• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.830-835
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• 2011

Total soil microbial activities have great impact to soil management for organic farming. This study was evaluated in the soil microbial community by fatty acid methyl ester (FAME) in a controlled horticultural field for strawberry organic farm. Experimental plots were prepared with a high level of soil electrical conductivity (EC) and a optimum level of soil EC. Soil microbial biomasses and communities of total bacteria, Gram-negative bacteria, Gram-positive bacteria, actinomycetes, fungi, and arbuscular mycorrhizal fungi in the high level of soil EC were significantly larger than those in the optimum level of soil EC. Lower ratios of cy17:0 to 16:$1{\omega}7c$ and cy19:0 to 18:$1{\omega}7c$ were found in the optimum level of soil EC than those in the high level of soil EC, indicating that microbial stress decreased.

• Korean Journal of Organic Agriculture
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• v.31 no.2
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• pp.135-155
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• 2023

The purpose of this study is to investigate the relationship between the service quality of WPL (Work Place Learning) and the revisit intention through customer satisfaction, targeting users who use the WPL. Data to achieve the purpose of this study were conducted for trainees who had received on-the-job training at 4 selected WPL in Jeollabuk-do. Out of the 210 copies of questionnaires, 170 were picked up, and all of them were used for analysis. As a result of the analysis, First, as a result of analyzing the relationship between service quality and customer satisfaction in WPL, it was discovered that among the service quality components, Responsiveness, Assurance, and Empathy had a substantial influence on customer satisfaction, while Tangibles and Reliability of service quality did not appear to have any significant effect. Second, it was discovered that customer contentment had a considerable influence on revisit intention after evaluating the link between customer satisfaction and revisit intention. It can be shown that the higher the level of client happiness, the greater the likelihood of returning. Third, as a result of analyzing the relationship between service quality and revisit intention of WPL, among service quality factors, Reliability, Responsiveness, and Empathy were found to have a significant effect on revisit intention. As a result of verifying the mediating effect of service quality at WPL on revisit intention through customer satisfaction, responsiveness, assurance, and empathy of service quality were found to be significant in their relationship with revisit intention.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.93-97
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• 2012

This study was conducted to evaluate the efficiency of various inorganic and organic materials to improve physical properties of soil. Saline sodic soil (saturation percentage = 40.36%, $EC_e=5.15dS\;m^{-1}$, $pH_s=8.70$, $SAR=18.84(m\;mol\;L^{-1})^{1/2}$, bulk density =$1.49Mg\;m^{-3}$) was collected, brought to wire house and filled in pots after laboratory analysis for various parameters. Different sources of organic nutrients like farm manure (FM), press mud, compost, poultry manure and sesbania green manure were analyzed for their chemical composition. The experiment comprised of 12 treatments replicated thrice; $T_1$: control (recommended NPK), $T_2:{\frac{1}{2}}$ recommended NPK, $T_3$: FM at 1.5% by soil weight, $T_4$: pressmud at 1.5% by soil weight, $T_5$: compost at 1.5% by soil weight, $T_6$: poultry manure at 1.5% by soil weight, $T_7$: sesbania green manure at 1.5% by soil weight, $T_8:T_2$ + FM at 0.75% by soil weight, $T_9:T_2$ + pressmud at 0.75% by soil weight, $T_{10}:T_2$ + compost at 0.75% by soil weight, $T_{11}:T_2$ + poultry manure at 0.75% by soil weight, $T_{12}:T_2$ + sesbania green manure at 0.75% by soil weight. These treatments were applied using completely randomized (CR) design and appropriate time was given to decompose these organic nutritional sources. Seeds of wheat cultivar Sahar-2006 were sown. After harvesting the wheat, soil samples were collected from each pot and analyzed for various physical properties like bulk density, porosity and saturation percentage. An improvement in physical properties (bulk density, porosity and saturation percentage) of soil was noticed with the application of various organic nutritional sources but role of compost alone ($T_5$) remained prominent.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.1
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• pp.43-52
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• 1999

This study was carried out to investigate how much coal fly ash could be substituted for sawdust as a bulking agent for livestock waste composting. The mixtures of coal fly ash and sawdust in the weight ratio of 8 to 2, 7 to 3, 6 to 4, 5 to 5, 4 to 6, 3 to 7 and 2 to 8 were added to livestock waste as the bulking agent. The same amount of the bulking agents and livestock waste was mixed and composted during 21 days. Following effects were analyzed during composting experiment : the variation of temperature, pH and various compound contents. The results were summarized as follows: The more the sawdust was added, the higher the maximum temperature in slurry type livestock farm but faster it reached in scrapper type. Water content was maintained under good condition by adding the bulking agent mixed of the same amount of coal fly ash and sawdust. pH was in the range of 7~10 by adding the bulking agent mixed of the same amount of coal fly ash and sawdust. The more the sawdust was added, the higher organic matter content was measured. Nitrogen content with increasing the amount of sawdust added but it was higher did not showed any tendency Organic matter/Nitrogen ratio reduced during the composting period in scrapper type but it showed contrary tendency in slurry type with that of scrapper type.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.4
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• pp.105-110
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• 2014

It is required to improve the efficiency and the reliability of the polymer solar cells (PSCs) as the energy saving optical device for the future application of the smart farm facilities. In this study, we fabricated the bulk hetero junction PSCs with organic passivation film layer for the reliability improvement of the devices. The effects of the passivation layer on the electrical properties of the PSCs were studied. The materials of passivation layer are composed of poly vinyl alcohol (PVA) and ammonium dichromate, and the passivation films were fabricated by the spin coating method on the P3HT:$PC_{61}BM$/LiF/Al substrate. The prepared structure of the device is the glass/ITO/PEDOT:PSS/P3HT:$PC_{61}BM$/LiF/Al/passivation layer. The performances of the PSCs with the organic passivation film showed better electrical properties compared with the PSCs without passivation layers. The power conversion efficiency (PCE) values of passivated PSCs decreased from 3.0 to 1.3% after air exposure for 140 hrs. In contrast, the PCE values for the devices without passivation decreased sharply from 3.5 to 0.1% under the same exposure condition.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.369-375
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• 2012

Loess-sulfur complex has been widely used as an environmental friendly organic materials for insecticides and fungicides in crop cultivation. However, there are high concerns about skin and eye irritation for farm workers due to the high alkaline properties of loess-sulfur complex. The acute toxicity evaluation was conducted with three samples of loess-sulfur complex in different pH (pH 9, 10, 11) in order to supply the evidentiary data for selecting the optimal product among the test materials. The results of acute oral toxicity using rats showed $LD_{50}$ of over 2,000 mg/kg b.w. for all three samples of loess-sulfur complex. The calculated acute dermal $LD_{50}$ of all tested materials was over 4,000 mg/kg b.w.. The Skin and eye irritation indicated that all tested materials have no irritation. Consequently, it was suggested that loess-sulfur complex be low in acute toxicity at all different pH values (pH 9~11).

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.61-70
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• 1998

This research has been made for influence of forest environmental changes, such as tree-clearcutting affecting to soil chemical and physical properties, on water storage capacity at forest fire land in Keumsan, Chungnam. The analyzed factors were bulk density, porosity, field moisture saturated hydraulic conductivity air permeability and organic matter content, Field moisture saturated hydraulic conductivity and air permeability at uncutting sites were higher than those at clearcutting sites, especially the most differences were appeared at lower slope. After 2 years passed since forest fire, the most changeable parts of soil characteristics were 5-l5cm depth below soil surface. Total Porosity, coarse pore and fine pore at uncutting sites were higher than those at clearcutting sites. Also, as soil depth increased, total porosity and coarse pore were decreased. Bulk density at uncutting sites was lower than that at clearcutting sites, and was decreased as soil depth increased. The order of the change trend in field moisture saturated hydraulic conductivity, air permeability and porosity was slope lower>middle>upper. Organic matter content at uncutting sites were higher than those at clearcutting sites, and decreased as soil depth increased. As soil depth increased, bulk density had the positive correlation, in other hand, porosity, coarse pore, field moisture saturated hydraulic conductivity, air permeability and organic matter content had the negative correlation. It was concluded that forest environmental changes by forest fire degrade soil physical and chemical properties.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.62-66
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• 1997

This study was designed to obtain the mean values of thirteen soil physico-chemical properties for different paddy soil management groups, and to serve the basic information for improving the soil using amendments. Computerized data on the results of detailed soil survey were used in this study. The clay contents in the B horizon of paddy soil management groups were 28.3% in the well adapted type, 11.8% in the sandy textured type, and 26.8% in the newly reclaimed type. Soil pH of B horizon in the paddy soil management groups except poorly drained type and acid sulfate type were higher than those of A horizon. In the river side paddy soils of well adapted type, the clay contents of A and B horizons were 16.8%, 23.1%, respectively, and soil organic matter contents of those horizons were 42g/kg, 18g/kg, respectively. And also available phosphate content of well adapted type was higher than the other types. Frequency of distribution of soil organic matter content levels in the B horizons of sandy textured type and newly reclaimed type were higher in the organic matter content range of below 10g/kg. And those of well adapted, poorly drained, and saline type were higher in the organic matter content range of 10~20g/kg. Correlation coefficients between 13 variables in the B horizon of well adapted type were all highly significant at 1% or 5% level, respectively.

• Korean Journal of Organic Agriculture
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• v.10 no.2
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• pp.95-109
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• 2002

This study focussed to find out the agronomic effect of high quality compost mixed with brown seaweed and to determine the optimum mixing rate of seaweed to compost for environmentally benign organic farming. The experiment was conducted in lysimeters at Experimental Farm of Dankook University with Chinese Cabbage(Bulam #1), and the crop growth such length and width of leaf, biomass of Chinese Cabbage were checked, the content of chlorophyll, sugar, vitamin C, nitrate in outer leaf and idler leaf was determined. It was observed that nitrate content was dramatically decreased in the plot of mixture with seaweed, while biomass and content of Vitamin C were increased steeply in the plot of mixture with seaweed. The best result was gained the 0.25% mixture of brown seaweed with compost.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.3
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• pp.27-33
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• 2021

CO I gene sequence analysis was applied to earthworms that had been used as test animals in toxicity test in Institute of Kyeongbook Agrochemicals and earthworms used as vermicomposting agents in the farm of Youngdong province to identify their species names. In terms of molecular species, the former was identified as Eisenia fetida and the latter was Eisenia andrei. Cocoons produced from Eisenia fetida was more than those from Eisenia andrei. And No. of adults developed from eggs of Eisenia fetida was more or less higher than those developed from eggs of Eisenia andrei. These results were contradictory to previous reports on two Eisenia spp.. When Eisenia fetida was crossed with Eisenia andrei, hybridized eggs were produced and adults were developed from those eggs, but cocoons and adults were much less than those from non-crossed Eisenia fetida or Eisenia andrei. This indicated that two Eisenia spp. were not distinctly different biological species because there was no complete 'reproductive isolation' between Eisenia fetida and Eisenia andrei. However, this also meant that Eisenia fetida and Eisenia andrei had already been on the tract of speciation.