• Journal of the Korean association of regional geographers
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• v.6 no.3
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• pp.37-52
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• 2000

Generally speaking, the metropolitan agricultural regions have some advantages from the high accessibility to markets. But agriculture inevitably rests on the biological process. This study shows what characteristics of the agricultural management are found in these less favored metropolitan areas with bad natural conditions and how farm household live there. From the view point of farm household, the quality of labors they can get is quite low, and insufficient in quantity. The shortage of labor can be made up for the farming on Trust Farming System And the relatively less favored agricultural conditions prevent people from immigrating into these kind of areas, if they don't have any relationship with there. With bad natural conditions, the farm households usually cultivate relatively small areas for the purpose of self-sufficiency, and with smaller cultivating units(Baemi) of the land than in open fields. The scale of the agricultural management is largely affected by the ages of agricultural managers. The more aged the managers are, the smaller scale of the agricultural management. How to use lands is determined in accordance with the natural conditions such as percentage of sunshine and accessibility to drainage facilities -the two major factors- and more. Either owner-run farmlands or leased farmlands doesn't show any difference in each growing crops. Depending on the conditions of the lands, rice paddy is used for growing rice and field is used for growing self sufficient plants including vegetables for the farm household. Although the lack of infrastructure causes the inconvenience of living, and there exist less favored agricultural conditions, this kind of life and agricultural management style -self-sufficiency type- seems to be sustained quite longer. The less favored natural conditions for farming keeps the agricultural management style from being developed to be the level of commercialization. And the poor economic situation of farmers are continuing again and again. With the result of this study, there should be two conditions to be established previously if they want to develop these regions. First, each farm household should get to know of the importance of commercialization and try to spread it. The commercialization. should be attained through the expansion of the environmental friendly agriculture and the improvement of the previously established distribution system of the crops. Secondly, there should be a support from the government. The support will include the expansion of the infrastructures for fanning to improve the fanning conditions and the compensation system directly from the government to the farmers.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.489-507
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• 1996

The purpose of this study is to examine the increasing number of unregistered manufacturing plants and related problems, and to recommend alternative solutions to the problems. Data are obtained from a field survey of randomly selected small scale manufacturing plants in Seoul and its suburban cities. A total number or respondents are 533, and 416 of them are unregistered plants. The Capital Regional Planning has had a goal during last three decades to lead a balanced regional economic development by restriction manufacturing plants in the Capital Region and by encouraging them in other regions in the nation. It was 1984 when a comprehensive planning was established to achieve this goal. Sets of various regulations, by-laws and codes have been implemented to regulate manu-facturing activities in the Capital Region to achieve the goal. The region is divided into three sub-regions, and a different degree of regulations is applied to each sub-region. Only a certain types of industries are allowed in a particular sub-region. For instance, a plant manufacturing high-technology products could be allowed in the most urbanized sub-region. All manu-facturing plant in the Capital Region which has ares size of larger than 200"\;"$m^2$ is compulsory to register to the local government office. In practice, however, it is not common or sometimes almost impossible to get approval for many applicant manufacturers because of strict regulations. There have been increasing number of plants in the Capital Region during last several decades, despite the strict regulations. Many of those newly established plants are without formal registration at the local administration office. howerver. These are so called 'unregisterd' plants. Surveyed data and many government official data show that many of unregistered plants have been established in recent years. which indicate that current regulations are no longer effective. The number of unregistered plants are increasing tin the Capital Region because of many locational advantages in the region for plants, particularly those in small scale. Unregistered plants are the source of many problems, such as local water pollution or noise pollution in residential areas. There are also many administration problems, bed\cause they are not registered. The central government has attempted to cure the problems of unregistered plants. For example, the government allowed a unregistered plant to remain at present site for three ydars, if it met certain conditions in three years. However, this program was unsuccessful because many of those plants were not able to meet the concitions. Three times the government renewed the term for those which did not meet conditions since 1989, but it was afraid to be without success. There are many evidences that current policies to control manufacturing plants are not effective. The Capital Region must face mounting problems if ploicies are not reformed soon. This study suggests that the policy of the Capital Regional Planning has to be reoriented to provide more favorable policies for manufacturing plants in the Capital Region than current regulations which is aimed to restrict manufacturing activities. It is time to improve many existing problems in the region through reforms and of current regulations to foster unregistered plants. This study also proposes many smaller-area sub-divisions instead of current three large area sub-regions which is too broad to apply single kind of regulation, or codes. Flexible regulations and codes can be applied to such a small-area sub-divivisions based on location and industrial characteristics of the individual sub-divisions. It is necessary to provide decent industrial environment in the Capital Region, which is best equipped to provide many favorable industrial locational factors in the nation, thus this nation can be further prepared to compete in an inter-national market at an era of globalization in manufacturing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.219-225
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• 2012

Seed size has been considered as an effective criteria for selection of the most vigorous seeds in sorghum [(Sorghum bicolor (L) Moench]. The smaller seeds were inferior to the larger sizes in emergence and grain yield. This study was conducted to determine germination rate, field emergence and vigor of sorghum for selection of high quality seed by different seed size. Sorghum cultivar of two (Hwanggeumchal and Tojong) were separated into five seed size proportion (<2.36, 2.80, 3.15, 3.35 and >3.55 mm diam.) according to seed size. The larger seed was more higher 1,000 seeds weight, seed density, carbohydrates and protein content. Total seed germination performing varied 92% at the largest size (>3.55 mm diam.) frequently inferior to slightly 67% at smaller seed (2.36 to 2.80 mm diam.) in the standard germination test. Seed size did have a significant effect on mean emergence time (MET) and maximum emergence rate index (ERI) and percentage of emergence. It should be noted that the results refer to MET of sorghum seeds ranging from 4.26 to 4.74 days. The relationship of seed size was not only to stand establishment but to grain yield. Yield was most affected by seed size and large seeds were superior to the smaller seed in 25~37% of the cases. Especially, yield was significant under 3.15 mm the beginning.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.305-317
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• 2005

This study addresses the preliminary results of rock slope stability analyses including hazard assessments for slope failure conducted on the selected sections of rural road cut slope which are about 4 km long. The study area is located in the Mt. Chuntae northeast of Busan and mainly composed of Cretaceous rhyolitic ash-flow tuff', fallout tuff, rhyolitc and andesite. The volcanic rock mass in the area has a number of discontinuities that produce a potentially unstable slope, as the present cut slope is more than 70 degrees in most of the slope sections. Discontinuity geometry data were collected at selected 8 scanline sections and analyzed to estimate important discontinuity geometry parameters to perform rock slope kinematic and block theory analyses. Kinematic analysis for plane sliding has resulted in maximum safe slope angles greater than $65^{\circ}$ for most of the discontinuities. For most of the wedges, maximum safe cut slope angles greater than $45^{\circ}$ were obtained. Maximum safe slope angles greater than 80" were obtained fur most of the discontinuities in the toppling case. The block theory analysis resulted in the identification of potential key blocks (type II) in the SL4, SL5, SL6 and SL8 sections. The chance of sliding taking place through a type ll block under a combined gravitational and external loading is quite high in the investigated area. The results support in-field observations of a potentially unstable slope that could become hazardous under external forces. The results obtained through limit equilibrium slope stability analyses show how a stable slope can become an unstable slope as the water pressure acting on joints increases and how a stable slope under Barton's shear strength criterion can fail as the worst case scenario of using Mohr-Coulomb criterion.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.685-693
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• 2008

The rates of oxidative degradation of perchloroethene (PCE) and trichloroethene (TCE) using $KMnO_4$ solution were evaluated under the flow condition using a bench-scale transport experimental setup. Parameters which are considered to affect the reaction rates tested in this study were the contact time (or retention time), and the concentration of oxidizing agent. A glass column packed with coarse sand was used for simulating the aquifer condition. Contact time between reactants was controlled by changing the flow rate of the solution through the column. The inflow concentrations of PCE and TCE were controlled constant within the range of $0.11{\sim}0.21\;mM$ and $1.3{\sim}1.5\;mM$, respectively. And the contact time was $14{\sim}125$ min for PCE and $15{\sim}36$ min for TCE. The $KMnO_4$ concentration was controlled constant during experiment in the range of $0.6{\sim}2.5\;mM$. It was found that the reduction of PCE and TCE concentrations were inversely proportional to the contact time. The exact reaction order for the PCE and TCE degradation reaction could not be determined under the experimental condition used in this study. However, the estimated reaction rate constants assuming pseudo-1st order reaction agree with those reported based on batch studies. TCE degradation rate was proportional to $KMnO_4$ concentration. This was considered to be the result of using high inflow concentrations of reactant, which might be the case at the vicinity of the source zones in aquifer. The results of this study, performed using a dynamic flow system, are expected to provide useful information for designing and implementing a field scale oxidative removal process for PCE/TCE-contaminated sites.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.171-177
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• 2012

Pepper seedlings of 6-leaf stage were inoculated with cell suspension of Xanthomonas euvesicatoria 1523 7 days after the application of Bion-M by soil-drenching. Disease severity in the treatment with 20 ${\mu}g\;mL^{-1}$ of acibenzolar-S-methyl, with which Bion-M was composed, was 19%, whereas that of the untreated control was 75%. The resulting control value of acibenzolar-S-methyl was calaulated as much as 74.7%. The control value of acibenzolar-S-methyl was dependent with the applied concentrations and ranged 29.3% to 49.3% at 4.0 and 0.8 ${\mu}g\;mL^{-1}$ of acibenzolar-S-methyl, respectively. Phytotoxicity was observed at 20.0 ${\mu}g\;mL^{-1}$, as lower leaves became to be yellowed and defoliated. The cell density of inoculum suspension of X. euvesicatoria 1523 affected the control value of acibenzolar-S-methyl. With optical density (O.D.) of 0.5 the control value of 4.0 ${\mu}g\;mL^{-1}$ of acibenzolar-S-methyl was 86.0%. However, the control value improved as high as 97.8% at the O.D. value of 0.1. The control value was 75.0% in adult plant of pepper, when acibenzolar-S-methyl was treated by soil-drenching 7 days before inoculation with cell suspension of X. euvesicatoria 1523. The control effect of acibenzolar-S-methyl on pepper bacterial spot was obtained in pepper field, showing that the control value at 10.0 ${\mu}g\;mL^{-1}$ was 71.2%.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.217-221
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• 2012

This study was carried out to evaluate residual characteristics of tolclofos-methyl in ginseng and elucidate the reason for its high detection rate from fresh ginseng selling at markets. Seeds of ginseng were sowed after seed dressing with tolclofos-methyl and after a year of growth, the young seedlings were transplanted to field. They were then harvested annually until three-years of growth and the pesticide residue was analyzed in them. LOD and LOQ of the pesticide were 0.001 and 0.003 mg/kg, respectively. Recovery test was carried out to validate the analytical method for tolclofos-methyl in ginseng. The ginseng seedlings were fortified with the test pesticide at the level of LOQ, ten times of LOQ and maximum residue concentration of tolclofos-methyl. Its recovery ranged from 77.37 to 100.16%. Residual concentration of tolclofos-methyl in ginseng seedlings just before transplanting and two-year-old ginseng were from 7.58 to 8.05 and from 6.46 to 6.79 mg/kg, respectively. In case of three-year-old ginseng, it was found to be from 4.18 to 4.35 mg/kg. As a result of annual pesticide residue analysis, concentration of the pesticide was found to decrease time-coursely in ginseng. This may be due to decomposition and increasing of fresh weight of the ginseng during the cultivation periods of three years.

• Research in Plant Disease
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• v.24 no.2
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• pp.153-161
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• 2018

We selected eight resistant cultivars including 'Heukryongsamcheok', 'Heukgeumsolsamcheok' and 'Gangryeoksamcheok' showing high suppressive effect against cucumber downy mildew (CDM) through plastic film house and field trials in spring and autumn season in 2015. Of them, these three varieties, 'Heukryongsamcheok', 'Heukgeumsolsamcheok' and 'Gangryeoksamcheok' were used to evaluated suppressive effect against CDM by comparing disease severity (area under disease development progress curve, AUDPC) with those of three susceptible varieties under plastic film house condition. AUDPC of three resistant cultivars was in the range of 10.9 to 23.6, meanwhile those of three susceptible cultivars was in the range of 286.7 to 290.3. Consequently, we confirmed that cultivation of the selected resistant cultivars can reduce CDM in vivo. When disease severity (diseased leaf area) was investigated on a resistant cultivar ('Heukryongsamcheok') sprayed without any organic materials and susceptible cultivars sprayed single-, two times- and three times with Bordeaux mixture, sulfur-loess mixture and $Kocide^R$ (copper hydroxide), respectively, it was the lowest in the resistant cultivar plot compared to susceptible cultivar plots sprayed with any organic materials. In addition, we evaluated control effect of the selected resistant cultivar by comparing that of organic materials including lime sulfur mixture, Bordeaux mixture and garlic extract. As a result, Bordeaux mixture showed the highest control effect against CDM. AUDPC of Bordeaux mixture, resistant cultivar, lime sulfur, garlic extract and untreated control was 3.9, 10.6, 95.6, 24.9, and 258.7, respectively. Based on the above-mentioned results, we think that the resistant cultivars and Bordeaux mixture can be effectively used to control CDM as one of control measures under the farmhouse condition.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.77-101
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• 2009

Organic farming in Korea has mainly focused on producing vegetables in plastic film house and cereals in paddy field. For high productivity of vegetables and cereals, most Korean farmers have not applied crop rotation in the cropping system. Thus, this study was carried out to evaluate the effects of crop rotation on the yield of red pepper and green onion, the changes in soil fertility and the potential as green manure of rye and hairy vetch. Rye and hairy vetch were cultivated for winter season every year, and directly incorporated into the soil. The yield of red pepper fruits in organic farming using crop rotation (OFCR) decreased 23 to 36% compared with conventional farming system (CFS). Whereas, green onion showed the increased yield of about 13%. In OFCR, total carbon content of soil was higher, however available phosphate content lower than conventional farming. As a result of measuring the bulk density of soil, OFCR and CFS were 1.26 to $1.35Mg/m^3$ and 1.37 to $1.42Mg/m^3$, respectively. Carbon and nitrogen contents of microbial biomass in OFCR were obviously higher compared with the CFS. In the plot cultivated rye for winter season, the weed germination was strongly reduced (about 52 %). Balance of macro nutrient elements, nitrogen and phosphate, in the application of rye and hairy vetch had a minus value. For potassium, the output value was higher than the input one, therefore organic farming under red pepper-rye or hairy vetch systems requires applying additional potassium input. Also, we selected two hairy vetch varieties of cv. Hungvillosa and Ostsaat which can be adapt at Korea climate. In order to estimate a yield of green manures, the weight of shoot and root was measured. The ratio of shoot and root between rye and hairy vetch showed 0.88 and 1.91, respectively. The potential levels of nitrogen, phosphate and potassium which could be supplied from rye were 7.7, 7.8 and 21.9 kg/10a and from hairy vetch were 17.0, 8.6 and 22.9 kg/10a, respectively. So we recommend that cultivating hairy vetch, as a nutrient supplier, and rye, as an amendment to enhance the soil physical property, for winter season be practical method in Korea organic farming system.

• Korean Journal of Organic Agriculture
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• v.18 no.1
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• pp.93-104
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• 2010

This study was conducted screening of the population densities of fungal pathogens and insect and observed the disease symptoms on the organic sweet corn seed producing field from 2008 to 2009. The dissemination spores, Alternaria sp., Cladosporium sp., Helminthosporium sp., Pyricularia sp., Collectotrichum sp., and Bipolaris sp., were detected and the three fungal spores from the front were observed for whole growth stage. Seed and seedling diseases were shown as the rotted seed and damping-off seedling caused by Penicillium sp. and Rhizoctonia sp.. The larva of Black cutworm cut down the root crown of seedlings. The damaged plants were ranged from 14% to 16%. On the Oriental corn borer, the population densities and the percentage of damaged plants were showed a low difference between two sweet corn varieties. The population densities of Oriental corn borer were scored as from 3.5 to 20.5 in 2008 and from 0.5 to 6 in 2009. Also the percentage of damaged plants were significantly increased until harvesting stage and was recorded from 7.5% to 21% in 2008 and from 1% to 46% in 2009. On the Corn leaf blight, the percentage of diseased plant were scored from 7% to 34% in 2008. The first occurrence of date was after June 18, and the percentage of diseased plant was continuously increased after August 21 and the values of diseased plants was ranged from 56% to 69% in 2009. On common smut, the percentage of diseased plant was recorded from 5% to 15% in 2008, and the first occurrence date were delayed as 17 days (July 17) and were showed less than 8% of diseased plants in 2009. Corn Southern Leaf spot was scored as average 11% at early stage and showed high score as 62% at September 19 in 2008. In 2009, the first occurrence date were advanced about 20 days (after June 8), and continuously increased up to 86% in 2009.