• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.70-76
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• 1999

Since high concentrations of N, P, and organic C cause the excessive eutrophication in water systems, the control of nutrient export from agricultural nonpoint sources has become important. This study was conducted to estimate discharges of N, P, and organic C from a small agricultural watershed of the upper Imgo stream in Youngchun, Kyongbuk. Of the total area(1.420ha), 25% was agricultural land including paddy, upland and orchards and most of the remainder was forest. The resident population in the watershed was 194 in 80 households and relatively small numbers of livestocks including cow were raised. Mean concentrations of nutrients in the stream water were 4.95, 0.80, 6.72, 0.07 and 2.52mg/L for $NO_3-N$, $NH_4-N$, Total N, Total P and COD respectively. Annual discharges in 1997 were 28,991kg of $NO_3-N$. 3,010kg of $NH_4-N$, 37,006kg of Total N. 590kg of Total P, and 29,138kg of COD. There was a strong positive relationship between stream flow and precipitation, and also most of the nutrient discharges occurred in the rainy season (May to August). Since there was no any other industries in the watershed, agricultural practices and sewage from the resident households, forest runoff and livestock wastes were the major sources of NPS discharges. A combination of management options, including management of soil erosion and fertilizer application, could lead to reductions in nutrient exports.

• Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.23-31
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• 2008

An experiment was conducted in twelve 0.02-ha rain-fed earthen ponds for 18 weeks to evaluate the effects of including pangasiid catfish (Pangasius hypophthalmus) in polycultures of major Indian carps, catla (Catla catla), rohu (Labeo rohita), and mrigal (Cirrhinus cirrhosus), on yield and economic gain. Treatment 1 ($T_1$) consisted of 5,000 catla+2,500 rohu+2,500 mrigal per ha, treatment 2 ($T_2$) consisted of 5,000 catla+2,500 rohu+2,500 mrigal+2,500 pangasiid catfish per ha, treatment 3 ($T_3$) consisted of 5,000 catla+2,500 rohu+2,500 mrigal+5,000 pangasiid catfish per ha, and treatment 4 ($T_4$) consisted of 5,000 catla+2,500 rohu+2,500 mrigal+7,500 pangasiid catfish per ha. The growth performance of fishes was evaluated by calculating specific growth rate, daily weight gain, and percent weight gain. Inclusion of pangasiid catfish in the carp polyculture resulted in significant increases in the growth and yield of catla and rohu. Catla and rohu grew most in $T_4$, with 7,500/ha of pangasiid catfish. The presence of pangasiid catfish did not influence the growth of mrigal. The growth of pangasiid catfish varied with stocking density, and they grew best at 5,000/ha ($T_3$). The carp and the combined fish yields were significantly higher in the carp polycultures with pangasiid catfish than with carps alone. The total carp and the combined fish yields were highest in $T_4$, in which the density of pangasiid catfish was greatest. However, the total carp and the combined fish yields in $T_3$ and $T_4$ were not significantly different. Profit differed significantly among treatments. Economic gain was highest in $T_3$, with 5,000/ha of pangasiid catfish, and lowest in $T_1$. The inclusion of pangasiid catfish in major carp polycultures results in higher fish yields and greater economic gain.

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.110-115
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• 2016

This study was conducted in order to investigate the growth and morphological development of Cypselurus hiraii larvae and to obtain basic data for taxonomic research. Specimens for this study were collected using a scoop net (aperture Ø60 cm) at the Geomun Island in Yeosu-si, Jollanam-do in July and August of 2013, and the mean water temperature was $20.6{\pm}1.84^{\circ}C$ and the mean salinity was $32.1{\pm}0.46$‰ during the collection. In post-larvae of total length 9.58~9.69 mm (average $9.63{\pm}0.04mm$, n=5), the mouth was opened, and the maxilla was shorter than the mandible. The length of the dorsal fin did not exceed that of the ventral fin, and the dorsal fin was on the same line as that of the ventral fin. In post-larvae of total length 18.0~18.5 mm (average $18.2{\pm}0.22mm$, n=5), with the growth accelerated, the pectoral fin was developed broadly and their caudal fin was differentiated into the heterocercal tail. These characteristics suggest the development of swimming ability and resultant active feeding activities. In post-larvae of total length 22.4~23.0 mm (average $22.7{\pm}0.21mm$, n=5), striped melanophores deposited in the pectoral fin, and small spot-like melanophores expanded in the processes formed on the mandible. The dorsal and anal fins were on the same line, and the anal fin was situated behind the dorsal fin.

• Journal of Distribution Research
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• v.16 no.5
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• pp.123-140
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• 2011

This study analyzed large distributors' trade features with local suppliers and their direct purchase features through the survey and the interview targeting some MDs(Merchandisers) in large retailers responsible for buying fresh foods (agricultural, fishery, livestock and proceeded products). As the result of conducting the survey targeting the large purchase MDs, it was found that when they select local suppliers, they importantly consider the factors of stable products supply, the quality management, the aggressive management attitude, the affordable (cheap) price, and the suggestion of differentiated goods in order. Concerning their direct purchases in local places, their preference toward the direct-purchase traders were higher than that toward vendors and whole markets as their existing major traders. Among the traders for direct purchase, they preferred farm corporations (including agricultural corporations) the most, and followed the National Agricultural Cooperative, and the unit agricultural cooperative in order. Regarding to the trades with suppliers, when they set the trade price, the merchandisers (MDs) of large distributors preferred long-term trades over 2 years, and utilized the factors of market rate(50.9%), production cost(31.2%) and sale price in the same industry(18.0%). For the local distribution organizations to aggressively counteract the changes of distribution environment in the consumption places, it needs some strategies to organize the agricultural production, to expand the production size and to specialize the distribution channels. And the supply system's continuality and stability are required, so it needs to establish the counteract system enabling to supply all year round through the link of production organizations. Additionally, as an effort to intensify the market negotiation ability, it should collect various market information from the consumption places.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.879-886
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• 2014

This study was conducted to test in vitro the antagonistic effect of composted liquid manure (CLM) against soil-borne turfgrass pathogenic fungi, Rhizoctonia solani AG-2-2 (IIIB) (brown patch), R. solani AG-2-2 (IV) (large patch), and Sclerotinia homoeocarpa (dollar spot) for environmentally friendly turfgrass management. CLMs were collected from 9 livestock excretion treatment facilities around the country including Gunwi (GW), Hapcheon (HC), Hoengseong (HS), Icheon (IC), Iksan (IS), Muan (MA), Nonsan (NS), and Yeoju (YJ). CLMs of IC, GW, and IS showed s ignificant (p < 0.05) mycelium growth inhibition that was 17.8%, 20.4%, and 48.0% against R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. A t otal of 110 bacterial isolates were obtained from the CLMs that showed antagonistic effects. Among them, 5, 4, and 10 microbe isolates showed promising antifungal activity against mycelium growth of R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. The bacterial isolates ICIIIB60, GWIV70, and ISSH20 effectively inhibited the mycelial growth of three soil-borne turfgrass pathogens. Selected bacterial isolates were identified as Alcaligenes sp., Bacillus licheniformis Ab2, and B. subtilis C7-3 through 16s rDNA gene sequence analysis. Among 5 fungicides, the most compatible fungicide with ICIIIB60, GWIV70, and ISSH20 was tebuconazol, toclofos-methyl and toclofos-methyl, respectively. These findings suggested that CLMs could be effectively used not only as organic liquid fertilizer sources but also as biological control agents for soil-borne turfgrass diseases such as brown patch, large patch, and dollar spot.

• Korean Journal of Organic Agriculture
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• v.27 no.2
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• pp.193-204
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• 2019

The aim of this study was to investigate the effect of hazard analysis and critical control point (HACCP) system application on microbial hazard management levels of pork and manufacturing environments. In this study, we compared and analyzed microbial levels in raw meat, finished products, and manufacturing environments (knifes, gloves, and cutting boards) of HACCP and non-HACCP meat markets. In addition, we surveyed the hygiene statuses of HACCP and non-HACCP meat markets. The general bacterial counts in raw meat, finished products, and manufacturing environments were lower in HACCP meat markets than in non-HACCP meat markets. Particularly, non-HACCP meat markets exceeded the Ministry of Food and Drug Safety microbiological recommendation criteria for raw meats (8.7%) and finished products (8.7%). Escherichia coli and coliform counts in raw meat, finished products, and manufacturing environments were also lower in HACCP meat markets than in non-HACCP meat markets. The biological hazard levels of finished products from non-HACCP meat markets were affected by raw meat and manufacturing environment. Moreover, according to questionnaire survey results, personal hygiene, manufacturing environment, and facility standards were lower in non-HACCP meat markets than in HACCP meat markets. Implementation of HACCP at meat markets is expected to minimize food poisoning by reducing the biological hazard levels to provide safe livestock products to consumers.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.369-378
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• 2011

Incidence of mastitis is highest in dairy cows and it is a leader of all diseases and the economic losses, in dairy farms. The objective of this study is to analyse the incidence of clinical mastitis using the lactation number, lactation month and season of calving. In this study, we used 3,779 lactation data and animal health records collected from 1990 to 2006 at the National Institute of Animal Science. Out of 3,779 cows, a total of 1,721 cows were reported with clinical mastitis, which was 46.3%. The frequency of mastitis increased from 36.9% from first lactation to 56.0% by the fifth lactation. As many as 766 cows (46.9%) showed a recurrence of mastitis after 14 days, apart for two or more and chronic mastitis that were recorded for 657 cows (20.3%). This came to a total of 3,010 cases that had clinical mastitis in the herd for sixteen years. The distribution of incidence of clinical mastitis was highest during the first month of lactation at 24.4%, and it reached to 43.4% by the third month. The incidence of mastitis was even higher for cows in first lactation, showing 28.6% in the first month, and 42.9 percent by third month of lactation. Cows calved during the summer and winter months showed higher rate of incidence with 59.9% and 57.9% within 30 days of lactation, respectively. It is urgently needed to establish a preventative management for heifer cows during their expected first lactation and the clinical specific dry-period management strategies that influence the rate of clinical mastitis during the next lactation. The aim of this study is to present information that might be useful to improve clinical mastitis prevention.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.6
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• pp.117-129
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• 2021

The movement of animals is one of the primary factors that influence the variation of livestock emissions. This study evaluated the relationship between animal activity and three major emissions, PM₁₀, PM_2.5, and ammonia gas, in weaning, growing, and fattening pig houses through continuous monitoring of the animal activity. The movement score of animals was quantified by the developed image analysis algorithm using 10-second video clips taken in the pig houses. The calculated movement scores were validated by comparison with six activity levels graded by an expert group. A comparison between PMs measurement and the movement scores demonstrated that an increase of the PMs concentrations was obviously followed by increased movement scores, for example, when feeding started. The PM₁₀ concentrations were more affected by the animal activity compared to the PM_2.5 concentrations, which were related to the inflow of external PM_2.5 due to ventilation. The PM₁₀ concentrations in the fattening house were 1.3 times higher than those in the weaning house because of the size of pigs while weaning pigs were more active and moved frequently compared to fattening pigs showing 2.45 times higher movement scores. The results also indicated that indoor ammonia concentration was not significantly influenced by animal activity. This study is significant in the sense that it could provide realistic emission factors of pig farms considering animal's daily activity levels if further monitoring is carried out continuously.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.273-288
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• 2021

We analyzed the spatio-temporal distribution characteristics of water quality and phytoplankton communities in the Isa Stream systems (ISS) from Sangsa Lake to Suncheon Bay. Sangsa Lake showed relatively oligotrophic and mesotrophic conditions, but the freshwater and mixed brackish water zones showed more severe eutrophication than Sangsa Lake and Suncheon Bay due to the influence of industrial waste such as livestock waste. In terms of the phytoplankton community, the number of phytoplankton species was higher in freshwater and mixed brackish water zones than in Sangsa Lake and Suncheon Bay, but the cell density and Chlorophyll-a concentrations (Chl-a) were relatively high in Sanga Lake and Suncheon Bay. In particular, the mesotrophic species Fragilaria crotonensis and Asterionella formosa showed different dominance in the surface and bottom layers, and the influence of A. formosa was significant in the freshwater and mixed brackish water zones in spring and summer. However, Skeletonema costatum-ls, a eutrophic indicator species, dominated in mixed brackish water zones to seawater in autumn and winter. Thus, the severe eutrophication and rapid environmental changes in the ISS could seriously damage the coastal ecosystem in Suncheon Bay. These ecosystem changes are threatening in terms of conservation and management of the UNESCO Suncheon Biosphere Reserve and Yeoja Bay including Suncheon Bay, which recorded the first Ramsar wetland in Korea. Therefore, further research is needed to establish an in-depth management plan.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.667-675
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• 2022

Agroforestry is an ecological and economic land-use system that enables sustainable agriculture by combining forestry, agriculture, and livestock industries. North Korea chose agroforestry as a strategy for the restoration of sloping land and deforested land. Agroforestry was proposed for the inter-Korean forest cooperation subcommittee meeting and is currently highlighting carbon removal and promoting the '2050 Carbon Neutral Strategy' and 'Korea Peninsula Green Détente.' The study area, Suan-gun, Hwanghaebuk-do, is a constant deforestation monitoring area and a pilot site for management by the International Center for Research in Agroforestry. The requirements for agroforestry were analyzed through literature analysis. The agroforestry site-suitability map was visualized by applying GIS overlap analysis. Approximately 8,839 ha of sloping area was selected as suitable for agroforestry management, which is about 15% of Suan. We compared the map with Google Earth images and visually detected the land use status, such as agroforestry in Suan, to verify the results. As a future study, we will consider both natural-environment and socioeconomic factors and evaluate the relative importance of the factors to produce a high-accuracy agroforestry sitesuitability map at the national scale with the goal of producing basic data for the inter-Korea forest cooperation policy for long-term goals.