• Journal of Ginseng Research
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• 제40권1호
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• pp.28-37
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• 2016

Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIO-LOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes. Results: The analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade. Conclusion: The key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates.

• 한국잡초학회지
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• 제30권4호
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• pp.405-411
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• 2010

휴경논에 분포하고 있는 식생구조에 대해 식물사회학적 연구를 수행하였다. 총 22개 조사구에 대한 식생자료의 분석은 Zurich-Montpellier 학파의 방법을 이용하였다. 휴경논 식생조사 결과 1아군집, 5군락으로 구분되었다. 고마리군집(Polygonetum thunbergii Lohm. et Miyawaki 1962)의 고마리전형아군집, 골풀군락, 갈대군락, 물달개비군락, 사마귀풀군락, 부들군락. 요인분석에서 식생단위와 환경과의 상관관계를 보면, 사마귀풀군락과 물달개비군락은 토양 전질소와 음의 상관관계, 갈대군락과 고마리아군집은 토양 pH가 낮은 지역에 분포하는 것으로 분석되었다.

• 농촌지도와개발
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• 제3권1호
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• pp.67-81
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• 1996

Our agricultural extension system with all its success and failures, rewards and punishment was introduced 50 years ago with particular reference from United States. Some of the established principles and policies of effective extension work were shaken off for immediate result. But the results were not praiseworthy. The purpose of this study is to throw some light on the question of systems and approaches on agricultural extension that can adequately meet the challenges of the future. Our extension system is `special government type` which administers a nation-wide network of extension and training services in close collaboration with that of the experiment station. This type, however, has innate weakness which inclined to be standardized, inflexible, and irrelevant to actual needs of farming communities and problems of farmers. In this regard, it is necessary to consider another approaches of agricultural extension: `Government Type`, `Agricultural University`, `Farmers Organization`. The characteristics features, advantages and disadvantages of these models have been discussed. Each model has been found wanting in one way or another to meet the needs and interest of the present Korean situation. In view of the agricultural situation, and considering the expected changes of farmers and technologies in the years ahead, the `modification (especially to the direction of provincial government) of preset system` was expected which would be operationally flexible and organizationally unified and decentralized. The modification of present system should include the following characteristics: 1) universal contact with client system, 2) local planning based on the needs of clients, 3) using multiple method of nonformal education, 4) fitting with both general and specialized farming systems, 5) accommodating variable clients, technologies and educational objects.

• 한국토양비료학회지
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• 제48권2호
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• pp.81-86
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• 2015

Soil management for orchard depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 orchard (5 sites for sandy loam, 7 sites for silt loam, and 13 sites for loam) in Gyeongnam Province by fatty acid methyl ester (FAME) method. The average values for 25 orchard soil samples were $270nmol\;g^{-1}$ of total FAMEs, $72nmol\;g^{-1}$ of total bacteria, $34nmol\;g^{-1}$ of Gram-negative bacteria, $34nmol\;g^{-1}$ of Gram-positive bacteria, $6nmol\;g^{-1}$ of actinomycetes, $49nmol\;g^{-1}$ of fungi, and $7nmol\;g^{-1}$ of arbuscular mycorrhizal fungi. In addition, silt loam soils had significantly low ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ compared with those of loam soils (p < 0.05), indicating that microbial activity increased. The average soil microbial communities in the orchard soils were 26.7% of bacteria, 17.9% of fungi, 12.6% of Gram-negative bacteria, 12.5% of Gram-positive bacteria, 2.5% of arbuscular mycorrhizal fungi, and 2.2% of actinomycetes. The soil microbial community of Gram-negative bacteria in silt loam soils was significantly higher than those of sandy loam and loam soils (p < 0.05).

• Animal Bioscience
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• 제34권9호
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• pp.1559-1568
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• 2021

Objective: Bedding materials directly contact hooves of dairy cows and they may serve as environmental sources of lameness-associated pathogen. However, the specific composition of bacteria hidden in bedding materials is still not clear. The aim of this study was to determine the effect bedding material and its bacterial composition has on lameness of Holstein heifers. Methods: Forty-eight Holstein heifers with similar body weights were randomly assigned into three groups including sand bedding (SB), concrete floor (CF), and compost bedding (CB). Hock injuries severity and gait performance of dairy cows were scored individually once a week. Blood samples were collected at the end of the experiment and bedding material samples were collected once a week for Illumina sequencing. Results: The CF increased visible hock injuries severity and serum biomarkers of joint damage in comparison to SB and CB groups. Besides, Illumina sequencing and analysis showed that the bacterial community of CB samples had higher similarity to that of SB samples than CF samples. Bacteria in three bedding materials were dominated by gastrointestinal bacteria and organic matter-degrading bacteria, such as Actinobacteria, Firmicutes, and norank JG30-KF-cM45. Lameness-associated Spirochaetaceae and Treponeme were only detected in SB and CB samples with a very low relative abundance (0% to 0.08%). Conclusion: The bacterial communities differed among bedding materials. However, the treponemes pathogens involved in the pathogenesis of lameness may not be a part of microbiota in bedding materials of dairy cows.

• The Plant Pathology Journal
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• 제38권6호
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• pp.583-592
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• 2022

Root-knot nematode disease is a widespread and catastrophic disease of tobacco. However, little is known about the relationship between rhizosphere bacterial community and root-knot nematode disease. This study used 16S rRNA gene sequencing and PICRUSt to assess bacterial community structure and function changes in rhizosphere soil from Meloidogyne incognita-infected tobacco plants. We studied the rhizosphere bacterial community structure of M. incognita-infected and uninfected tobacco plants through a paired comparison design in two regions of tobacco planting area, Yuxi and Jiuxiang of Yunnan Province, southwest China. According to the findings, M. incognita infection can alter the bacterial population in the soil. Uninfested soil has more operational taxonomic unit numbers and richness than infested soil. Principal Coordinate Analysis revealed clear separations between bacterial communities from infested and uninfested soil, indicating that different infection conditions resulted in significantly different bacterial community structures in soils. Firmicutes was prevalent in infested soil, but Chloroflexi and Acidobacteria were prevalent in uninfested soil. Sphingomonas, Streptomyces, and Bradyrhizobium were the dominant bacteria genera, and their abundance were higher in infested soil. By PICRUSt analysis, some metabolism-related functions and signal transduction functions of the rhizosphere bacterial community in the M. incognita infection-tobacco plants had a higher relative abundance than those uninfected. As a result, rhizosphere soils from tobacco plants infected with M. incognita showed considerable bacterial community structure and function alterations.

• 농촌지도와개발
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• 제5권1호
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• pp.61-70
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• 1998

이 연구는 인구 4,000에서 6,000명 가량의 농촌 지역사회에서의 서비스 및 용역의 제공기능의 활성화 정도와 관련하여 지도자들의 특성을 파악하고자 한다. 지역사회 지도자들간의 공식적이고 수평적인 연계와 지도자들과 지역사회 외부 조직들간의 연계를 중심으로 분석이 이루어졌다. 성(性), 교육정도, 연령, 수입, 지역사회 출신 여부, 그리고 지역사회에서의 거주기간을 포함하는 농촌 지역사회 지도자들의 개인적 특성은 지역사회 서비스 및 용역의 제공기능과 관련이 없었다. 그러나, 농촌 지역사회의 서비스 및 용역의 제공기능 활성화 정도는 그 지역사회의 지도자들이 지역사회 외부의 사람들 및 조직들과 연계를 맺고 있는 정도와 관련이 있었다. 또한 이 연구에서는 농촌 지도자들의 공식적인 지역사회 개발 활동에 능동적으로 참여하는 능력이 지역사회 서비스 및 용역 제공기능의 활성화 정도와 정적으로 관련이 있음이 밝혀졌다.

• 농촌지도와개발
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• 제13권1호
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• pp.123-134
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• 2006

The purpose of this study was to establish the effective model for community-centered youth development in Korea. The research methods used the extensive review of related literatures and consultation with a panel of experts in this field. Based on the major results, the implications and suggestions were as follows. First, community youth development will need to provide the opportunities of competencies and a full complement of positive connections to youth activities. Second, communities promote to engage youth as partners with adults in the process of positive youth development. Third, youth development organizations operate to support the programs to prevent or treat specific problems in terms of community youth contexts. Finally, collaboration and network are necessarily required among youth, adults, home, school, organizations within the community.

• 농촌지도와개발
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• 제15권3호
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• pp.417-432
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• 2008

The purpose of this study were to discuss on the importance of community youth development programs and review the enhancement of competence in youth The research methods used the extensive review of related literatures. Based on the major results, the implications and suggestions were as follows. First, community youth activity will need to provide the opportunities of enhancing the competencies and a full complement of positive connections to youth programs. Second, communities promote to engage youth as partners with adults in the process of positive youth development. Third, youth development organizations operate to support the programs to prevent risky-behaviors or treat specific problems in terms of community youth contexts. Finally, collaboration and network are necessarily required among youth, adults, family, school, organizations within the community. Changes to work and workplace are so significant that policies refer to 'the knowledge society' at the same time 'information society'. Future workers will need to have the skills of information and communications management and control.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.252-255
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• 2001

This study aimed at proposing an policy improving directions of the rural empty homes grant scheme in Korea. The implementation procedures and results of the relevant schemes / projects on optimum use of rural empty homes at home and abroad were reviewed by literature and internet searches. From the reviewing results, an tentative set of policy directions for project improvement were proposed ; extension of project scope to all the redundant resources, dual focussing of project objectives on housing innovation and economic regeneration of communities, and systematization of project plan and implementation especially in the statutory aspects.