• Title/Summary/Keyword: SOIL DEPT

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Future Directions and Perspectives on Soil Environmental Researches (토양환경분야 연구동향 및 전망)

  • Yang, Jae-E.;Ok, Yong-Sik;Chung, Doug-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.6
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    • pp.1286-1294
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    • 2011
  • This paper reviews the future directions and perspectives on the soil environmental researches in the 21 century. Previously, the principal emphasis of soil environmental researches had put on the enhancement of food and fiber productions. Beside the basic function of soil, however, the societal needs on soil resources in the 21st century have demands for several environmental and social challenges, occurring regionally or globally. Typical global issues with which soil science should deal include food security with increasing agronomic production to meet the exploding world population growth, adaptation and mitigation of climate change, increase of the carbon sequestration, supply of the biomass and bioenergy, securing the water resource and quality, protection of environmental pollution, enhancing the biodiversity and ecosystem health, and developing the sustainable farming/cropping system that improve the use efficiency of water and agricultural resources. These challenges can be solved through the sustainable crop production intensification (SCPI) or plant welfare concept in which soil plays a key role in solving the abovementioned global issues. Through implementation of either concept, soil science can fulfill the goal of the modern agriculture which is the sustainable production of crops while maintaining or enhancing the ecosystem function, quality and health. Therefore, directions of the future soil environmental researches should lie on valuing soil as an ecosystem services, translating research across both temporal and spatial scales, sharing and using data already available for other purposes, incorporating existing and new technologies from other disciplines, collaborating across discipline, and translating soil research into information for stakeholders and end users. Through the outcomes of these approaches, soil can enhance the productivity from the same confined land, increase profitability, conserve natural resource, reduce the negative impact on environment, enhance human nutrition and health, and enhance natural capital and the flow of ecosystem services. Soil is the central dogma, final frontier and new engine for the era of sustainability development in the $21^{st}$ century and thus soil environmental researches should be carried according to this main theme.

Geoenvironmental Characteristics of Sorted Soil From Unregulated Landfill Wastes (불법매립폐기물에서 선별된 토사의 지반환경공학적 특성 분석)

  • Chung, Ha-Ik;Kim, Sang-Keun;Ryu, Kwon;Lee, Yong-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.605-610
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    • 2001
  • There has been a steady increase in geoenvironmental engineering projects where geotechnical engineering has been combined with environmental concerns. Many of these projects involve some investigation on geoenvironmental characteristics related to waste landfill and waste soil. This study was carried out to evaluate the geoenvironmental properties of sorted soil from unregulated landfill wastes. The physical, mechanical, and environmental Properties of sorted soil were investigated for utilization in civil works.

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Effects of Soil Organic Matter on Surface Charge Characteristics of Paddy and Upland Soils (논과 밭 토양의 표면전하 특성에 미치는 토양 유기물 영향)

  • Lim, Sook-Il;Lee, Moon-Yong;Hyun, Seung-Hun;Lee, Sang-Eun;Jeong, Chang-Yoon;Kim, Jeong-Gyu
    • Korean Journal of Soil Science and Fertilizer
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    • v.31 no.4
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    • pp.414-419
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    • 1998
  • The contribution of soil organic matter on the soil surface charge characteristic of paddy and upland soils weathered from granite or limestone was evaluated. The surface charge characteristics of the soils with and without soil organic matter by pre-treatment with hydrogen peroxide was determined at pH 3.5~9.0 range using the ion adsorption method. Regardless of soil organic matter removal, the soil surface negative charge increased linearly by the increase of pH with high statistical significance at all kinds of soils. Here, the differential increasement of soil surface negative charge by pH inclease, dCEC/dpH, was proposed as the parameter of pH dependency of the soil surface charge. The dCEC/dpH of soils with organic matter was in the range of 0.91~4.59, while it was dramatically decreased to the range 0.16~1.91 by the removal of organic matter. The soil surface charge derived from soil organic matter ranged from 15% to 82% to the total amount of surface charge. The magnitude of surface charge carried by 1% of soil organic matter showed considerable differences between soils from 0.22 to $5.03cmol^+\;kg^{-1}$. The effect of soil organic matte on the dCEC/dpH was higher in paddy soils with high oxalic acid extractable Fe than upland soils.

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Modified FHWA Design Method Considering Bending Stiffness of Soil Nail (휨강성을 고려한 수정 FHWA 쏘일네일 설계법 제안)

  • Kim, Nak-Kyung;Jung, Jung-Hee;Ju, Yong-Sun;Kim, Sung-Kyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1406-1416
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    • 2008
  • Soil nailing is used as a method of slope stabilization and excavation support. The design method of soil nail are based on experience or assumption of interaction between soil and reinforcement. Most design methods simply considers the tension of reinforcement for analysis of slope stabilization. Soil nails interact with soils under combined loading of shear and tension. Jewell & Pedley(1990) suggested a design equation of shear force with bending stiffness and discussed that the magnitude of the maximum shear force is small in comparison with the maximum axal force. However, they have used a very conservative limiting bearing stress on nails. This paper discusses that the shear strength of soil nails should not be disregarded with proper bearing stresses on nails. The modified FHWA design method was proposed by considering shear forces on nails with bending stiffness.

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Turfgrass Establishment of USGA Putting Greens Related with Soil Physical Properties (USGA 공법으로 조성된 그린의 토앙물리성과 Bentgrass의 생육)

  • Kweon Dong-Young;Lee Jeong-Ho;Lee Dong-lk;Joo Young-Kyoo
    • Asian Journal of Turfgrass Science
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    • v.19 no.2
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    • pp.95-102
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    • 2005
  • USGA green specification is currently accepted in construction method of Korea. This study was carried out to find the factors influencing growth of turfgrass associated with soil physical properties of soil root-zone on golf green constructed with USGA method. Three putting greens in poor turfgrass and one in good turfgrass condition were selected for investigation on one golf course site at mid-South Korean peninsula. Soil hardness, moisture content, root length, and turf density were measured on-site greens, and soil physical properties and soil chemical properties also analyzed in laboratory. As a result of on-site surveys and soil physical tests in laboratory, soil physical properties were most important factors which influenced on turfgrass growth at tested greens. The results of soil particle analysis on green No. 2, in good turf condition, matched USGA sand particle recommendations. But those greens such as Nos. 1, 11 and 16, in poor putting greens, showed high soil compaction and improper soil particle distribution. Those factors created low leaf density, poor root depth, and higher moisture content compared with lower part of topsoil. Such phenomena caused inadequate turfgrass growth with soil hardening associated with poor drainage. Therefore, declines of soil physical properties associated with improper particle distribution caused a major factor influencing on turfgrass growth in golf green. Adequate test of soil particle analysis by USGA specification and proper construction method followed by adequate turf maintenance should be performed to obtain optimal turf quality on putting green.

Comparison of soil erosion simulation between empirical and physics-based models

  • Yeon, Min Ho;Kim, Seong Won;Jung, Sung Ho;Lee, Gi Ha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.172-172
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    • 2020
  • In recent years, soil erosion has come to be regarded as an essential environmental problem in human life. Soil erosion causes various on- and off-site problems such as ecosystem destruction, decreased agricultural productivity, increased riverbed deposition, and deterioration of water quality in streams. To solve these problems caused by soil erosion, it is necessary to quantify where, when, how much soil erosion occurs. Empirical erosion models such as the Universal Soil Loss Equation (USLE) family models have been widely used to make spatially distributed soil erosion vulnerability maps. Even if the models detect vulnerable sites relatively well by utilizing big data related to climate, geography, geology, land use, etc. within study domains, they do not adequately describe the physical process of soil erosion on the ground surface caused by rainfall or overland flow. In other words, such models remain powerful tools to distinguish erosion-prone areas at the macro scale but physics-based models are necessary to better analyze soil erosion and deposition and eroded particle transport. In this study, the physics-based Surface Soil Erosion Model (SSEM) was upgraded based on field survey information to produce sediment yield at the watershed scale. The modified model (hereafter MoSE) adopted new algorithms on rainfall kinematic energy and surface flow transport capacity to simulate soil erosion more reliably. For model validation, we applied the model to the Doam dam watershed in Gangwon-do and compared the simulation results with the USLE outputs. The results showed that the revised physics-based soil erosion model provided more improved and reliable simulation results than the USLE in terms of the spatial distribution of soil erosion and deposition.

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Remediation of Contaminated Soil with Organic Contaminants using Microemulsion (마이크로이멀젼을 이용한 유기오염물로 오염된 지반의 정화)

  • Park, Ki-Hong;Kwon, Oh-Jung;Park, Jun-Boum
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.597-604
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    • 2003
  • In the soil washing process, the contaminants are usually removed by abrasion from soil particles using mechanical energy and water However, organic contaminants with low water solubility like polycyclic aromatic hydrocarbons (PAH) are remained on soil particles. Previous studies have shown that surfactant possessing amphipathic activity enhances the solubility of organic materials. For this reason solutions with surfactants have been used to improve removal of organic contaminants on soil washing process. But, in this manner, many problems were found like complete loss of surfactants and additional contamination by surfactant. The remediation method using microemulsion has been introduced to overcome these disadvantages. In this case, surfactants are recycled by phase separation of microemulsion after remediation. In microemulsion process, the surfactant will be recycled by phase separation of the microemulsion into a surfactant-rich aqueous phase and an oil phase after extraction. That is why remediation concept applying microemulsion as washing media has been Introduced. Suitable microemulsion have to be used in order to have the chance of refilling the soil after decontamination and to avoid any risk due to toxicity. The purpose of this research is to evaluate effect of microemulsion to remediation of contaminated soil. We performed test with various organic contaminants like Pyrene and BTEX, also compared efficiency of remediation in microemulsion process with soil washing

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The Effect of Air Injection Quantity on Stabilization of Screened Soil in Aerobic Bioreactor Landfill (호기성 Bioreactor 매립지에 있어서 공기주입량이 선별토사의 안정화에 미치는 영향)

  • Park, Jin-Kyu;Lee, Nam-Hoon;Kim, Nack-Joo
    • Journal of the Korea Organic Resources Recycling Association
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    • v.12 no.1
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    • pp.104-109
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    • 2004
  • In this study, we stabilized the screened soil from landfills by using aerobic bioreactor and evaluated aerobic decomposition of it. Four lab-scale bioreactors (anaerobic and 1 PV/day aeration, 5 PV/day aeration, 10 PV/day aeration) filled with screened soil were operated to investigate the effect of air injection quantity on stabilization of screened soil. In case of aerobic bioreactors, the decomposition of organics in screened soil was higher than anaerobic bioreactor. According to the results of landfill gas and soil respiration test, the air injection quantity of 5 PV/day was most efficient in stabilization of screened soil.

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A Study for Characteristics of Geofiber Reinforced Soil System Practiced on Stone Gabion Bank of River (하천 돌망태 호안에 적용된 토목섬유보강토공법의 녹화 특성)

  • Jeong, Dae-Young;Kim, Jae-Hwan;Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.6
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    • pp.81-90
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    • 2008
  • Recently, geofiber(polyester) reinforced soil was added on soil-seed mixture spray to control erosion and to improve vegetation growth on rocky slope sites. This research was conducted to compare vegetation effects and soil hardness on three types of soil-seed mixture spray on stone gabion river bank [A type : soil-seed mixture spray underlying 30cm thick sand with geofiber(geofiber reinforced soil system), B type : soil-seed mixture spray underlying 30cm thick sand without geofiber, C type : soil-seed mixture spray]. Evaluation were made concerning vegetation coverage, soil hardness and moisture content. The results of this study showed that A type system was effective for the growth of vegetation and soil hardness when compareed to B type and C type. A type and B type showed higher covering rate than C type on stone gabion river bank, and especially A type showed the highest covering rate. Soil hardness and water content were high on A type vegetation system compared to B type and C type. We noted that high soil hardness and high moisture content with geofiber(geofiber reinforced soil system) were effective both to control erosion from water current impact and to be high coverage and species of vegetation on stone gabion river bank.

Application of KORSLE to Estimate Soil Erosion at Field Scale (한국형 토양유실공식에 의한 토양유실량 현장예측)

  • Song, Jae Min;Yang, Jae E;Lim, Kyoung Jae;Park, Youn Shik
    • Journal of Soil and Groundwater Environment
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    • v.24 no.5
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    • pp.31-41
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    • 2019
  • In 2013, the Ministry of Environment in South Korea promulgated a new regulatory bulletin that contained revised enforcement ordinance on soil management protocols. The bulletin recommends the use of Universal Soil Loss Equation (USLE) for the soil erosion estimation, but USLE has limited applicability in prediction of soil erosion because it does not allow direct estimation of actual mass of soil erosion. Therefore, there is a great need of revising the protocol to allow direct comparison between the measured and estimated values of soil erosion. The Korean Soil Loss Equation (KORSLE) was developed recently and used to estimate soil loss in two fields as an alternative to existing USLE model. KORSLE was applied to estimate monthly rainfall erosivity indices as well as temporal variation in potential soil loss. The estimated potential soil loss by KORSLE was adjusted with correction factor for direct comparison with measured soil erosion. The result was reasonable since Nash-Stucliff efficiency were 0.8020 in calibration and 0.5089 in validation. The results suggest that KORSLE is an appropriate model as an alternative to USLE to predict soil erosion at field scale.