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The earthworm Pontoscolex corethrurus (Müller, 1857) is reported for the first time from Punjab, India. This species was first described by German naturalist Fritz Müller in 1857 from Santa Catarina state of Brazil. It is commonly found in gardens, cropland and fallow lands. It tolerates wide range of climatic and edaphic factors due to its endogeic ecological category. P. corethrurus has high efficiency for organic matter assimilation and has ability to live in new habitat due to which it can survive even in very poor soil. The life cycle of this species is well documented and this species has economic importance due to its use in waste management.
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The present paper discusses the role of earthworms in recycling of sugar industrial wastes. The wastes generated from sugar industry are pressmud, bagasse, bagasse fly ash, sugar cane trash, sugar beet mud, sugar beet pulp, molasses etc. These wastes when mixed with other organic substrates become ideal mixtures for growth of earthworms. These wastes if stored in open field’s causes contamination in the environment and may cause several diseases in public health. But the governments have been unable to tackle the menace of solid waste pollution due to dearth of appropriate technologies, finance and space. Therefore, environment friendly and cost effective technologies for nutrient recycling or remediation of wastes are being advocated as an alternative means for conserving and replenishing natural resources of the ecosystems. Vermicomposting is one such technology that synergises microbial degradation with earthworm’s activity for reducing, reusing and recycling waste materials in a shorter span of time. Earthworm technology can convert sugar industrial wastes into valuable fertilizing material. The final product (vermicompost) produced during the process of vermicomposting is nutrient rich organic fertilizer with plant available nutrients such as nitrogen, potassium, calcium and phosphorus. In the present study an attempt has been made to document the role of earthworms in reuse of sugar industry waste.
A preliminary survey on earthworm species from north Karnataka region, Gulbarga district, Karnataka state, India, has been conducted from January 2012 to December 2013. Survey was conducted in three regions of Gulbarga district i.e. Afzalpur, Chittapur, and Sedam taluk. Six species of earthworms were identified belonging to four families namely lumbricidae, Octochaetidae, Megascolecidae and Eudrilidae. Eisenia fetida belonging to family lumbricidae, Dichogaster bolaui belong to family Octochaetidae, Polypheretima elongate, Perionyx sansibaricus and Perionyx excavates belong to family Megascolecidae and Eudrilus eugeniae belonging to family Eudrilidae. Among the species, Eudrilus eugeniae does not occur naturally and are produced from external sources for vermicomposting units.
Earthworms, as ecosystem engineers, strongly regulate microbial activities and microorganism-mediated processes in the soil; their effects differ among species and ecological groups. Lumbricids are suggested to have density-dependent regulation of species populations, but it is not known whether their effects on soil processes are density-dependent. In a field experiment, litter/soil microcosms contained monocultures of five common lumbricid species belonging to epigeic, anecic and endogeic ecological groups, at various density levels. After 6 and 15 weeks, respiration rates of soil systems were measured and (after subtraction of approximately calculated earthworm respiration) microbial respiration rates estimated. In the presence of earthworms, respiration of soil systems tended to increase. After 6 weeks, this increment was explained by earthworm's own respiration. However, after 15 weeks earthworm respiration comprised 12–80% of the respiration increment; hence, microbial respiration was stimulated by earthworm activities. In any earthworm species, total community and microbial respiration were correlated with its density increase. However, specific respiration increments (per unit earthworm biomass) were not significantly affected by lumbricid density. The lack of density-dependent patterns indicates a weak impact of lumbricid intraspecific interactions on soil respiration. However, specific respiration increments and stimulation of microbial respiration varied across earthworm species, being higher for endogeic than for epigeic/anecic species. This is explained by a relatively lower microbial grazing by endogeics and a depletion of litter (a resource and environment for the microbial community) by epigeic/anecic earthworms. Overall, the results support the view that microbial community adapts to the presence of earthworms by switching to a smaller, but a more active one.
The aim of this study was to assess the possibility of using biological and biochemical parameters in the evaluation of forest soil quality and changes caused by land use. The study attempted to determine a relationship between the enzymatic activity of soil, the number of earthworms and soil physico-chemical properties. The study was carried out in central Poland in adjoining Forest Districts (Przedbórz and Smardzewice). In soil samples taken from 12 research plots, basic physico-chemical properties, enzyme activity (dehydrogenase, urease) and density and biomass of earthworms were examined. Enzyme activity showed a large diversity within the forest site types studied. The correlations between the activity of the enzymes studied and C/N ratio indicated considerable importance of these enzymes in metabolism of essential elements of organic matter of forest soils. Urease and dehydrogenase activity and earthworm number showed susceptibility to soil pH, which confirmed relationships between enzyme activity and abundance of earthworms and soil pH in H2O and KCl.
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