• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.149-155
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• 2003

Objectives of this research were to fractionate heavy metals in soil samples in the upper Okdong River basin and to assess the potential pollution index of each metal fraction. Soil samples were collected from cultivated land soils and analyzed for physical and chemical properties. pH of cultivated soils ranged from 5.2 to 7.6. Contents of total kelhaldal nitrogen and loss on ignition were in the ranges of 0.6∼2.5%, and 1.9∼12.9%, respectively. Heavy metals in the cultivated land soils were higher in the abandoned closed coal mine near field soils than those in the paddy soils. Total concentrations of metals in the cultivated land soils were in the orders of Zn > Pb > Ni > Cu > Cd, exceed the corrective action level of the Soil Environment Conservation Law and higher than the naturals were abundance levels reported from uncontaminated cultivated land soils. Mobile fractions of metals were relatively small compared to the total concentrations. Soil Pollution Assesment Index(SPAI) values of each fraction of metals were leveled from Non polluted to Moderately polluted based on total concentrations. SPAI values of mobil fractions were lower than those of immobile fractions. Results on metal fractions and SPAI values of the cultivated land soils indicate that field soils samples were contaminated with heavy metals and had potential to cause a detrimental effects on plants. A prompt countermeasure to prevent field soils in the abandoned closed coal mine near fields are urgently needed.

• Journal of Soil and Groundwater Environment
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• v.8 no.4
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• pp.53-63
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• 2003

Objectives of this research were to fractionate heavy metals in soil samples in the upper Okdong River basin and to assess the potential pollution index of each metal fraction. Soil samples were collected from the cultivated land soils and analyzed for physical and chemical properties. pH of cultivated soils ranged from 5.2 to 7.6. Contents of total kelhaldal nitrogen and loss on ignition were in the ranges of 0.6∼2.5%, and 1.9∼12.9%, respectively. Heavy metals in the cultivated land soils were higher in the abandoned closed coal mine near field soils than those in the paddy soils. Total concentrations of metals in the cultivated land soils were in the orders of Zn > Pb > Ni > Cu > Cd, exceed the corrective action level of the Soil Environment Conservation Law and higher than the naturals were abundance levels reported from uncontaminated cultivated land soils. Mobile fractions of metals were relatively small compared to the total concentrations. Soil Pollution Assesment Index (SPAI) values of each fraction of metals were leveled from Non polluted to Moderately polluted based on total concentrations. SPAI values of mobil fractions were lower than those of immobile fractions. Results on metal fractions and SPAI values of the cultivated land soils indicate that field soils samples were contaminated with heavy metals and had potential to cause a detrimental effects on plants. A prompt countermeasure to prevent field soils in the abandoned closed coal mine near fields are urgently needed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.1-15
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• 2006

As the imports of foreign agricultural products are liberalized and the consumption of agricultural products declines, abandoned rice paddy fields continues to rise. However, such abandoned rice paddy fields has not been precisely surveyed yet. In this backdrop, a necessity to develop technology to utilize such abandoned rice paddy fields has emerged. Utilization of abandoned rice paddy fields as wetlands may be a good example. This study aimed to survey the current status and characteristics of wetlands created within abandoned rice paddy fields by selecting abandoned rice paddy fields throughout the nation and conducting field surveys on the sites that had transformed into wetlands. The abandoned rice paddy fields almost transformed into wetland and the types of wetlands transformed from abandoned rice paddy fields were mainly Inland/Moutain/Depression/Abandoned rice paddy fields/Marsh/Phragmites communis community and Inland/Moutain/Depression/Abandoned rice paddy fields/Swamp/Salix koreensis community. Abandoned rice paddy fields that had transformed into wetlands was depending heavily on waterways for water supply than other reservoirs and lakes do. Abandoned rice paddy fields transformed into wetlands was most observed in mountainous area. Abandoned rice paddy fields are because agricultural land is no longer profitable due to international and social changes and is not cultivated as government policy. Wetland period and dimension originated from abandoned rice paddy fields are very various and its surrounding land its mostly forest and the next largest follow roads and rural community. The abandoned rice paddy fields transformed into wetlands is mostly deserted currently. Despite their value as wetlands, no restoration and utilization efforts are made in Korea today. Therefore, it is imperative to conduct a precise current status survey on these areas and introduce management and restoration plans at the government level in the case of important habitats.

• Journal of Korean Society of Rural Planning
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• v.15 no.3
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• pp.81-87
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• 2009

It may be said that a farmer's crisis deepens from the number of farm households and a trend of the number of cultivated land of the farmer attracting attention for the most fundamental numerical value of the Census of Agriculture 2005. A rate of decline of number of farm households seems to have been stopped, but expansion lasts a number of farm households rate of decline. I can, so to speak, watch weakening of flatland area and luck of mountainous areas and a situation to say if I look in that according to classification agricultural area. I can nominate the effect of a direct payment system for farmers in hilly and mountainous areas enforced in 2000 for the background. It is located in case of the policy introduced preceding it while the rural community and the community including the urban area being paid attention as the last resort of a regional reproduction now. In particular, the character as the village activation subsidy has been strengthened in case of the 2nd stage institutional revise.

• Journal of Ecology and Environment
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• v.42 no.3
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• pp.128-138
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• 2018

Background: This study investigated the variation of soil organic carbon in four land cover types: natural and mixed forest, cultivated land, Eucalyptus plantation and open bush land. The study was conducted in the Birr watershed of the upper Blue Nile ('Abbay') river basin. Methods: The data was subjected to a two-way of ANOVA analysis using the general linear model (GLM) procedures of SAS. Pairwise comparison method was also used to assess the mean difference of the land uses and depth levels depending on soil properties. Total of 148 soil samples were collected from two depth layers: 0-10 and 10-20 cm. Results: The results showed that overall mean soil organic carbon stock was higher under natural and mixed forest land use compared with other land use types and at all depths ($29.62{\pm}1.95Mg\;C\;ha^{-1}$), which was 36.14, 28.36, and 27.63% more than in cultivated land, open bush land, and Eucalyptus plantation, respectively. This could be due to greater inputs of vegetation and reduced decomposition of organic matter. On the other hand, the lowest soil organic carbon stock under cultivated land could be due to reduced inputs of organic matter and frequent tillage which encouraged oxidation of organic matter. Conclusions: Hence, carbon concentrations and stocks under natural and mixed forest and Eucalyptus plantation were higher than other land use types suggesting that two management strategies for improving soil conditions in the watershed: to maintain and preserve the forest in order to maintain carbon storage in the future and to recover abandoned crop land and degraded lands by establishing tree plantations to avoid overharvesting in natural forests.

• Journal of the Korean association of regional geographers
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• v.7 no.3
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• pp.74-90
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• 2001

Serious depopulation has occurred since the rapid economic growth after $1965{\sim}1995$. As a result, nowadays most of mountain villages face difficulty in maintaining and managing their settlement, because of the elderly population and the extremely small size of the settlement. Population change is understood as the origin of depopulation problems and the criterion for the depopulation. This study aims to identify the problems of over-depopulation in rural Korea and to classify the patterns and process of follow and to provide policy alternatives. It consists with the three parts : identifying the problems of over- depopulation, classifying the socio-economic factors of fallow land, analyzing a detailed case study of follow land in over-depopulation rural area-Sangju Gun and to provide policy alternatives. The results are summarizes as follows: 1) In the study area, the amount of fallow and abandoned cultivated land has increased since 1975. With the increased urbanization, the cause of the increase in fallow and abandoned cultivated-land is the labor shortage of quantity and quality. The underlying reasons for the abandonment of farmland are poor field conditions and the lack of rented farmland. 2) The secondary cause is a relative labor shortage through specialization into intensive horticulture. In the study area, specialization into pear requires intensive labor input. It has caused a relative labor shortage. 3) The third causes are landowner and the lack of rented farmland due to labor shortage. The declining of agriculture and forestry have caused out-migration and increased non-residents' landowner. 4) The fallow patterns are devided into two types the less favored farmland fallow type, non-residents' landowner(out-migrator) fallow type. The significant causes of the increase in fallow and abandoned cultivated land are the labor shortage, intensive farming, less favored farmland conditions, non-residents' landowner. The factors which caused the follow processes in Korea are socio-economic factors (labor shortage, intensive farming, less favored farmland conditions) and cultural factor(non-residents' landowner, psychological ties between rural areas and urban areas).

• The Korean Journal of Ecology
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• v.20 no.3
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• pp.191-200
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• 1997

The present study was undertaken to classify and describe the weed communities of the fields in Korea by methods of the ZM school of phytosociology. On the basis of the data obtained, the following vegetation units were recognized: A. summer weed community of rice field A-1. Oryzetea sativae: Sagittario-Monochorietum, A-2. Lemnetea minoris: Lemna paucicostata-Spirodela polyrrhiza community B. spring weed community of rice field B-1. Bidentetea tripartitae: Stellario-Ranunculetum cantoniensis C. summer weed community of arable land C-1. Chenopodietea Pinellio ternatae-Euphorbietum pseudochamaesyceslsynonym: Acalypho australis-Digirietum pectiniformis and Cephalonoploso segetti-Geranietum eriostemonii of North Korea in Dostal다 et al.(1990)] and Phyllantho urinariae-Lindernietum crustaceae D. weed community of fallow field D-1. Erigeron sumatrensis-Erigeron anmus community, D-2. Digitaria adscendens-Portulaca oleracea community, D-3. Chenopodium album community, and D-4. Erigeron canadensis-Erigeron annuus community. Generally compared to the Korean Peninsula, the weed communities in the fields of Cheju Island is much plentiful in their species composition.

• Economic and Environmental Geology
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• v.31 no.6
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• pp.499-508
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• 1998

The Imgok Creek is located in the Gangreung coal field, which has been known that sulfides are more abundant than other coal fields in Korea, and it has been severly contaminated by acid mine drainage (AMD) discharging from the abandoned coal mines, such as the Youngdong, the Dongduk and the Waryong coal mines. The purposes of this study are to synthetically assess the contamination of natural water, stream sediment and cultivated soils, and to provide the basic data for AMD treatment. Geochemical samples were collected in December, 1996 (dry season) and April, 1997 (after three day's rainfall). TDS of the Youngdong mine water was remarkably higher than those of other mine waters. In the Imgok Creek, concentrations of most elements, except Fe decreased with distance by dilution caused by the inflow of uncontaminated tributaries. From the results of NAMDI and $I_{geo}$ calculation, the Youngdong coal mine was the main contamination source of the study area. Groundwater pollution was not yet confirmed in this study and the paddy and farm land soils were also not yet contaminated by mining activity based on the pollution index ranging from 0.27 to 0.47.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.1-9
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• 2012

As topographic characteristics of Korea where 64 % of the national land area is forest and only 17 % is being used as farmland, remediation of farmland contaminated by heavy metals is a considerably important issue. In this study, as an alternative of practically and effectively remediating farmland which was abandoned as its crop plants exceeded maximum residue limit of heavy metals due to mining impact, applicability of stabilization method was examined through the pilot-scale field experiment. Three plots ($L{\times}W{\times}D=3m{\times}2m{\times}0.3m$) were installed at the selected farmland and in plot 1, only soil of the selected farmland was applied, in pilot 2, soil of the selected farmland plus 3 % limestone (w/w) was applied and in pilot 3, soil of the selected farmland plus 3 % limestone was applied and then uncontaminated soil was covered thereon (0.3 m). After that, seeds of radish, Korean cabbage and soybean of which characteristics of edible portions are different were sowed on each plot and cultivated. Afterwards, at a proper harvesting time (app. 80 days later), crop plants and soil were collected and phytoavailability (0.11 M HOAc extractable) of heavy metals in soil and accumulated concentration of heavy metal in edible portion of crop plants were examined. As a result, it was revealed that phytoavailability of heavy metals in soil added with limestone (plot 2) was clearly reduced compared with plot 1 (untreated) and owing to this treatment, accumulated concentration of heavy metals in edible portion of crops was also clearly reduced compared with plot 1. While radish cultivated in plot 1 had exceeded maximum residue limit of agricultural products, in particular, plot 2 using limestone had shown concentration lower than maximum residue limit and this plot had shown little difference with 3 plot where crop was cultivated in uncontaminated soil cover. Therefore, it was considered that for abandoned farmland like the selected farmland, reducing mobility and phytoavailability of heavy metals and reducing crop uptake through stabilization method would be an effective and practical alternative for producing safe agricultural products on a sustained basis.

• Journal of Korean Society of Rural Planning
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• v.15 no.3
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• pp.107-112
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• 2009

In Japan, the direct payment scheme for mountainous areas was introduced in order to enhance multifunctionality of less-favored areas in 2000. A comprehensive ex post assessment showed that the scheme effectively contributed to prevention of abandoned cultivated lands, maintenance and enhancement of multifunctionality of agriculture, continuous assistance for agricultural production, and revitalization of community. In 2005 a second round of the scheme started and urged encouraging core farmers, improving productivity, and reinforcing inter-village coalition as to promote autonomous and sustainable rural economies. A new different scheme such as 'measures to conserve and improve land, water and environment' was launched for strengthening conservation and management of rural resources over all areas in 2007. It covers one third of paddy fields with regards to maintenance of water facilities and practice of group eco-farming beyond less-favored area. A lot of public programs have been developed for rural revitalization recently. Additionally some have a complementary role to enlarging cultural multifunctionality in rural societies. We could interpret the institutional progress as an evolutionary path of rural development and environmental schemes for the past decade. Much experience of community works through the direct payment scheme for mountainous areas may have resulted in accumulation of social competence for elaboration of rural management..