• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.69-69
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• 2000

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.1
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• pp.79-89
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• 2005

Forest soils were analyzed on their biological and physicochemical properties for the ecological restoration of burnt forest soil using organic wastes and proper microorganisms. Three kinds of soil samples were collected from undamaged soil(US), naturally restoring soil(NS) and artificially restoring soil(AS). All soil samples were sandy soil and acidic soil, ranged pH 5.34~5.78. Moisture content was higher in the soil of NS region. And the others were similar. Total organic matter and soluble sugar were higher at the surface, generally. Heterotrophic soil microbes were abundant at the surface soil of NS and subsoil of AS. Dehydrogenase, cellulase and phosphatase activities were higher at the NS soil. Especially, Dehydrogenase activity as primary index of soil microbial process showed high correlationship with moisture content(r=0.90, P < 0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.145-151
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• 2009

This study was conducted to develop rational soil management and enhance the productivity of lands converted from paddy soils. Specifically, the changes in the soil physical properties brought about by the change in land usage from paddy soil were evaluated. This was carried out from 1999 to 2001 at 50 site in large-scale converted paddy fields of Kimcheon, Youngcheon, Gyeongsan and Milyang in the Youngnam region, categorized according to soil texture and drainage class. The ridge height of converted paddy soils was higher in coarse-textured and poorly-drained soils than in fine-textured and well-drained soils. The gray color of the surface soil was of lesser degree in converted soils than paddy soils and more notable in welldrained soils. The porosity ratio and the formation of aggregate structure were higher, and the appearance of soil mottling was deeper in converted paddy fields than in paddy soils. The glaying layer "g" of surface soil degraded with time. The porosity and amount of water stable aggregate was found to increase with time after conversion. The penetration resistance of the converted paddy soil was lower and deeper with time after conversion. The soil aeration of the converted paddy soil was lower in sandy loam than in loamy soil. Furthermore, soil aeration was influenced by ridge height and drainage class in poorly-drained soils.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.338-341
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• 2003

유기염소계 농약 중 대표적인 살충제 $\delta$-BHC(hexachlorocyclohexane)와 1, 2-DCB (1, 2-dichlorobenzene)에 대한 논, 밭 토양 및 풍화 토에 흡착 배치실험을 통하여 토양 특성과 유기오염물간의 흡착 관계를 규명하였다. 13개의 토양시료에 대하여 pH, CEC, 유기물 함량, 비표면적, 입도분석, 원소조성분석을 통하여 토양의 물리ㆍ화학적 특징이 토양 흡착에 미치는 영향을 규명하고자 하였다. 유기염소계 농약의 흡착량을 Freundlich isotherm으로 나타내어 흡착분배계수(K$_{d}$)를 산출하였다. $\delta$-BHC는 유기물 함량이 높은 soil-4$_{d}$에서 가장 높은 $K_{d}$ 값을 보였으며, 1,2-DCB의 경우 CEC, 비표면적이 가장 낮은 soil-5에서 낮은 $K_{d}$ 값을 보여 토양 내 유기물 함량과 비표면적이 유기오염물 흡착량에 중요한 요소로 작용함을 알 수 있었다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.362-365
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• 2002

토양의 물리/화학적 특성에 따른 토양의 유기오염물 흡착능 변화를 규명하기 위하여, 토양 내 clay 함량 및 유기물 함량변화, 수용액 내 TCE 농도변화에 따른 TCE 의 토양내 흡착량 변화를 측정하였다. 수용액의 pH와 실내온도는 일정하게 유지시켰으며 clay는 표면적이 다른 Ca-montmorillonite, Na-montmorillonite, kaolin을 이용하였고, 유기물질로는 활성탄을 사용하였다. 일정한 토양성분과 실제토양에 대해 수용액 내 TCE의 농도를 변화시켜 농도변화에 따른 흡착량 변화를 측정하였다. 실험결과 유기물과 점토함량의 증가에 따라 흡착량은 모두 증가하였으나 활성탄에 의한 TCE 흡착량이 점토에 비해 매우 높았으므로 유기물에 의한 TCE 흡착영향이 점토에 의한 흡착 영향보다 큰 것으로 나타났다. TCE 농도변화에 따른 흡착결과는 실제토양과 모사토양에서 모두 농도가 증가함에 따라 흡착 증가율이 증가하다가 감소하는 Langmuir isotherm 형태를 보여 주었다.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.102-108
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• 2010

The internal structure of a river embankment must be delineated as part of investigations to evaluate its safety. Geophysical methods can be most effective means for that purpose, if they are used together with geotechnical methods such as the cone penetration test (CPT) and drilling. Since the dyke body and subsoil in general consist of material with a wide range of grain size, the properties and stratification of the soil must be accurately estimated to predict the mechanical stability and water infiltration in the river embankment. The strength and water content of the levee soil are also parameters required for such prediction. These parameters are usually estimated from CPT data, drilled core samples and laboratory tests. In this study we attempt to utilise geophysical data to estimate these parameters more effectively for very long river embankments. S-wave velocity and resistivity of the levee soils obtained with geophysical surveys are used to classify the soils. The classification is based on a physical soil model, called the unconsolidated sand model. Using this model, a soil profile along the river embankment is constructed from S-wave velocity and resistivity profiles. The soil profile thus obtained has been verified by geotechnical logs, which proves its usefulness for investigation of a river embankment.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.379-382
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• 2006

본 연구에서는 다양한 토지이용의 불교란 토양칼럼 시료를 대상으로 토양 물리화학 특성 및 자연강우에 대한 토양배수 양상을 분석하였다. 공극률은 토양컬럼에서의 유효공극률과 투수계수 및 자연강우에 대한 배수율과 대체로 정의 상관관계를 보인다. 미국 통일분류법에 따라 토양을 분류하였을 때 소성성이 낮은 실트질 토양과 점토질 토양은 유효공극률이 낮으면서 배수율도 낮고, 소성성이 없는 실트질이 섞인 자갈(유구-논)과 실트질 모래는 유효공극률이 비교적 높으면서 배수율이 다소 높았다. 불교란 토양컬럼을 완전 포화상태에서 자연배수할 때 대부분의 토양은 50시간 전후로 거의 다. 배수되며 $150{\sim}200$시간 경과되면 거의 모든 토양에서 완전배수가 되었다. 일부 500여시간이 경과되어도 지속적으로 배수되는 토양이 있는데 이는 토양수분보유특성에 기인하는 것으로 사료된다. 배수량으로 가정한 함양량 실측실험에서는 오송(전의)임야 > 무주-밭, 무주-논 > 유구-임야 > 김해-밭 > 유구-논, 유구-밭 순으로 높았으며 이들 시료들의 함양률은 50% 이상이었다. 토성에 따른 자연강우 배수상태를 보면, 소성성이 낮은 실트질 토양의 배수율이 낮고, 실트질 모래는 다양한 배수상태를 보이나 대체로 배수율이 높다. 그리고 1차, 2차 실험에서 선행 강우 5mm 미만은 토양배수에 영향을 미치지 않았다.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.163-172
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• 1989

In order to study spatial variability of soil physical properties accross the land-partitioned boundary on Hwadong silt clay loam soil (Fine clayey, mixed, mesic family of Aquic Hapludalfs), all measured data were analyzed by means of kriging, fractile diagram, smooth frequency distribution, and autocorrelation. Sampling for soil particle size distribution analysis was made at 225 intersections of $15{\times}15$ grid with 10m interval. Field capacity, bulk density and saturated hydraulic conductivity were measured in situ at 594 intersections of $33{\times}18$ grid with 2.5m interval in only $6,000m^2$ reselected from $22,500m^2$ of sampling area for particle size distribution analysis. Sampled or measured soil depths were 0 to 10cm 25 to 35cm and 50 to 60cm at each intersections. The results are summarized as follows: 1. The coefficient of variance (CV) of various physical properties ranges from 4.8 to 128.8%. Saturated hydraulic conductivity is classified into the high variation group with CV greater than 100%, while the low variation group with CV smaller than 10% consists of bulk density. Other properties belong to the medium variation group with CV between 10 and 100%. 2. The appropriate number of soil samples for the determination of various physical properties with error smaller than 10% are calculated as one for bulk density, six for field moisture capacity, 16 for silt, 19 for clay, 69 for sand and 686 for saturated hydraulic conductivity. 3. Smooth frequency distribution and fractile diagram show that saturated hydraulic conductivity is in lognormal distribution while other physical properties are in normal distribution. 4. Serial correlation analysis reveals that the soil physical properties have spatial dependence between two nearest neighbouring grid points. Autocorrelation analysis of physical properties measured between the serial grid points in the direction of south to north following section boundary shows that the zone of influence showing stationarity ranges from 7.5 to 40m. In the direction of east to west across section boundary, the autocorrelogram of many physical properties shows peaks with the periodic interval of 30m, which are similar to the partitioned land width. This reveals that the land-partitioned boundary causes soil variability.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.530-537
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• 2022

This study was conducted to compare the physical and chemical properties of soils in Quercus acutissima, Q. mongolica, Q. serrata, and Q. variabilis stands. A total of 423 plots (Q. acutissima 72 plots, Q. mongolica 150 plots, Q. serrata 97 plots, and Q. variabilis: 104 plots) were examined to determine the soil properties of A and B horizons throughout the country. The physical and chemical properties of soils were significantly different among the four different Quercus spp. stands. The sand content in both horizons was significantly higher in Q. acutissima stands than in the other three oak stands, whereas the clay content was lowest among the four stands. The soils in Q. mongolica and Q. serrata stands were more acidified than those in Q. acutissima and Q. variabilis stands. The concentrations of organic carbon and total nitrogen in both soil depths were significantly higher in Q. mongolica stands than in Q. serrata, Q. variabilis, and Q. acutissima stands. The content of available phosphorus was significantly higher in Q. mongolica and Q. serrata stands than in Q. acutissima and Q. variabilis stands; whereas the contents of exchangeable potassium, calcium, and magnesium were lower in Q. mongolica and Q. serrata stands than in Q. acutissima and Q. variabilis stands. The cation exchange capacity was highest in Q. mongolica stands, followed by that in Q. serrata, Q. variabilis, and Q. acutissima stands. These data indicate the need to design a nutrient management plan to enhance the low soil pH and exchangeable cation in Q. mongolica and Q. serrata stands.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.567-575
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• 2018

The soil physical quality is a core factor in achieving two of sustainable agriculture's goals: productivity and environment. The purpose of this study was to assess changes in soil physical properties for nearly a decade through periodic monitoring of three cultivation types: upland, orchard, and paddy. Field surveys and lab analysis were conducted to determine the soils physical properties after every 4 years; upland (2009, 2013, and 2017), orchard (2010 and 2014), and paddy (2011 and 2015). In each year soil samples from 162-338 sites were collected. The bulk density of upland subsoil decreased from $1.53Mg\;m^{-3}$ to $1.50Mg\;m^{-3}$ while the plowing depth and subsoil organic matter increased from 13.7 cm to 19.5 cm and from $12.6g\;kg^{-1}$ to $18.3g\;kg^{-1}$ respectively during the period 2009-2017. Plowing depth for orchard increased from 16.7 cm to 18.9 cm. However, organic matter content decreased from $15.9g\;kg^{-1}$ to $15.4g\;kg^{-1}$ during the 2010-2014 period. For paddy, plowing depth and subsoil organic matter decreased from 17.5 cm to 16.7 cm and from $17.5g\;kg^{-1}$ to $15.8g\;kg^{-1}$ respectively. The subsoil bulk density increased from $1.47Mg\;m^{-3}$ to $1.52Mg\;m^{-3}$ from 2011-2015. Excess ratio for soil physical standards increased from 16% to 22% in orchard, 56% to 62% in paddy, and decreased from 41% to 29% in upland. The overall soil physical quality had been ameliorated for upland, but degraded for paddy. Improved tillage practices and application of appropriate organic matter is necessary to enhance the quality of soils, especially in the paddy field.