• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.24-28
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• 2005

Waste of the hydroponic solution from the plastic film house cultivation was recycled to grow the red pepper(Capsicum annum L.) in upland fields as supplement for plant nutrients and irrigation sources. Application of hydroponic waste solution increased the pH and EC of the soils, coupled with the increases in the concentrations of exchangeable cations(Ca, Mg, and K), total nitrogen, $NH_4-N,\;and\;NO_3-N$. Growth and yield of red pepper were highest when the treatment of chemical fertilizer(70%) was combined with hydroponic waste solution(30%). Amounts of the daily producing hydroponic waste solution were 2,880 L $ha^{-1}\;day^{-1}$ from the experimental facilities and this could irrigate $409.86m^2$ of area to compensate for the amount of water loss by evapotranspiration(3%). The overall results demonstrated that hydroponic waste solution could be recycled as plant nutrients and irrigation water resources for enhancing soil fertility and environmental quality.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.518-524
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• 2013

A pilot-scale test-bed was operated employing three soils with different grain sizes dredged from the Nakdong River to obtain the design and operation parameters of the multi-purpose filtration pond, such as the filtrate productivity of the filter sand, the appropriate removal period of the surface clogging and the contaminant removal efficiency. The cross-flow velocities were applied stepwise ranging from 0 to 40 cm/sec in order to simulate the various velocities in the artificial stream of the pond. Results showed that a filtrate production rate of 5~3 $m^3/m^2-day$ was maintained by removing the surface clogging every 7 to 13 days and that the filtrate quality was not affected by the factors of the filtrate production rate, the grain size of the filter sand and the cross-flow velocity. Results also showed that most of the removal occurred within 50 cm of the top soil and that the removal efficiencies with the filtration distance of 2.4 m were 80~95% for turbidity, 20~30% for COD, 75~90% for BOD, 5~20% for total nitrogen and 20~60% for total phosphorus, which suggested that particulate matters had a high removal efficiency.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.157-165
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• 2005

The purpose of this study is to examine the relationship between land use patterns of riparian zones and water quality in the Geumho River watershed. A GIS database included digital land use maps (1:25,000), stream network extracted from digital topographic maps (1:5,000) and riparian zones maps by multi-buffering method. Pearson's correlation analysis was used to explain the relationship between the environmental conditions of a 30 meter buffer strip on each side and water quality. According to the result of investigation of riparian-level land use patterns, sub-watersheds on the lower Geumho River including Daegu metropolitan city were mainly developed as urban area such as residential, commercial and industrial ones, while sub-watersheds on the middle Geumho River and the main course of Nakdong River, agricultural ones such as a paddy, a dry field and an orchard. Meanwhile, the area-rate of riparian forests which play an important role in filtering nitrogen, phosphorus and sediment was estimated below the average 16%. The proportion of urban area in a 30 meter riparian bufferstrip had a negative correlation with water quality in each sub-watershed. But the proportion of forest area had a positive correlation with water quality. Henceforth, it is necessary to establish landscape planning for preparing and restoring the riparian buffer zones, concerning land form, soil type, the present land use pattern and economic aspects.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.429-438
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• 1993

This is a report on the early vegetation and the secondary succession in the burned area of SeobJe-Go1 of $IIwasan-MY\v{o}n,\;Y\v{o}ngch\v{o}n-Gun,\;Ky\v{u}ngsangbuk-do$ Province. The forest fire occurred on April 8, 1982 and the pine forest and its floor vegetation were burned down. The investigation was done six times from August 20, 1982 to August 13, 1983. The results are summarized as follows: the floristic composition of burned areas $B_1,\;B_2$, and unburned areas $U_1,\;U_2$ were composed of 25, 23, 32, and 27 kinds of vascular plants. respectively. The biological spectra showed the $H-D_1-R_5-e$ type in both the burned and unburned areas. The species of Arundinella hirta, Miscanthus simnsis var. purpurascens and Cares hurnilis var. nana were dominant species in the burned area, while Pinus densiflorrr, Corex humilis var. nana and Rhododendron mucronulatum var. ciliafum were dominant species in the unburned area. Degree of succession of the unburned area was comparatively higher than that of the burned area. Species diversity index and evenness index of the burned area were similar to those of the unburned area. Indices of similarity in sampling sites showed that $B_1\;and\;B_2$ stands were the most similar. pH, total nitrogen, available phosphorus and exchangeable potassium of soil increased but organic matter and total organic carbon decreased after fire.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.305-313
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• 2002

The physico-chemical characteristics of water and sediment, and structures of vegetation of the vascular hydrophytes were investigated in the West Nakdong River. Water quality was eutrophic according to the mean values and the ranges of water properties such as pH, DO, BOD, chlorophyll a, total nitrogen and phosphate, and other nutrients. A few cases were hypereutrophic for chlorophyll a level in summer. Soil reaction was weak acid. Composition of sediment was mainly sand except in SI(Sinan chideung) of which was mainly clay, and SU(Suan chideung) of which was mainly silt. Flora of vascular hydrophyte had 26 species and 1 variety comprising 16 families. Trapa japonica was dominant species in the sites of DU(Dunchido), GA(Garak chideung) and SU. Nymphoides peltata and Hydrocharis dubia dominated in DA and SI, respectively. Species diversity and evenness were relatively high in SI and SU but dominance was high in DA. After June, water lettuce(Pistia stratiotes) and water hyacinth(Eichhornia crassipes) were flowed from tributary to the river. Standing crop of macrohydrophytes was high in DA from April to August, but it showed maximum standing crop (445g·dw/㎡) in DU after disturbance by explosive growth of exotic plants in October. In comparison with those in 1985, total productivities in DU and GA decreased to 33.5%, and the reduction ratio of dominant species, Trapa japonica was 56.7%. Najas marina, N. minor, Myriophyllum spicatum and Nymphoides indica have disappeared ever since the Nakdong barrage was constructed in the Nakdong river. They were divided into three groups (GA-SU-DU, DA, SI) by cluster analysis. Introduction of the exotic species in this river caused decreasing of endemic plants including endangered species Euryale ferox and rare species Hydocharis dubia, and food plants for waterfowl such as Trapa japonica, Vallisneria asiatica and Potamogeton crispus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.479-483
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• 2003

Knowledge of N accumulation during the vegetative growth stage of rice (Oryza sativa L.) is useful for determining the need for topdressing fertilizer N at panicle initiation and booting stage. The chlorophyll content showing SPAD threshold values generated by a simple and portable diagnostic instrument, chlorophyll meter, enables implement the measures of greenness and/or relative chlorophyll contents of leaves. Two-year field experiment was conducted to evaluate the possible application of the chlorophyll meter for N diagnosis in transplanted paddy rice. The chlorophyll meter threshold values (SPAD reading) were taken from uppermost fully expanded leaves at 10days interval from 10 days after transplanting. SPAD readings and N contents of rice leaf blade were closely related at the maximum tillering stage. SPAD readings during growth period showed M-shaped distribution, sharply finished to drop at 20 days after heading date. As N fertilizer increased, the SPAD readings increased. The SPAD readings showed more critical and clear difference in immature paddy field than in ordinary paddy field, where the former soil showed higher response to N fertilizer topdressed. Based on the PAD readings for obtaining an optimum sink size bearing the maximum grain yield, N fertilizer to be dressed at the panicle initiation stage is to be adjusted within the SPA$\times$tillers value range 888 in ordinary paddy, and 800 in immature paddy vice. Among the cultivars tested, Huckhyangbyeo, Jinpumbyeo, Ansungbyeo, Sobibyeo, Manpungbyeo, Sangmibyeo, Jinbongbyeo, showed high SPAD values, whereas the cultivars, Nonghobyeo, Saechuchungbyeo, Hwabongbyeo, Mananbyeo, did low values and others intermediate SPAD threshhold values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.359-366
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• 1993

Molds are eucaryotic, multicellular, multinucleate, filamentous organisms that reproduce by forming asexual and sexual spores. The spores are readily spread through the air and because they are very light-weight and tend to behave like dust particles, they are easily disseminated on air currents. Molds therefore are ubiquitous organisms that are found everywhere, throughout the environment. The natural habitat of most molds is the soil where they grow on and break down decaying vegetable matter. Thus, where there is decaying organic matter in an area, there are often high numbers of mold spores in the atmosphere of the environment. Molds are common contaminants of plant materials, including grains and seeds, and therefore readily contaminate human foods and animal feeds. Molds can tolerate relatively harsh environments and adapt to more severe stresses than most microorganisms. They require less available moisture for growth than bacteria and yeasts and can grow on substrates containing concentrations of sugar or salt that bacteria can not tolerate. Most molds are highly aerobic, requiring oxygen for growth. Molds grow over a wide temperature range, but few can grow at extremely high temperatures. Molds have simple nutritional requirements, requiring primarily a source of carbon and simple organic nitrogen. Because of this, molds can grow on many foods and feed materials and cause spoilage and deterioration. Some molds ran produce toxic substances known as mycotoxins, which are toxic to humans and animals. Mold growth in foods can be controlled by manipulating factors such as atmosphere, moisture content, water activity, relative humidity and temperature. The presence of other microorganisms tends to restrict mold growth, especially if conditions are favorable for growth of bacteria or yeasts. Certain chemicals in the substrate may also inhibit mold growth. These may be naturally occurring or added for the purpose of preservation. Only a relatively few of the approximately 100,000 different species of fungi are involved in the deterioration of food and agricultural commodities and production of mycotoxins. Deteriorative and toxic mold species are found primarily in the genera Aspergillus, Penicillium, Fusarium, Alternaria, Trichothecium, Trichoderma, Rhizopus, Mucor and Cladosporium. While many molds can be observed as surface growth on foods, they also often occur as internal contaminants of nuts, seeds and grains. Mold deterioration of foods and agricultural commodities is a serious problem world-wide. However, molds also pose hazards to human and animal health in the form of mycotoxins, as infectious agents and as respiratory irritants and allergens. Thus, molds are involved in a number of human and animal diseases with serious implication for health.

• Journal of the Korean GEO-environmental Society
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• v.17 no.10
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• pp.45-53
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• 2016

At present, coffee consumption amount is annually on the rise in Korea, which results in about 0.27 million tons of coffee waste annually. They are mostly classified as food waste and deserted with moisture contained, being a serious environmental issue. Existing slope greening techniques, which are vegetation based soil-media hydroseeding measures, have problems such as lack of coherence, dryness or lack of organic matters. Therefore in order to assess usability of Spent Coffee Ground (SCG), medium-to long-term growth test was conducted under the indoor and outdoor conditions. According to the result of growth test, when SCG was mixed with existing base materials, moisturizing power increased and organic matter content was reinforced, promoting germination and growth in a medium term. Among others, under the condition when supply of water was discontinued, withering rate was lower than existing base materials and diverse phenomena resulting from lack of nutrition decreased. Therefore, SCG as a waste organic matter with abundant nitrogen has the characteristic of inhibiting early growth but was found to have a quality favorable to long-term growth resulting from water containing ability and the supply of organic mater and is judged to be a material to replace or complement existing base materials.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.223-235
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• 2011

Juncus effusus is mostly found in freshwater wetlands and is widely used for landscaping and creating artificial wetlands due to its high ecological value. J. effusus tends to dominate during the early stage (3-10 years) of the second succession in abandoned paddy fields. This study focused on the environmental characteristics of J. effusus to create habitat for an endangered species, Nannopya pygmaea, which lives in wetlands dominated by J. effusus. Considering the distribution of J. effusus and N. pygmaea, 63 quadrats at eight wetlands were investigated between May and June 2006 during the critically dry period. Fifty-three species from 28 families co-occurred with J. effusus, and Persicaria thunbergii was the most abundant (63.5%). The optimal ranges of distribution (ORD) for the water variables were water depth, -2 to 10 cm; dissolved oxygen, 0.99-3.55 mg/kg, conductivity (CON), 23.40-115.40 ${\mu}s/cm$, total dissolved solid, 12.53-57.60 mg/L; pH, 5.00-6.87; $K^+$, 0.11-1.46 mg/L; $Ca^{2+}$, 1.53-5.85 mg/L; $Na^+$, 3.16-7.47 mg/L; $Mg^{2+}$, 0.11-1.96 mg/L; $NO_3$-N, < 0.001-0.072 mg/L; $NH_4$-N, 0.005-0.097 mg/L; and $PO_4$-P, 0.006-0.047 mg/L. ORDs for the soil variables were water content, 1.05-2.96%; loss-on ignition method (LOI), 5.07-7.81%; CON, 23.70-59.70 ${\mu}s/cm$; pH, 4.40-5.16; extracted (e) $K^+$, 4.34-15.73 cmol/kg; $eCa^{2+}$, 31.56-191.56 cmol/kg; $eNa^+$, < 0.01-2.61 cmol/kg; eMg, 0.04-19.82 cmol/kg; $eNO_3$-N, 0.514-1.175 mg/kg; $eNH_4$-N, 0.033-0.974 mg/kg, $ePO_4$-P, 0.491-11.552 mg/kg; total nitrogen, 0.016-0.200%; and total carbon, 1.06-2.37%. The appearance of rush during early succession indicated relatively lower levels of these physicochemical parameters, and that ORDs should be maintained for the J. effusus community.

• KSBB Journal
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• v.23 no.3
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• pp.219-225
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• 2008

For the production of an antifungal compound, one strain (I-8) was selected from approximately 400 strains isolated from various soil samples. The optimum carbon source, nitrogen source and pH culture conditions for the production of the antifungal compound were investigated. ISP No. 2 medium (yeast extract 0.4%, malt extract 1% and dextrose 0.4%, at pH 8) was determined to be the optimum medium. Strain I-8 showed broad antifungal activity against the plant pathogenic fungi tested, including Sclerotinia sclerotiorum KACC 41065, as well as cellulase and chitinase activities in an agar plate assay. The extraction of antifungal compounds was performed using ethyl ether and ethyl acetate. In a culture broth of strain I-8, the ethyl acetate extract exhibited effective growth inhibition against 14 of the 20 phytopathogenic fungi tested. By mixing the ethyl acetate extract from I-8 with the ethyl ether extract from the fungus 13-16, which shows specific antifungal activity against Colletotrichum orbiculare KACC 40808, the antifungal activity of I-8 against phytopathogenic fungi was confirmed to be slightly increased. Strain I-8 showed strong growth inhibition against 16 phytopathogenic strains in agar plate tests.