• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.194-204
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• 2015

Six study sites in Gumi, Goryeong in Gyeongbuk province and Naju in Jeonnam province were selected to investigate soil properties of poorly drained horizons in paddy soils. The horizons were re-established layers which were parent material layers originated from fluvial deposits. Topsoil layers were differentiated from piled parent materials while soil structure of the topsoil layer was massive with striated microstructure. Compaction at soil re-establishment and a lack of structure and aggregate development in these soils may cause the limitation of vertical water movement and result in poorly drained horizons. Soil samples were taken from paddy fields with top soils of sandy loam, silt loam and silty clay loam and re-established soils of coarse and fine texture. The samples were taken from each horizon for the analyses of soil chemical and mineral properties. Soils with re-established soils of coarse texture had greater amounts of sands from top soil texture distributions, while soils with fine texture had greater amounts of silts. Chemical properties of top soils were analyzed from rice cultivated soils at the time of re-establishments and one year after the re-establishments. The coarse texture of the re-established horizons decreased in EC values from 0.23 to $0.11(dS\;m^{-1})$, available phosphate values from 112 to $54(mg\;kg^{-1})$, and exchangeable Ca values from 6.6 to $4.9(cmol_c\;kg^{-1})$. On the other hand, soils with fine texture showed decrease only in pH and exchangeable Ca values. Especially, organic matter and available phosphate contents showed heterogeneous distributions from each horizon. This result may be caused by mixture of plough layer and subsurface layer during and consolidation. Hydraulic conductivity values were low at the boundaries of top soil and parent material layers except SL/coarse soil. Soil microstructure was massive structure without soil clods or pores and showed striated structure. Therefore, re-established paddy fields with fluvial deposits as parent material layers showed limited vertical movements of soil water because of occurrence of compacted layers and less-development of soil clods and aggregates.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.554-567
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• 2019

Recently, concerns regarding the environmental impact due to nutrient input in croplands have increased. Therefore, the government is promoting the introduction of a nutrient management system in croplands to solve the problem of excessive nutrient input. This study was carried out to establish nutrient indicators in regional croplands to facilitate the introduction of the national nutrient management system in Korea. The nutrient load and balance indicators for nitrogen and phosphorus were analyzed for nine provinces (Gang-won, Gyeong-gi, Chung-buk, Chung-nam, Jeon-buk, Jeon-nam, Gyeong-buk, Gyeong-nam, and Jeju). In the correlation analysis between the nutrient load and nutrient balance, the correlation coefficient (r) for nitrogen was 0.2504, which was not statistically significant at the 5% significance level. However, the correlation coefficient for phosphorus was 0.7375, which was statistically significant at the 5% significance level. In the nutrient management index, phosphorus showed mutual compatibility between the nutrient load and the nutrient balance indicators, but nitrogen showed no mutual compatibility between the nutrient load and the nutrient balance indicators. Therefore, utilization of the nutrient balance indicator, reflecting the characteristics of the agricultural environment, was more reasonable as a nutrient management index for regional nutrient management.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.702-709
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• 2014

Luffa cylindrica Roem (sponge gourd) belongs to the Cucurbitaceae family and has been cultivated as an ornamental plant in Korea. Recently, its cultivation area has been increased with an increase in demand for it as an ingredient in cosmetics, herbal medicines, and health supplements. We analyzed inorganic components of sap collected from land race sponge gourds. We also measured antioxidant enzyme activities and antimicrobial activities of the plant, seed, and sap to examine functional properties of sponge gourd. The sap of the sponge gourd contained high levels of K, Ca, P, and Mg, with the most abundant mineral in the sap being K ($470mg{\cdot}L^{-1}$). The amounts of Ca and Mg were 2 and 1.7 times more than those found in cucumber (Cucumis sativus), respectively. Ascorbate peroxidase was more active than catalase and superoxide dismutase in various plant parts of sponge gourd. Antioxidant activities were much lower in stems than in other plant parts such as leaves, roots, flowers, fruits, seeds, and sap. In addition, sap showed a very low level of antimicrobial activity against two food-borne pathogens, Vibrio parahaemdyticus and Propionibacterium acne, and none against the other eight tested food-borne pathogens. Antimicrobial activities against Candida albicans and Malassezia furfur, which causes dermatitis, appeared to be higher in sap than in other parts of sponge gourd plants. Overall, the antimicrobial activity against Malassezia furfur appeared to be higher than against Candida albicans.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.210-216
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• 2007

The cadmium (Cd) and zinc (Zn) contamination of soils and cultivated crop plants by zinc smelting activities was studied. In the study area of the vicinity of ${\triangle}{\triangle}$ zinc smelting factory in Korea, soils and corn plants were sampled at corn harvesting stage and analyzed Cd and Zn concentration as well as Cd and Zn fraction and chemical properties in soils. At 600 m radius of studied area, Cd and Zn were highly accumulated in the surface soils (0 - 20 cm) showed greater than the Korean warning criteria (Cd 1.5, Zn 300 mg $kg^{-1}$) with corresponding values 1.7 and 407 mg $kg^{-1}$, respectively. The leaf part gave higher Cd concentration with the corresponding value of 9.5 mg $kg^{-1}$ as compared to the stem and grains pare (1.6 and 0.18 mg $kg^{-1}$), respectively. Higher Zn concentration was also obtained from the leaf part of the corn plant which gave the value of 1,733 mg $kg^{-1}$. The stem and grain part gave corresponding values of 547 and 61 mg $kg^{-1}$. The order of the mean Cd concentration in fractions is F3 (oxidizable fraction) > F2 (reducible fraction) > F4 (residual fraction) > F1 (exchangeable + acidic fraction). A highly positive correlation is observed between F2 and concentration of Cd and Zn in both plant pare, leaf and grain. Highly positive correlations are shown in the pH exchangeable Ca and Mg, and CEC when correlated with Cd and Zn bound to F4 fractions. To reduce Cd and Zn uptake by corn plant in an arable land heavily contaminated with Cd and Zn as affected by smelting factory, an efficient and effective soil management to increase soil pH and CEC is thus recommended.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.48-54
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• 2011

This study was performed to analyze the possibility of using Korean native Aster koraiensis Nakai for phytoremediation at various fields. A. koraiensis was cultivated at paddy, upland and forest soils contaminated with heavy metals. After 8 weeks of cultivation, and growth and its absorbing capacity of heavy metals were analyzed. The results showed that A. koraiensis was grown well even at the soil highly contaminated with heavy metals, which means it has a tolerance to heavy metals. As analysis results of arsenic, cadmium, copper, lead and zinc contents absorbed from various soils contaminated with heavy metals, heavy metal absorbing capacity of A. koraiensis was depending on the heavy metal contents in the soils and soil property. In case of arsenic, cadmium and copper, heavy metal accumulation capacities of Aster koraiensis were much influenced by contents of heavy metals in the soils. Absorbing capacity of plants was increased when heavy metal contents in the soils were high. Lead absorbing capacity was depending more on soil property than lead contents in the soil, and was great at sandy soil of forest. Zinc absorbing capacity was influenced by both soil properties and Zn contents in the soil, was increased at paddy soil contaminated with high concentrations of heavy metals and upland soils. In general, A. koraiensis had a tolerance to heavy metals and showed great absorbing capability of heavy metals. So A. koraiensis can be used as a good landscape material for phytoremediation at various soils contaminated with heavy metals.

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.69-77
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• 2010

The Jeongdori windbreak forests of Wando island, located between the sea and the land, are very important as ecological succession areas that protect cultivated lands and fishing villages. Among the Jeongdori windbreak forests, the rocky seashore areas are occupied by Sageretia theezans mantle community, and their inner sections by sub-tree layers such as Ligustrum japonicum and Ligustrum obtusifolium. More specifically, the inner sections of the rocky seashore areas were found to be the habitat of Ligustrum japonicum-Quercus variabilis community, Ligustrum jarponicum-Viburnum erosum community, Ligustrum japonicum-Cinnamomum japonicum community, Cinnamomum japonicum-Carpinus tschonoskii community, and Pinus densiflora-Viburnum erosum community. The average height of tree layers of the Jeongdori windbreak forests is 10.3m, and the average diameter at breath height are 30.3cm. Though the windbreak forests was artificially made, it is now virtually natural forest and deserves protection for ecological reasons. Designated as a scenic spot 3, it is always in the danger of being damaged by frequent tourist visits. So the Jeongdori windbreak forest needs to be continuous maintenance and management by the National Park Service. Considering of the precious cultural treasures of the famous pebble stones covering Gugyedeung and the naturality of the Jeongdori windbreak forests, the Jeongdori windbreak forests as a scenic spot have to designated as the national monument in future and will preserve by the Cultural Properties Administration.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.480-487
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• 2012

The field study was carried out to investigate runoff characteristics of non-point source (NPS) by cultivation activity in river district. Two sites were selected mainly as G region (paddy field, green house), located in Kwangju, Gyeonggi Province, and S region (ordinary field), located in Namyangju, Gyeonggi Province, those belong to Paldang reservoir watershed. The paddy field with water storage capacity showed a slow increase in runoff as rainfall intensity increases. Meanwhile, both green house and ordinary filed revealed a rapid increase. The average BOD runoff concentration of paddy field, green house, and ordinary field was 2.0 mg/L, 2.8 mg/L, 7.9 mg/L, respectively. It indicates that ordinary field shows the highest value in BOD, SS, T-N, and T-P concentration due to the soil loss during rainfall. As a result of runoff load estimation according to the field, a T-N runoff load of paddy field was 1,793.9 kg/year, higher than that of ordinary field. It was estimated that a SS runoff load of ordinary field was 69,704 kg/year and accounts for more than 70% of overall runoff load.

• Journal of Ginseng Research
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• v.40 no.1
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• pp.28-37
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• 2016

Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIO-LOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes. Results: The analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade. Conclusion: The key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.4
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• pp.82-94
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• 1999

According to Korean's geographical features of Taek Li Ji, the best location for human settlements is on the vicinity of a stream among a stream, an river and a sea, and not far from a ridge. The researcher chose one of best village which is called Yougokmaeul in Bonghwa-Gun, Kyungsang-Do. This village was created a gathering village with the same surname, can be translated as a hen and the front mountain can be seen as a rooster in the view of the shape of geographical features. As it were, the shape of this village and the cultivated land seems to be an egg inside a nest of a parent's chicken in the respect of the analogy of the theory of P'ungsuchiri which is known as Feng Shui in China and geomancy in the western world, and to effect the defensive psychology of the living environment in the terrain inland. This village is the studying place, Suckchunjungsa as the lecturing and studying place for their following students within the Chunghadonchun, the studying Yougok village, and even the ritual place performing ancestral sacrifices and the first incoming ancestor's graves in the same geographical system. The house site of the first incoming resident is surrounded the countian and is located in the front of Backsulryount which is the main mountain through Moonsu-san in the branch mountain of Korean's mountain system. Backsulryoung which is to be seen as the white peak, is symbolized the head of a hen which is to relate to a mysterious turtle in the view of P'ungsuchiri. And the pavilion which is called Chungamjung is sited on the rock of a shape of turtle which is symbolized to live longer. In the section of the mountain and water, Lee Jung Hwan mentioned a living place near the mountain stream is the best residential area and a landscape which is composed by a stream between mountains make a pleasure spirit and a bright feeling and make a refined person. If one can reach in the graceful mountain make a pleasure split and a bright feeling and make a refined person. If one can reach in the graceful mountain half day away, this kind of place must be a best living residential area to live. But this village was structured all in one place. And one of the ideas tangibly reflected in traditional Korean society's view of life and nature is the seclusion based on the Taoism. This kind of a dreamy thoughts make a dream to keep the paradise in our ancestors' mind. This kind of utopia is Chunghadonchun which is structured 5 aspects from the utopian gate near the Samgaesuewon to the village. These 5aspects is expressed by some Confucian thoughts as a small cosmos individually. On the third aspects which is the center among these aspects, the Suckchunjungsa which was made a seclusion place to devoting himself to his studies with refined tastes. The word of Jiju-am, Gangpung-dae, Jaewol-dae and Biryoung-pock are all expressed to cultivate one's moral character and to seek the truth by the Confucius'theory through the nature.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.515-523
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• 2012

Recent development and enlargement of reclaimed lands along the sea shores required to explore alternatives to existing crops, which are suitable to grow well and to declare higher profits. The objectives of this study were to investigate yield-related parameters for development of new leafy vegetables, and to screen some candidates among New Zealand spinach genotypes which were collected in Korea. Initially all the collected genotypes were grown for 7 weeks in a greenhouse of the experiment field in Chungnam National University, and then transplanted into the field to measure morphological or physiological parameters (plant height, branch number, stem diameter, chlorophyll content, and maximum canopy diameter), and yield-related parameters (leaf number, leaf length, leaf width, fresh weight and dry weight). Those parameters were quantitatively measured at 1, 5 or 9 weeks after transplanting (WAT). Parameters exhibiting statistically significant difference among the accessions were plant height, branch number, maximum canopy diameter, chlorophyll content, and leaf length. In contrast to highly correlated parameters with fresh and dry weight obtained in salt-affected soil in the earlier report, fresh weight was correlated significantly with leaf length (r=0.72), leaf width (r=0.64), and canopy diameter(r=0.66), while dry weight was correlated significantly with plant height (r=0.46), leaf length (r=0.72), leaf width (r=0.73), fresh weight (r=0.79), chlorophyll content (r=0.47), and canopy diameter (r=0.87). Based on the significantly correlated with yield parameters, the candidate accessions which were ranked in top statistical groups include CNU06A01, CNU06A13, CNU06A26, CNU06A35, CNU06A38, and CNU06A55. In order to be cultivated in reclaimed lands, it is necessary to screen out salt tolerant accessions among the above high-yielding genotypes.