid wastes (textile sludege, biogas sludge, domestic sludge, and fly ash sludge) through vermicomposting process by earthworm (Eisenia foetida) was undertaken. Conclusions were drawn from analyses of compost mix for pH, electrical conductivity, total nitrogen, and total organic carbon before and after vermicomposting. Results obtained for various sludge levels (100, 75, 50 & 25%) of mixing (sludge:cowdung) indicated reduction in total organic carbon content and increase in total nitrogen content invariably in all treatments and reduction in electrical conductivity also indicated the quality of the compost obtained.
Natchimuthu Karmegam, Thilagavathy Daniel (India) Effect of Application of Vermicasts as Layering Media for an Ornamental Plant, Codiaeum variegatum (L.) Bl. (pp 100-104)
Original Research Paper: In this paper, the effect of vermicasts (VC) on the growth performances of an ornamental plant, Codiaeum variegatum (L.) Bl. var. pictum (Lodd.) Muell. Arg. in layering experiments was studied in comparison with peat moss. The vermicasts were collected from the vermibeds of Lampito mauritii Kinb. and of Perionyx ceylanensis Mich. cultured in three kinds of organic substrates i.e., leaf litter of Polyalthia longifolia (LP), Pennisetum typhoides cobs (PT) and a weed Rottboellia exaltata (RE) in combination with cowdung (1:1). The vermicasts recovered from each vermibed were used alone and in combination with peat moss (PM; 1:1) as layering media for C. variegatum and the results were compared with PM. Root initiation, root length, total number of roots developed, fresh and dry weight of the roots were higher in the layering experiments with VC and VC + PM than that of PM which served as control. All these parameters showed significant differences between VC and PM (control). Vermicasts either alone or in combination with PM were able to initiate earlier rooting and development of roots better than in the layering experiments conducted only with PM. The enhanced root initiation and development in this study can be partially explained by the elevated levels of NPK contents in the vermicasts. The variation within VC + PM and VC on the growth parameters in layerings of C. variegatum were also observed, which might be due to the difference in vermicasts obtained from different vermibed substrates. The results of the present study show that PM can be substituted with vermicasts in layering media for the ornamental plant, C. variegatum.
Deepanjan Majumdar, Gauravi Seth, Poonam Mehta (India) Polynomial Trend in Short-Term Surface CO2 Emissions during Vermicomposting of Paint Sludges with Various Organic Substrates (pp 105-110)
Original Research Paper: Two types of sludge generated from effluent treatment plants of two different paint industries and customarily disposed in landfills were used for vermicomposting in conjunction with organic substrates like cow dung, camel dung, poultry dropping and de-oiled Karanja cake, among which poultry dropping was found to be unsuitable for earthworms and hence not used. The selected wastes were used in various ratios (1:1:1, 1:1:2, 1:1:4 or 1:1:1:0.2) for vermicomposting for a month and half with Eisenia fetida Savigny after a pre-composting period of 10 days for initial breakdown of waste mixtures. Flux of CO2 (mg m-2 d-1) from surface of vermibeds during vermicomposting was monitored for just more than three weeks and was found to be moderately variable temporally (coefficient of variation, CV = 17-34%) with peaks appearing towards the end of two weeks, a period of maximum respiratory activity of the microorganisms and earthworms in the waste mixtures. Average daily CO2 flux from all the treatments followed a perfect 4th degree polynomial trend. Carbon lost via total CO2 emission from various treatments during the study period ranged from 0.6 to 0.9% of the total C added to these treatments.
Nandhitha Madhusudhan, Preetha Nair, Radha D. Kale (India) Isolation and Culturing of Earthworm (Eudrilus eugeniae) Coelomocytes (pp 111-114)
Original Research Paper: Coelomocytes, the immune cells present in the coelomic fluid of Eudrilus eugeniae were isolated using electric, cold and heat shocks in two different media, phosphate buffer saline (PBS) and Hank’s balanced salt solution (HBSS) for demonstrating the ideal treatment for isolation of invertebrate cells and for their further multiplication in the given media. Results of all the methods showed concurrent cell density from the time of isolation to subculturing. Cell viability was measured using hemocytometer and trypan blue exclusion method. It was found that all the three treatments had higher viability in HBSS media compared to PBS media. For isolation of coelomocytes, the most appropriate method was found to be by using cold shock treatment in HBSS media, indicating least cell damage with good recovery of cells. The present study can serve as a useful aid in further immunocytochemical studies.
Angel I. Ortiz-Ceballos, María Eréndira C. Hernández-García, Jorge Galindo-González (Mexico) Nest and Feeding Chamber Construction for Cocoon Incubation in the Tropical Earthworm: Pontoscolex corethrurus (pp 115-118)
Original Research Paper: Details on how earthworm cocoons are deposited in soil have not been documented, nor whether they are abandoned or protected. This study provides the first detailed description of nest- and feeding-chamber construction for tropical earthworm species. The reproductive behaviour of the earthworm Pontoscolex corethrurus was observed using 11 “Evans Box” terraria, including one earthworm each. During the progression of the reproductive behaviour of P. corethrurus, observations were made at regular intervals for a period of 120 days. P. corethrurus built nest chambers with the mouths, coating them internally with a compact layer of fine soil and mucus. One cocoon was deposited in each nest chamber, then suspended from the nest walls by mucus filaments. During incubation, P. corethrurus frequently entered nest chambers for repairing or cleaning the inner walls. Besides, earthworms left no casts on the soil surface, but deposited them into underground nests built close to the site where the cocoon was deposited, and entered these underground nests to feed. Juveniles that emerged left the nest to feed on casts deposited in the feeding chamber. Our observations suggest that P. corethrurus displays parental care by building and caring for nest and feeding chambers, an aspect which deserves further investigation.
Angel I. Ortiz-Ceballos, Jorge Galindo-González (Mexico) Influence of Adult Pontoscolex corethrurus on Development of Cocoons and Hatchlings (pp 119-121)
Short Communication: Despite many decades of intensive research on earthworms, some fundamental questions remain unsolved. This study investigates the effect of the tropical Pontoscolex corethrurus on its cocoon biomass and hatchling growth. A controlled experiment was set up manipulating the presence of adult P. corethrurus based on three treatments, each with 20 replicates: Removal of P. corethrurus (RPc), No Removal of P. corethrurus (Control) and Controlled Removal, where P. corethrurus was removed and reintroduced again (RIPc). In all treatments, P. corethrurus deposited cocoons inside specially built chambers. No significant differences were observed in the number of cocoons and hatchlings produced between treatments (P > 0.1206 and P > 0.8707, respectively). Mean cocoon biomass was significantly (P > 0.001) higher in the Control (30.3 ± 3.5 mg) and RIPc (29.1 ± 3.6 mg) treatments relative to RPc (25.1 ± 2.7 mg) treatment. By contrast, mean hatchling biomass in RPc (46.7 ± 27.6 mg) was significantly higher than in RIPc (29.3 ± 9.0 mg) and the Control (31.8 ± 9.5 mg) groups (P < 0.0270). Based on these findings, we concluded that the parental presence of P. corethrurus significantly contributed to maintain cocoon biomass although it was related with a decrease in hatchling growth.
Swati Pattnaik, M. Vikram Reddy (India) Bioconversion of Municipal (Organic) Solid Waste into Nutrient-rich Vermicompost by Earthworms (Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus) (pp 122-128)
Original Research Paper: Changes in the concentrations of major nutrients of vermicompost of Municipal Organic Solid Waste [MOSW] processed by three species of earthworms viz., Eudrilus eugeniae, Eisenia fetida, and Perionyx excavatus and its simple compost were assessed during different intervals. The bulk mass of MOSW was reduced up to 65, 55 and 40% by vermicomposting mediated by E. eugeniae, E. fetida and P. excavatus, respectively, and up to 20% in the compost. The pH, electrical conductivity (EC), and concentrations of major nutrients – nitrogen, phosphorus, potassium, calcium and magnesium in the vermicompost and compost gradually increased while the organic carbon, C/N and C/P ratios decreased as the composting process progressed from 0 to 60 days (P<0.05). The vermicompost of all the earthworm species possessed significantly higher concentrations of nutrients than the compost and substrate (P<0.05). Moreover, among them, vermicompost of E. eugeniae acquired higher nutrients than that of E. fetida, P. excavatus, and compost (P<0.05). Thus, E. eugeniae may be chosen for vermicomposting of MOSW over the other two species of earthworms.
Reidun Pommeresche, Anne-Kristin Løes (Norway) Relations between Agronomic Practice and Earthworms in Norwegian Arable Soils (pp 129-142)
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Original Research Paper: This paper presents Norwegian studies of earthworms (density, biomass, burrows density, species, juvenile to adult ratios) in arable soil in Norway conducted during the last 20 years. The effects of crop rotations, fertilization, soil tillage and compaction on earthworms are presented, based on various field experiments. Geophagous (soil eating) species such as Aporrectodea caliginosa and A. rosea dominate the earthworm fauna in Norwegian arable soil. Lumbricus terrestris is also present; in our studies even frequently found in an all-arable crop rotation with annual ploughing. In southern Norway, L. rubellus, and A. longa are commonly found. Earthworm density, recorded in autumn varied between 30 and 350 individuals m-2 in different studies, with the lowest values found in conventional all-arable farming systems. One year of ley in the crop rotation increased earthworm burrow density, earthworm density and biomass. Even short-term leys for green manure had a positive effect, likely due to high clover content. Application of animal manure increased earthworm density and biomass. Because geophagous species prefer the upper soil layer, shallow ploughing (15 cm depth) was expected to be detrimental. However, the earthworm density and biomass was not lower with shallow as compared to deep ploughing (25 cm depth). With earthworm densities such as those found in farming systems with ley and animal manure, an estimated amount of 221 tonne of topsoil per hectare passes through the earthworm digestion system within one year. Field-collected geophagous earthworm casts had considerably higher concentrations of plant nutrients than bulk soil (28% higher concentration of Tot-N, 36-53% for PAL, 40-59% for KAL). Hence, earthworm casts are significant natural sources of plant nutrients, also in soils with high dominance of geophagous earthworm species.
Kuppuraj Raja Sekar, Natchimuthu Karmegam (India) Suitability of Vermicasts as Carrier Material for a Biofertilizer, Azosprillum brasilense (MTCC 4036) (pp 143-146)
Research Note: The vermicasts of an epigeic earthworm Eudrilus eugeniae Kinb was used as carrier material for a biofertilizer, Azospirillum brasilense (MTCC 4036). The study was conducted for a period of 10 months with the observation on the viable count of A. brasilense at regular intervals of 15 days. Results showed that about 1 × 107 g-1 viable cells of A. brasilense was found in some combinations of carrier materials (vermicasts: lignite) and that was significantly higher than experimental control i.e. lignite. The viable cells of A. brasilense showed a negative correlation with incubation period. A trend of increasing survival rate in A. brasilense in respect to increasing proportion of vermicasts in carrier material was observed. Results thus indicate the potential of vermicasts as carrier material for biofertilizers for sustainable crop production.
Subpiramaniyam Sivakumar, Young Chae Song, Duraisamy Prabha, Chandra Venkatasamy Subbhuraam (India) Life Cycle Parameters of the Earthworm Eisenia fetida Exposed to Cr(III) and Cr(VI) Amended Organic Substrates (pp 147-153)
Original Research Paper: The effects of Cr(III) and Cr(VI) on the growth and reproduction of the earthworm Eisenia fetida have been assessed in organic substrate media. Both Cr species caused dose dependent reduction in the growth and maturation rates in earthworms; however, Cr(VI) was more toxic than Cr(III). The difference between the EC50 (50% effect concentration) and NOEC (no observed effect concentration) values for both Cr species to induce changes in earthworm growth was more than fivefold. The reproductive parameters (cocoon production, hatching success and hatchlings produced per worm) showed a decreasing trend as the treatment concentration of Cr was increased. The EC50 values of Cr(III) for cocoon production and hatchling numbers were more than four times higher than the values recorded for Cr(VI). The NOEC values for Cr(III) and Cr(VI) for earthworm growth and reproduction show that growth was less sensitive to both Cr species, than was reproduction. The body concentration of Cr in worms generally increase with an increase in the treatment concentration of both species of Cr. Compared to control P generation worms, the life cycle parameters of the F1 generation worms did not show significant changes when exposed to uncontaminated organic substrate.