• The Korean Journal of Ecology
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• v.17 no.3
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• pp.287-297
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• 1994

To elucidate the cause of growth decline of pitch pine (Pinus rigida) in Seoul, tree density, tree age and physico-chemical properties of soils were investigated at 33 sites of pitch pine forests in metropolitan Seoul, its vicinity and rural areas. The physical properties of soils except for soil texture in Seoul did not differ from those in rural areas. pH values, base saturation, and Ca and Mg contents of soils in Seoul, however, were significantly lower than those in suburbs and rural areas. In contrast, soluble Al and $S0_4^{2-}-S$ contents in Seoul were higher than those in rural areas. Low pH of forest soils in Seoul and suburbs seems to be caused by acid deposition. According to multiple regression analysis, growth of pitch pine in Seoul was affected by several factors in the following order: soil bulk density < Al content of soils < tree density < Mg contents of soil < tree age. We concluded that the acidification of forest soil can be a predisposing factor for the growth decline of pitch pine in metropolitan areas.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.98-104
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• 2001

Cultivation area of the plastic film-house has been continuously increased with the increase of consumers' income. Intensive land use without fallowing or crop rotation caused severe problem such as salt accumulation in soils and in turn retarded growth and low productivity. This study was carried out to solve them derived from longterm intensive farming practices. Seven farmers who are practicing plastic film-house cultivation were recommended for case study by municipal government and selected for their excellency of cultivation and soil management. The cultivation periods of these systems were in the range of 5 to 40 years in the regions mainly located in alluvial soil cultivated with cucumber, tomato and red pepper. The soils texture of the excellent farmers' fields were silt loam or sandy loam, ranged from 7 to 15 percents of clay contents. Soil bulk density, depth of plowing layer and soil aggregates contents of the farmers' soils were 0.89, 23.1 cm, 61.6% whereas those in neighboring soils were 1.10, 17.8 cm, 54.2 %, respectively. And pH, OM and $NO_3-N$ of the farmers' soils also were better than those of neighboring soils. There was no difference in population densities of nematode between the good farmers' and neighboring soils, but actinomyces and Fusarium densities of recommended farmers' soils were better than neighboring soils. The major farming practices by the good farmers were characterized by deep plowing with flooding, amendment of crude organic matter, and reduction of chemical fertilizer application before transplanting, and also drip irrigation and liquid manure application after planting. They also conducted solar sterilization with or without flooding, removal of plastic films during rainy days and culturing rice or corn as rotation crops to avoid the problems mentioned above.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.296-300
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• 1989

This study was carried out to evaluate the effects of clay loam soil, zeolite, and high molecular organic compounds on the improvement of soil physico-chemical properties and soybean yield in a sandy loam soil. Soybean was cultivated from 1987 to 1988. CEC, moisture retention of soil were increased, but soil bulk density and hardness were decreased by soil conditioners. Clay loam soil addition enhanced the soybean yield by 5% at 10ton 10a plot, 7% at 20ton/10a plot. Also zeolite application increased the soybean yield by 6~10%. Effects of soil conditioner application of the 1rst year were greater than that of 2nd year. Some experiments were conducted in laboratory for the effect of soil conditioners on soil physical properties. The nutrient and water holding capacity were highest by K-SAM treatment, but the soil aggregates was most stable by AN-905SH and Primal treatments.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.6
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• pp.832-840
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• 2019

Recently, pollution from gunpowder due to shell shootings at military drilling sites has raised various environmental concerns. The purpose of this study is to predict the contamination level of RDX in the soil area of the firing range zone near Anwol river watershed, the study site, and the intake area, Anwol river and Imjin river, as a function of time and space. In this study, a multimedia model was developed to predict the variation of RDX contamination by rainfall. The range of the medium was limited to soil, water, and sediment, and excluded the atmosphere, taking into account the physical and chemical properties of RDX with low vapor pressure and low Henry's constant. The pollutant levels of the waters of compartments, including the last section of the Imjin River affecting the water intake, was compared with the environmental standard for RDX.

• Geomechanics and Engineering
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• v.18 no.2
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• pp.179-188
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• 2019

This paper presents an experimental study to evaluate the effect of palm oil on the selected basic physical-chemical and geotechnical properties of kaolin. The experimental findings are further compared with literature outcomes investigating similar properties of fine grained soils subjected to contamination by different types of oils. To this end, palm oil was mixed with oven dried kaolin samples-aiding oil's interaction (coating) with dry particles first, in anticipation to emphasize the effect of oil on the properties of kaolin, which would be difficult to achieve otherwise. Oil content was limited to 40% by dry weight of kaolin, supplemented at intervals of 10% from clean kaolin samples. Observations highlight physical particle-to-particle bonding resulting in the formation of pseudo-silt sized clusters due to palm oil's interaction as evinced in the particle size distribution and SEM micrographs. These clusters, aided by water repellency property of the oil coating the kaolin particles, was analyzed to show notable variations in kaolin's consistency-measured as liquid and plastic limits. Furthermore, results from compaction tests indicates contribution of oil's viscosity on the compaction behavior of kaolin - showing decrease in the maximum dry unit weight (${\gamma}_{d,max}$) and optimum moisture content ($w_{opt}$) values with increasing oil contents, while their decrease rates were directly and inversely proportional in ${\gamma}_{d,max}$ and $w_{opt}$ values with oil contents respectively. Comparative study in similar terms, also validates this lower and higher decrease rates in ${\gamma}_{d,max}$ and $w_{opt}$ values of the fine grained soils respectively, when subjected to contamination by oil with higher viscosity.

• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.745-754
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• 2013

This study evaluated the optimal soil washing conditions for toxic metals considering the removal efficiency of toxic metals from contaminated soils as well as from soil washing effluents. In the contaminated soils, As was the major contaminant and extracted by sodium hydroxide solution better than by sulfuric acid. However, in the case of the treatment of soil washing effluents, sodium hydroxide was less effective extractant because soil organic matter extracted by sodium hydroxide prevented the solid-liquid phase separation and toxic metal removal. In the treatment of soil washing effluents with sulfuric acid, toxic metals in the effluents were mostly precipitated at the pH above 6.5. In addition, granular ferric oxide (GFO) as an adsorbent enhanced the removal of As and Pb indicating that toxic metals in the washing effluents can be removed almost completely by the use of combined adsorption-neutralization process. This study suggests that soil washing techniques for toxic metals should be optimized based on the physical and chemical properties of the contaminated soils, the nature of chemical extractant, and the removal efficiency and effectiveness of toxic metals from the soils as well as soil washing effluents.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.334-338
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• 2006

This study was conducted to evaluate the effect of improvement of soil physical properties such as deep plowing, subsoil breaking and diagnostic fertilization on the yield of rice and nitrogen-use efficiency in direct seeding on flooded paddy surface of rice. The effects of deep plowing, subsoil breaking and diagnostic application of N, P, K fertilizers, Latex coated urea(LCU), compost, silicate were investigated. The soil physical properties, such as bulk density, hardness and porosity were improved and the content of organic matter and available $SiO_2$ were also increased by deep plowing and subsoil breaking. The amount of $NH_4-N$ in soil was highly increased by diagnostic fertilization and deep plowing at 5th leaf stage. The nitrogen-use efficiency was the highest at the diagnostic application of LCU 70% applied as basal dressing with subsoil breaking. The yield of rice increased by 8% under the diagnostic application of LCU 70% applied as basal dressing with subsoil breaking compared with the conventional application.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.444-450
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• 2012

The physical and chemical properties of soil in the Mangyeong and Dongjin river basin had been investigated in order to establish the most optimum soil improvement plan on the reclaimed land. The total soil area by reclamation in Saemangeum basin is 113,971 ha. The classification by the distribution of soil series and soil texture is as following. 13 soil series including Chonnam, Buyong and Chonbuk series are period-unknown areas. Regarding the soil texture, they are fine silty ~ clayey very fine. From 1920s to 1960s, Mangyeong, Gwanghwal and Chonbuk series had coarse silty textured soil. After the 1970s, Mangyeong, Gwanghwal, Munpo, Yeompo, Poseung, Gapo and Hasa series have more sandy soil ~ moderately coarse loamy textured soil. Regarding the chemical properties, the concentrations of EC, Exch. $K^+$, $Mg^{2+}$, $Na^+$ and pH are high regardless of the time of reclamation. On the other hand, organic matter (OM) of top soil were 3.3~16.1 g $kg^{-1}$. The organic matter contents were very low though the soil had been farmed for a long time. Furthermore, the deep soil had almost no organic matter with 5.6~1.1 g $kg^{-1}$. The reason is believed that there had not been any movement of OM and clay because pressure or induced pans had been formed by large agricultural machineries and poor vertical drain. Regarding the forming of illuvial horizon (B layer) which tells the development extent of soil, only in the Hwapo reclaimed area where rice had been cultivated for past 90 years, Fe and Mn from top soil are deposited at underground 20~30 cm with 7~8 cm thickness by the movement of clay. It is believed that it had been possible because the earthiness is silty clay loam soil with relatively high content of clay. The soils are soil with concern of damage from sea water, soil on flimsy ground and sandy soil. Therefore, soil improvement for stable crop production can be expected; if the water table would be lowered by subsurface drainage, the water permeability would be enhanced by gypsum and organic matter, and the sandy soil would be replaced by red soil with high content of clay.

• Journal of Soil and Groundwater Environment
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• v.27 no.1
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• pp.60-70
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• 2022

We evaluated the performance of in-situ capping to prevent the release of phenol, one of hazardous chemicals of concern for their impact on sediment. Sediment near the estuary of Hyeongsan River, Korea, and commercially-available sand were collected to evaluate their physical properties and phenol sorption characteristics. Biodegradation kinetics of phenol spiked into the sediment was evaluated under freshwater and estuarine salinity conditions. These experimental measurements were parameterized and used as input parameters for executing CapSim, a software predicting the performance of in-situ capping. The CapSim simulation demonstrated that capping with 50-cm sand reduced the phenol release by several orders of magnitude over 0.25- and 1-year duration for almost all simulation scenarios. The variables tested, i.e., cap thickness, pore-water movement, and biodegradation rate, showed high correlation to each other to influence the extent of phenol release from sediment to the water column. The findings and the framework employed to evaluate the performance of in-situ capping in this study can be adopted to determine whether in-situ capping is appropriate remedial approach at sediment sites impacted by hazardous chemicals due to accidental spills.

• Asian Journal of Turfgrass Science
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• v.6 no.1
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• pp.11-22
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• 1992

To determine the use of waste materials as root zone soil mixtures for turfgrass culture, the effects of paper mill sludge and briquet ash on physical and chemical properties of soil and growth of turfgrasses were examined. Three turfgrass species of zoysiagrass(Zoysia japonicaSteud.). kentycky bluegrass(Poa pratensis L. 'Ram I') and creeping bentgrass(Agrostis panistris Huds 'Persucross') were cultured in 32cm diameter plastic pots containing various soil mixtures. The basic ingredients used for mixtures included sand(SD), field soil(SL), paper mill sludge(PS), sphagnum peat moss(PM) and briquet ash(BA). Seven combinations using these ingreients were mixed in different percentage by volume as follows: SD+SL+PM(80:10.10), SH+SL+PS(80:10:10), SD-PM(80:20), SD+PS (80:20), SD+BA(80:20), SD+BA+PM(60:20:20) and SD+BA+PS(60:20:20). 1. Paper mill sludge showed pH of 6.6, more than 30% of organic matter content, and higher concentrations of total N, P, k, Ca, Mg and CEC. Bulk density, fild moisture capacity and electrical conductivity of soil mixtures were increased by the comimation of 10~20% PS by volume. 2. Briquet ash showed pH of 8.0, and higher levels of P, k, Ca and Mg than those of field soiks. Bulk density, field moisture capacity and hardenss of soil mixtures were increased but vertical water flow rate and electrical conductivity were decreased by the combination of 20% BA by volume. 3. Phytotoxic effects of PS and BA on growth of turfgrasses were not found. Shoot growth of all three species was higher in soil combination of SD+BA+PS than that of SD+SL+PM added with fertilizer. However, root growth was better in soil mixtures combined with PM. Soil mixtureomposed of 60% SD, 20% BA and 20% PS by volume was most effective on growth of all three species. 4. Paper mill sludge resulted in higher N level in the leaf tissue. The contents of heavy metals such as Cd and Ph did not vary significantly among soil mixtures and species. However, the Mn level was 2~3 times higher in plants growh in mixtures containing PM compared with others, and especially it was higher in creeping bentgrass than other species.