• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.383-397
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• 1999

For sites to be investigated, the results of such an investigation can be used in determining foals for cleanup, quantifying risks, determining acceptable and unacceptable risk, and developing cleanup plans t hat do not cause unnecessary delays in the redevelopment and reuse of the property. To do this, it is essential that an appropriately detailed study of the site be performed to identify the cause, nature, and extent of contamination and the possible threats to the environment or to any people living or working nearby through the analysis of samples of soil and soil gas, groundwater, surface water, and sediment. The migration pathways of contaminants also are examined during this phase. Key aspects of cost-effective site assessment to help standardize and accelerate the evaluation of contaminated soils at sites are to provide a simple step-by-step methodology for environmental science/engineering professionals to calculate risk-based, site-specific soil levels for contaminants in soil. Its use may significantly reduce the time it takes to complete soil investigations and cleanup actions at some sites, as well as improve the consistency of these actions across the nation. To achieve the effective site assessment, it requires the criteria for choosing the type of standard and setting the magnitude of the standard come from different sources, depending on many factors including the nature of the contamination. A general scheme for site-specific assessment consists of sequential Phase I, II, and III, which is defined by workplan and soil screening levels. Phase I are conducted to identify and confirm a site's recognized environmental conditions resulting from past actions. If a Phase 1 identifies potential hazardous substances, a Phase II is usually conducted to confirm the absence, or presence and extent, of contamination. Phase II involve the collection and analysis of samples. And Phase III is to remediate the contaminated soils determined by Phase I and Phase II. However, important factors in determining whether a assessment standard is site-specific and suitable are (1) the spatial extent of the sampling and the size of the sample area; (2) the number of samples taken: (3) the strategy of taking samples: and (4) the way the data are analyzed. Although selected methods are recommended, application of quantitative methods is directed by users having prior training or experience for the dynamic site investigation process.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.970-976
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• 2011

Strip tiller equipment was developed to reduce soil erosion in the slope land for highland agricultural area. The equipment consisted of 4 rows strip tillage device and fertilizer applicator. The field was tilled in 10 cm width and in 10 cm depth by the equipment, of which tilled surface was 16.7% of full-width tillage. The working time and fuel consumption of the equipment were $3.8hours\;ha^{-1}$ and $24.4L\;ha^{-1}$ respectively, which were 59% and 74% less than those of the conventional tillage. Fertilizer efficiency of the equipment in cultivation of Chinese cabbage was 1.7, 1.6 and 1.5 times higher in nitrate, phosphorous and potassium respectively, than conventional tillage. When the equipment was used after covering of rye residue, the quantity of runoff was 49~67% lower than the conventional tillage. And the quantity of soil loss were 1.3 and $0.2Mg\;ha^{-1}$ at right after and 30 days after planting of Chinese cabbage respectively, while 11.5 and $4.1Mg\;ha^{-1}$ in conventional tillage. In conclusion, the strip tillage equipment developed in this study can be applicable to slope land, so that soil loss of 90% can be reduced.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.923-929
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• 2010

This study was conducted to investigate the relations between soil chemical properties and Korean raspberry (Rubus coreanus Miq.) growth. Soils were collected from 54 sampling sites in 1 to 6 years old Korean raspberry cultivation fields (RCFs) at Gochang-gun, Jeollabuk-Do, Korea. In RCF with two to six years old plants, soil pH and exchangeable $Ca^{2+}$ and $Mg^{2+}$ contents were higher at the leaf-emergence time, but EC, available phosphorus content, CEC, and total nitrogen content were higher at the harvesting time; especially at the harvesting time, the content of available phosphorus in the RCF with 3~6 years old plants were at least three times higher than in the RCF with 2 years old plants. Water-soluble anions ($Cl^-$, ${NO_3}^-$, ${PO_4}^{2-}$, and ${SO_4}^{2-}$) in the RCF were also measured. The contents of ${NO_3}^-$ and ${SO_4}^{2-}$ were always higher in the RCF with older plants than in the RCF with younger plants, which were not affected by sampling time and sampling locations (rhizosphere and non-rhizosphere sites). However, soils collected from non-rhizosphere at the leaf-emergence time contained higher ${PO_4}^{2-}$ content, but $Cl^-$ content was higher in the soils collected from rhizosphere at the harvesting time. In general, soils in the RCFs contained excess amounts of inorganic nutrients such as available phosphorus and exchangeable $K^+$. Thus, optimal levels of soil properties for Korean raspberry cultivation should be reconsidered.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.364-370
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• 2009

This study was conducted to survey, analyze on the compaction layer and the plow layer at Jeonbug and Jisan series paddy soil, which is the representative soil in fluvio-marine and local alluvium, respectively. The depths of surface soil were 12.6 and 12.7 cm in Jeonbug and Jisan series, respectively. A plowing depth was 10.5 cm. The properties of compaction layer in two soil series were as follows. The hardness were $14.7kg\;cm^{-2}(25.3mm)$ and $8.7kg\;cm^{-2}(22.1mm)$ in Jeonbug and Jisan series, respectively. The thickness were 22.3 cm and 17.8 cm in Jeonbug and Jisan series, respectively. The depth of soil compaction, which means depth from surface, were 15 and 20 cm in Jeonbug and Jisan series, respectively. The relationship between the hardness of compaction layer and the depth of surface soil showed negative correlation, however relationship between the hardness and the thickness of compaction layer showed positive correlation. Soil temperature was lower in compaction layer than in plow layer. This temperature differences between compaction layer and plow layer were from 1.0 to $2.5^{\circ}C$ in Jeonbug series and from 0.7 to 2.1 in Jisan series. The soil physical properties of compaction layer were higher in bulk density and solid phase and lower in porosity and gaseous phase than those of plow layer in all soil series. The soil chemical properties of compaction layer were higher in pH, content of available silicate, exchangeable calcium and magnesium but lower in total nitrogen, content of organic matter and available phosphate than those of plow layer in all soil series. Cation exchangeable capacity and content of exchangeable potassium were similar between compaction layer and plow layer in Jeonbug series, however, in Jisan series these were lower in compaction layer than in plow layer. Elution amount of inorganic nitrogen were lower in compaction layer than in plow layer in all soil series. The content of soluble Fe and Mn were plenty in compaction layer compared with plow layer and these tendency was apparent in Jeonbug series. The water depth decrease were fast until the latter part of June, and were slow as $1{\sim}3mm\;day^{-1}$ for July and August, and were fast again from september. Rice roots distributions as each soil series and tillage method were 25 cm at rotary plowing in Jeonbug series, 30 cm at deep plowing in Jeonbug series, and 20 cm at tillage in Jisan series. Dry weight per m2 at heading stage were much in order of deep plowing in Jeonbug series, rotary plowing in Jeonbug series, and tillage in Jisan series.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.287-295
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• 2021

As facilities such as dam reservoir wetlands and agricultural irrigation reservoir wetlands are built, sedimentation occurs over time through erosion, sedimentation transport, and sediment deposition. Sedimentation issues are very important for the maintenance of reservoir wetlands because long-term sedimentation of sediments affects flood and drought control functions. However, research on resignation has been estimated mainly by empirical formulas due to the lack of available data. The purpose of this study was to calculate and compare the sediment deposition rate by developing a multiple regression model along with actual data and empirical formulas. In addition, it was attempted to identify potential causes of collapse by applying it to 64 reservoir wetlands that suffered flood damage due to the long rainy season in 2020 due to reservoir wetland sedimentation and aging. For the target reservoir, 10 locations including the GaGog reservoir located in Miryang city, Gyeongsangnam province in South Korea, where there is actual survey information, were selected. A multiple regression model was developed in consideration of physical and climatic characteristics, and a total of four empirical formulas and sediment deposition rate were calculated. Using this, the error of the sediment deposition rate was compared. As a result of calculating the sediment deposition rate using the multiple regression model, the error was the lowest from 0.21(m³km²/yr) to 2.13(m³km²/yr). Therefore, based on the sediment deposition rate estimated by the multi-regression model, the change in the available capacity of reservoir wetlands was analyzed, and the effective storage capacity was found to have decreased from 0.21(%) to 16.56(%). In addition, the sediment deposition rate of the reservoir where the overflow damage occurred was relatively higher than that of the reservoir where the piping damage occurred. In other words, accumulating sediment deposition rate at the bottom of the reservoir would result in a lack of acceptable effective water capacity and reduced reservoir flood and drought control capabilities, resulting in reservoir collapse damage.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.128-140
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• 2021

This study applied the theory of Landscape Ecology to representative resources of Jeju Olle-gil, which is a representative subject of walking tourism, to identify ecological characteristics and to establish a technique for landscape ecological analysis of Olle-gil resources. Jeju Olle Trail type based on the biotope type, major land use, vegetation status around Olle Trail and roads were divided into 12 types. Based on the type of ecological tourism resource classification, the Jeju Olle-gil walking tourism resource classification was divided into seven types of natural resources and seven types of humanities resources, and each resource was characterized by Geotope, Biotope, and Anthropopope, just like the landscape ecology system. Geotope resources are strong in landscape characteristics such as coast and beach, rocks, bedrocks, waterfalls, geology and Jusangjeolli Cliff, Oreum and craters, water resources, and landscape viewpoints. The Biotope resources showed strong ecological characteristics due to large tree and protected tree, Gotjawal, forest road and vegetation communities, biological habitat, vegetation landscape view point. Antropotope include Culture of Jeju Haenyeo and traditional culture, potting and lighthouses, experience facilities, temples and churches, military and beacon facilities, other historical and cultural facilities, and cultural landscape views. Jeju Olle Trail The representative resources for each type of Jeju Olle Trail are coastal, Oreum, Gotjawal, field and Stonewall Fencing farming land, Jeju Village and Stone wall of Jeju. In order to learn about the components and various functions of the resources representing the Olle Trail's ecological culture, the landscape ecological technique was interpreted. Looking at the ecological and cultural characteristics of coastal, the coast includes black basalt rocks, coastal vegetation, coastal grasslands, coastal rock vegetation, winter migratory birds and Jeju haenyeo. Oreum is a unique volcanic topography, which includes circular and oval mountain bodies, oreum vegetation, crater wetlands, the origin and legend of the name of Oreum, the legend of the name of Oreum, the culture of grazing horses, the use of military purposes, the object of folk belief, and the view from the summit. Gotjawal features rocky bumps, unique microclimate formation, Gotjawal vegetation, geographical names, the culture of charcoal being baked in the past, and bizarre shapes of trees and vines. Field walls include the structure and shape of field walls, field cultivation crops, field wall habitats, Jeju agricultural culture, and field walls. The village includes a stone wall and roof structure built from basalt, a pavilion at the entrance of the village, a yard and garden inside the house, a view of the lives of local people, and an alleyway view. These resources have slowly changed with the long lives of humans, and are now unique to Jeju Island. By providing contents specialized for each type of Olle Trail, tourists who walk on Olle will be able to experience the Olle Trail in depth as they learn the story of the resources, and will be able to increase the sustainable use and satisfaction of Jeju Olle Trail users.

• Clean Technology
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• v.27 no.4
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• pp.359-366
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• 2021

Halloysite nanotubes (HNTs), the multiwalled clay mineral with the composition of Al₂Si₂O₅(OH)₄·nH₂O, have been highlighted as a low-cost adsorbent for the removal of dyes from wastewater. Although a powder of halloysite presents a high specific surface area, forming media are significantly considered due to sludge-clogging induced by the water-bound agglomeration. However, higher firing temperature to achieve the structural durability of the media and lower utilization rate due to longer penetration depth into the media act as hurdles to increase the dye-adsorption capacity. In this work, the retention of the adsorption capacity of halloysite was evaluated with methylene blue solution after the heat treatment at 750 ℃. In order to improve the utilization rate, tubular media were fabricated by extrusion. The images taken by transmission electron microscopy show that HNTs present excellent structural stability under heat treatment. The HNTs also provide superb capacity retention for MB adsorption (93%, 18.5 mg g^-1), while the diatomite and Magnesol^® XL show 22% (7.65 mg g^-1) and 6% (11.7 mg g^-1), respectively. Additionally, compositing with lignin enhances adsorption capacity, and the heat treatment under the hydrogen atmosphere accelerates the adsorption in the early stage. Compared to the rod-type, the tubular halloysite media rapidly increases methylene blue adsorption capacity.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.18-43
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• 2011

The results of study on planting and cultivate of Hong Man-Seon(1643~1715)'s 'Salimkyungjae(The Economy of Forest)' the first summative textbook of agricultural skill of South Korea, are as follows. First, 'Salimkyungjae' suggests that one can enrich oneself, eat fruits in fall, enjoy the shade of trees in summer, and enjoy flowers in spring if one plants tree with 10 year plan with knowledge of ecology. Second, the number of plants had increased continuously from the early Chosun Dynasty to the mid Chosun Dynasty. The 52 plants in the book are classified into 31 trees, 8 shrubs, 3 others, and 10 herbs, and 28 of them are fruit trees. Hence, we can see that the book is for the promotion of welfare. Third, planting(transplantation) is the best on January of the lunar calendar, and the second on February, and fertile soil should be added much. Trees must be planted as deep as once it was planted, and buttressed. It will sprout well if it is planted at the depth of one inch, and planting a cutting should be carried out at the early March with 5 inch and finger-thick branches. Grafting is the best when it begins to sprout. Fruit trees will bear many fruits if they are grafted at the direction of South, and fruits will be greater if the trees' branches are cutting off on January. Especially, January was selected for the best season of planting traditionally. Fourth, flower trees are planted or sowed with manure around January and February of the lunar calendar, and it is recommended to replant them into flowerpots with manure when having flower buds around March and April of the lunar calendar. It would bloom earlier when using water mixed with stable manure, and sulfur smoke can be used in order to change the flower color from red to white. Flowerpots would be placed at half shaded lot with being supported by bricks. Pomegranate, gardenia, camellia and four-season flower should be planted after flowers fallen. When flower trees are beside walls, they need to be rotated frequently since their branches all point toward house. Seeds need to be preserved in a sunny hut, where its entrance and ventilating openings would be at south because it is convenient to manage pots. Fifth, insects hidden at fruit trees would be destroyed by torch smoke when roosters cry on New year's day of the lunar calendar. Insects would be decoyed into straw hanged at dawn of Cheongmyeongday(淸明日). Insects on fruit trees would be controlled using sulfur powder to close up holes or sulfur smoke to fumigate. Particularly, it suggests that utilization of fertile soil would be the best solution for growing health plants and preventing pest.

• Food Engineering Progress
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• v.21 no.1
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• pp.42-48
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• 2017

The purpose of this study was to verify the drying characteristics of steamed sweet potato and to establish optimal drying conditions for far-infrared drying of steamed sweet potato. 4 kg of steamed sweet potato was sliced to thicknesses of 8 and 10 mm, and dried by a far-infrared dryer until a final moisture content of $25{\pm}0.5%$. The far-infrared dryer conditions were an air velocity of 0.6, 0.8 m/s and drying temperature of 60, 70, and $80^{\circ}C$. The results can be summarized as follows. The drying time tended to be reduced as temperature and air velocity for drying increased. The Lewis and Modified Wang and Singh models were found to be suitable for drying of steamed sweet potato by a far-infrared dryer. The color difference was 35.09 on the following conditions: Thickness of 8 mm, temperature of $80^{\circ}C$, and air velocity of 0.8 m/s. The highest sugar content ($59.11^{\circ}Brix$) was observed on the conditions of a thickness of 8 mm, temperature of 80, and air velocity of 0.8 m/s. Energy consumption decreased on the conditions of higher temperature, slower air velocity, and thinner steamed sweet potato.

• The Korean Journal of Mycology
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• v.49 no.3
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• pp.337-349
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• 2021

This study aimed to isolate wild yeasts from water and soil sample of the Nonsan stream and Sapgyoho (lake) in Chungcheonnam-do, Korea, and to further characterize previously unrecorded wild yeast strains. In total, 102 strains, representing 55 different species of wild yeast were isolated from 95 samples collected from the Jangseoncheon and Ipchoncheon of Nonsan stream in Jellabuk-do and Chungcheonnam-do. Among these, 33 strains were isolated from alkalophilic yeast extract-peptone-dextrose (YPD) medium (pH 9.0), and 9 strains were isolated concurrently on general YPD medium (pH 6.5) and alkalophilic medium. Seventeen strains of Cryptococcus laurentii were predominantly isolated. Additionally, 65 strains, representing 27 different species of wild yeast were isolated from 58 samples obtained from Sapgyoho (lake). Among the 82 isolated wild yeast strains, 8 strains, including Candida fructus JSC 72-1(JSL-GGU 015), had not previously been recorded. All 8 previously unrecorded yeasts were oval in shape except C. fructus JSC72-1(JSL-GGU-015), and only the Filobasidium chernovii JSC39-1(JSL-GGU-013) strain formed spores. All strains except Pseudosydowia eucalypti JSC23-6(JSL-GGU-012) grew well in yeast extract-peptone-dextrose (YPD) and yeast extract-malt extract media and grew in vitamin-free medium. Four strains, including P.eucalypti JSC23-6(JSL-GGU-012) grew well in 15% NaCl-containing YPD medium. F.chernovii JSC39-1(JSL-GGU-013) and Sirobasidium intermedium JSC7-3(JSL-GGU-014) assimilated lactose, and five strains, including F. chernovii JSC39-1(JSL-GGU-013) also assimilated starch. All strains were resistant to 800 ppm of Ca, Cu, Li, and Mg ions.