• Title/Summary/Keyword: soil characteristics

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Influence of Various Soil CharacteriBtics in GinBeng Field or the Growth and the Yield of Ginseng (Panax gisoseng C. A. Meyer) (인삼전지의 토양특성이 인삼의 생육및 수량에 미치는 영향에 관한 연구)

  • 이일호;육창수;한강완;박찬수;박현석;남기열
    • Journal of Ginseng Research
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    • v.4 no.2
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    • pp.175-185
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    • 1980
  • A study was made to clarify the topographical. and Physical characteristics of ginseng field in terms of soil science and to find the relationship between soil characteristics and ginseng growth, as well as yield of ginseng roots Forty nine farmer's red ginseng field of ginseng growing area were chosen for this study and investigated for two years. The results obtained were as follow. 1. Ginseng fie1ds with high yield which represent the more than 1.8kg of ginseng root per 3.2m2 were found in soil series of Bancheon, Yeongog, Weongog, etc. whose texture were the clay loam to clay soil. On the other hand, ginseng field with low yield were observed in soil series of seogto whose texture was loamy soil with high content of gravels. 2 Soil of ginseng field with high yield had higher content of clay. silt soil moisture and soil pore as compared with soils of low yields. These soil characteristics were positively correlated with stem length stem diameter and root weight of ginseng plsnt and negatively correlated with rate of missing plant 3. The adequate ranges of soil 3 phase from high yield ginseng field were 40 to 50% of solid Phase, 22 to 35% of liquid phase, 25 to 35% of gaseous phase in top soil and 45 to 55% of solid phase. 28 to 30% of liquid phase. 15 to 20% of gaseous phase in subsoil respectively.

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Soil Habitat Characteristics of Cicada Nymph in an Urban Apartment Garden (도심 아파트 단지 화단에 나타나는 매미 약충의 토양 서식처 특성)

  • Kim, Keonhee;Kim, Jae Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.3
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    • pp.47-55
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    • 2011
  • Cicada is a very familiar insect to people but habitat characteristics of them are not well known. To investigate habitat characteristics of cicada nymph, plant species, plant cover, soil hardness, accumulated organic mass, organic content in soil, and root density were investigated at 11 sites in an apartment complex garden in Seoul. Selected sites had different densities of cicada nymph case above the ground. Density of cicada nymph case was positively correlated with accumulated organic mass, organic content in soil, and root density and negatively correlated with soil hardness. Even though shrub coverage was not linearly correlated with the density of cicada nymph case, 80% cover of shrub was necessary for the high density of them. Data in this study suggested that organic matter in addition to root density be the primary limitation factor of cicada nymph and high amount of litter-fall decrease soil hardness through the increase of soil organic matter. This study suggests that the density of cicada nymph can be managed through organic content in soil.

Characteristics of Shear Strength for an Unsaturated Soil with the Matric Suction (흡인력에 따른 불포화토의 전단강도 특성)

  • Song, Chang-Seob;Choi, Dook-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.1
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    • pp.82-90
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    • 2007
  • In order to analyse the strength problems for an unsaturated soil, it is required to examine closely the characteristics of the parameters of shear strength which was changed with the metric suction and void ratio. To this ends, a triaxial compression test was conducted on the three samples-granular soil, cohesive soil and silty soil. The specimen was made by pressing the static pressure on the mold filled soil and was controled the void ratio with the different compaction ratio. And the test was performed by using the modified apparatus of the triaxial compression tester. The range of matric suction was 0-90 kPa.The measured results for the deviator stress and parameters of shear strength were analysed with the void ratio and the compaction ratio, and they were examined closely the characteristics of the strength for an unsaturated soil.

Characteristics of Permeability for an Unsaturated Soil (불포화토의 투수특성)

  • Song, Chang-Seob;Shin, Chang-Seob
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.4
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    • pp.35-41
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    • 2005
  • In order to analyse the flow problems for an unsaturated soil, it is required to examine closely the characteristics of the coefficient of permeability which is changing with the matric suction. To this ends, a permeability test was conducted on the three samples;granular soil, cohesive soil and silty soil. The specimen was made by pressing the static pressure on the mold filled with soil and the void ratio was controled with the different compaction ratio. And the test was performed by using the modified apparatus of the steady state method which was proposed by flute (1972). The range of matric suction was 0-90 kPa. The measured results for the coefficients of permeability were analysed with the void ratio and the compaction ratio, and it was examined closely the characteristics of the permeability for an unsaturated soil.

The influence of heavy metal on microbial biodegradation of organic contaminants in soil (토양내의 중금속이 유기오염물질 생분해에 미치는 영향 연구)

  • 최재영;박재우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.196-201
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    • 2000
  • The influence of adsorption on cadmium toxicity to soil microorganisms in smectite-rich soils and sediments was quantified as a function of solution and sorbent characteristics. Adsorption and surface complexation experiments were conducted to infer Cd sorption mechanisms to a reference smectite and three fractions of a Veritsol soil, and to elucidate the effects of the surface complexation on Cd bioavailability and toxicity in soils and sediments. Cadmium adsorption isotherms conformed to the Langmuir adsorption model, with adsorptive capacities of the different samples dependent on their characteristics. Equilibrium geochemical modeling (MINTEQA2) was used to predict the speciation of Cd in the soil suspensions using Langmuir and Triple Layer surface complexation models. The influence of adsorption and surface complexation on cadmium toxicity to soil microorganisms was assessed indirectly through the relative change in microbial hydrolysis of fluorescein diacetate (FDA) as a function of total Cd concentration and sorbent characteristics. Adsorption decreased the toxicity of Cd to soil microorganisms. Inner-sphere complexation is more effective than outer-sphere complexation in reducing the bioavailability and toxicity of heavy metals in soils and sediments.

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Workability Characteristics of Fiber Mixed Soil (섬유 보강 혼합토의 워커빌리티 특성)

  • Song, Gyoo Bog;Lee, Sang Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.1
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    • pp.53-59
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    • 2016
  • This study was conducted by the slump test and the consistency test of the fiber mixed soil which is soil reinforced with fiber as a reinforced material to investigate and estimate the difficulty degree of work and the proper water content. So I would like to present the fundamental data that establishes the work standard of the fiber mixed soil. In conclusion, in this study the slump value of the fiber mixed soil increases over-all according to the increase of the water content although it has a little difference of the increase range and it is smaller than one of the soil. It is estimated that the aggregating and throwing work of the fiber mixed soil would be fine when it has the about 25 % water content and the wall and floor plastering work is the about 30 % ~ 35 % and the flowing and pouring work is the about 40 % water content as well as the mold compacting work is the about 20 %. There is no decreasing of the workability when the soil is reinforced by the fiber because the workability characteristics of the fiber mixed soil is similar to the one of the soil. Therefore, It is estimated that using the fiber as a reinforced material of soil would be appropriate for the construction.

Effects of Mixed Characteristics of Oily Soil on Detergency of PET Fabric in Oily/Particulate Soil Mixed System (지용성/고형오구의 혼합오염계에서 지용성오구의 혼합특성에 따른 PET직물의 세척성)

  • Kang, In-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.10
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    • pp.1242-1251
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    • 2011
  • This study investigates the effect of mixed characteristics of oily soil such as mixed ratio, polarity of oily soil on contact angle of fabric, removal of oily and particulate soil from PET fabric in oily/particulate soil mixed system. The contact angle of fabric in the surfactant solution with suspended oily soil was examined as a fundamental environment of detergency of soil from fabrics. Detergency was investigated as function of mixed ratios of oily/ particulate soil, type of oily soil, surfactants concentration, surfactant type and temperature of detergency in surfactant solution. The contact angle of fabric in surfactant solution sharply increased with mixing nonpolar oily soil; in addition, the contact angle slightly increased with increasing contents of oily soil and decreased with increasing surfactant concentration. The removal of oily and particulate soil from fabric was higher in the solution mixed with polar versus nonpolar oily soil. The detergency increased with increasing surfactant concentration and the increased temperature of surfactants solution that were relatively improved in NPE compared to DBS solutions, The results indicated that the detergency of oily and particulate soil showed a similar trend in oily/ particulate mixed soil systems. The general contact angle of fabric was well related with the detergency of oily and particulate soil in oily/particulate mixed soil system, therefore, the primary factor determining the detergency of soil in oily/particulate mixed soil system may be the contact angle of fabric caused by wettability.

Effects of Soil and Air Flow Characteristics on the Soil-Air Heat Exchanger Performances (토양과 공기유동특성이 토양-공기 열교환기 성능에 미치는 영향)

  • 김영복;김기영
    • Journal of Biosystems Engineering
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    • v.23 no.1
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    • pp.21-30
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    • 1998
  • A theoretical model was developed to evaluate the effects of soil and airflow characteristics on the soil-air heat exchanger performances. The model, which includes three-dimensional transient energy and mass equilibrium-equation, was solved by using a computer program that uses Finite Difference Methods and Gauss-Seidel iteration computation. Energy gains, heat exchange efficiencies, and outlet air temperature are presented including the effects of soil moisture content, soil conductivity, soil thermal diffusivity, and soil initial temperature. Also, data related to the effects of airflow rate and inlet air temperature on the thermal performance of the system are presented. The results indicated that energy gains depend on soil conductivity, soil thermal diffusivity, and soil initial temperature. Heat exchange efficiencies relied on air mass flow rate and soil moisture content.

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Effect of Rainfall Intensity, Soil Slope and Geology on Soil Erosion (토양침식에서의 강우특성, 토양경사 및 지질의 영향)

  • Nam, Koung-Hoon;Lee, Dal-Heui;Chung, Sung-Rae;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.24 no.1
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    • pp.69-79
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    • 2014
  • This study aims to elucidate the relative importance of geological characteristics, soil slope, and rainfall intensity in relation to soil erosion. To this end, indoor rainfall simulation experiments were carried out under different conditions of rainfall intensities, soil slope, and geological characteristics. The test results show that the factors affect soil erosion in the order of soil slope > rainfall intensity > organic content in the soil. Erosion rates were proportional to rainfall, and increase with increasing clay content. Therefore, the soil erosion rate increases strongly with increasing organic content and clay content. The results show that the soil erosion rate in areas of metamorphic rocks shows a marked increase compared with areas of steep slope and sedimentary rocks. These results indicate that the geological characteristics to produce soil are closely related to sedimentation before and after erosion, providing basic information for the development of models to predict soil erosion rates.

Characteristics of Soil Moisture Distributions at the Spatio-Temporal Scales Based on the Land Surface Features Using MODIS Images (MODIS 이미지를 이용한 지표특성에 따른 토양수분의 시·공간적 분포 특성)

  • Kim, Sangwoo;Shin, Yongchul;Lee, Taehwa;Lee, Sang-Ho;Choi, Kyung-Sook;Park, Younshik;Lim, Kyoungjae;Kim, Jonggun
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.6
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    • pp.29-37
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    • 2017
  • In this study, we analyzed the impacts of land surface characteristics on spatially and temporally distributed soil moisture values at the Yongdam and Soyang-river dam watersheds in 2014 and 2015. The soil moisture, NDVI (Normalized Difference Vegetation Index) and temperature values at the spatio-temporal scales were estimated using satellite-based MODIS (MODerate Resolution Imaging Spectroradiometer) products. Then the Pearson correlations between soil moisture and land surface characteristics (NDVI, temperature and DEM-digital elevation model) were estimated and analyzed, respectively. Overall, the monthly soil moisture values at the time step were highly influenced by the precipitation amounts. Also, the results showed that the soil moisture has the strong correlation with DEM while the temperature was inversely correlated with the soil moisture. However the monthly correlations between NDVI and soil moisture were highly varied along the time step. These findings indicated that water loss near the land surface are highly occurred by soil and plant activities as evapotranspiration and infiltration during the no/less precipitation period. But the high precipitation amounts reduce the impacts of land surface characteristics because of saturated condition of land surface. Thus these results demonstrated that soil moisture values are highly correlated with land surface characteristics. Our findings can be useful for water resources/environmental management, agricultural drought, etc.