• Journal of the Korea Organic Resources Recycling Association
• /
• v.15 no.4
• /
• pp.93-99
• /
• 2007

Vertical distribution of tiger worm(Eisenia fetida) population in the earthworm rearing bed was investigated with feeding paper mill sludge. More than 50% of larva and adult population of Eisenia fetida lived within the depth of 5 cm from the surface of rearing bed. And more than 96% of the population of larva, adult and cocoon lived within the depth of 20 cm. Percental vertical distribution of Eisenia fetida population in the rearing bed was not much influenced by the changes in the height of rearing bed or density of earthworm population.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.16 no.3
• /
• pp.52-64
• /
• 2008

Aged sewage sludge with food waste leachate sludge or paper mill sludge was fed to earthworm (Eisenia fetida) populations and the effect of it on feeding and growth rate of earthworm population was investigated. Feeding rate of earthworm population on sewage sludge aged with food waste leachate sludge for 30 days was higher than that aged for 10 and 20 days. At 90 days after feeding, the density of earthworm population decreased regardless of aging period. And earthworm population growth to next generation was blocked by sewage sludge. The feeding rate and the density of earthworm population aged with paper mill sludge for 20 days were higher than that on sewage sludges aged for 10 and 30 days. Until 90 days after feeding, the density of earthworm population increased regardless of aging period of sewage sludge, however, since then decreased. There were comparatively higher feeding rate and growth rate of earthworm population on the sewage sludge which had been mixed with paper mill sludge and aged for 20 days, which rendered the probable pretreating method for vermicomposting sewage sludge.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.19 no.1
• /
• pp.115-122
• /
• 2011

Ecotoxicological effects of synthetic detergents such as laundry detergent and $Shampoo^{(R)}$ on cocoon productivity, hatchability, number of hatched individuals per cocoon and growth of next generation of Eisenia fetida population were evaluated. Synthetic detergents mixed with earthworm feed increased the cocoon productivity, number of hatched individuals per cocoon and growth of next generation of Eisenia fetida population, but there was no effect on hatchability. From those results, it could be concluded that synthetic detergents that might be present in the sewage sludge would not cause ecotoxicological effect on Eisenia fetida population.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.18 no.4
• /
• pp.45-53
• /
• 2010

Feeding rate and growth rate of earthworm population on the variously pretreated spent materials of the agaric-mushroom cultivation were investigated. When the spent mushroom substrates with different aging periods were supplied to earthworm, feeding rate and growth rate of earthworm population on spent mushroom substrates aged less than 10 days were higher than that on spent mushroom substrates aged more than 20 days. Feeding rate and growth rate were not increased when the spent mushroom substrate mixed with vermicasts or nitrogenous fertilizer was supplied. Feeding rate and growth rate on the ground mushroom substrate were higher than that on the non-ground mushroom substrate. Especially when the ground mushroom substrate was mixed with rice bran and supplied to earthworms, growth rate was much higher than that on the non-ground spent mushroom substrate; it increased 1.85 times.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.20 no.1
• /
• pp.50-60
• /
• 2012

This study was carried out to evaluate the ecotoxicological effects of Alum and Ferric chloride on the population of Eisenia fetida in vermicomposting of sewage sludge. Using contact filter toxicity test, it was shown that LC50 of Alum and Ferric chloride on adult Eisenia fetida were 457.4 mg $kg^{-1}$ and 1,665.2 mg $kg^{-1}$, respectively,which meant Ferric chloride had much higher acute toxicity on earthworm than Alum. Alum didn't affect on cocoon production, hatchability and number of hatched larvae of Eisenia fetida. Ferric chloride didn't have any efects on number of hatched larvae per cocoon, but reduced cocoon production and hatchability. Larval density of next generation was reduced by the food containing Alum and Ferric chloride. Above results indicated that the Alum and Ferric chloride could be one of the hazardous materials that made extinction of earthworm population when the sewage sludge treated with Alum and Ferric chloride was supplied to the earthworms.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.4
• /
• pp.104-112
• /
• 2006

Population growths of earthworm were investigated when the earthworm populations with different levels of initial densities per unit area were fed with cow dung mixed with paper mill sludge. The tested levels of earthworm densities were as follows; $1kg/m^2$, $2kg/m^2$, $3kg/m^2$, $5kg/m^2$. There were no significant differences in population growth rates 60 and 90 days after feed supply among the tested densities of earthworm. Therefore, it was suggested that initial densities of earthworm populations per unit area higher than $3kg/m^2$ should not be favorable because of the cost for purchasing earthworm. Vermicomposting rates of earthworm on feed were also investigated when different amounts of feed were supplied repeatedly to unit area of nursery bed with $5kg/m^2$ of initial densities earthworm populations. The tested amounts of feed at each supplying time were as follows; $16kg/m^2$, $24kg/m^2$, $32kg/m^2$, $40kg/m^2$. The more the amount of feed at each supplying time, the higher vermicomposting rate and population growth rate. Therefore, it should be more favorable for earthworm breeders to supply more than $40kg/m^2$ of feed at each supplying time, because it would reduce time and labor cost.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.11 no.4
• /
• pp.66-78
• /
• 2003

The effects of several factors such as heavy metals, living microorganims, high molecular conglomerator in sewage sludge were analysed. And the effects of the sewage sludges which were mixed with other organic waste such as paper mill sludge or night soil sludge upon the feeding rate and biomass of earthworm population were also estimated. The earthworm populations could not survive when newly produced sewage sludges were fed without any pretreatment. The contents of heavy metals were under the levels that could inhibit earthworm's growth. The living microorganisms and the high molecular conglomerator in the sewage sludge had no relations with ecotoxicological effects of sewage sludge upon the earthworm population. Sewage sludge which had been mixed with paper mill sludge and aged for more than 21 days showed no ecotoxicological effects on tiger worm(Eisenia fetida) population. And the feeding rate of earthworm population and the turnover rate of earthworm biomass were higher in those sewage sludges than in the sewage sludges pretreated by other ways.

• Korean Journal of Organic Agriculture
• /
• v.20 no.3
• /
• pp.369-383
• /
• 2012

This experiment was carried out to investigate the optimal stocking rate of earthworm populations grown under different stocking rates. The stocking rate in terms of ratio of biomass of earthworms to biomass of feeds(organic resources) is an important factors for biomass productivity of earthworms and vermicast production. The different stocking rates were 1:16(S-1), 1:32(S-2), 1:48(S-3) and 1:64(S-4), as the ratios of biomass of earthworm to biomass of organic dairy cow manure, respectively. The stocking rate of 1:32(S-2) and 1:46(S-3) were obtained a higher values on increasing rates and conversion efficiency of organic matter to earthworm biomass than other stocking rates. Thus, a stocking rates of 1:32 and 1:46 estimated an optimal stocking rates for maximum biomass productivity of earthworms. A stocking rate of 1:16(S-1) showed a significantly highest values of vermicast production and ratios of vermicasts during the rearing periods.($$P{\leq_-}0.05$$) A stocking rate of 1:48(S-3) showed a highest values of the number of cocoons and vermicasts production per earthworm biomass among the treatment ($$P{\leq_-}0.05$$) The contents of nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate and rearing progressed. Vermicasts have a great deal of potential for crop production and protection in sustainable organic cropping systems.

• Korean Journal of Environmental Biology
• /
• v.25 no.2
• /
• pp.100-106
• /
• 2007

This study was carried out to investigate the species composition in the plastic greenhouse bed for cultivation of cucumber in June 2006. Four genera and seven species found are as follows: Aporrectodea trapezoides (Duges 1828), Aporrectodea tuberculata (Eisen 1874), Bimastos parvus (Eisen 1874), Amynthas koreanus (Kobayashi 1938), Amynthas corticis (Kinberg 1867), Amynthas hupeiensis (Michaelsen 1895), and Drawida japonica (Michaelsen 1892). Of them, Amynthas koreanus is Korean endemic species. Their descriptions are provided including photographs.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.13 no.2
• /
• pp.98-106
• /
• 2005

Population dynamics in the vermicomposting bed was investigated. And harvesting efficiencies of earthworm attracting traps with different attractants, mesh sizes of net and covering materials was evaluated. Peak density of earthworm population was $5kg/m^2$ and therafter its desity kept $4.4{\sim}5.0kg/m^2$. It was evaluated that suitable mesh size of the net was 7mm and proper covering materials of the earthworm attracting trap was cotton quilt. The earthworm harvesting efficiency of trap with attractant was much higher than that of trap without attractant. With more amount of attractant in the trap and with longer setting period of trap onto the vermicomposting bed, the earthworm attracting trap harvested more earthworms. Crushed pear-peel attracted much more earthworms than paper mill sludge, but it was difficult to supply enough amount of crushed pear-peel for practical need. Sugar solution(10%) with tab water was proven to be an alternative to crushed pear-peel because its attracting effect on earthworm was as high as crushed pear-peel and it was easy to prepare and supply in large quantity.