• Journal of the Mineralogical Society of Korea
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• v.21 no.3
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• pp.313-320
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• 2008

Hectorite was synthesized under hydrothermal conditions and its physicochemical properties have been investigated in terms of temperature, pH, and organic agent to observe the change of doll basal spacing. The IR, CEC, MB, swelling volume and specific surface area of the hectorite were measured for the characterization. The solid/liquid ratio of hectorite to distilled water before mixing with other materials was also determined for its use as a multi-functional material. The $d_{001}$ basal spacing decreased from $12.63\;\AA$ at room temperature to $10.19\;\AA$ at $650^{\circ}C$ in the heating tests. As the pH of hectorite slurry increased. the $d_{001}$ basal spacing decreased. reaching the lowest value of $13.33\;\AA$ at pH 7 and afterward, increased. All the fool basal spacings of the hectorite increased when it was intercalated with the following solvents: $12.86\;\AA$ in diethyl ether, $13.31\;\AA$ in acetonitrile. $13.59\;\AA$ in methanol, $14.05\;\AA$ in ethanol, $15.69\;\AA$ in acetone, and $17.42\;\AA$ in ethylene glycol. Our IR analysis results were in good agreement with those of other researchers. The CEC, MB, swelling volume and specific surface area of hectorite were determined to be 105 cmol/kg, 80 cmol/kg, $68\sim74ml/2g$ and $213m^{2}/g$, respectively. Also, the hectorite to distilled water ratio of 2 to 100 was found to be most favorable for mixing with other materials such as the solvents mentioned above.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.384-394
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• 2021

The aim of this study was to investigate the correlation between soil properties and marker compounds contents of Paeonia lactiflora. The methods of determining marker compounds were validated by measuring the linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and recovery using UPLC analysis. P. lactiflora contained albiflorin at 0.04 ± 0.00 ~ 2.79 ± 0.21%, paeoniflorin at 1.98 ± 0.14 ~ 6.67 ± 0.84%. The root dry weight (RDW) of P. lactiflora was 0.06 ± 0.02 ~ 1.27 ± 0.28 kg. The soil properties analysis such as soil pH, electric conductivity (EC), organic matter (OM), total nitrogen (TN), available phosphate (Avail. P₂O₅), exchangeable cation and cation exchange capacity (CEC) were performed following standard analysis manual. The results of correlation analysis between soil properties and growth characteristics, available P₂O₅ was positively coreelated with the RDW of P. lactiflora. On the other hand, the RDW of P. lactiflora showed significantly negative correlation with contents of albiflorin and paeoniflorin. The results of this study was might be help to provide useful information on the establish of standard cultivation by the investigate correlation analysis between growth characteristics and marker compound contents of P. lactiflora.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.49-57
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• 1972

Varietal difference in root distribution and other root characteristics were investigated under fold and water culture condition. The results were as follows: 1. IR667 showed funnel type of root distribution in soil profit while Jinheung had barrel type, and each type appearance was more distinguishable with fertilizer application. 2. Root weight per tiller was smaller in IR667 than in Jinheung and IR667 had more root in 0 to 5cm of soil depth but Jinheung had more in 5 to l0cm depth. 3. Horizontal distribution of root was dencer near to stem base without fertilizer than with fertilizer in both IR667 and Jinheung indicating structural construction for intensive nutrient uptake. Between varieties this 'dence to stem base' trend accompaning 'dence to wide spacing side' was greater in IR667 without fertilizer and these were quite true with fertilizer in Jinheung. 4. The decreasing rates of root and ear weight by fertilizer application were greater in IR667 than in Jinheung. This and other characteristics indicated that the root of IR667 is likely to be panicle-number type comparing with Jinheung. 5. The root of IR667 had lower oxidizing power of ${\alpha}-naphthylamine$ than that of Jinheung indicating weaker resistance to reductive soil but cation exchange capacity of water-cultured root was higher in IR667 suggesting stronger nutrient uptake. 6. The content of phosphorus and especially potassium in root were higher with fertilizer but lower without fertilizer in IR667 than in Jinheung indicating that IR667 is more sensitive to root environment. 7. The contents of N, K and CEC were increasing toward root tip while P content was decreasing. The root from surface soil had higher N and K content than that from subsoil. The contents of N,P,K, and CEC of root at harvesting stage were about 1.0%, 0.1%, 0.5% and 15me/100g at dry weight base, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.330-336
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• 1984

These studies were aimed to find out the representative values of physico-chemical properties in Korean soils and to serve the basic informations to improve the soil properties for increasing the soil productivity. By the results of detailed soil survey, 14 physico-chemical properties (soil texture, moisture characteristics, organic matter content etc) were collected from 315 series of soils except Cheju soils, computerized the simple mean and the distributed area by weighted mean values with grouping of land use, drainage class and soil type. The results were as follows; 1. Simple mean values within the efficient soil depth in whole country soils were clay 20.0%, organic matter 2.03% and CEC 10.3me/100g. But weighted mean values with land area belonged to the same soil series were clay 18.0%, OM 1.85% and CEC 8.6me/100g. 2. Mean values of paddy soils weighted by area were clay 19.7%, OM 2.0% and CEC 9.1me/100g but those of upland soils were 17.9%, 1.8% and 8.1me/100g and forest soils were 16.7%, 1.8% and 8.6me/100g respectively. 3. Weighted mean values of moderately well soils with covered area were clay 18.9%, organic matter 1.7%, CEC 8.4me/100g but those of imperfectly drained soils were 21.3%, 2.2% and 9.5me/100g, and those of poorly drained soils were 15.1%, 1.8% and 9.9me/100g respectivcly. 4. Simple mean and area weighted mean values of clay content, pH, organic matter contents, cation exchange capacity and base saturation were calculated by the types of paddy and upland.

• Journal of Soil and Groundwater Environment
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• v.13 no.5
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• pp.8-19
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• 2008

The physicochemical properties of soils having high uranium content, located around Duckpyungri in Korea, were investigated and the lab scale soil washing experiments to remove uranium from the soil were preformed with several washing solutions and on various washing conditions. SPLP (Synthetic Precipitation Leaching Procedure), TCLP (Toxicity Characteristic Leaching Procedure), and SEP (Sequential Extraction Procedure) for the soil were conducted and the uranium concentration of the extracted solution in SPLP was higher than Drinking Water Limit of USEPA (30 ${\mu}g$/L), suggesting that the continuous dissolution of uranium from soil by the weak acid rain may generate the environmental pollution around the research area. For the soil washing experiments, the uranium removal efficiency of pH 1 solution for S2 soil was about 80 %, but dramatically decreased as pH of solution was > 2, suggesting that strong acidic solutions are available to remove uranium from the soil. For solutions with 0.1M of HCl and 0.05 M of ${H_2}{SO_4}$, their removal efficiencies at 1 : 1 of soil vs. washing solution ratio were higher than 70%, but the removal efficiencies of acetic acid, and EDTA were below 30%. At 1 : 3 of soil vs. solution, the uranium removal efficiencies of 0.1M HCl, 0.05 M ${H_2}{SO_4}$, and 0.5M citric acid solution increased to 88%, 100%, and 61% respectively. On appropriate washing conditions for S2 soil such as 1 : 3 ratio for the soil vs. solution ratio, 30 minute for washing time, and 2 times continuous washing, TOC (Total Organic Contents) and CEC (Cation Exchange Capacity) for S2 soil were measured before/after soil washing and their XRD (X-Ray Diffraction) and XRF (X-Ray Fluorescence) results were also compared to investigate the change of soil properties after soil washing. TOC and CEC decreased by 55% and 66%, compared to those initial values of S2 soil, suggesting that the soil reclaimant may need to improve the washed soils for the cultivated plants. Results of XRF and XRD showed that the structural change of soil after soil washing was insignificant and the washed soil will be partially used for the further purpose.

• Journal of Wetlands Research
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• v.12 no.1
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• pp.1-14
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• 2010

Changes in wetland soil properties of two constructed wetlands after their constructions were compared to those of a natural wetland to determine if they could be used for the evaluation of the success of constructed wetlands and the assessment of their functions. One natural wetland as a reference wetland and two constructed wetlands(treatment wetland and experimental wetland) with different contaminant inflow characteristics were selected for this study. Major physicochemical properties of wetland soil such as soil texture, water content, pH, CEC(cation exchange capacity), organic matter content, total nitrogen, and available phosphorus were monitored to investigate the effects of inundation and accumulation of organic matters and nutrients on the wetland soil development. There was a clear difference in soil texture between the natural wetland and the constructed ones, with the high sand content in the constructed wetlands as compared to the high clay content in the natural one. Gradual increases of silt and clay contents over time were observed in the constructed wetlands. The soil of the natural wetland was higher in water content and organic matter but lower in pH than those of the constructed wetlands. The pH of the constructed wetlands reached near neutral ranges after initial increase. CEC and nutrient concentrations of the constructed wetlands seemed to be affected mainly by outside inflows of organic matter and contaminants. Concentrations of organic matter and nutrients decreased over time in the experimental wetland where surface and deep soils with different characteristics were mixed during its construction, suggesting that changes in soil properties during wetland constructions may affect the development of wetland soils or wetland biogeochemistry. This study showed that changes in physicochemical properties of soils in constructed wetlands could be used to assess the success of constructed wetlands and their functions, and also the importance of reference wetlands for the appropriate assessment.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.499-506
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• 2014

This research was conducted to develop root media containing ground and aged pine bark (GAPB) and ground and raw pine bark (GRPB). After analysis of physico chemical properties, the pine barks were blended with peat moss (PM) or coir dust (CD) in various ratios to formulate 12 root media. Then, two out of 12 root media were chosen based on the physical properties for further experiments. The pre-planting nutrient charge fertilizers (PNCF) were incorporated into two root media and chemical properties were analysed again. The total porosity (TP), container capacity (CC), and air-filled porosity (AFP) of GAPB were 78.7%. 39.4%, and 38.3%, respectively, while those of GRPB were 74.7%, 41.2%, and 33.4%, respectively. The percentage of easily available water (EAW, from CC to 4.90 kPa tension) and buffering water (BW, 4.91-9.81 kPa tension) in GAPB were 12.7% and 8.5%, respectively, which were a little lower than the 13.5% and 8.8% in GRPB. The pH and EC were not different significantly, but cation exchange capacity was different between the two pine barks (GAPB: pH 5.26, EC $0.61dS{\cdot}m^{-1}$, CEC $15.7meq{\cdot}100g^{-1}$; GRPB: pH 5.19, EC $0.32dS{\cdot}m^{-1}$, CEC $9.32meq{\cdot}100g^{-1}$). The concentrations of exchangeable cations in GAPB were Ca 0.32, K 0.05, Mg 0.27 and $0.12cmol+{\cdot}kg^{-1}$, whereas those in GRPB were Ca 0.28, K 0.08, Mg 0.25 and $0.09cmol+{\cdot}kg^{-1}$. The concentrations of $PO_4$-P, $NH_4$-N and $NO_3$-N were 485.8, 0.62 and $0.91mg{\cdot}L^{-1}$ in GAPB and 578, 1.00 and $0.82mg{\cdot}L^{-1}$ in GRPB, respectively, when those were analyzed in the solution of the saturated paste. The TP, CC and AFP in the two selected media were 89.3 and 76.3, and 13.0% in PM+GAPB (8:2, v/v) and 88.2, 68.2 and 20.0% in CD+GRPB (8:2), respectively. The pHs and ECs were 3.8 and $0.24dS{\cdot}m^{-1}$ in PM+GAPB which were a little lower than 5.8 and $0.65dS{\cdot}m^{-1}$ in CD+GRPB. However, the pHs analysed before and after incorporation of PNCF in the two root media did not show large differences. This is because the solubility of dolomitic lime is very low, and the pH it is expected to rise gradually when crops are cultivated int he root media. The information obtained in this study should facilitate effective formulation of root media containing pine bark.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.73-82
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• 2023

This study was conducted to investigate the effect of soil physico-chemical properties and crop growth responses for application of biochar derived from substrate with post harvest of oyster mushroom. The biochar was produced at 450~600℃ using a top-light up draft gasifier (TLUD) production system. As a result of elemental analysis, the biochar used was C 76.2%, H 2.5%, N 3.2%, and H/C was 0.39, which met the international certification standards for biocarbons (IBI) below 0.7. The chemical properties were 10.1 for pH, 1.0% for P₂O₅, 1.8% for K₂O, and 2.5% for CaO. The application rates of biochar were 0, 100, 200, 300, and 500 kg/10a. For cultivation of chinese cabbage and welsh onion, soil organic matter (OM), total nitrogen (T-N), total carbon (T-C), Ex.cation K contents and cation exchange capacity (CEC) in the treatments were increased compared to the no treatment. In addition, the bulk density was lowered and the porosity was increased, improving the soil physical properties in the treated soil. The growth of chinese cabbage and green onion increased with the application of biochar, but the yields of chinese cabbage and green onion did not significantly different among the treatments. Soil carbon sequestration in the treatments enhanced with increasing the amount of biochar application. It is expected to apply the biochar derived from spent oyster mushroom substrate in the eco-friendly farm soil management, improving soil physico-chemical properties.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.65-72
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• 2006

Objective of this research was to remove the accumulated salts in the plastic film house soils by installing the perforated PVC (${\phi}10cm$) underdrainage pipes at 50 cm depth of soils with cultivating vegetables. Efficiency of the underdrainage pipes was assessed based on the changes of soil chemical properties such as pH, EC, and cations, and growth and yield parameters of the vegetables between the two treatments; the control and the underdrainage pipe treatments. The EC of the underdrainage pipes installed soils after two growing seasons were in the ranges of $1.42-2.88dS\;m^{-1}$ but those of the control were in the ranges of $3.86-4.53dS\;m^{-1}$, indication the underdrainage pipes effectively removed the accumulated salts in soils. The pHs of the control soils and the underdrainage pipe installed soil were in the ranges of 7.2-7.5 and 6.9-7.3, respectively. There was a significant correlation between pH and cation exchange capacity (CEC) of the soils ($CEC=17.107{\times}pH-106.2$, $r^2=0.759$, P < 0.05). The ECs of the soils at different depths were compared between the two treatments after cultivating vegetables with lettuce-lettuce-garland chrysanthemum rotation systems. The ECs of the control soils at depths of 0-10, 10-20, 20-30, 30-40, and 40-50 cm were 3.45, 3.47, 3.03, 2.03, and $2.28dS\;m^{-1}$, respectively, with decreasing with soil depths. On the other hand, the respective ECs of the underdrainage pipes installed soils were 2.43, 2.52, 2.28, 4.00, and $4.23dS\;m^{-1}$ with increasing with soil depths. This might be derived from the salts moved downward with the draining water into the subsoil. The order of cations moved downward was Mg > Ca > K, based on the ratios of cations at specific depth over those at the surface soil. The survival rates of lettuce after 15 days of transplanting in the underdrainage pipe installed soils were 98.2% as compared to 86.6% of the control. The underdrainage pipe treatment also increased the diameter of the lettuce stalk from 12.9mm of the control to 13.7mm. Overall results demonstrated that the installment of the underdrainage pipes in the subsoils of the salt accumulated plastic film house soil effectively removed the salts by leaching downward,resulting in lowering soil EC and enhancing the growth and yield of vegetables.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.366-377
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• 2002

This study investigated the ecological environment of Dongguneung, which royal tombs of the Joseon Dynasty aye in. The aim of this study is to do an effective preservation, management and restoration of the royal tomb and garden of the Joseon Dynasty distributed in Seoul and Kyunggi Province through using the data of Dongguneung. In general, Dongguneung contains the predominant Oak class such as Quercus serrata-Quercus mongolica community, while a flatland surrounding its control office, which is often flooded with the rainy season in summer, is mainly Alnus japonica community, Pinus densiflora community ranges around the royal tomb. The subcommunity of Quercus serrata -Quereus mongolica community is distributed into Robinia pseudo-acacia, Pinus rigida, Pinus koraiensis, Carpinus laxiflora and typical subcommunity and so on. In particular, Robinia pseudo -acacia, Pinus rigida and Pinus koraiensis subcommunity, and Alnus japonica community were forested. The soil class of Dongguneung was mainly a sandy loam and its pH was an average of 4.67 (from 4.36 to 5.68). The content of heavy metals including Cu, Pb and Zn etc. in the soil was about twice as much as the natural content in the forest soil. The content of organism and total nitrogen in the topsoil layer was the average of 4.87% and 0.21% respectively, slightly higher than those (organism； 4.55%, total nitrogen； 0.20%) of the forest soil generated from granite bedrock. Cation exchange capacity as the indicator of soil fertility was 15.0 cmol $kg^{-1}$, higher than that in the granite forest soil. However among base exchangeable cations, contents of $Ca^{2+}$ (2.07 cmol $kg^{-1}$), $Mg^{2+}$ (0.40 cmol $kg^{-1}$) and K+ (0.25 cmol $kg^{-1}$) were slightly lower than that. The above results could reflect the need of soil fertilization and liming for the improvement of nutritional status and buffer process.