• Journal of Environmental Policy
• /
• v.8 no.1
• /
• pp.73-95
• /
• 2009

The fact that soil loss causing to increase muddy water and devastate an ecosystem has been appearing upon a hot social and environmental issues which should be solved. Soil losses are occurring in most agricultural areas with rainfall-induced runoff. It makes hydraulic structure unstable, causing environmental and economical problems because muddy water destroys ecosystem and causes intake water deterioration. One of three severe muddy water source areas in Soyanggang-dam watershed is Jawoon-ri region, located in Hongcheon county. In this area, many cash-crops are planted at illegally cultivated agricultural fields, which were virgin forest areas. The purpose of this study is to estimate soil loss with current land uses(including illegal cash-crop cultivation) and soil loss reduction with land use conversion from illegal cultivation back to forest. In this study, the Sediment Assessment Tool for Effective Erosion Control(SATEEC) ArcView GIS was utilized to assess soil erosion. If the illegally cultivated agricultural areas are converted back to forest, it would be expected to 17.42% reduction in soil loss. At the Jawoon-ri region, illegally cultivated agricultural areas located at over 30% and 15% slopes take 47.48 ha(30.83%) and 103.64 ha(67.29%) of illegally cultivated agricultural fields respectively. If all illegally cultivated agricultural fields are converted back to forest, it would be expected that 17.41% of soil erosion and sediment reduction, 10.86% reduction with forest conversion from 30% sloping illegally agricultural fields, and 16.15% reduction with forest conversion from 15% sloping illegally agricultural fields. Therefore, illegally cultivated agricultural fields located at these sloping areas need to be first converted back to forest to maximize reductions in soil loss reduction and muddy water outflow from the Jawoon-ri regions.

• Korean Journal of Microbiology
• /
• v.35 no.1
• /
• pp.65-71
• /
• 1999

This study was carried out utilzing ability of sole carbon sources in soil microbial communities used by Biolog GN microplate. Cluster analysis showed that soil microbial cornmuties were categorized into three groups as forest, non-forest soil and naked soil of microbial group. Soil microbial commutites in a forest soil of Qirercus mongoIica was divided into another group microbial communites in Qirercus dendata vegetation soil and Pinus dnzsqlora vegetation soil by Multidimensional scaling(MDS). Generally, sole carbon utilzing abilties were higher in order of polymer, amino acids and carboxylic acids, but it was lower in amides substrates carbon group. From the result: it was supposed that metabolic diversity of microbial communities was corresponded to vegetation succession.

• Journal of Radiation Protection and Research
• /
• v.24 no.2
• /
• pp.55-63
• /
• 1999

For understanding the radiation environment in the land of Korea and acquiring baseline data to be referred to at the time of a nuclear accident, cultivated soils in the $0{\sim}15cm$ layer were sampled at 33 sites scattered all over the country and $^{137}Cs$ concentrations were measured by $\gamma$-spectrometry. The soil $^{137}Cs$ concentrations were in the range of $0.7{\sim}17.7$ Bq/kg-dry in the paddy field and $1.2{\sim}27.8$ Bq/kg-dry in the upland field, The means were 6.9 Bq/kg-dry and 9.9 Bq/kg-dry, respectively. In the paddy field, the soil $^{137}Cs$ concentration was positively correlated to the organic matter content and negatively correlated to the clay content. In the upland field, it was positively correlated to the cation exchange capacity. It was revealed that soil organic matter play an important role in the change of soil $^{137}Cs$ concentration.

• Korean Journal of Soil Science and Fertilizer
• /
• v.12 no.1
• /
• pp.35-41
• /
• 1979

A study was conducted to investigate the status of organic phosphorus in soils originated from different parent materials and under different uses(Virgin, rice soil, upland). The results are summarized as a following. 1. Regardless of parent materials and land uses, the contents of different forms of organic phosphorus are in the order of unidentified organic-P>Inositol-P>Sugar-P>Lipid-P. 2. In case of Inositol-p, the contents were in the order of rice soil>upland>virgin soil. 3. The contents of Sugar-P and Lipid-P in cultivated soils are higher than in uncultivated soil. 4. RNA and DNA are not identified in any soil when detected by ultra-violet absorption method. 5. There is highly significant correlation between the content of soil organic matter and that of organic phosphate. However, there is remarkable difference in the pattern of correlation between cultivated soils and uncultivated soils. 6. Comments were made on the factors on plant availability of various organic phosphorus.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.2
• /
• pp.156-160
• /
• 1985

24 cultivation areas at fields of the Tobacco Experiment Station in Suweon, Eumseong, and Daegu were selected to get the fertilizer response and evaluate fertility level of upland soil. Fertilizer levels treated were 0, 70, 100, and 130kg/10a of compound fertilizer (10-10-20) for tobacco. The results are as follows; 1. Fertility level could be evaluated by dry weight of tobacco loaves harvested from non-fertilized fields. 2. There was significant in yield differences between fertilizer levels of 70 and 100kg/10a but was no difference between 100 and 130kg/10a of fertilizer level. The lower fertilizer efficiencies were showed at the fields harvested high yield of tobacco leaf without fertilizer. 3. Optimum fertilizer level for non-fertilized field with leaf yield less than 208.5kg/10a was 100kg/10a, and at low productive field with dry leaf weight less than 33.3kg/10a, higher level of fertilizer, 130kg/10a, was considered to be the optimum to get the got income with tobacco cultivation.

• Applied Biological Chemistry
• /
• v.38 no.2
• /
• pp.157-162
• /
• 1995

A reservoir located at Chollanam-do province was selected to estimate annual deposition rate, volume of annually deposited material, and annual soil loss from the watershed using Cs-137 redistribution. Sediment profiles of the reservoir indicated an average annual deposition rate of 1.56 cm $yr^{-1}$ and the total deposited volume of $166530\;m^3$ since 1963/64. Annual soil loss from the watershed was 25 ton $ha^{-1}$. Particle size analysis showed that most of the particles were silt-sized ones.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.3
• /
• pp.241-245
• /
• 1988

The characteristics of some hillside soils in Yeongnam area were investigated to obtain the basic informations for reclamation. Some physico-chemical properties of the soils were discussed with erodibility factor (K) and aggregate stability. The domain clay mineral of soils was identified as Kaoline. Their exchangeable AI, Fe contents were high, and phosphate adsorption coefficients were ranged from 246 to 551 p mg/100g. The improvement of their physico-chemical properties is required in advance to reclaim at those soils.

• Proceedings of the Korean Society of Tobacco Science Conference
• /
• 2000.05a
• /
• pp.34-34
• /
• 2000

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2003.09a
• /
• pp.46-49
• /
• 2003

우리나라 고령지는 특이한 지형조건 때문에 집중강우가 많고 기상변동이 심하며 지역 간의 차이도 크다. 또한 고령지 밭토양은 경사지가 많아 유실이 심하여 대부분의 경작지는 토양환경이 불량한 상태에서 농업활동이 이루어진다. 이러한 고령지의 기상과 토양특성은 고랭지 농업생산성에서 볼 때 대단히 불리한 조건으로 작용하게 된다. 특히 토양의 수분상태는 작물의 수량에 직접적인 영향을 미칠 뿐만 아니라 병해의 발생에도 주요한 요인으로 작용하여 풍흉을 좌우하기도 한다.(중략)

• Journal of the Korean Association of Geographic Information Studies
• /
• v.9 no.1
• /
• pp.56-65
• /
• 2006

In the past, flooding is commonly occurred in the Bockha stream watershed area with inundation by the water and eroded sediments. The purpose of this study is to find the relationship between area under cultivation and amount of soil erosion in each watershed areas using geographic information system(GIS) for decreasing the damages of flooding. The soil erosion amounts were computed on GIS using by universal soil loss equation(USLE). Small catchment areas was divided by topography and computed soil erosion amounts. The mean amount of soil erosion is 0.03 $ton/ha{\cdot}yr$ on the condition of the 1,329 mm/yr annual precipitation. The high erosion area(0.05 $ton/ha{\cdot}yr$) is shown in farm areas of the Sangyong-ri in Baeksa-myeon. The high erosion watershed area is related on the slopes of the farm lands and bare soil areas adjoining between the mountain slope and fluvial streams show much amount of soil erosion.