• Journal of Ecology and Environment
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• v.42 no.4
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• pp.205-210
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• 2018

To assess the environmental factors determining the zonation between Phacelurus latifolius and Phragmites australis, vegetation survey and soil analysis were performed at a tidal marsh. The vegetation of the tidal marsh was classified into P. latifolius and Suaeda japonica dominated quadrats, P. latifolius and P. australis dominated quadrats, P. australis dominated quadrats, and P. australis and other land plants dominated quadrats. The density of P. latifolius ($83.7{\pm}5.5\;shoots\;m^{-2}$) was higher than that of P. australis ($79.3{\pm}12.1\;shoots\;m^{-2}$) in each dominated quadrat but height of two species were similar. Soil environmental characteristics of P. latifolius dominated quadrats appeared to be affected by tide based on higher soil electric conductivity ($EC_{PL}=1530{\pm}152{\mu}Scm^{-1}$ ; $EC_{PA+PL}=689{\pm}578{\mu}Scm^{-1}$ ; $EC_{PA}=689{\pm}578{\mu}Scm^{-1$) and lower pH ($pH_{PL}=5.96{\pm}0.16$ ; $pH_{PA+PL}=6.28{\pm}0.31$ ; $pH_{PA}=6.38{\pm}0.22$). In redundancy analysis, environmental characteristics of P. latifolius dominated quadrats and P. australis dominated quadrats were clearly separated and those of P. latifolius and P. australis co-dominated quadrats were similar to P. australis dominated quadrats. From our investigation, P. latifolius showed relatively high competitiveness when compared to P. australis in lower tidal zone rather than upper tidal zone. Zonation of P. latifolius and P. australis seems to be a transitional zone between halophytes and land plant species.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.334-339
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• 2005

Although phosphogypsum can have profound effects on both the physical and chemical properties of certain soils with supplying the essential elements, no widespread use of by-product phosphogypsum will be made unless such uses pose no threat to the public health and soil contaminations. This study was conducted to evaluate the effects of phosphogypsum on the growth of oriental melon and soil properties in plastic film house. Phosphogypsum was treated at the rate of $70kg\;CaO\;10a^{-1}$ and the effects were compared with the treatment of Ca-Mg carbonate. In the treatment of phosphogypsum, early growth of oriental melon was significantly increased comparing to the growth in the Ca-Mg carbonate treatment. Total fruit yield was not different between the treatments of phosphogypsum and Ca-Mg carbonate, but marketable fruit yield was higher in the phosphogypsum treatment. Although Ca and S contents in oriental melon were increased in the phosphogypsum treatment, contents of toxic heavy metals including As, Cd, Cr, Cu, and Pb were not different between the two treatments. Also, soil pH and contents of extractable toxic metals in the soil were not significantly different between the two treatments after the experiment. These results suggest that phosphogypsum can be a valuable substitute for lime materials in high pH soils of plastic film house.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.5
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• pp.30-44
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• 2002

This study is conducted to analyze the change of location and soil characteristics effect on the condition of urban forest in Urban Park and Green Open Space The results of this study are as fallows; 1. Soil acidity is indicated pH 3.88 in Sasang park, pH 4.38 in Hwaji park, pH 4.40 in Daeyeon park, pH 4.68 in Sanseong amusement park, pH 5.15 in Molundae amusement park. 2. Species diversity indices of indicated Sasang park 0.9932, Hwaji park 1.1975, Daeyeon park 1.2160, Sanseong amusement park 1.3080, Molundae amusement park 1.3233 is due to location and soil environment in addition to air pollution effects. 3. The vitality of Pinus thunbergii 27.5ER in Sasang park, 24.9ER in Hwaji park, 24.5ER in Daeyeon park, 23.6ER in Sanseong amusement park, 21.0ER in Molundae park. This shows that tree vitality are impacted by location and soil characteristics. On the basis of the result above, vegetation devices are suggested : 1) Robinica pseudo-acacia management, 2) removing the hazard plants; Smilax china, Humulus japonicus, Pueraria thungergiana, 3) improving soil hardness and soil acidity.

• The Korean Journal of Ecology
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• v.20 no.4
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• pp.275-283
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• 1997

Vertical and temporal characteristics of desalinized reclaimed soil were analyzed from reclaimed coastal land on the western coast of Korea. Of the vertical changes during desalting, pH valuse were the lowest at the topsoil without regard to reclaimation time. The content of C1 were designated as the early period (the first 2-4 years) which decreased exponentially and the later period(the last 5-7 years) which was almost constant, from top to down. In temporal changes of the soil attributes, pH values increased for 5 years and decreased at 6 year after reclamation. Chlorine leaches more rapidly than Na does, K and Ca are constant but Mg increases as time elapsed after reclamation. Sometimes the content of Ca and K in the reclaimed soil are of higher concentration than that of the seawater after reclamation. During desallinization as exemplified by decreasing EC of the soil, Cl and Na are rapidly leached, but K, Ca and Mg are somewhat enhanced. The ration of Na/Cl in the soil equals 1 when the EC registers 5 mmho and then increases dramatically as the EC decreases. Rapid leaching of $Cl^{-}$ elicits an increasing pH valus. The electrostatic balance of the soil is achived by replacement of $Cl^{-}$ with $OH^{-}$ until stationary or until a decreasing pH value is reached again.

• Korean Journal of Environmental Agriculture
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• v.23 no.2
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• pp.104-110
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• 2004

Although silicon (Si) has been Down to be an essential element fer rice growth, the optimum soil level of Si for upland crops remains unestablished. This study was conducted to estimate the availability of Si fertilizer in upland soils, and also effect of the Si fertilizer on soil pH was examined. Different application rates of Si fertilizer were tested using faur soils of different available Si levels and pHs in a series of laboratory incubation study. The treatments included Si fertilizer levels of 100, 200, and 300 kg/10a. Also to examine the effects of compost and lime on the availability of Si fertilizer in upland soil, treatment of silicate fertilizer 200 kg/10a + compost 1,000 kg/10a and lime alone treatment were included. Changes of Si availability in the soils during the incubation period were measured by 1 N NaOAc extraction procedure. Availability of Si fertilizer was different among the tested soils, and about $9.1{\sim}19.2%$ of the applied Si fertilizer was extracted after 60 days laboratory incubation. Application rate could not influence the availability of Si fertilizer. Application of compost with Si fertilizer could not increase Si availability in upland soils, but lime treatment could increase Si availability. Soil pH increased by application of Si fertilizer, but the effect of Si fertilizer on soil pH was minimal. When Si fertilizer is applied on the purpose of Si nutrition in acid upland soils, lime treatment should be coupled with the Si fertilizer for remediation of soil acidity.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.203-209
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• 1999

This study was conducted to obtain the basic data on agricultural use of arbuscular mycorrhizal fungi(AMF) in salt accumulated plastic film house soil by evaluating the density of AMF spores in plastic film house in Yeong Nam area and surface sterility condition, germination rate of AMF spores, and hyphal growth in vitro. The density of AMF spores in plastic film house soils was highest in the site of water melon, and those of cucumber, melon, hot pepper sites were followed in order. The number of AMF was in the range of 101-207 per 100 g dry soil. With decreasing the ratio of bacteria to fungi(B/F), the population density of AMF was increased, and available $P_2O_5$ content of soil was significantly correlated to the population densities of AMF($r=0.416^*$). The surface sterility rate and spore germination of AMF isolated in plastic film house soil were more than 50% in 2% chloramin T and 2% chloramin T + antibiotic and 0.5% NaOCl treatments. The germination rate of Gigaspora margarita in the range of initial pH 5~9 of the medium was more than 56%. Hyphal growth was increased as pH of the medium increased. However the germination rate of Acaulospora spinosa was highest in the medium of pH 9, and hyphal growth in vitro was poor and not related to pH of the medium.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.122-132
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• 2011

Mercury accumulates in biota mainly as methylmercury. In nature, methylmercury shows high affinity to organic matter and $CH_3Hg^+$-organic matter complexation affects the mobility and bioavailabiity of methylmercury. In this study, we examined the methylmercury binding sites in an aquatic humic acid as affected by the pH condition using Hg $L_{III}$-edge extended X-ray absorption fine structure (EXAFS). We evaluated methylmercury binding humic ligands using methylmercury-thiol, methylmerury-carboxyl, and methylmercury-amine complexation models. When $CH_3Hg^+$-to-humic reduced sulfur ratio is 0.3, we found that most of $CH_3Hg^+$ binds to thiol ligands at pH 5 and 7. At pH 7, however, some carboxyl or amine ligand contribution is observed, unlike at pH 5 where $CH_3Hg^+$ almost exclusively binds to thiol ligands. The carboxyl or amine ligand contribution may indicate that some types of thiol ligands in the natural organic matter have relatively low complexation constants or acid dissociation constants compared to those of some carboxyl or amine ligands. Analysis results indicate that ~0.2 fraction of methylmercury binds to amine or carboxyl ligands and ~0.8 to thiol ligands at pH 7.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.272-276
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• 2003

본 연구는 제주지역 지하수의 수질 특성 중 pH에 주목하여 공간적 분포특성을 파악하였다. 먹는 물 수질기준의 경우 pH는 5.8∼8.5의 범위를 요구하고 있다. 제주지하수의 대부분은 이 범위 내에 속하나 특정지역의 경우 상한선을 초과하는 경우도 있다. 이의 원인을 규명키 위한 기초적 조사로서 우선 공간적 분포 특성을 조사하였고 조사결과 지하수위 구성암질 및 오염원과의 명확한 상관성은 판단하기 어려우나 추후 연속적인 측정과 자료분석을 토대로 검토예정이다.

• Journal of Soil and Groundwater Environment
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• v.22 no.5
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• pp.30-39
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• 2017

In this study, the predictive toxicity of barley Hordeum vulgare was estimated using a modified terrestrial biotic ligand model (TBLM) to account for the toxic effects of $CuOH^+$ and $CuCO_3(aq)$ generated at pH 7 or higher, and this was compared to that from the original TBLM. At pH values higher than 7, the difference in $EA_{50}\{Cu^{2+}\}$ (half maximal effective activity of $Cu^{2+}$) between the two models increased with increasing pH. As Mg concentration increased from 8.24 to 148 mg/L in the pH range of 5.5 to 8.5, the difference in $EA_{50}\{Cu^{2+}\}$ increased, and it reached its maximum at pH 8. The difference in $EC_{50}[Cu]_T$ (half maximal effective concentration of Cu) between the two models increased as dissolved organic carbon (DOC) concentration increased when pH was above 7. Thus, for soils with alkaline pH, the toxic effect of $CuOH^+$ and $CuCO_3(aq)$ are greater at higher salt and DOC concentrations. The acceptable Cu concentration in soil porewater can be estimated by the modified TBLM through deterministic method at pH levels higher than 7, while combination of TBLM and species sensitivity distribution through the probabilistic method could be utilized at pH levels lower than 7.

• Journal of the Korean Geotechnical Society
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• v.39 no.8
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• pp.41-48
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• 2023

Microbially induced calcite precipitation(MICP) is a novel cementation method meant to enhance soil engineering properties through the use of microorganisms. This study investigates the effect of different MICP concentrations on plant growth. Tall fescue seeds are grown in plant columns filled with Jumunjin sand. Following plant growth, the soil samples are treated with MICP via spraying method. The results indicate that the MICP-treated plants exhibit hampered growth compared with the untreated plants. pH and electrical conductivity(EC) tests are performed to analyze the changes in soil properties by MICP. The MICP-treated soils exhibit a pH = 7, similar to the untreated soil. However, the EC dramatically increases with the increase in the MICP concentration, which leads to an increase in the osmotic pressure of the soil surrounding the plant roots. Eventually, the higher osmotic pressure in MICP-treated soil hinders the absorption of water and nutrients in plant roots, thus inhibiting plant growth.