• 제목/요약/키워드: property soil

검색결과 733건 처리시간 0.031초

Release Pattern of Urea from Metal-urea-clay Hybrid with Montmorillonite and Its Impact on Soil Property

  • Kim, Kwang-Seop;Choi, Choong-Lyeal;Lee, Dong-Hoon;Seo, Young-Jin;Park, Man
    • 한국토양비료학회지
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    • 제44권4호
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    • pp.545-550
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    • 2011
  • Urea intercalated into montmorillonite (MT) exhibits remarkably enhanced N use efficiency, maintaining its fast effectiveness. This study dealt with the release property of urea from metal-urea-clay hybrid with MT (MUCH) under continuous-flow conditions and the cumulative impacts of its successive application on physicochemical properties of soils. Releases of urea were completed within 4 hrs under continuous-flow condition regardless of the types and the leaching solutions. However, urea release property was significantly affected by both the form of fertilizer and the presence of electrolytes in solution. The fast release property of urea from MUCH in continuous-flow condition was not significantly affected by soil properties such as soil pH and soil texture. In addition, its successive application did not lead to any noticeable change in soil physicochemical properties, water stable aggregate rate, water holding capacity and cation exchange capacity in both sandy loam and clay loam soils. Therefore, this study strongly supported that urea intercalated into MT could be applied as fast-effective N fertilizer, in particular for additional N supply.

흙다짐 적용을 위한 흙의 선정 및 입도조건에 관한 연구 (A study on selection and size of Earth in application of Rammed Earth)

  • 황혜주;김태훈;양준혁
    • KIEAE Journal
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    • 제9권2호
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    • pp.65-71
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    • 2009
  • Results from tests for what mixing rate of soil and sand is proper for the rammed earth and for how much additives are optimum are as under. 1) In the test to evaluate what mixing rate of soil and sand is desirable, peptizing property and surface sticking rate are found similar in its degree, but compression strength is found most stable when the ratio of soil and sand mixing shows 30:70 which indicates the best mixing rate of soil and sand. 2) In a test to add hydrated lime, compression strength, peptizing property, and surface sticking rate are found best when the mixing rate of soil and sand shows 23:7. 3) In a test to add sea weeds, the peptizing property goes down at 75% of sea weeds input a little bit more than at 100%, but compression strength shows best at 75% which is thought to be the best rate. 4) In a drop test, more soil powder mixed, the sticking strength gets better and more sands are contained, the sticking strength gets far worse to be scattered in powder type. 5) As concluding all results mentioned in the above item, the most desirable mixing rate of soil, sand, and hydrated lime is found to be 23:7:70 for the rammed earth where compression strength, peptizing property, and surface sticking rate are best.

실시간 지중 전력케이블 용량 평가를 위한 토양 열 특성 및 온도 측정 시스템 개발 (Development of the Soil Thermal Property and Temperature Measurement System for the Real-time Ampacity Estimation of Underground Power Cables)

  • 정성환;김대경;최상봉
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 A
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    • pp.22-24
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    • 2002
  • This paper introduces the real-time soil thermal property analyzer and temperature measuring system which is combined with radio telecommunication technique. To measure the thermal parameters in real-time, the radio telecommunication technique are used the personal communication service (PCS) which is in the world-wide serviced commercially firstly by CDMA. The thermal property analyzer has an ability of measuring thermal resistivity, thermal diffusivity and thermal stability. To estimate the soil thermal properties, the curve fitting algorithm by means of the least square method are used. TCP/IP protocol and MTM are used to install the real-time soil thermal property and temperature measurement system at multiple locations along routes of the underground power cables and to reduce the cost of telecommunication.

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The effect of disease insidence to BaYMV by the physio-chemical property of BaYMV by the physio-chemical property of infected soil.

  • Hyun, Jong-Nae;Hong, Yeon-Kyu;Kim, Hyun-Tae;Park, Kee-Do;Kim, Soon-Chul;Lee, Woon Key
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2002년도 총회 및 추계학술발표회
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    • pp.107.2-108
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    • 2002
  • Barley Yellow Mosaic Virus(BaYMV) is responsible for ane of the most improtant disease in malting Barley in Korea. It is transcitted by soil borne fungus, Polymyza graminis To estimate the occurrence pattern of BaYMV by the physio-chemical property of soil collected from farmer's sield, this study was conducted. The rate of didsease occurrence to BaYMV investigated at 19 spots of 10th regions. The sample soil was collected by 20 pots among an ifected field and analyzed th soil characters in 2002. The rate of disease occurrence to BaYMV was about 79%,60%,65% in Sacheon, Kosung and Hadong areas, respectively, which is malting Barley growing regions but Pohang, Yeongduk, Euesung, Gunwee, which are growing Covered Barley doesn't infected BaYMV. The tested of RT-PCR was showed that the BaYMV, BMMV.SBWMV. were identified in Milyang but the others regions was infected only to BaYMV. The physio-chemical property of soil collected from infected soil show various range such as pH(4.98~8.05), EC(0.44~2.7%),OM(1.61~6.85), P2O5958~519), K(0.22~1.82), Ca(2.3~9.7), Mg(0.5~2.6), Na(0.14~0.43) The correlation coefficient between physio-chemical property fo the infected soil and infection rate shows significant to pH at 5% level. Although OM and Ca were high scores, it doesn't significant at 5% but it need to be more study in future.

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토양의 침식과 보존에 관한 이론적 분석 2. 토양침식의 내성에 관한 이론 (The Theoretical Analyses of the Soil Erosion and Conservation 2. The Theoretical Expresion of Erosion Tolerance for the Soil Conservation)

  • 장남기
    • 아시안잔디학회지
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    • 제10권1호
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    • pp.31-40
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    • 1996
  • The mechanical expresion provides for the use of Soil property reserves and permanent protec-tion or improvement of soil resources in accordance with measurable standards. If the functions I (initial soil property), E (soil erosion), R (soil renewal), and M. (minimum allowable value) are assumed to be integrable in region A, erosion tolerance over a region is leaded to ${\int}_A{\int}I(m, cl, re, ch, b)dA-{\int}_A{\int}{\{\int}_{to}^{\infty}[E(w, re, c, re, ch, b, t)-R(m, ch, re, b, t)]dt}\dA{\geqq}{\int}_A{\int}M_i(m, cl, re, ch, b)dA$ were variable factors are m=parent material of soil, cl=climate, re=relief or topography, ch=soil characteristics, r=rain or water, w=wind, b=biota, and t=time.

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Prediction of dynamic soil properties coupled with machine learning algorithms

  • Dae-Hong Min;Hyung-Koo Yoon
    • Geomechanics and Engineering
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    • 제37권3호
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    • pp.253-262
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    • 2024
  • Dynamic properties are pivotal in soil analysis, yet their experimental determination is hampered by complex methodologies and the need for costly equipment. This study aims to predict dynamic soil properties using static properties that are relatively easier to obtain, employing machine learning techniques. The static properties considered include soil cohesion, friction angle, water content, specific gravity, and compressional strength. In contrast, the dynamic properties of interest are the velocities of compressional and shear waves. Data for this study are sourced from 26 boreholes, as detailed in a geotechnical investigation report database, comprising a total of 130 data points. An importance analysis, grounded in the random forest algorithm, is conducted to evaluate the significance of each dynamic property. This analysis informs the prediction of dynamic properties, prioritizing those static properties identified as most influential. The efficacy of these predictions is quantified using the coefficient of determination, which indicated exceptionally high reliability, with values reaching 0.99 in both training and testing phases when all input properties are considered. The conventional method is used for predicting dynamic properties through Standard Penetration Test (SPT) and compared the outcomes with this technique. The error ratio has decreased by approximately 0.95, thereby validating its reliability. This research marks a significant advancement in the indirect estimation of the relationship between static and dynamic soil properties through the application of machine learning techniques.

광반사를 이용한 한국 논 토양 특성센서를 위한 샘플링과 캘리브레이션 요구조건 (Sampling and Calibration Requirements for Optical Reflectance Soil Property Sensors for Korean Paddy Soils)

  • 이규승;이동훈;정인규;정선옥
    • Journal of Biosystems Engineering
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    • 제33권4호
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    • pp.260-268
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    • 2008
  • Optical diffuse reflectance sensing has potential for rapid and reliable on-site estimation of soil properties. For good results, proper calibration to measured soil properties is required. One issue is whether it is necessary to develop calibrations using samples from the specific area or areas (e.g., field, soil series) in which the sensor will be applied, or whether a general "factory" calibration is sufficient. A further question is if specific calibration is required, how many sample points are needed. In this study, these issues were addressed using data from 42 paddy fields representing 14 distinct soil series accounting for 74% of the total Korean paddy field area. Partial least squares (PLS) regression was used to develop calibrations between soil properties and reflectance spectra. Model evaluation was based on coefficient of determination ($R^2$) root mean square error of prediction (RMSEP), and RPD, the ratio of standard deviation to RMSEP. When sample data from a soil series were included in the calibration stage (full information calibration), RPD values of prediction models were increased by 0.03 to 3.32, compared with results from calibration models not including data from the test soil series (calibration without site-specific information). Higher $R^2$ values were also obtained in most cases. Including some samples from the test soil series (hybrid calibration) generally increased RPD rapidly up to a certain number of sample points. A large portion of the potential improvement could be obtained by adding about 8 to 22 points, depending on the soil properties to be estimated, where the numbers were 10 to 18 for pH, 18-22 for EC, and 8 to 22 for total C. These results provide guidance on sampling and calibration requirements for NIR soil property estimation.

토양 물리성 측정을 위한 디지털 장치 개발(I) - 디지털 전단저항 측정장치 - (Development of a Digital Device for Measuring Soil Physical Properties (I) - Digital Shear Stress Sensor -)

  • 박준걸;이규승;조성찬;이동훈;장영창;노광모
    • Journal of Biosystems Engineering
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    • 제33권6호
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    • pp.416-422
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    • 2008
  • This study was performed to design and construct a digital soil shear stress sensor in order to replace the conventional devices for measuring soil shear property. The developed digital shear stress measuring device can store measured data with GPS position information as a vector format into a computer. Based on the experiments at various field conditions, the measuring characteristic of the device was quite similar to that of a conventional device, SR-2 that has been a major tool to measure the soil shear property. It was concluded that the digital shear stress measuring device was an effective and comprehensive sensor for measuring soil shear property.

Monitoring physical and chemical properties of soil in Chungcheongbuk-do

  • Yun-Gu Kang;Jae-Han Lee;Taek-Keun Oh
    • 농업과학연구
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    • 제49권4호
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    • pp.667-676
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    • 2022
  • The soil physical and chemical properties are the main factors that influence plant productivity and soil fertility. Since 1999, South Korea has been conducting a survey on changes in the agricultural environment survey every four years. The purpose of the present study is to monitor the physical and chemical properties of soil in Chungcheongbuk-do. Soil samples were collected from the exact sites of the aforementioned environment survey, and land use and cultivated crops were also investigated. From a Pearson correlation analysis, it was found that the total carbon contents were most negatively affected by the soil depth. The bulk density of soil increased up to a depth of 40 cm but decreased to a depth of 60 cm. The porosity and moisture of soil generally decreased, but the porosity increased at a depth of 50 - 60 cm. Chemical properties of soil gradually decreased with an increase of the soil depth from 0 to 70 cm, but little change was observed in soil pH with soil depth. In addition, the organic matter contents of the soil at a depth of 30 cm or more were below the optimal range. The soil of Chungcheongbuk-do thus requires organic matter application as a whole, and correction of items that are partially out of the optimal range is necessary.

바텀애시 재활용 인공토양 적용 옥상녹화 유니트 시스템의 열특성 (Thermal Property of the Roof Green Unit System Using Artificial Lightweight Soil Recycled with Bottom Ash)

  • 유종수;이종찬;오창원
    • 한국건설순환자원학회논문집
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    • 제8권1호
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    • pp.49-55
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    • 2020
  • 본 연구에서는 바텀애시 재활용 인공토양을 적용한 옥상녹화 유니트 시스템의 표면 온도변화를 계절별로 측정하여 바텀애시 재활용 인공토양의 열특성을 분석한 결과, 바텀애시 인공경량토양이 기존 토양보다 우수한 열차단 특성이 있음을 확인하였다. 또한, 기존 옥상녹화 유니트 시스템과 개발 옥상녹화 유니트 시스템의 열차단 효과를 분석하기 위해 계절별 일교차를 측정한 결과 기존 녹화 유니트 시스템은 현장 포설형 녹화시스템보다 열차단 효과가 낮은 반면 격막을 탈거하여 바텀애시 인공경량토양을 연속된 층으로 형성하는 개발 유니트 녹화 시스템은 기존 현장 포설형 녹화시스템과 유사한 열차단 효과를 갖는 것으로 분석되었다.