• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.69-74
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• 2002

This study was conducted to investigate the milk quality produced from dairy farms in Jeju province and to analyze the variety of pathogenes and the number of somatic cells in the milk. Data were collected from 262 lactating cows from 8 farms of three regions and the results obtained are summarized as follows. 1. The average daily milk yields and milk fat contents from June and October were 22.3 kg and 3.7%, respectively. 2. The average number of bacterial counts in raw milk was 1.5${\times}10^4$/ml, but that in farm A was over 3.0${\times}10^4$/ml. 3. The somatic cell counts were 2.5${\times}10^5$/ml in average and those in farm G and H were higher than those in other farms. Their distribution in 262 lactating cows from June to October was as follows; less than 2.0${\times}10^4$ /ml in 68.8% of cows, 2.0-5.0${\times}10^4$/ml in 18.8% of cows and more than 5.0${\times}10^4$/ml in 12.4% of cows. 4. Of the 113 isolates (compartments of cow udder) from mastitic milk, Staphylococcus aureus was found in 47, Streptococcus ogalatiae in 17 and Bacillus in 12. 5. The average monthly income of the farmers was 407 thousand won/head, and that in farm A or E was higher than that of farm H (456-475 thousand won vs. 314 thousand won) In conclusion, to improve income dairy farmers should reduce the somatic cell counts in the milk and mastitis infection through regular disinfection and inspection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.84-90
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• 1986

An experiment was conducted to know the effects of planting dates (March 5, 15, and 25 and April 4) and transparent polyethylene (P.E.) film treatments(tunnel, tunnel slit, and mulch) on air and soil temperatures and growth and yield of a sweet corn variety, Great Bell. Maximum air and soil temperatures and minimum air and soil temperatures were greater at tunnel>tunnel slit>mulch in that order. Differences in maximum air and soil temperatures among the P.E. film treatments were much greater than those in minimum air and soil temperatures. However, when film was opened due to high air temperature over 40$^{\circ}C$ in the tunnel, air temperature was similar but soil temperature was lower com-pared to mulch. High temperature stress could be avoided in tunnel slit without opening film by increase in the number of slits. Cold damage of corn seedlings was avoided by tunnel and reduced by tunnel slit, and frost-damaged seedlings under the mulch were recovered in few days. The number of days from planting to silking was reduced as planting date delayed. At early plantings, tunnel enhanced early growth and silking, but it delayed at late plantings because tunnel was opened during the most of day time due to high temperature. Black streaked dwarf virus(BSDV) disease was more severe at early plantings and it was reduced in tunnel slit at late plantings because plants were grown under the film at the time of infection. The number of marketable ears was similar among all treatments except mulch at March 5 planting where BSDV was severely infected. Gross income was high in tunnel and tunnel slit at March 25 planting which had more larger marketbale ears and tunnel and tunnel slit at March 5 planting which had higher market price.

• Journal of Sericultural and Entomological Science
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• v.24 no.1
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• pp.19-24
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• 1982

This experiment was carried out to develope a new planting system from the economical point of view, using the various sizes of mulberry saplings ranged from 3mm to 7mm (3, 4, 5 and 7mm) in diameter of branches. They were planted densely (2,285 trees/10a) in vinyl film-and non-mulching system. The results are summarized as follows. 1. There are no differences in growth and yield of the planting year between 6mm and 7mm saplings. 2. The vinyl mulching affords an abundant growth of the saplings due to retaining of soil temperature and moisture. The dense planting with vinyl film mulching gave rise to 26% and 7% increase of leaf yield, using the saplings sized of 7mm and 5mm, respectively. 3. On the other hand, it was evident that the use of 6mm saplings in non-mulching and 5mm ones in mulching redused possibly the sapling cost. It was also noteworthy an additional profit took places in the yield increase, the cost reduction of saplings and weeding by using the 7mm and 5mm saplings in mulching system. It amounted to the increase of ￦33,800 and ￦24,520, respectively over the use of 7mm saplings in non-mulching system.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.426-433
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• 2012

This study was carried out for preliminary feasibility review to consult forest farmer, to make policy and to search improvement for Ligularia fischeri forest farm. The survey for eight Ligularia fischeri forest farmer in Inje-gun was conducted. And the case study was conducted with computing labor input, gross margin, net margin in each planting stages, which is contented each cultivating stage from creating to harvesting. B/C ratio, Net Present Value and Internal Rate of Return were used for profitability analysis. The results applied 3% of discount rate showed IRR 48.6%, B/C ratio 1.5 and NPV 41 million KRW, which means high profitability. Forest farming is early step in Korean forestry so that standard methods of cultivation for that haven't established yet, and differences among farmers in productivity are being. Establishing organized methods of cultivation in each stages and being political supports are essential for income generation to forest households, supply of safe food and rest place for urbanity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.538-545
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• 2020

This study measured the economic impact (from 2012 through the end of 2017) of the KOR-USA FTA (Free Trade Agreement) on the Korean citrus industry according to importing orange from the USA after the implementation of the KOR-USA FTA. Citrus fruits were divided into field citrus grown in open fields, house citrus grown in green houses, and late-maturing citrus (including winter season citrus) based on the cultivation methods and the varieties of citrus. We specified the structural and dynamic recursive demand-supply equilibrium models of three citrus fruits to analyze policy simulations. The results showed that for field citrus, due to the impact of some amounts of TRQ, the annual average of the real gross revenue dropped by 2.39 billion KRW between 2012 and 2017. As for house citrus, due to the impact of oranges and cherries, the annual average of the real gross revenue declined by 3.01 billion KRW between 2012 and 2017, and for late-maturing citrus (including winter season citrus), the annual average of the real gross revenue fell by 15.11 billion KRW between 2012 and 2017. This paper also suggests several policy implications.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.373-386
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• 2017

The study was conducted to investigate seasonal nutrient dynamics in rice-cultivated soils collected from farmhouses of three large-scale environment-friendly agricultural districts (LEAD), Jangheung, Suncheon, and Okcheon in which environmental-friendly agriculture has been exemplarily practiced in Korea. Among three districts, Crop- livestock cycling organic farming system had been introduced only in Jangheung. pH and EC of farmhouse soils of three LEADs were ranged between 5.5 - 6.7 and $0.4-1.0dS\;m^{-1}$ from March to September, respectively. T-N was observed to be high on the farmhouse soil in Suncheon and K was observed to be lowest on farmhouse soil in Okcheon. Concentration of $NH_4-N$ in soil was observed to be highest on June, in particular on the farmhouse in Jangheung, but rapidly decreased due to the loss of fertilizer applied in Spring. Yield and harvest index were the highest on the farmhouse in Okcheon in which total annual gross production $ha^{-1}$ was nearly three time higher than those of other two farmhouses. Farmhouse soil of Okcheon was maintained the highest seasonal nutrient balance due to the high input of fertilizer. It was estimated that K balance in the farmhouse soil in Suncheon dropped to $-60kg\;ha^{-1}$ on September, and it might have some effect on the less rice productivity due to K deficiency. Farmhouse soil in Jangheung was maintained low seasonal balance of T-N and P but showed the highest N use efficiency in the rice grain. Based on above-mentioned results, we think Jangheung farmhouse can be recommended as a model farmhouse of LEADs.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.248-253
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• 2015

This study applied the portfolio approach as a means to provide decision-making information for the establishment of the optimal production plan for non-timber products. The target items of non-timber forest product were Chestnut, Jujube, Walnut and Astringent Persimmon. The data used in this study were the annual report of forestry production cost survey which contains the annual production, annual gross income, and annual product cost from 2008 to 2013. These data were used to calculate the expected return of non-timber forest product. The objective function in the portfolio models was to minimize the expected return volatility, called risk and the constrain was to achieve the minimum expected return rate. Results indicated that the production ratio of the nuts and fruits in 2013 was 7% for Chestnut, 20% for Jujube, 5% for Walnut and 68% for Astringent Persimmon. Furthermore, portfolio presented that the production ratio was 10% for Chestnut, 9% for Jujube, 3% for Walnut and 78% for Astringent Persimmon in the near future. The cause was analyzed due to maintain stable production and income of Astringent Persimmon and Chestnut. Meanwhile, the revenue of Walnuts and Jujube was in great variation with relatively higher revenues.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.401-407
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• 2007

This study analyzed an economic efficiency of oak mushroom cultivation in order to provide data needed for formulating related policies. 88 farmhouses in major producing areas were interviewed with. The average production cost per 100 bed-logs was 151,699 won. Among production costs, material costs accounted for 56.0% and labor costs 41.8%. Oak mushroom cultivation was labor-intensive and labor input was a significant factor determining the production costs. There was 3 7.2% gap in production costs between Chungbuk, the highest cost area and Gyeonggi, the lowest cost area of oak mushroom due to difference in labor input. Average revenue per 100 bed-logs was 178,627 won. Average income per 100 bed-logs, which is variable production costs of 116,613 won subtracted from the revenue, was 62,014 won and thus income rate was 34.7%. Income rate in Jeonbuk, the highest area, was higher than that in Gyeonggi, the lowest area, by 15.8% points due to difference in quantities produced, grade, and variable production costs, in particular, labor costs. The result of the economic analysis indicates that reduction in establishment and labor costs, accounting for the highest portion in production costs is priority issue for the enhancement of the competitiveness of the oak mushroom industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.725-731
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• 2020

This study analyzed the impact of increasing orange imports on the domestic fruit markets, focusing on the period January to May when oranges were imported and sold intensively after implementation of the Korea-US FTA. In this study, only citrus fruits that compete with U.S. oranges were limited to domestic fruits; of these, Hallabong, which is consistent with consumption of U.S. oranges, was selected as an analysis target. A dynamic recursive simulation model was established to evaluate the ex-post effects of the Korea-U.S. FTA, and to conduct mid and long-term forecasts for the Hallabong market. In addition, major policy simulations were performed on the Hallabong market to assess the effect of each scenario. The ex-post impact evaluation reveals that between December and February, Hallabong had no effect on the seasonal tariff of oranges. However, from 2012 to 2017, the actual import decreased by 21.9 billion won annually due to the TRQ, with the accumulated 6-year decrease being 131.5 billion won. Major policy simulation analysis shows that the change in the unit cost of import due to the U.S orange crop and the increase of Hallabong export will help in expanding the market, and thus effectively increase income.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.108-114
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• 2021

Green colored citrus is the immature fruit of the field citrus crop in Jeju, and its demand has been growing recently as it is known to contain a large amount of carotinoid, pectin, and vitamin C. It differs from the traditional varieties of blue tangerine, which are green in February and turn in yellow in March-April. This study analyzed the effects of the increased demand in green citrus on the field citrus industry. For our analysis, a partial equilibrium supply-demand model was established with a dynamic recursive structure using data from 1989-2017. Model calibration was also conducted to determine the best supply-demand model and then, the impacts of increasing demand for green immature citrus in Jeju for 2018-2030 was simulated. The simulation results show that there is no significant impact on the producing area prior to 2022, but there is a distinguishable increase of 18ha in 2023, 52ha in 2025, and 142ha in 2030. It was also predicted that revenue would increase by KRW 7.75 billion on average from 2021-2030.