• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.172-180
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• 1993

Chemical properties of the soils were surveyed in the field of vinyl houses concentrated in the area of Bunpyong-dong and Shinchon-dong of Cheongju, Chilgeum-dong of Chungju and Gageum-myeon of Jungweon-gun. Chungcheongbuk-do province. 1. Content of chemical component of the soil in the vinyl house was higher than in open field. In more than half of the vinyl house soils surveyed, electric conductivity was more than 4.0 mmhos/cm and available phosphate was more than 1,000ppm. 2. Contents of availble phosphate and exchangeable potassium were increased with years of cultivation and their content of accumulation in soil were in the order of Bunpyong-dong>Shinchon-dong>Gageum-myeon>Chilgeum-dong. While their mobility was comparatively low. 3. $NO_3$-N content was remarkably higher in vinyl house soil and the older in cultivation made $NO_3$-N content higher same as the case of available phosphate content. However easy leaching of $NO_3$-N through soil profile is expected due to the fact that $NO_3$-N content was rapidly decreased by removal of polyethylene film cover from the frame of house after harvest of crops. 4. It is a tendency that various chemical contents of vinyl house soils wer higher in 1992 than in 1988~1990, especially much higher from the area of Bunpyong-dong and Shinchon-dong of Cheongju. 5. Salt accumulation in vinyl house soil has been increased with continuing cultivation. Therefore amount of fertilizer application should be controlled in order to avoid salt toxicity, quality deterioration for crop and salt contamination of ground water.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.303-309
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• 2008

The physico-chemical properties of the rainfall interception culture (85 sites) and the open field culture soils (85 sites) in the area of Gochang-gun, Jeollabuk-do were surveyed. Soil textural distribution of the rainfall interception culture and the open field culture soils was 74% and 64% for silt loam, 16% and 35% for loam, and 10% and 1% for clay, respectively. The percentage of aggregate rates was higher in the open field culture soils (60.06%) than rainfall interception culture soils (55.84%). Electrical conductivity, exchangeable cations, and anions in the rainfall interception culture soils were higher than those in open field soils. Specially, accumulated amount of anion in rainfall interception culture soils was remarkably higher 2~3 times than open field culture soils. The results from the analyses of rainfall interception culture soils suggested that the most critical problem is the salts accumulation caused by over-fertilization of chemical fertilizer and compost. Therefore, application rates of chemical fertilizer and compost should be controlled in order to conservation of soil and water for sustainable agriculture.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.72-81
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• 2013

The objective of this study was to verify whether SCB(Slurry Composting & Bio-filtration) system can be applied for the treatment of anaerobic digestion(AD) wastewater and also, to identify the most effective set among three filtration compost beds tested. Results can be summarized as these; (a) When AD wastewater was sprayed on the top of beds which were mainly composed of sawdust and/or other media and, subsequently, filtrates collected and analyzed, there were large drop in the values of Electric Conductivity(EC), Total Suspended Solid(TSS), Biochemical Oxygen Demand(BOD), and Chemical Oxygen Demand(COD). In contrast, Total Nitrgen(T-N) and Total Phosphorus(T-P) were progressively elevated. We consider these changes as positive if the filtrate are to be utilized as liquid fertilizer. (b) When three sets of filtration beds (T1, T2, T3) were compared for their effectiveness, no significant difference was found among them. These indicate that expensive sawdust can be replaced in part with cheaper media such as woodchip, rice husks, or others. (c) At early stage of operation (within 20 days), BOD in filtrates were maintained at high level probably due to the lack of microbial activity. During the same stage, T-N, T-P was at low level but, were elevated to higher levels thereafter. These data, when combined, indicate that the filtration system needs at least a couple of weeks for the optimized microbial functioning. (d) The temperatures of the experimental beds were progressively dropped as the experiment continued through the fall season, although filtration effectiveness was not noticeably influenced.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.109-116
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• 2002

The objective of this study was to know the qualities of soil and shallow groundwater in plastic film house fields around Central Part of Korea. The study was conducted at 11 sites in Suweon, Hwasung, Pyungtaek, Yongin and Chuncheon through May to August in 1999. Soil textures of plastic films house were mainly sandy loam or loam. Electric conductivity and organic matter content of surface soils mostly exceeded the critical levels for crop production. Average concentration of $NO_3-N$ in the sha]low groundwater was 19.1 mg/L, and it reached almost the limiting level of agricultural groundwater quality (20 mg/L). Moreover about 36% of survey sites exceeded the limiting level of agricultural groundwater quality. Sulfate concentrations also at some sites exceeded agricultural groundwater quality limit level (50 mg/L). Nitrate-N, one of the most important factors in the groundwater quality, had positive correlations with other ions in foundwater.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.79-86
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• 2003

This research was conducted to present reference data to be used as newly reclaimed tidal land management. We investigated vegetation succession at 4 reclaimed/reclaiming project areas and discussed relationship with soil and vegetation trhrough investigation and analysis soil chemical characteristics at 2 areas. 14 families 58 kinds were investigated. Vegetation were variou at Dea-Ho conservation polt and Seok-Mun National Industrial Area which are maintaining naturally. Vegetation were simple at Hong-Bo and Dongjin and MinKyong river areas which effected sea water. Common species that were investigated at 9 sites were Suaeda asparagoides, Aster tripolium, Phragmites australis, Suaeda maritima, Suaeda japonica, Carex scabrifolis. As soil desalinization progressing, soil classified at first saline-soidc soil, the nest saline soil and then normal soil. Chenopodiaceae revealed at about 30 dS/m of soil ECe and existed to 10 dS/m of soil ECe. At about 20 dS/m of soil ECe. Aster tripolium, Calamagrostis epigeios, and Sonchus brachyotus revealed and then non-halophytes and common plants at inland revealed at low soil ECe of about 10 dS/m. However it was not to progress vegetation sucdession and soil desalinization at the same time, owing to input of seeds or plants ect from out-ecosystem. So for promotion of vegetation at newly reclaimed tidal land, we proposed that it was very effective to plant artificially halophytes or suitable species through soil test.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.1-10
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• 2005

Macroinvertebrates from a first order stream at Mt Jumbong, Kangwon-do, was examined for their abundance and biomass. Sampling was done by using a pipe sampler (${\phi}$ 20 cm) for 11occasions (n = 5) at 4${\sim}$6 weeks intervals during November 1997 through October 1998. Water temperature and electronic conductivity of the study stream ranged $0\;{\sim}\;14^{\circ}C$ and 15${\sim}$25 ${\mu}s$/cm, respectively. During the study, 53 insect taxa and 3 non-insect taxa were collected. Annual mean number of individuals (${\pm}$1 SD) was 77741${\pm}$69232${\cdot}$m$^{-2}$ ${\cdot}$yr$^{-1}$, being high in winter (${\pm}$1 SD) (December: 171178${\pm}$130468 $m^{-2}$) and low in summer (${\pm}$ 1 SD) (June: 29872${\pm}$13078 $m^{-2}$). Non-predatory subfamilies of Chironomidae and Nemoura sp. occupied 53.3% and 21.8% of annual abundance. Annual mean biomass was 10g${\cdot}$m$^{-2}$${\cdot}$yr$^{-1}$ in ash free dry weight (AFDW), being high in late winter (February: 16 gAFDW $m^{-2}$.) and low in summer (June: 3 gAFDW $m^{-2}$). Gammarus sp. represented 39.8% of the total biomass and was followed by non-predatory subfamilies of Chironomidae (15.2%) and Hydatohylax sp. (8.5%, Limnephilidae: Trichoptera). Since the non-predatory subfamilies of chironomidae were composed of many species, Nemoura sp. was the most abundant taxon. However, Cammarus sp. was surely the most important taxon to the functional aspects of this first order stream ecosystems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.308-318
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• 2013

Korean soybean varieties, 'Seonyu' and 'Hwangkeum' were planted in 2012, and three temperature gradient, Tc($19.8^{\circ}C$, ambient temperatured), $Tc+1.7^{\circ}C$, and $Tc+2.5^{\circ}C$, were artificially created by controlling the green house system during seed filling period. Mature seeds that developed under these conditions were analyzed for variances in physicochemical properties. The 100-seed weight and seed-coat ratio of soybean were decreased, but small seed rate was increased by high temperature during seed filling period. Protein content was increased, but oil content was decreased significantly with increasing the seed filling temperature. The decrement of carbon to nitrogen ratio (C/N), and the increment of monosaccharide, fructose and sucrose, in seeds explained that carbohydrate assimilation during seed filling was restricted by high temperature. Rapid increments of seed volume and weight were observed in the seeds of high seed filling temperature, but as soaking time increased the highest values were observed in the seeds of ambient seed filling temperature. The 100-seed weight and seed-coat ratio of soybean were closely related not only to the increment of soaking volume and weight, but also the increments of total dissolved solids (TDS) and electro conductivity (EC). Whereas protein content and C/N ratio showed less relationship with the soaking properties, but they had a positive correlation with TDS and EC. From the results, it was considered that high values of TDS and EC in the seeds of high temperature were mainly due to the incomplete conversion of assimilates into storage compounds. However, sugar content showed less influence on the soaking properties and the values of TDS and EC.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.336-342
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• 2012

Inorganic materials were commonly used as container media in domestic plant factories. Objective of this research was to secure the information in soil physical and chemical properties of inorganic materials such as vermiculites and perlites. To achieve this, 12 gold and silver vermiculites from China, Zimbabwe, and South Africa and 5 perlites from China were collected based on the marketing grades (MG) in particle sizes and analyzed for determination of their characteristics. The percentage of particles larger than $710{\mu}m$, in China perlite MG 3~5 mm, China silver vermiculites MG > 8 mm and MG 3~8 mm were 99.9%, 99.8%, and 99.7%, respectively, which were much higher than 28.4% in China gold vermiculite MG 0.3~1.0 mm, 14.0% in perlite MG < 1.0 mm, and 12.6% of Zimbabwe silver vermiculite MG < 1.0 mm. The container capacities of perlite MG < 1.0 mm and South Africa silver vermiculite MG 0.25~1.0 mm were 72.0% and 71.1%, respectively. The air space in China silver vermiculite MG 3~8 mm was 49.3% which was higher than other materials tested. However, the China gold and silver vermiculites MG 0.3~1 mm had 3.5% and 2.4% in air space indicating that possible problems could occur in soil aeration when they are used for container media. The percentage of easily available and buffering water of China gold vermiculite MG 0.3~1 mm and perlite MG < 1.0 mm were the highest among test materials. The ranges of pH and electrical conductivity were 6.36 to 10.7 and 0.032 to $0.393dS{\cdot}m^{-1}$ in vermiculites and 7.78 to 8.62 and 0.030 to $0.041dS{\cdot}m^{-1}$ in perlite, respectively. The cation exchange capacity of China silver vermiculite MG 0.3~1 mm were $14.7cmol{\cdot}kg^{-1}$ that was 10 times as high as $0.34cmol{\cdot}kg^{-1}$ in perlite MG 1~2.5 mm. The vermiculites had the higher contents of exchangeable cations such as Ca, K, and Na, than those of perlites.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.29-46
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• 2004

It is important to identify geometries of fracture that act as a conduit of fluid flow for characterization of ground water flow in fractured rock. Fracture geometries control hydraulic conductivity and stream lines in a rock mass. However, we have difficulties to acquire whole geometric data of fractures in a field scale because of discontinuous distribution of outcrops and impossibility of continuous collecting of subsurface data. Therefore, it is needed to develop a method to describe whole feature of a target fracture geometry. This study suggests a new approach to develop a method to characterize on the whole feature of a target fracture geometry based on the Fourier transform. After sampling of specimens along a target fracture from borehole cores, effective frequencies among roughness components were selected by the Fourier transform on each specimen. Then, the selected effective frequencies were averaged on each frequency. Because the averaged spectrum includes all the frequency profiles of each specimen, it shows the representative components of the fracture roughness of the target fracture. The inverse Fourier transform is conducted to reconstruct an averaged whole roughness feature after low pass filtering. The reconstructed roughness feature also shows the representative roughness of the target subsurface fracture including the geometrical characteristics of each specimen. It also means that overall roughness feature by scaling up of a fracture. In order to identify the characteristics of permeability coefficients along the target fracture, fracture models were constructed based on the reconstructed roughness feature. The computation of permeability coefficient was performed by the homogenization analysis that can calculate accurate permeability coefficients with full consideration of fracture geometry. The results show a range between $10^{-4}{\;}and{\;}10^{-3}{\;}cm/sec$, indicating reasonable values of permeability coefficient along a large fracture. This approach will be effectively applied to the analysis of permeability characteristics along a large fracture as well as identification of the whole feature of a fracture in a field scale.

• Economic and Environmental Geology
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• v.38 no.4 s.173
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• pp.435-450
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• 2005

The purpose of the study is to analyze the hydrogeochemical characteristics by multivariate statistical method, to interpret the hydrogeochemical processes for the new variables calculated from principal components analysis (PCA), and to infer the groundwater flow and circulation mechanism by applying the geostatistical methods for each element and principal component. Chloride and nitrate are the most influencing components for groundwater quality, and the contents of $NO_3$ increased by the input of agricultural activities show the largest variation. The results of PCA, a multivariate statistical method, show that the first three principal components explain $73.9\%$ of the total variance. PC1 indicates the increase of dissolved ions, PC2 is related with the dissolution of carbonate minerals and nitrate contamination, and PC3 shows the effect of cation exchange process and silicate mineral dissolution. From the results of experimental semivariogram, the components of groundwater are divided into two groups: one group includes electrical conductivity (EC), Cl, Na, and $NO_3$, and the other includes $HCO_3,\;SiO_2,$ Ca, and Sr. The results for spatial distribution of groundwater components showed that EC, Cl, and Na increased with approaching the coastal line and nitrate has close relationship with the presence of agricultural land. These components are also correlated with the topographic features reflecting the groundwater recharge effect. The kriging analysis by using principal components shows that PC 1 has the different spatial distribution of Cl, Na, and EC, possibly due to the influence of pH, Ca, Sr, and $HCO_3$ for PC1. It was considered that the linear anomaly zone of PC2 in western area was caused by the dissolution of carbonate mineral. Consequently, the application of multivariate and geostatistical methods for groundwater in the study area is very useful for determining the quantitative analysis of water quality data and the characteristics of spatial distribution.