• Title/Summary/Keyword: soil moisture characteristics

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Effect of Coarse Materials on Compaction of Soil (조립재가 흙의 다짐에 미치는 영향)

  • 윤충섭;김호일;김현태
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.33 no.4
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    • pp.84-95
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    • 1991
  • The compaction ratio of the field dry density to the maximum dry density is generally adopted as the index of quality control for embankment of earthfill structures such as Earth Dam, Sea Dike, River Bank and Road. In case of coarse materials are included in the earth material, the compaction ratio will be varied in wide range since the dry density is influenced by quantity of coarse material in the soil. The treatment for the coarse material should be controlled carefully in testing. In this study, the compaction characteristics of the soil contained the coarse materials were researched and calibration of the suitability of field quality control methods were carried out. 28 Samples were made of clay(CL) and sandy soil (SM) mixed with gravel whose content were 0, 4, 6, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45, and 60% in Weight. The compaction characteristics depending on the coarse material content were analysed through 4 types of compaction tests which are A-1, B-i, C-i and D-1. The adjusting coefficients for density and moisture content namely a and ${\beta}$ respectively were proposed in order to consider the effects depending on content of the coarse materials. The test methods to control reasonably and promptly the quality of earthfill were proposed after analysing the ranges of possible errors on the relative compaction ratio between laboratory compaction methods and field density testing methods.

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Soil Moisture Content Affecting Rooting of Cutting and Height Growth of Populus alba × P. glandulosa and Parents (토양수분(土壤水分)이 Populus alba × P. glandulosa 및 교배양친수(交配兩親樹)의 삽목발근(揷木發根)과 생장(生長)에 미치는 영향(影響))

  • Son, Doo Sik;Shin, Jong Bok
    • Journal of Korean Society of Forest Science
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    • v.66 no.1
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    • pp.74-78
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    • 1984
  • The highest cutting ratio and the best growth performance of the P. alba, P. alba ${\times}$ P. glandulosa and P. glandulosa were at -0.05 bars of soil water potential (${\Psi}_s$). Their growth and rooting ability of cuttings were better in suitable soil moisture contents, 19.650, but were worse in low soil moisture contents, 11.41% and 16.66%, respectively. Specially, P. alba ${\times}$ P. glandulosa appeared hybrid vigor in high soil water potential (${\Psi}_s$= -0.05 bars) but not appeared it below ${\Psi}_s$ = -0.5 bars. It is believed that P. glandulosa is a natural hybrid between P. davidiana and P. alba in view of morphological characteristics. Aspen, normally, does not have the rooting ability of cuttings, however, P. glandulosa showed the rooting ability, though the ratio was low, 23%. It is estimated that this rooting ability was originated from P. alba. In addition, its growth rate was between P. alba and P. davidiana, and the sensitivity of water requirement for the growth was also really equal to P. alba. This facts prove P. glandulosa to be natural hybrid between P. alba and P. davidiana.

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Effects of Super Absorbent Polymer on the Growth of Vine Plants (고흡수성 합성고분자가 덩굴성 식물의 생육에 미치는 영향 분석)

  • Kim, Jeong-Ho;Oh, Deuk-Kyun;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.22 no.7
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    • pp.801-810
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    • 2013
  • To improve the physical and chemical properties of the soil and increasing water-retaining property of the soil, Superabsorbent synthetic polymeric materials have been used. The experiment carried out from April to July 2012 after the influence evaluation of Superabsorbent synthetic polymeric materials to vines plant. The result shows that the study of Hedera japonica Tobler, the growth and the survival rates rank as media > hydroponic > superabsorbent synthetic polymers, and the growth and the survival rates are considerably pessimistic in the experiment of hydroponic and superabsorbent synthetic polymers. In the study of Trachelospermum asiaticum var. intermedium, the growth and the survival rates rank as hydroponic > media > superabsorbent synthetic polymers, the difference between the experiment of hydroponic and is very small and the survival rates are not very good in the experiment of superabsorbent synthetic polymers. In the study of Euonymus fortunei var. radicans Rehder,it is insignificantly difference among the different of planting based. Judging from these results, the differences are depending on the species of plants. The thesis holds that the characteristics of plant should be considered in plant cultivation and soil improvement in the future, and it is desirable to use the appropriate mixing ratio of soil in soil improvement as well.

A Study on Treatment of a Contaminated Soil by Oil using Continuous System of High Temperature Heating Element and Microwave (마이크로웨이브와 고온발열체를 이용한 연속식 공정의 유류오염토양 처리에 관한 연구)

  • Ha, Sang-An;You, Mi-Young
    • Journal of Soil and Groundwater Environment
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    • v.17 no.1
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    • pp.8-12
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    • 2012
  • This study is maintains the condition of high temperature (above $600^{\circ}C$) within a short time using on microwave and high temperature heating elements. And removal characteristics according to changes in soil moisture, microwave power and temperature through the decomposition of the contaminated soil by oil. The difficulty resolvability material was sort of lubricating oil having long carbocyclic (C18-C50) and TPH removal rate reached 85.2% at 6 kW and $700^{\circ}C$ and thus the contaminant was removed 1,788 mg/kg within a process time of 40 minutes. In the case of light oil, gasoline contaminated soil, the removal amount showed 567 mg/kg and the treatment rate reached 98.4% at 6 kW, $500^{\circ}C$ and 20 minute. In the case of non-resolvability reached TPH concentrations on 2,000 mg/kg of worrisome level of soil contamination in the 3 zones at 6 kW, $700^{\circ}C$ and 30 minute. At the time, showed up processing costs 8,173 won per ton.

Fate and Toxicity of Spilled Chemicals in Groundwater and Soil Environment II: Flammable (사고 누출 화학물질의 지하수 및 토양 환경 내 거동 및 환경 독성 특성 II: 인화성 물질을 중심으로)

  • Jho, Eun Hea;Shin, Doyun
    • Journal of Soil and Groundwater Environment
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    • v.23 no.6
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    • pp.1-8
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    • 2018
  • In this study, formaldehyde and benzene were selected as the arbitrary chemicals in accidental leakage to environment, and their physicochemical and biological characteristics and toxicity were studied. Also, the fate of these chemicals in soil and groundwater was studied based on the results of previous studies. They can be released into the atmosphere as gas or vapor phase, which then can be photochemically degraded. Since they have relatively high water solubility, they are likely to have high mobility in water and soil. Volatilization of these chemicals from soil is affected by the soil moisture content. Biodegradation of formaldehyde and benzene is one of the important pathways as well. Therefore, it is necessary to study the environmental impacts of leakage accidents of flammable chemicals such as formaldehyde and benzene. Further research on the fate of flammable chemicals in the environment is needed to take appropriate response actions to leakage accidents of flammable chemicals, and this will contribute to the development of practical guidelines to cope with leakage accidents.

A Study on the Growth Characteristics of Native Plants by Seeding Amounts of Cool-season Turfgrasses on the Disturbed Slope (훼손비탈면의 한지형 잔디 파종량에 따른 자생식물의 생육특성에 관한 연구)

  • Kim, Jae-Hwan;Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.5
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    • pp.1-12
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    • 2009
  • This research was initiated to investigate the revegetation characteristics under the seeding amount treatments of cool-season turfgrasses on the disturbed slope. 4 different seeding amounts of cool-season turfgrasses (0.0 $g/m^2$, 1.5 $g/m^2$, 3.0 $g/m^2$, 6.0 $g/m^2$) with the same seeding amounts of native woody (Rhus chinensis, Albizzia julibrissin) and herbaceous plants (Lotus corniculatus var. japonicus, Dianthus sinensis, Aster yomena) were treated with 3 replications on the experimental disturbed slope. Data such as soil hardness (mm), moisture content (%), surface coverage rate (%), the number of each germinating plant and plant height were analyzed. There were no statistic differences observed in the soil hardness and the soil moisture content while a significant difference was observed in the surface coverage rates. The surface coverage rates were higher in 3.0 $g/m^2$ and 6.0 $g/m^2$ plots compared to the rest two plots of cool-season turfgrasses. However, the emergence of native woody and herbaceous plants was relatively low in 3.0 $g/m^2$ and 6.0 $g/m^2$ plots of high seeding amounts of cool-season turfgrasses. This result indicated that high seeding amounts of cool-season turfgrasses could decrease the emergence of native woody and herbaceous plants. We concluded that 1.5 g~3.0 $g/m^2$ seeding amounts of cool-season turfgrasses was optimum level for the balanced emergence of cool-season turfgrasses, native woody and herbaceous plants in the viewpoint of the ecological disturbed slope revegetation.

Characteristics of Water Relation Parameters for Pinus densiflora at Different Aspects in Central South Korea (입지 유형에 따른 중부지방 소나무의 수분생리 특성)

  • 신만용;정동준;신창섭
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.6 no.1
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    • pp.18-23
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    • 2004
  • This study was conducted to provide a national forest management method for natural Pinus densiflora forest stands in central South Korea based on growth characteristics and water relations. Average stand volume per hectare was 259.3㎥ in the pine study site. Basal area, volume, annual mean increment and periodic annual increment of DBH for 10 years at each slope aspect appeared to decrease as the aspect shifts from north to south. Stems per hectare showed the lowest value at the northern aspect. Maximum water potentials measured between 12 and 14 o'clock were analyzed by aspect and elevation. Water potential of pine decreased as the aspect changed from north to south, and water potential increased at lower elevations. Soil water content for the pine stands tended to decrease as the aspect shifted from north to south. Water potential and soil moisture content were highly correlated. Soil water deficits indicate that pines have a higher moisture requirement on the ridge and the southern aspect.

Environmental and Growth Characteristics of Pimpinella brachycarpa Habitat in Mt. Jeombong, Korea (점봉산 참나물 자생지의 환경 및 생육 특성)

  • Park, Yun Mi;Kim, Mahn-Jo
    • Journal of Korean Society of Forest Science
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    • v.100 no.4
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    • pp.687-692
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    • 2011
  • Pimpinella brachycarpa, a summer-green perennial herb, is narrowly distributed in the moist forest floors. We investigated environmental characteristics and growth patterns of Pimpinella brachycarpa depending on the microenvironment in Mt. Jeombong located in the central part of Korea. P. brachycarpa populations were located at an altitude of 978~1016 m and the average atmospheric humidity hovered at 80 percent. Also, it was found that the soil moisture content was remarkably high, 26.7%, in the populations; organic matter 11.1~11.7%; the nitrate nitrogen 0.60%; available phosphorus 19.5~39.0 ppm; CEC $20.8{\sim}21.3cmolckg^{-1}$; soil pH 4.7~4.8 respectively. In case of growth pattern, the shoot length of individuals under the improved light condition in the sunny forest was statistically longer than in the dense forest. Therefore, we presumed that high humidity and ample soil moisture are abiotic factors of the growth of P. brachycarpa and that the amount of light affects the relative growth rate of individuals.

Native Environment and Growth Characteristics of Dendropanax morbifera Lev. In Korea

  • Park, Seong-Kyu;Park, Kyong-Ju;Lee, Jong il
    • Korean Journal of Plant Resources
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    • v.10 no.3
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    • pp.271-273
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    • 1997
  • This study was carried out to obtain basic envirinmental information of the native area and growth characteristics at different age of Dendropanax morbifera LEV. In the southern Korea. The Dendropanax morbifera LEV. Was grown naturally at Wando, Cheju(Mt. Halla), Yecheon(Kermoon island),Sinan(Hong isand), Jindo(Mt. Chermchill) and Haenam(Mt. Taeroon), all between 30 to 450m above the sea level. The soil characterisitics of the native area had a pH of 5.3 to 5.4 with 8.4 to 9.8% content of organic matter and 18.2 to 21.3% soil moisture. Flowering starting in the middle of July begun when the trees were 6 years old. Six year old trees are 129 cm in stem height, 34 mm in stem diameter,15.4 in number of leaves with petioles 12.9 cm long. Xylem sap can be obtained from over 10 year old trees that grew well and have over 10 cm stems in diameter.

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Effects of Soil Textures by Soil Addition on the Growth and Quality of Oriental Melon (Cucumis melo L. var. makuwa Mak.) under Protected Cultivation (객토시 토성이 시설참외의 생육과 품질에 미치는 영향)

  • ;;;;Khan Zakaullah
    • Journal of Bio-Environment Control
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    • v.13 no.3
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    • pp.156-161
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    • 2004
  • This study was conducted to investigate the effects of soil amendment with different characteristics on plant growth, fruit yield and quality of oriental melon for continuous cropping under protected cultivation. Humus layers in arable soil was disturbed because soil amendment from hillside to oriental melon field was continued to resolve problems for continuous cropping. Water potential and hardness of soil was decreased in sandy loam with lower clay contents compared with loam and silty clay. Leaf length and area, fresh and dry weight of plant at earlier growing stage were higher, but chlorophyll contents of leaves were dropped in sandy loam compared with silty clay soil. Fruit size and weight was higher in sandy loam, but soluble solid and color of fruit were increased in silty clay. Marketable and unmarketable yield and quantity of fermented fruit were the highest in sandy loam. Hardness and weight of fruit were decreased by longer storage period and soluble solids of fruit was peaked at 5 day after storage, but decreased by prolonged continued storage. Because of these results, soil characteristics of amendment to oriental melon field should be considered as an important factor for quality and yield of oriental melon.