• Korean Journal of Microbiology
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• v.50 no.4
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• pp.313-318
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• 2014

The world is in need of sustainable and eco-friendly energy sources such as microalgal biodiesel due to global warming and fossil fuel shortages. In this study, we compared the effectiveness of liquid fertilizer produced from swine manure and agriculture grade solid fertilizers as nutrient sources for microalgal biomass production. Mixed culture (Chlorella spp., Scenedesmus spp., Stigeoclonium spp.; CSS) was cultivated for 28 days in Small Scale Raceway Pond (SSRP) using various nutrient sources (swine manure liquid fertilizer, agricultural solid fertilizer, and mixture of these two fertilizers). Biomass and lipid productivity of fertilizer mixture were the highest at 0.8 g/L and 5.8 mg/L/day, respectively. These results indicate that the fertilizer mixture can provide microalgae necessary nutrient sources for stable biodiesel production and biomass growth. In addition, overall cost of microalgal cultivation and subsequently biodiesel production would be significantly reduced.

• Journal of Korean Society of Rural Planning
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• v.25 no.4
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• pp.13-26
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• 2019

The rural areas in South Korea have changed rapidly in the process of national land development. Rural landscapes have become discoloured, and their attractiveness has decreased as cities have expanded. But the attractiveness or multifunctional values of rural areas has become more important in contemporary society around the world. According to this social demand, the efforts of conserving the rural landscape are of high priority and the recovery of ruralism in the area is required. This study has tried to understand how the public image of ruralism in South Korea has been influenced by the news media. The study retrieved news articles using the web searching portal site from the six keywords, commonly used to refer to ruralism, including 'rural landscape', 'rural community', 'rural tourism', 'rural life', 'rural amenity', and 'rural environment'. News data from the six keywords were also collected respectively from within the year-period of 2004-05, 2007-08, 2012-13, and 2016-17. In the text mining analysis, the nouns with high Degree Centrality were figured out, and the changes by year-period were identified. Then, LDA topic analysis was performed for text datasets of six keywords. As a result, the study found that the news articles gave an informed focus on only a handful of issues such as 'poor rural living condition', 'regional or village improvement projects', 'rural tourism promotion projects', and 'other government support projects'. On the other hand, nouns related to virtues and values in the rural landscape were less shown in news articles. These results have become more apparent in recent years. In the topic analysis, 35 topics were identified. 'village development projects', 'rural tourism', and 'urban-rural exchange projects' were appeared repeatedly in several keywords. Among the topics, there are also topics closely related to ruralism such as 'rural landscape conservation', 'eco-friendly rural areas', 'local amenity resources', 'public interest values of agriculture', and 'rural life and communities'. The study presented an image map showing ruralism in South Korea using a network map between all topics and keywords. At the end of the study, implications for Korean rural area policy and research directions were discussed.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.2
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• pp.469-480
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• 2019

The purpose of this study is to enhance the cultural heritage value of the Juk-Bang-Ryeum (Bamboo Weir) and prove the originality through the review of historical literature. The main industry of Korean was agriculture and fishery from ancient. In the ancient, fishery instruments are not enough due to the lack of fishing technology. The Juk-Bang-Ryeum was considered as important national resources and asset. It give us many implications about the wisdom of our ancestors because of it's scientific principle of the structure. It is surely a cultural heritage to preserve in the future because it is considered as important community asset as well as more natural and environment oriented fishing method. In the literature, the origin of 'Juk-Bang-Ryeum' can be found as 'Eo-Ryang' or 'Bang-Ryeum'. The records on this terminology go back to the Corea Dynasty, but their documentary records are rare, and most of them are records of the Chosun Dynasty. In this study, we surveyed mainly the literature records about the southern coast region in the period of Chosun Dynasty. This study contributes for preserving the cultural assets of our ancestors who pursued eco-friendly fishery method, and it is also of great significance to produce objective data based on records for the registration of the World Record Heritage.

• Journal of the Korean Wood Science and Technology
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• v.49 no.4
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• pp.315-327
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• 2021

Purpose of this study is reviewing the use method for the sawdust (sawmilling by-product) and rice husk (Agriculture by-product) by adding charcoal, an eco-friendly material. Mixed composite boards were manufactured with those materials with each density and mixing ratio, and bending performance was investigated. When the addition ratio of sawdust, rice husk and charcoal is 50:20:20 and the resin addition ratio is 10%, as the density of the prepared mixed board ranges from 0.5 g/cm³ to 0.7 g/cm³, the bending strength was 0.42~3.24 N/mm², dynamic modulus of elasticity was 94.5~888.4 N/mm², and the static modulus of elasticity was in the range of 31.4~220.7 N/mm². As the density increased, the bending performance increased, indicating that the density had a significant effect on the bending performance. In a board prepared by setting the density of 0.6 g/cm³, the addition ratio of sawdust to 50%, and the addition ratio of rice husk and charcoal at different ratios, the bending performance showed a tendency to decrease as the addition ratio of charcoal increased. The relationship between the addition ratio of rice husk and charcoal, bending strength, resonance frequency, and dynamic and static bending modulus showed a rather low correlation with the values of the coefficient of determination (R²) of 0.4562, 0.4310, 0.4589, and 0.5847, respectively. Thus, we found that the effect of the addition ratio on the bending performance was small.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.3
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• pp.137-146
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• 2022

Seed disinfection is a necessary process to decrease Bakanae disease in rice and is carried out at 30℃ to increase disinfection efficiency. However, the length of sprout after seed disinfection is not suitable for sowing, so additional processes such as seed soaking is needed. For this reason, this study was conducted to develop the efficient and effective seed disinfection method. When the seed disinfection finished after soaking seeds in cold water for 2 days, length of sprout was about 1.0 mm and sowing can be done without additional processes. In addition, the incidence of Bakanae disease was greatly reduced by 64% compared to conventional method. In order to find out why the newly developed method (disinfection after soaking) is more efficient than conventional method, soaked and not soaked seeds were stained using methylene blue staining. It was found that soaked seeds were more easily stained with about 50% of internal and external endosperm stained. Therefore, pesticide can be absorbed easily into internal endosperm of soaked seeds and efficiently destroy the spore of pathogen. As a results of this study, newly developed method will be useful as it can improve efficiency of agricultural work and also effectively decrease Bakanae disease compared to conventional method.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.2
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• pp.17-28
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• 2022

The application of supplemental activated biochar pellet fertilizers (ABPFs) was evaluated by investigating key factors such as changes of surface paddy water and soil chemical properties and rice growth responses during the growing season. The treatments consisted of control, activated rice hull biochar pellet (ARHBP-40%), and activated palm biochar pellet (APBP-40%) applications. It was shown that the lowest NH₄⁺-N and PO₄^--P concentrations were observed in surface paddy water to the ARHBP-40%, while the NH₄⁺-N concentration in the control was abruptly decreased until 30 days after transplant in the soil. However, the lowest NH₄⁺-N concentration in the blended biochar application was 9.18 mg L^-1 at 1 day of transplant, but its ABPFs application was observed to be less than 1 mg L^-1 at 56 days after transplant. The lowest PO₄^--P concentration in paddy water treated ARHBP-40% ranged from 0.06 mg L^-1 to 0.08 mg L^-1 until 30 days after transplant among the treatments. For the paddy soil, the NH₄⁺-N concentration in the control was abruptly decreased from 177.7 mg kg^-1 to 49.4 mg kg^-1, while NO₃^--N concentration was highest, 13.2 mg kg^-1 in 14 days after transplant. The P₂O₅ concentrations in the soils increased from rice transplants until the harvesting period regardless of the treatments. The highest K₂O concentration was 252.8 mg kg^-1 in the APBP-40% at 84 days after transplant. For the rice growth responses, plant height in the control was relatively high compared to others, but grain yield was not significantly different between the control and ARHBP-40%. The application of ARHBP-40% can minimize nitrogen and phosphorous application rates into the agro-ecosystem.

• Journal of Mushroom
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• v.21 no.3
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• pp.132-139
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• 2023

Light plays an important role in fruit-body development and morphology during Pleurotus spp. cultivation. To understand the effects of light color on fruit-body properties, we evaluated the fruit-body characteristics of Pleurotus spp. Varieties cultivated under blue, red, and purple LED light sources. The main results are as follows: The overall fruit-body shape showed differences depending on the color of the LED light. The fruit-bodies of mushroom cultivated under blue and purple light were generally similar to the mushroom shapes typically produced, while those of mushroom cultivated under green light were abnormally shaped, probably due to the absence of effective light source. The average cap lightness of mushrooms cultivated under blue, green, and purple LED lights was 57.0, 57.4, and 59.4, respectively. The average cap lightness of all varieties except Wonhyeong1ho and Hwang-geumsantari cultivated under the three LED light sources were statistically significantly different (P<0.05). The cap redness varied significantly depending on the LED lighting and variety. Only Gonji7hoM, the cap color mutant of Gonji7ho, showed negative cap redness values under all three LED light sources. Among the eight varieties excluding Gonji7ho, the highest cap redness was observed when cultivated under the blue LED. The average harvest weight of the varieties cultivated under purple, blue, and green LED light were 68.0, 58.3, and 50.1 g, respectively. The yield of Gonji7ho, the mushroom variety with the highest yield, cultivated under blue, green, and purple LED light were 92.8, 77.1, and 98.6 g, respectively. The earliness when grown under the purple, blue, and green LED lights were 5.3, 5.8, and 5.8 days, respectively. Among the varieties, six, three, and two cultivars showed the shortest earliness under the purple, green, and blue LED, respectively. The fruit-body lengths were 66.4, 51.8, and 46.8 mm when cultivated under green, purple, and blue lights, respectively. These results are expected to serve as a foundation for producing mushrooms with traits demanded in the market.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.773-788
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• 2017

This study was carried out to investigate the damage patterns, the occurrence and migration time of Pseudococcus comstocki and in order to improve the control effect of organic agricultural materials (OAMs). The experiment was carried out at Okcheon's organic vineyard ($2,500m^2$, sandy loam, manure) where planted 8~9 year old 'Muscat of Alexandria' vines. The comstock mealybug's migration to grape clusters occurred from the middle of July, and produced eggs in the grape clusters from the end of July, and the density of the comstock mealybug was highest at $0.6cm^2$ in late August. The number and fruit damage of comstock mealybug in eco-friendly vineyards were higher than in conventional culture vineyard. And the marketability of green variety grape was more damaged from comstock mealybug than the black variety grape. Toxicities of 8 OAMs were evaluated to comstock mealybug at the recommended concentration. As a results, Lightyellow sophora and Derris extracts exhibited strong insecticidal activity with 100% mortality. When the Lightyellow sophora extract was uniformly distributed on the vine from early-July to mid-July, fruit damage reduction rate was 96.2% and 84.6%, respectively. So commercial grapes could be harvested. Therefore, it was considered to be effective to reduce fruit damage by controlling in early - late July (the green stage) when the comstock mealybug migrated to grape clusters in the vine greenhouse. In the future, it will be necessary to study the effect of external exposure time and momentum on the control of OAMs.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.535-542
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• 2012

This study was carried out from 2011 to 2012 in order to analyze the cultivation technology system by six organic rice cultivation types in the southern provinces for the purpose of utilizing organic rice farming guidelines. This surveys were conducted by site visit on 8 counties and 115 farms in southern area. Cultivation technology system by six organic rice cultivation types were cultivated by the principle of minimum input or non-input. cropping systems, a mixture of barley and rice, or rice green manure crops were grown. Cultivars were mixture of the local cultivars and Japanese varieties. Soil were managed by a self-manufactured compost, indigenous microorganisms and barley straw without any fertilization. Pest control was mainly practied by purchased eco-friendly organic materials or herbal medication residue and indigenous microbial self-manufactured. Weed was controled by snails and barley straw. In addition, considering the restore of a longtail pitching shrimp and grasshoppers, the fuction of environmental ecology of six organic rice cultivation type proved to be excellent all. Meanwhile, the productivity of the organic farming per 10a were the order of Life and environment > Natural circulation > Stevia > Ji jang > Art and nature > Taepyoung of Farming Methods, but the farmers received prices showed the opposite tendency. Simple profitablity did not show a big difference. But, the productivity of all type of the organic farming were lower then the conventional farming. Finally, If we want to conduct safety and easy farming, we can suggest stevia farming, Natural circulation farming and life and environmental farming out of 6 organic rice cultivation types.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.268-273
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• 2015

BACKGROUND: Petroleum-contaminated soil from leaking above- and underground storage tanks and spillage during transport of petroleum products is widespread environmental problem in recent years. Application of compost may be the most promising, cost-effective, and eco-friendly technology for soil bioremediation because of its advantages over physical and chemical technology. The objective of this study was to evaluate effect of compost application on degradation of total petroleum hydrocarbon (TPH) in petroleum hydrocarbon-contaminated soil.METHOD AND RESULTS: An arable soil was artificially contaminated by diesel, and compost was applied at the different rate of 0, 10, 30, and 50 Mg/ha. Concentration of TPH in the soil decreased as application rate of compost increased. Degradation efficiency was highest at compost 30 Mg/ha; however, it slightly decreased with compost 50 Mg/ha. Kinetic modeling was performed to estimate the rates of chemical reaction. The correlation coefficient (R2) values for the linear plots using the second-order model were higher than those using the first-oder model. Compost 30 and 50 Mg/ha had the fastest TPH degradation rate in the second-order model. Change of microbial population in soil with compost application was similar to that of TPH. Microbial population in the soil increased as application rate of compost increased. Increasing microbial population in the contaminated soil corresponded to decreased in TPH concentration.CONCLUSION: Conclusively, compost application for soil bioremediation could be an effective response to petroleum hydrocarbon-contaminated soil. The increase in microbial population with compost suggested that compost application at an optimum rate might enhance degradation of TPH in soil.