• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.177-182
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• 2004

This experiment was conducted to compare the agronomic characteristics and productivity inintroduced vetch cultivar at the experimental field of Grassland and Forage Crops Division, National Livestock Research Institute from 1999 to 2000. The experiment was arranged in a randomized block design with three replications. The vetch cultivar used in this study were 8 cultivar(Haymaker plus, Common, Capello, Namoi, Victa, Aneto, Popany, Korean milk vetch). Namoi, Victa and Aneto cultivar were died during winter. The cultivar having the fastest flowering date was Korean milk vetch while the flowering date of Common was the latest as 22th May. The average dry matter(DM) content was 14.7% and crude protein(CP) content was 20.9%. Common showed the highest CP content by 23.1% and Korean milk vetch showed the lowest content by 18.0%. Average acid detergent fiber(ADF) and neutral detergent fiber(NDF) content were 33.5 and 42.5% respectively. All cultivar showed the first grade of RFV(relative feed value). The productivity of vetch cultivar were severely different according to the winter hardness. Common showed the highest DM yield by 8,664kg/ha, but the DM yield of Capello and Popany were low by 3,004 and 2,114kg/ha, respectively. The yield of CP and TDN(total digestible nutrient) also was high at Common. The results of this experiments indicated that the productivity of vetch cultivar was effected greatly depending on winter hardness, therefore it was thought winter hardness is the main factor for introducing vetch cultivar.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.2
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• pp.105-121
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• 2011

The operation of tidal power facility may induce severe changes of water quality in Shihwa Lake. Current water quality data are quite important to water quality management policy of Shihwa Lake. Thus, the water quality data of Shihwa Lake and its adjacent sea in 2010 were presented to characterize the temporal and spatial changes of water parameters such as pH, SS, DO, COD, dissolved nutrients, chlorophyll-a, TN and TP. Highest levels of water quality parameters were observed near the Shihwa and Banweol industrial complexes and the levels of water quality parameters were on a decreasing trend to those near the water gate. It suggests that the horizontal distributions of water quality levels are mainly controlled by the supply of fresh water from streams and the inflow of outer seawater by operation of water gate. Although the higher concentrations of TN and TP were observed in the location being affected by Sorae port, the levels of water quality parameters in outer sea of Shihwa Lake were lower than those in Lake. In summer season, hypoxic condition was well developed in bottom water by strong stratification and active decomposition of organic matter. Thus, the vertical distributions of dissolved nutrient, TN and TP concentrations showed the concentrations to be higher in bottom seawater than those in surface seawater whereas the vertical distributions of chlorophyll-a, COD and POC concentrations showed the concentrations to be higher in surface seawater than those in bottom water. Results of Pearson's correlation matrix for surface seawater demonstrated that salinity showed negatively good correlation with not only dissolved nutrients except for ammonium but chlorophyll-a, COD and POC This result indicates that the supply of dissolved nutrients through several streams might significantly affect phytoplankton bloom and increase of COD concentration in surface seawater.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.909-918
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• 2009

As a part of dissolved organic matter, dissolved organic carbon (DOC) or biodegradable DOC (BDOC) fraction in particular is one of important issues in water treatment. Due to role as a nutrient source for bacteria, BDOC, therefore, may cause regrowth problems in water distribution system. The main objectives of this study were to investigate the possibility to minimize the concentration of BDOC in advance water treatment process. DOC in water is fractionized into four fractions such as AnBDOC (adsorbable and non-biodegradable DOC) which possesses adsorption properties but no biodegradation ability; nABDOC (biodegradable and non-adsorbable DOC) which has biodegradation properties but no adsorption ability; ABDOC (adsorbable and biodegradable DOC) which has adsorption properties and biodegradable characteristic; and non-removal DOC (nAnBDOC) which do not have either adsorbability or biodegradability. BAC process was effective for adsorbable DOC (AnBDOC+ABDOC) removal. However, in some cases, the removal ratio of adsorbable DOC was not sufficient. BDOC removal rate is very low or irremovable. Thus, for the control of residual DOC, it is necessary to change the operation condition by BAC process. From the analysis results of DOC fractions, water treatment processes appeared to be effective because it could grasp a remarkable amount of biodegradable, adsorbable and non-removal DOC. The concentration of AOX in non-prechlorination process was reduced from 7.1 ${\mu}g$/L to 0.51 ${\mu}g$/L in BAC process followed by ozonation.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.657-662
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• 2006

This study was carried out to investigate the changes in soil chemical properties after thinning for a Quercus acuta stand in Wan-do Arboretum, Jeollanam-do. The stem density after thinning was determined referring to that of Quercus acutissima with 10 cm diameter at breast height and soil samples were collected 7 years after thinning. There was no considerable difference in soil pH values after thinning. However, the concentrations of soil organic matter, total nitrogen and available phosphorus significantly increased after thinning. In addition, thinning significantly increased cation exchange capacity (C.E.C) and the concentrations of exchangeable cations ($K^+$, $Na^+$, $Ca^{2+}$, and $Mg^{2+}$). From this study, it was revealed that the nutrient concentrations of this study site were generally lower than those of other forest soils. Therefore, it is need to improve the warm temperate forests through thinning and to develop forest treatment for regeneration.

• Journal of Korea Foresty Energy
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• v.7 no.1
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• pp.11-21
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• 1987

To estimate the biomass, net production and nutrient distribution of Pinus Koraiensis and Quercus mongolica stand, experimental plots located in Kwangju of Kyonggi-do were selected. Ten sample trees selected account of DBH distribution were felled and the diagram of oven-dry weight distrubution of leaves, branches and stems for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the variable of $(DBH)^2$ H obtained. The standing crops were estimated to be as much as 152.07 and 156.02 tons of dry matter per hectare in P. koraiensis and Q. mongolica stand respectively. The net production was estimated as 24.66 and 20.35t/ha$\cdot$yr and the net assimilation rate was 1.90 and 3.42kg/kg$\cdot$yr in same order. Particulary large proportions of nitrogen. calcium and magnesium were found in soil of P. koraiensis stand, phosphours and potassium in overstory of it. At Q. mongolica stand, large proportions of nitrogen. phosphorus. potassium and magnesium were found in soil and calcium in overstory. The amounts of litter fall was 4.013t/ha$\cdot$8 months in P. koraiensis stand and 3.490t/ha$\cdot$8 months in Q. mongolica stand.

• Journal of Korea Foresty Energy
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• v.1 no.2
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• pp.20-27
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• 1981

Populus alba x glandulosa shows greater growth performance in the lower part of the hill than in the upper part. In order to study this reason, correlation between the soil factors and the growth was examined. The results were as follows. 1. Annual mean height growth was 1.29m in foot hill but 0.7m in upper part, showing 184$\%$ better growth in the foot hill than in the upper part and the similar situation was shown in the diameter growth. The longer slope distance, the better growth: generally the good growth shows in the first harf of the distance. 2. High positive correlation shows between the growth performance and soil moisture: r=0.76 in the hight and r=0.71 in the diameter, and also positive correlation between soil depth and the growth performance. r=0.65 in the height and r=0.79 in the diameter. On the other hand, negative correlation between the slope and soil depth are considered as limiting factors to the growth. 3. A significant correlation appeared between growth performance and organic matter and between the growth performance and total nitrogen as well. This shows that the nutrient elements were contained much in the foot hill. 4. The correlation between the height growth and potassium, and between the growth and calcium and pH were shown . 5. However, no correlation was shown between the growth and available phosphate, magnesium and available managanese .

• Journal of Korea Water Resources Association
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• v.35 no.2
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• pp.149-159
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• 2002

The monthly water quality data measured at 19 stations located in the Sapkyo reservoir watershed were clustered into 2 to 7 clusters and factor analysis was conducted to characterize the water quality, using the information obtained from cluster analysis. The result of cluster analysis shows that Sapkyo reservoir and each stream (Sapkyo stream, Muhan stream and Kokkyo stream) in Sapkyo reservoir watershed hove their own water quality characteristics. The result of water quality analysis indicates that the concentration of suspended solids from Sapkyo reservoir is much higher than those of other streams, and which is probably because of increment of phytoplankton biomass with rich nutrient flowing Into Sapkyo reservoir from the upper stream of watershed. Furthermore, the concentrations of biochemical oxygen demand and chemical oxygen demand were 3.5 to 4.8 times and 1.7 to 2.5 times those of other streams, respectively. The overall water quality of Sapkyo reservoir watershed was considered to exceed eutrophic condition. Based on factor analysis, the water quality characteristics of Sapkyo stream and Muhan stream were closely related with farm land and residence. The water quality of Kokkyo stream was influenced by superabundant organic matter flowing from Chonan city and district wastewater treatment plant located in the upper stream of Kokkyo stream. The water quality factor influencing Sapkyo reservoir was closely related with water quality factors of other three streams.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.221-228
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• 2012

This study was performed to investigate the effects of various parts of sorghum-sorghum hybrid (SSH) silage on nutritive values and qualities of SSH round bale silage and trench silage. SSH "SS405" was harvested at heading stages and ensiled. Samples of SSH silage used in this study were collected in three different parts (outer, middle and inner). The contents of crude protein (CP) and neutral detergent fiber (NDF), and in vitro dry matter digestibility (IVDMD) in SSH round bale silage showed trends similar to SSH trench silage. However, the contents of acid detergent fiber (ADF) and total digestible nutrient (TDN) in SSH trench silage appeared slightly an increased trend, as compared to SSH round bale silage. The contents of CP in inner parts of both SSH round bale silage and trench silage were lower than those of Outer and middle parts (p<0.05). However, The contents of NDF, ADF and TDN, and IVDMD were not different between the parts of SSH silage. The content of lactic acid in SSH round bale silage was significantly decreased (p<0.05), as compared to SSH trench silage. The content of acetic acid appeared an decreased trends, but there is not significantly different between SSH round bale silage and trench silage. In addition, the contents of lactic acid, acetic acid and butyric acid were not different between the parts of SSH silage.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.111-116
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• 1988

The aquatic plants were cultivated in pots containing pig waste water, adjusted to three levels of $NH_4-N$ concentration 50, 100 and 200ppm. The aquatic plants were Eichhornia crassipes solms-laub, Monochoria korsakowii Regel et maack, Zizania caduciflora, Typha orientalis, Acorus asiaticus, Cyperus exaltaus, Colocasia antiquorum var. Yield, content and amount of nitrogen and phosphorus absorped by plants, and growth status were investigated. The results obtained are as follows. 1. The content and removal amount of nitrogen and phosphrus by plants were the highest in Eichhornia crassipes solms-laub. 2. Yield of dry matter in plants in 100ppm $NH_4-N$ was in the order of Eichhornia crassipes solms-laub>Zizania caduciflora>Typha orientalis>Monochoria korsakowii Regel et maack>Acorus asiaticus. 3. The removal amount of nitrogen by plants in the 100ppm $NH_4-N$ was in the order of Eichhornia crassipes solms-laub>Zizania caduciflora>Monochoria korsakowii Regel et maack>Typha orientalis>Acorus asiaticus>Colocasia antiquorum var>Cyperus exaltatus. Removal amount of phosphorus was in the order of Eichhornia cras sipes solms-laub>Monochoria korsakowii Regel et maack>Zizania caducilora>Typha orientalis>Acorus asiaticus> Cyperus exaltatus>Colocasia antiquorum var. 4. Concentration causing growth damage was 200ppm of $NH_4-N$ in Eichhornia crassipes solms-laub, Zizania caduciflora and Typha orientalis and 100ppm in Monochoria korsakowii Regel et maack and Acorus asiaticus. 5. Nitrogen content was the highest in leaf and phosphorus content was the highest in float of the water hyacinth. 6. The number of panicles of the water hyacinth increased by 752 pieces and dry matters were about 5,000kg/l0a during one year.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.173-178
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• 1984

Correlation study was conducted to establish the optimum test level of soil improvement for good growth of corn from the relationships between the corn yield and soil chemical properties in 16 farmers' demonstration fields. Significant positive correlations between the corn yield and soil chemical properties ; pH, available phosphorus, exchangeable potassium, calcium, magnesium, cation exchange capacity. available silica, and base saturation percentage were showed but organic matter and nitrogen content were not. The proper nutrient contents in soil for expecting corn yield, 1.000kg/10a could be estimated as pH 5.6, available phosphorus 327ppm, exchangeable potassium 0.39me/100g, exchangeable calcium 5.5me/100g, exchangeable magnesium 1.3me/100g, cation exchange capacity 11.5me/100g, available silica 116ppm, base saturation percentage 58 from the relationships between the corn yield and soil chemical properties. Exchangeable aluminium were negatively correlated with not only corn yield but also pH, available phosphorus, exchangeable potassium and exchangeable calcium.