• Advances in environmental research
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• v.12 no.1
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• pp.51-64
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• 2023

The sustainable management of rice straw is essential for protection of human health and environment. This study assesses the impact of stock density of earthworm (Eisenia fetida) and Neem leaves (Azadirachta indica) on the quality of the final vermicompost. The vermicompost is produced using different combinations of rice straw, Neem leaves, and cow dung (bulking agent) by varying stock density of earthworms. The vermicomposting experiments are performed in plastic containers (32 cm × 28 cm × 28 cm) in open for 90 days under laboratory conditions. The stock density of the earthworm is found to be an important factor to influence nutritional quality of the final vermicompost. There is observed significant improvement in the total nitrogen (91.8%), phosphate (73.4%), potassium (38.8%), and calcium (59.05%) content of the vermicompost produced with the highest stock density of the earthworms. All the treatments showed decrease in TOC and C:N content after 90 days of vermicomposting. The treatment with Neem leaves showed maximum growth of earthworms (2.65 fold). Neem leaves brought positive changes in the quality of final vermicompost by enhancing the growth and reproduction of the earthworms. The calcium content increased by 39% in the final vermicompost with the addition of Neem leaves at the same stock density of the earthworms. The stock density of the earthworms and Neem leaves are found to significantly improve quality of the final vermicompost as compared with the compost (control). The surface morphology in SEM images showed high degree of fragmentation in the vermicompost as compared with the compost. The combined action of microbes and earthworms resulted in high degree of disintegration in the vermicompost.

• Journal of Biomedical Engineering Research
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• v.38 no.5
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• pp.242-247
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• 2017

This study presents a bio-chemical energy harvesting system which can generate electric power from bioorganic substance contained in vermicompost. It produced electricity by inoculating microbial fuel cell(MFC) with earthworm-composted food waste. The generated electricity was converted into usable voltage level for mobile electronics through power conditioning circuits. The implemented prototype showed $200{\mu}W$ of maximum output electric power, which successfully supplied a beacon device which continuously transmitted data to nearby smartphone without a battery. The proposed system can help develop portable or bio-mimetic energy supply for sustainable use with further improvement.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.130-138
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• 2004

Food wastes with different regional origins were mixed with bulking agent such as paper mill sludge or night soil, and aged for 21 days or 28 days. And aged food wastes were fed to the earthworm(tiger worm, Eisenia fetida) for 60 days. There were no significant physico-chemical differences among the food wastes with different regional origins. EC values and NaCl concentrations in food wastes were too high for earthworms to survive. Food wastes mixed with paper mill sludge were vermicomposted more efficiently than food wastes mixed with night soil, but the over-all vermicomposting rates on the food wastes were much lower than that on paper mill sludge because EC values and NaCl concentrations were still high for earthworm to compost the feeds. Earthworm population did not increase its biomass on the food wastes mixed with paper mill sludge or night soil, whereas earthworm population fed with paper mill sludge increased its biomass by 20% for 60 days. It could be concluded that a solution for reducing NaCl concentrations in food waste should be developed to vermicompost food waste.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.305-308
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• 2004

Recently, with increasing concern for sustainable agriculture and safe agricultural products, organic farming has become widely adapted as an alternative to conventional farming. This study was conducted to investigate the effects of earthworm casts (EWC) with $100\%$ organic compost on the growth and yield characteristics of fall-cropping potato (Solanum tuberosum L. cv. Dejima) in Jeju. The treatments consisted of seven plots: 2-, 4-, 6-, 8-, and 10-ton $ha^{-1}$ EWC-treated plots, 1.2-ton $ha^{-1}$ complex fertilizer $(N-P_2O_5-K_2O,\;10-10-14)-for-potato$ (CEP)-treated plot as conventional practices, and a control plot. The plant heights were greater in the plots where EWC and CFP were applied than in the control plot. Tuber diameter, number of stems per plant, and chlorophyll level tended to increase in the plots where 8-10 tons $ha^{-1}$ of EWC were applied. The application of CFP and EWC showed an increment in the average tuber weight per plant, but there was minimal significant difference. The application of 8-10 tons $ha^{-1}$ of EWC resulted in an increase in the total tuber yield (21.61-21.87 tons $ha^{-1}$) as compared to the other plots. The highest yield of market able tubers was $69.8\%$ of the total yield from the 10-ton $ha^{-1}$ EWC-treated plot. Consequently, with regard to the growth and yield characteristics of fall-cropping potato, the effects of EWC application were more favorable than the effects of the application of a chemical fertilizer.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.91-100
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• 2004

This study was on a recyling system of food waste using poultry and earthworms. Food waste was fed to the egg-raising hens(Gallus gallus) or ducks(Anas platyrynchos). And the excrement of poultry after ingestion of food waste was mixed with other organic waste such as paper mill sludge or night soil sludge, aged and then provided to the earthworms(Eisenia andrei). An egg-raising hen and a duck ate up 0.40kg and 0.79kg of food waste per day, respectively. And the percental rate of exctretion(the amount of excrement/the amount of food waste eaten up) of an egg-raising hen and a duck was 71.0% and 53.7%, respectively. The excrement of poultry that had been mixed with paper mill sludge and aged was vermicomposted more easily than the excrement that had been mixed with night soil sludge and aged. The excrement of poultry aged for more than 21 days was more suitable to vermicompost than the excrement of poultry aged for less than 21 days. Even though, the earthworm lost its biomass on the mixed feeds regardless of their aging periods, which was supposed to be caused by high salinity in poulty's excrements.