• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.4
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• pp.380-391
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• 2003

Surface sediments were collected from Gwangyang and Yeosu Bays to evaluate their sedimentological characteristics and geochemical aspects of both the benthic environment and heavy metal pollution. The grain size distribution includes both sandy and muddy sediments. Sand-rich sediments occur mainly near the POSCO and the channel between Namhedo and Yeosu Bando, while elsewhere mud-dominated sediments are present. TOC content ranges from 0.2 to 2.1 % and C/N ratios indicate that the range arises from the mix of organic matter. The C/S ratios of this organic matter show that parts of the study area are anoxic or have sub-anoxic bottom conditions. The hydrogen sulfide content of the sediment has a range of 0.7 to 301 ppm, with a high content occurring inshore of Myodo Island, where it indicates a polluted environment. The enrichment factor (Ef) and index of accumulation rate (Igeo) of ten heavy metals (Co, Ni, Cu, Cd, Pb, Li, Zn, V, Cr, Ba) show that parts of the study area contain from one to seven times more Pb and Ba, and from 0.8 to 3.5 times more of the other elements than the mean sediment value. The Igeo values of V and Cd show that different parts of the area can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted. Those areas that have both high levels of enrichment and high accumulation rates of heavy metals contain predominantly fine sediments with a high organic matter and hydrogen sulfide content.

• The Korean Journal of Quaternary Research
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• v.8 no.1
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• pp.1-8
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• 1994

한국서해 경기만 남부 반월조간대 퇴적층에서 망간과구리의 함량특성을 밝히기 위 하여 총 3개의 주상시료를 채취하여 퇴적물의 입자와 유기탄소(organic carbon)함량을 일차 적으로 분석하였고 이에 따른 중요 시료에 대하여 망간과 구리의 함량을 분석하였다. 이러 한 분석결과는 연구지역의 망간함량이 연근해역 퇴적물의 망간함량에 비해 낮고 구리함량은 상대적으로 높다. 연구지역 내에서도 환원환경인 중부와 하부조간대에서 망간함량이 낮고 구리의 함량이 높게 나타났다. 이와같이 반월조간대 퇴적물의 망간 함량이 낮은 이유는 환 원환경에 공급괸 망간 산화물이 수 mm 깊이의 퇴적층에서 용해되고 그결과 생성된 용존 망간이 퇴적층과 해수와의 경계면(interface)으로 이동 제거 되었기 때문이다. 그러나 구리- 유기물 결합체는 퇴적물내에서 분해되고 그결과 생성된 용존구리는 황화물로 재 침전 되기 때문에 높은 함량을 나타내는 것으로 해석된다, 이와같은 결과는 반월 조간대 퇴적층의 초 기속작용의 영향을 받는 것으로 사료된다.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.285-290
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• 1998

Thermophilic Bacillus species was studied as a microbial indicator to pursue the compost a application history. Thermophilic Bacillus species could be easily determined by the plate culture method within 12 hours in $65^{\circ}C$ incubator. The density of thermophilic Bacillus species in soils was gradually increased with the application rate of rice straw compost, and correlated to the soil organic matter content in $R^2=0.835^{**}$(n=32) coefficient on the 43-year-long term rice paddy fields.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.3
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• pp.156-161
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• 1982

In ginseng fields, soil organic matter content showed significant positive correlation with soil moisture content and root yield. Soil moisture content showed significant positive correlation with root yield, stem diameter and stem length but significant negative correlation with relative missing plant rate, defoliation and alternalia bright infection. For more than 2 Kg yield per Kan under present cultivation technique, soil moisture appeared to be greater than 17% and organic matter 2%. Many fields (58%) were below this requirement and belong to sand loam and loam soils.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.55-61
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• 1987

A series of laboratory experiments were carried out to find the effects of soil organic matter contents, soil temperature, pH values, kinds and amount of nitrogen fertilizers on the denitrification-$N_2O$ gas evolution-. The results obtained were summarized as follows: 1. Denitrification rate, amount of $N_2O$ gas evolution, was influenced the order of organic matter contents>soil temperature>pH values>kinds of N-fertilizer>levels of N-fertilizer. 2. The highest dentrification rate was observed in organic matter content of 3.0%, pH values at 6.0 with application of $KNO_3$ at levels of 20 mgN/100g soil. 3. For the evolution of I mole $N_2O$ gas, averaged carbon consumption was obtained as 0.5 mole in all these experiment condition. However, the highest carbon consumption rate was obtained in organic matter contents for 1.0% with application of $(NH_4)_2SO_4$ at levels of 10 mgN/100g soil (1.06 mole) while lowest carbon consumption rate was obtained in organic matter contents for 3.0% with application of $KNO_3$ at levels of 20 mgN/100g soil (0.13 mole). 4. According to Michaelis-Menten's equation, the V/2 values for evolution of $N_2O$ gas was estimated by progress curve. The results obtained was as 550 ug for $(NH_2)_2CO$ and 1100 ug $N_2O/100g$ soil by application of $KNO_3$ in organic matter contents of 1.0% soil. On the other hand, when the application $(NH_4)_2SO_4$ the V/2 values of $N_2O$ gas was obtained as the amount of 490 ug/100g soil while V/2 values of $N_2O$ gas by application of $KNO_3$ was on the linear line in soil organic matter contents of 3.0%.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.404-409
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• 2012

In order to obtain optimum mixing conditions with animal cadaver residue and sawdust for composting using rendering treatment method for agricultural recycling, changes of chemical characteristics and compost quality after composting were investigated. Initial mixing ratios with animal cadaver residue and sawdust were adjusted 100 : 0, 50 : 50 and 30 : 70. Temperature, pH, contents of ammonia and carbon dioxide were rapidly increased in 3 days and then decreased with time. Organic matter content was similar in all conditions. In mixing ratio of 50 : 50, the compost quality was satisfied with compost depending on official standard for product fertilizer. Thus, the optimum mixing ratio of animal cadaver residue and sawdust were 50 : 50.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.33-40
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• 1969

1. Physicochemical properties of sea water and soil of Korean tidal flats densely populated with species of Mactra veneriformis, Cyclina sinensis, Meretrix lusoria, and Tapes philippinarum, were investigated in order to find out the index of environmental factors in marine bivalve culture. 2. The turbidity varied with the change in concentrations of organic matter, silicate, and the exchangeable copper in sea water. All of these concentrations in Inchon, Kunsan, and Hansando were higher than those in Yusoo. In the 5 areas investigated the lowest were ditected at Kangnung. 3. The minerals and organic matter content in sea water dia not vary significantly among the different bivalve beds. And it was presumed that the soil texture was one of the most important environmental factors for the density of the bivalves in tidelands. 4. The soil texture index of the different bivalve beds was obtained as follow: 5. There were no significant differences of pH, the exchangeable calcium, and the exchangeable copper contents of bottom soils in the 4 different bivalve beds. As important factors in these areas, it seems that the amount of chemical properties might not affect the distribution of bivalve species. 6. Among the 4 beds the soil organic matter content was highest at the T. philippinarum bed and varied with the total nitrogen content. 7. Among the different bivalve beds, it was significant that the water holding capacity and available phosphorus content were highest at the M. veneriformis bed.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.155-159
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• 1993

This study was initiated to obtain the scientific information for the improvement of paddy soil. Mean values and mutual relationships of bulk density, pH values and the content of organic matter were investigated at the 124 field sites shown to be nationwide high-yielding, young seedling field s and their neighboring fields under the different soil textures and depths. The soil samples were collected and those samples were analyzed in the laboratory of Agricultural Sciences Institute. Mean values among the different soil textures and depths were estimated with loam-textured. Bulk density were significantly correlated with sand and silt in topsoil, and that were appeared to be correlated to sand, silt + clay, pH and content of organic matter highly significant in 1% level. Regression equation of soil bulk density(Y) to clay(C), orgnic matter (OM) and content of silt + clay(S+C) were as follows for the topsoil, Y=1.365+0.006C-0.003(S+C)~0.034OM (R=0.067*), and for the subsoil, Y=1.548 -0.002C-0.0007 (S+C) -0.036OM (R=0.122**).

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.102-108
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• 2020

This study is to analyze the growth response of the Quercus dentata seedlings to four environmental factors and measure the ecological niche breadth. Environmental factors were light, moisture content, soil texture, and organic matter, treated with four gradients. The more quantity light increased, the heavier the leaves biomass, aboveground biomass, belowground biomass and plant biomass was. In treatment of water content and soil texture, growth response was no difference. The more organic matter increased, the heavier aboveground biomass was, but the remaining trait of plant was no difference. The ecological niche breadth was 0.865 in light, 0.995 in moisture content, 0.994 in soil texture and 0.988 in nutrient. Ecological niche breadth was the widest in the moisture content treatment and the narrowest in the light treatment. This means that the growth of Q. dentata seedlings grows well as the amount of light increases, and is sensitive to light, Thus, it is determined a growth and ecological niche breadth by light factors.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.743-753
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• 2020

This study analyzed heavy metal concentration, mineral composition, and spectral characteristics of heavy metal contaminated soil samples of cropland and rice field located in downstream of abandoned Okdong coal mine. X-ray fluorescence analysis detected heavy metal elements including cadmium, copper, arsenic, lead, zinc and nickel in the soils. Both cropland and rice field samples were severely contaminated with arsenic showing higher concentration over the concerned standard. The pollution index of cropland samples was higher than that of rice field samples. X-ray powder diffraction analysis identified that the mineral composition of cropland and rice field samples is similar with quartz, calcite, kaolinite, illite, smectite, magnetite and hematite. The range of organic matter content were more widely distributed in cropland samples. The spectral analysis showed that the reflectance spectra and the absorption features of cropland and rice field samples were alike. The absorption features that appeared near 490nm and 900nm were attributed to the ferric iron, and clay minerals such as kaolinite and smectite caused the absorption features at 1410nm, 1910nm and 2200nm. The reflectance of the soil spectral decreased with an increase in organic content. The absorption depths of both types of soil samples decreased with higher organic matter content at 490nm and 1916nm as well as higher heavy metal concentration.