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        검색결과 183

        61.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        This study aims to investigate the effects of climatic variability on the citrus yield in Jeju-do. This study analyzed the relationship between the citrus yield and climate elements(temperature, rainfall, sunshine duration etc) at each growing season. Temperature shows a positive relationship with the period of flower bud for the yield of citrus. The rainy days of bud bursting period have a negative relation in Seogwipo area. The sunshine duration of the 1st physiological fruit drop period was positively related to citrus yield in Jeju and Seogwipo area. The maximum temperature of the 2nd physiological fruit drop period and the fruit enlargement period were negatively related to the citrus yield. In Jeju and Seogwipo area, about 60% of the variation of citrus yield is explained by the variation of climatic factors. The sunshine duration of the 1st physiological fruit drop period and fruit enlargement period were selected to the yield estimation in Jeju. In Seogwipo, the number of rainy days and the sunshine duration of the 1st physiological fruit drop period were selected.
        62.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        Background: Some phenolics detected in the soil may inhibit the seed germination and seedling growth of ginseng (Panax ginseng). This study investigated the effect of irrigation and ginseng root residue addition on the soil microbial community and root rot disease in 2-year-old ginseng. Methods and Results: Each 20 ℓ pot was filled with soil infected with ginseng root rot pathogens, and irrigated daily with 2 ℓ of water for one month. After the irrigation treatment, ginseng fine root powder was mixed with the irrigated soil at a rate of 20 g per pot. In descending order, NO3 −, electric conductivity (EC), exchangeable Na (Ex. Na) and K (Ex. K) decreased due to irrigation. In descending order, NO3 −, EC, Ex. K, and available P2O5 increased with the additon of ginseng powder to the soil. The abundance of Trichoderma crassum decreased with irrigation, but increased again with the incorporation of ginseng powder. The abundance of Haematonectria haematococca increased with irrigation, but decreased with the incorporation of ginseng powder. The abundance of Cylindrocarpon spp. and Fusarium spp., which cause ginseng root rot, increased with the incorporation of ginseng powder. The abundance of Arthrobacter oryzae and Streptomyces lavendulae increased with irrigation. The abundance of Streptomyces lavendulae decreased, and that of Arthrobacter spp. increased, with the incorporation of ginseng powder. Aerial growth of ginseng was promoted by irrigation, and ginseng root rot increased with the incorporation of ginseng powder. Conclusions: Ginseng root residues in the soil affected soil nutrients and microorganisms, and promoted ginseng root rot, but did not affect the aerial growth of ginseng.
        63.
        2018.10 서비스 종료(열람 제한)
        Background : This study was conducted to investigate the resistance of Collectotrichum gloeosporioides to 9 fungicides. Methods and Results : With 3 isolates of Collectotrichum gloeosporioides obtained from diseased leaf of ginseng, it was conducted to detect the fungicide resistance of C. gloeosporioides against 9 chemicals through an agar dilution method. PDA medium was used for monitoring the resistance. Among the chemicals, fenhexamid・prochloraz manganese complex, fluazinam and metconazole exhibited high antifungal activity to the ginseng anthracnose fungus. When measuring the effectiveness for the prevention of anthracnose, 3 fungicides at 10 ㎍/㎖ showed 88.1 - 94.7% of preventive effect against C. gloeosporioides. But, the isolates resist to dimethomorph・dithianon, iminoctadine tris (albesilate), kasugamyci n・thiophanate-methyl, dimethomorph・pyraclostrobin, azoxystrobin. Conclusion : In summary, to develop the control system with fungicides, 3 fungicides (fenhexamid・prochloraz manganese complex, fluazinam and metconazole) were applied on ginseng at the indicated time. A reduced spray program based on efficacious fungicides will be useful for ginseng growers and provide more options for controlling anthracnose in Korea.
        64.
        2018.10 서비스 종료(열람 제한)
        Background : Root rot is a major factors of replanting failure in ginseng cultivation. Some of the phenolics detected in the soil could inhibit the seed germination and seedling growth of ginseng. Methods and Results : Water of 2 ℓ was irrigated per pot (20 ℓ) into the soil infected with ginseng root rot pathogens for one month every day. After the irrigation treatment, the powder of ginseng fine root of 20 g per pot was mixed with the irrigated soil. NO3 -, electric conductivity (EC), exchangeable Na (Ex. Na) and K (Ex. K) were decreased in descending order by irrigation. NO3 -, EC, Ex. K, and available P2O5 were increased in descending order by incorporation of ginseng powder into soil. Trichoderma crassum was decreased by irrigation, but it was increased again by incorporation of powder. Haematonectria haematococca was increased by irrigation, but it was decreased by incorporation of powder. Cylindrocarpon spp. and Fusarium spp. causing ginseng root rot were increased by incorporation of powder. Arthrobacter oryzae and Streptomyces lavendulae were increased by irrigation. Streptomyces lavendulae was decreased, and Arthrobacter spp. was increased by incorporation of powder. Aerial growth of ginseng was promoted by irrigation, and ginseng root rot was increased by incorporation of powder. Conclusion : The residues of ginseng root in the soil affected soil nutrients and microorganisms, and promoted ginseng root rot, but did not affect the aerial growth of ginseng.
        65.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to reveal the characteristics of climate-influenced landscape in the tundra with the case study of Cambridge Bay in Canada. This study was conducted for a part of regional study to understand the lifestyle of Arctic and Inuit people. Traditional knowledge and practices of indigenous peoples are emerged as adaptation issues to the changes of tundra environment. During august 2018, we interviewed local residents and experts at a field survey in Cambridge Bay, Nunavut, Canada. The contents of the study are descriptions on the climate-influenced landscape, utilizing interview, which mainly focused on buildings, infrastructure, and transportation. In building construction, they are applying the building method considering permafrost. The infrastructures are also adapting to extreme weather conditions, such as supplying water and sewage disposal by trucks instead of water and sewage systems using pipes. The way of transport has been changed from dog-sleds to modern snowmobiles and ATVs. The use of ATV is on the rise as the period of time without snow is getting longer.
        66.
        2018.07 KCI 등재 서비스 종료(열람 제한)
        본 연구는 순환골재를 사용한 콘크리트의 활용증대 방안으로 철근콘크리트 구조물의 노후화와 내구성 저하 시 보수․보강으로 사용되는 FRP (AFRP, CFRP) 판으로 보강된 순환골재 고강도콘크리트(40MPa, 60MPa) 보를 제작하여 순환골재 철근콘크리트 보의 휨 보강에 대한 적용성을 평가하고자 한다 기존의 표면매입보강에 따른 에폭시와 FRP 판의 부착력을 고려하지 않기 위해 콘크리트 타설 전 FRP 보강판을 거푸집에 미리 설치하였으며, 순환골재 치환율(30%), 콘크리트 강도(40MPa, 60MPa), 이형철근(D10, D13), FRP 판의 종류(AFRP 판, CFRP 판)를 변수로 12개 실험체를 제작하여, FRP 판과 순환골재 치환율에 따른 휨 성능을 분석하였다. 그 결과 FRP 판으로 보강한 실험체는 무보강 실험체에 비해 최대 17% 증가하는 경향을 나타내었으며 AFRP 판에 비해 CFRP 판의 보강 성능이 우수한 것으로 나타났다. 또한 순환골재 치환율에 따른 보강 성능의 차이는 없는 것으로 나타났다. 실험에 의해 측정된 균열모멘트는 파괴계수를 이용한 결과 기준식과 비슷한 값을 나타났으며 휨 모멘트는 FRP 판을 보강한 일부 시험체가 KCI 2012와 ACI 440-2R에서 제시한 기준을 만족하지 못하는 것으로 나타났다.
        67.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        Background: Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds. Methods and Results: The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. After May fumigation, the sowing date of maize was delayed by 15 days and thus its dry weight was decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, NO3, P2O5, and K significantly. Maize cultivation after May fumigation decreased fungi population and the ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different between treatment of May and September, but Fusarium solani showed a significant increase in September fumigation after maize cultivation. Conclusions: Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by the amendment of mineral composition and microorganism in fumigated soil.
        68.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        The safety of the future mankind becomes a world issue due to the climate change driven by global warming. It is inevitable to observe everywhere in daily life the impact of climate change. The level of emergency differs between long-term, mid-term, and short-term, which depends on situation. The impact of climate change in daily life is fairly diverse, and therefore multiple research units of different backgrounds often work together on the measuring and forecasting of the impacts. This paper aims to study the potentially useful methods to analyze and forecast the impact on the changes in transport activities of Canadian Inuit. This is part of the research on the climate change’s impact on the Northern Sea Route area. Either natural or man-made change of external environment forces human to adjust their daily life in order to maintain their utility level of life. Individual or individuals’ group react to the external impact, the way of which differ from others. This fact calls a simulation research on the whole set of input-intermediate process-output. Agents representing individuals or certain subpopulation are given a set of rules to react to stimulus and interact with other agents behave in the realm of simulation. This paper provides methodological discussions on how analyzing and forecasting future change in transport activities in response to climate change. The discussion goes around activity-based approaches that are recently popular in urban planning and transportation planning among available simulation approaches. This paper then discusses the implication and future research agenda.
        69.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        The study aims to investigate the effect of air temperature on growth date(bud bursting, flowering, blooming) of Citrus Unshiu in Jeju and Seogwipo, and estimate future growth date using air temperature data and growth date of Citrus Unshiu from 1998 to 2015. The trend and relationship between growth date of Citrus Unshiu and air temperature in Jeju and Seogwipo are analysed. As a result, The trend of growth date of Citrus Unshiu is delayed during study period. The correlation between Citrus Unshiu growth date and air temperature is negative. It means that air temperature related to the growth date of Citrus Unshui is decreasing. Future growth date of Citrus Unshiu is estimated to be earlier by future climate change scenarios. Air temperature expect to rise, but it can appear the low air temperature to be able to hurt citrus tree.
        70.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to identify the effectiveness of satellite images in detecting the areas of rice production in the Barisal of Bangladesh. We also investigated the effect of climate change on the crop production through comparative analysis of rice production area and production statistics with climate data at multi-temporal time scale. This analysis found that the classification of rice fields extracted through satellite image and made as the number of rice cultivation areas did not exceed 10 percent of the statistical data. Climate data analysis showed that the average temperature during the ripening stage has the greatest impact on Boro’s production. It would be more make sense if you can describe the results of how precipitation is also important for rice production in addition to temperature. Therefore, it is believed that this research could serve as a key basis for solving food security issues due to climate change.
        71.
        2018.05 서비스 종료(열람 제한)
        Background : A soil-borne pathogenic fungus, Ilyonectria radicicola (Cylindrocarpon destructans) species complex causing ginseng root rot is the major pathogen on ginseng. DNA extraction from soil is necessary to confirm the presence of ginseng root rot pathogen, I. radicicola. Methods and Results : In order to the increase the detection sensitivity of pathogens present in the soil, the existing soil DNA extraction method was modified to inctease the efficiency of the PCR reaction and to increase the amount of soil samples that can be analyed once by 500 times. For increase the DNA concentration, phenol : chloroform : isoamylalcohol (25 : 24 : 1) were used instead of chloroform : isoamylalcohol (24 : 1), and the sensitivity of PCR was increased by using purification kit. Conclusion : The modified DNA extraction method can detect ginseng root rot pathogen (I. radicicola) with DNA extraction and purification higher than the conventional method.
        72.
        2018.05 서비스 종료(열람 제한)
        Background : The soil-borne ascomycete fungus Ilyonectria rdicicola species complex is commonly associated with root rot disease symptoms in ginsneg. Its virulence has been attributed, among other factors, to the activity of hydrolytic cell wall-degrading enzymes (CWDE). Methods and Results : To establish a rapid and accurate detection of Ilyonectria rdicicola, a species-specific primer was developed based on the putative genes of cell wall–degrading enzyme (pectinase, polygalactose, xylanase, xylosidase). Species-specific primer based on the DNA sequences of gene amplified about 200 - 300 bp polymerase chain reaction (PCR) product for Ilyonectria mors-panacis. Conclusion : The primer pair yielded the predicted PCR product size exactly in testing with target pathogen DNAs, but not from the other species of Ilyonectria and species of other phytopathogenic fungi. The primer pair also showed only the species-specific amplification curve on realtime PCR on target pathogen DNA. The detection sensitivity of real time PCR using species-specific primer pair was 10 to 100 times higher than conventional PCR, with 1 to 10 pg/㎕. The approach outlined here could be further utilized as a rapid and reliable tool for the diagnosis and monitoring of the root rot of ginseng.
        73.
        2018.05 서비스 종료(열람 제한)
        Background : Replant failure of ginseng is caused by soil-born pathogens causing root rot such as Cylindrocarpon destructans and Fusarium solani. Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds. Methods and Results : The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil of field where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. Maize cultivation after May fumigation was delayed the sowing day by 15 days, and the fresh and dry weight decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, NO3, P2O5, and K significantly. Maize cultivation after May fumigation decreased fungi population and ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different among treatments, but Fusarium solani showed a significant increase in September fumigation after maize cultivation. Conclusion : Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by improvement of mineral composition and microorganism in soils.
        74.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this paper is three-fold: to analyze the macrotrend of North Korea’s food supply and demand; to confirm the food security situation in North Korea in various respects; and to seek the sustainable ways of agricultural production as a prerequisite for food security in North Korea. In particular, analyzing North Korea’s weather observation data, which has hardly been considered in previous studies, we investigated how North Korea’s agriculture had been affected by various natural disasters (flood, drought, soil loss etc.) caused by unusual weather. The results show the fact that the agricultural security systems of North Korea is vulnerable to both drought and flood due to extreme precipitation changes, which are closely related to the negative impacts on North Korea’s agricultural activities. In order to enhance the sustainability of North Korea’s agriculture, it is necessary to improve the system (dissolution of collectivization), increase the amount of agricultural materials, enhance soil fertility and develop agricultural machines. Most of all, this research reveals the fact that the most important and fundamental points for food security in North Korea, it needs the systematic strategies to cope with climate change.
        75.
        2017.11 KCI 등재 서비스 종료(열람 제한)
        This study analyzes the impacts of agricultural water shortages in Korea using a combined top-down and bottom-up model. A multi-region multi-output agricultural sector model with detailed descriptions of production technologies and water and land resource constraints has been combined with a standard CGE model. The impacts of four different water shortage scenarios were simulated. It is shown that an active adaptation of crop choices occurs in even the regions with relatively abundant water resources in order to respond to the change in relative output prices caused by water shortages. We found that although the losses in production values are not quite large despite water shortages due to the price feedbacks, the loss in GDP is substantial. We show that our combined approach has advantages in deriving region and product specific production effects as well as the overall GDP loss effect of water shortages.
        76.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        This study aims to investigate the characteristics of the disaster by heavy snowfall in South Korea based on the disaster yearbooks published from 1979 to 2014. We analyses the spatial distributions and temporal changes of disaster caused by heavy snowfall as well as the damage related to the snow depth. According to the change in the property loss by heavy snowfall and the snow depth, there was no major damage by heavy snowfall in 1980~1999 when the new snowfall tended to decrease by -1.4 cm/year. However, the fluctuation in the sum of new snowfall in the 2000s was also the most unstable, resulting in heavy damage by heavy snowfall. The sensitivity on the snow depth is different depending on the geographical regions, but the property loss by heavy snowfall increases as the sum of new snowfall and the maximum snow depth increase.
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