• 한국농공학회지
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• 제16권3호
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• pp.3477-3491
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• 1974

Following are the results of the study on the property of falling permeation of stratified soil in the close state under existence of stagnant water on a soil layer. 1. When on the stratified soil a least permeating layer was put on the soil layer the load Pressure was present owing to appearance of saturation close state driving decrease of the pressure in the lower layer, on the other hand when the least permeating layer was placed under the layer the lower least permeating layer pressure was decreased. 2. In the case of least permeating layer the variation of current gradient according to the respective level after treating the layer was enormous and due to usal storage phenomena for the Kl layer which was coarse that was trifle. 3. The permeability of the respective layer of stratified soil in the close state died not always coincide with that of single layer. 4. Generally Zunker's equation of average permeability was valid but actually calculated permeating velocity after treating the layer of stratified soil was seriously differ from the measured value owing to the variation of current gradient, especially when the pressure head at the layer boundany was discontinuous the validity of the equation of average permeability was seemed to be doubtful. 5. The permeating velocity of stratified soil was regulated by the least permeating layer, i.e. it is thought to be rational to estimate the value by calculating the current gradient with its proper permeability, pressure headon the layer and its thickness.

• 한국산림과학회지
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• 제56권1호
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• pp.66-76
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• 1982

사방시공지(砂防施工地)에 널리 조림(造林)되는 리기다소나무의 근계분포(根系分布)와 토양(土壤)의 견밀도(堅密度)의 관계(関係)를 구명(究明)하고자 표본지(標本地)를 선정(選定) 대표목(代表木)의 경사하측(傾斜下側)에 환상(環状)의 토양단면(土壤斷面)을 만들어 각토층별(各土層別)로 토양경도(土壤硬度)를 산중식(山中式) Soil hardness tester로 측정(測定)하고 수근(樹根) (중세근(中細根))의 분포(分布)를 조사(調査)하여 분포(分布)한바 다음과 같이 요약(要約)할 수 있었다. 1) 토양(土壤)의 견밀도(堅密度)는 토심(土深)이 깊어짐에 따라 점차(漸次) 증가(增加)하여 평균(平均) 지표경도(指標硬度)는 I층(層)에서 14.6mm II층(層)에서 16.2mm, III층(層) 17.2mm, IV층(層)에서는 18.3mm, V층(層)에서는 19.8mm였다. 2) 수근(樹根) (중세근(中細根))은 표층(表層)에 이를수록 많이 분포(分布)하여 토층(土層)이 깊어짐에 따라 그 수(數)가 감소(減少)하여 I층(層) 수근(樹根)의 수(數)를 1(31%)로 할때 II층(層)은 0.84(26%), III층(層)은 0.6(18%), IV층(層)은 0.4(12%), V층(層)도 0.4(13%)이다. 3) 토양(土壤)의 견밀도(堅密度)와 수근(樹根)의 분포(分布)는 음(陰)의 상관관계(相関関係)에 있어 견밀도(堅密度)가 높아지면 이에따라 수근(樹根) 수(數)는 감소(減少)한다. 각(各) 토층별(土層別) 토양(土壤)의 견밀도(堅密度)와 수근분포(樹根分布)의 상관계수(相関係数)는 I층(層)은 -0.3875, II층(層)은 -0.5299, III층(層)은 -0.5573, IV층(層)은 -0.6922, V층(層)은 -0.7325, 전체평균(全体平均)은 -0.9469로서 모두 유의적(有意的)이었다. 4) 리기다소나무의 수근(樹根) (중세근(中細根))의 성장(成長)에 최적합(最適合)한 토양(土壤)의 견밀도(堅密度)는 지표경도(指標硬度)는 12.0~14.9mm로서 이 계급(階級)에 속(屬)하는 지표경도(指標硬度)는 33%이고 수근(樹根)의 분포(分布)는 41.8%이다. 또 지표경도(指標硬度) 20.9mm까지는 82%이나 수근(樹根) 93.2%가 분포(分布)하고 있어 지표경도(指標硬度) 20.9mm이하(以下)까지가 리기다소나무의 수근(樹根)의 생장(生長)에 적합(適合)하다고 사료(思料)된다.

• Journal of Plant Biology
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• 제21권1_4호
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• pp.7-12
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• 1978

The results of the relationship between standing crop of Miscanthus sinensis grassland and soil morphological characteristics are as follows. The Miscanthus sinensis grassland seems to grow well in volcainc ash soil. The depth of A layer was closely related to the standing crop of the Miscanthus sinensis grassland. The root systems of Miscanthus sinensis reached to its maximum in A layer. The root systems of Miscanthus sinensis showed its maximum at 20mm and below(soil hardness). The soil texture of A layer showed SL-SiL. The soil structure of A layer contained Massive-Small Granular. The soil colors of A layer expressed Dark Yellowish Orange-Brownish Black.

• Geomechanics and Engineering
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• 제29권1호
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• pp.91-97
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• 2022

The cohesive non-swelling soil (CNS) cushion technology has been widely applied in the subgrade and slope improvement at expansive soil regions. However, the mechanism of the inhibition effect of the CNS layer on expansive soil (ES) has not been fully understood. We performed four outdoor model tests to further understand the inhibition effect, including different kinds of upper layer and thickness, under the unidirectional seepage condition. The swelling deformation, soil pressure, and electrical resistivity were constantly monitored during the saturation process. It is found that when a CNS layer covered the ES layer, the swelling deformation and electrical resistivity of the ES layer decreased significantly, especially the upper part. The inhibition effect of the CNS layer increases with the increase of CNS thickness. The distribution of vertical and lateral soil pressure also changed with the covering of a CNS layer. The electrical resistivity can be an effective index to describe the swelling deformation of ES layer and analyze the inhibition effect of the CNS layer. Overall, the CNS deadweight and the ion migration are the major factors that inhibit the swelling deformation of expansive soil.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.99-102
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• 2001

The soil-to-air fluxes of three PAHs(Phenanthrene, Pyrene, Benzo(a)pyrene) from a laboratory contaminated forest soil were investigated in experimental microcosms. The effects of soil temperature(45$^{\circ}C$, $25^{\circ}C$, 5$^{\circ}C$) and relative humidity(0%, 100%) were investigated according to existence of the humic layer(O layer) over the mineral layer(A layer). Volatilization flux experiments were carried out for a period of 96 hrs. The resulting PAHs volatilization fluxes from the different conditions were quantified and compared. In the mineral layer, highest volatilization flux among the individual PAHs was Phenanthrene >Pyrene> Benzo(a)pyrene on the conditions of 45 $^{\circ}C$, RH=100%. In the humic layer over the mineral layer, maximum volatilization flux was Phenanthrene on the condition of 45$^{\circ}C$, RH=0%. Results from flux experiments showed that volatilization fluxes of PAHs were dependent on soil temperature. Existance of humic layer over the mineral layer delayed transportation to the air of especially heaveir molecular PAHs. But, if humic layer is contained water sufficiently, it is possible that volatilization fluxes are enhanced by water convective flux according to variation of soil temperature and air relative humidity.

• 한국약용작물학회지
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• 제17권3호
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• pp.204-209
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• 2009

This study was conducted to assess water movement in paddy-upland rotation soil scheduled for ginseng cultivation through the measurement of infiltration and permeability of soil water. Soil sample was divided with four soil layers. The first soil layer (to 30cm from top soil) was loamy sand, the second and the third soil layers (30$\sim$70 ㎝) were sand, and the fourth (< 120 ㎝) was sandy loam. The soil below 130 ㎝ of fourth soil layer was submerged under water. The shear strength, which represents the resisting power of soil against external force, was 3.1 kPa in the first soil layer. This corresponded to 1/8 of those of another soil layer and this value could result in soil erosion by small amount of rainfall. The rates of infiltration and permeability depending on soil layers were 39.86 cm $hr^{-1}$ in top soil, 2.34 cm $hr^{-1}$ in 30$\sim$70 ㎝ soil layer, 5.23 cm $hr^{-1}$ and 0.18 cm $hr^{-1}$ in 70$\sim$120 ㎝ soil layer, with drain tile, and without drain tile, respectively. We consider that ground water pooled in paddy soil and artificial formation of soil layer could interrupt water canal within soil and affect negatively on water movement. Therefore, we suggest that to drain at 5 m intervals be preferable when it makes soil dressing or soil accumulation to cultivate ginseng in paddy-upland rotation soil to reduce failure risk of ginseng cultivation.

• 한국환경복원기술학회지
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• 제9권5호
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• pp.50-59
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• 2006

This study was initiated to investigate soil chemical properties under different soil systems. Data such as soil acidity(pH), electrical conductivity(EC), organic matter content(OMC), and cation exchange capacity(CEC) were analyzed with samples from multi-layer, USGA, and mono-layer systems. N, P, K and micronutrients were also measured. Multi-layer system was built up to 60-cm depth with rootzone layer, intermediate layer and two drainage layers. USGA system 45 centimeters deep was constructed with rootzone layer, intermediate layer and drainage layer. Mono-layer system, however, was made only with a 30-cm rootzone layer. Differences were observed in soil pH, EC, OMC, CEC and micronutrients. Soil pH was acceptable for turfgrass growth a year after establishment, being 5.5 to 6.5 in the study. Differences were greatly observed for EC among soil systems. Values of EC for multi-layer, USGA, and mono-layer systems were 39.79, 31.26 and 103.54 uS/em, respectively. The increase rate was approximately 4 to 8 times greater with mono-layer system than those with other two systems. Therefore, it was necessary to avoid micronutrient deficiency such as Fe, Mn etc. through an effective management program in mono-layer system because of its faster potential feasibility of salt accumulation. The greatest OMC was associated with USGA system, being 0.97% which was 11% over that of the other systems. Slight differences were observed for CEC among them. Mono-layer system produced 1.45 me/100g, 10.3% and 8.9% lower in CEC than those of multi-layer and USGA system, respectively. Micronutrients such as Fe, Zn, and Mn etc. were below the level required for turf growth, regardless of soil systems. It was considered that one year after turf establishment was not enough to build up micronutrients in sand-based soil systems to the normal level for a turf growth. These results demonstrate that intensive management program including grow-in concept fertilization should be integrated into sand-based soil systems, even after a year in establishment. Regular nutrient monitoring by soil analyses is a strong necessity to decide the kinds and amount of fertilizer. Also, strategic management program must be selectively employed according to sports turf soil systems.

• 한국작물학회지
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• 제44권1호
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• pp.20-25
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• 1999

This experiment was conducted to elucidate the relation-ship between vertical distribution of rice roots and yield traits under field conditions. Eight IRRI's new plant type rices (NPTRs) were tested in a volcanic ash soil paddy field under dense (IO 10 cm) and common (20 20 cm) planting densities. These lines were evaluated to have more spikelet numbers per panicle (SNP), lower filled grain rate (FGR), and lower rough grain weight per hill (RGWH). In dense planting, rough grain weight per stem (RGWS) was increased due to heavier culm and leaf dry weight (CLDW), and both RGWS and CLDW were related with the percentage of root distribution (%RWI) in the 10~30 cm soil layer, while in common planting, RGWS was not closely related with CLDW. SNP was highly related with root dry weight (RDW) in the 0~10cm soil layer. FGR was mainly affected by ROW in the 10~30 cm soil layer under both planting densities. RGWS was positively correlated with top dry weight (TDW) and harvest index (HI), and TDW was positively correlated with RWI under common planting or %RWI under dense planting, and HI was positively correlated with RWI in the 10~30 cm soil layer only under dense planting. RGWS was closely related with root weight index by dry weight (RWI) in the 10~30 cm soil layer and %RWI in the 0~30 cm or 10~30 cm soil layer under dense planting, and with only RWI in the 10~30 cm soil layer under common planting. But RGWH showed the close positive relationship with RDW and RWI in the 10~30 cm soil layer under dense planting, while under common planting, it showed the close positive relationship with RWI and %RWI in the 10~30 cm soil layer or %RWI in the 0~30 cm soil layer. The deeper root system in rice, especially under dense planting, is important for high yield of NPTRs focusing on the increment of top mass production and harvest index.

• Mycobiology
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• 제36권1호
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• pp.40-44
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• 2008

Various bacteria were isolated from the casing layer soil of the culture bed of P. ostreatus and their role in fruiting body induction of the edible mushroom, P. ostreatus, was investigated. Analysis of the bacterial community isolated from the casing layer soil revealed that the composition of genera and number of cultivable bacteria were different for each sterilizing treatment. Bordetella was predominant in the bulk soil whereas Flavobacterium was predominant after sterilization of the casing layer soil. Fluorescent Pseudomonas was predominant in the non-sterilized casing layer soil. Total number of the bacterial genera in the casing layer soil was higher than that in the bulk soil. In particular, an increase in the fluorescent Pseudomonas population was observed in the non-sterilized casing layer accompanied by induction of fruiting body and enhanced mushroom production yield. The results suggested that specific bacterial populations in the casing layer play an important role in the formation of primodia and the development of basidiome in P. ostreatus.

• 한국토양비료학회지
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• 제42권5호
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• pp.364-370
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• 2009

벼 재배시 하해혼성층 논토양의 전북통과 지산통 작토층과 경반층의 특성을 2년간(2005~2006)조사 분석한 결과를 요약하면 다음과 같다. 하해혼성층적층 대표토양인 전북통과 곡간충적층 대표토양인 지산통을 10개소에서 조사한 결과 작토심은 전북통 12.6 cm, 지산통 12.7 cm 이었고 플라우 경운깊이는 120필지에서 조사한 결과 10.5 cm 이었으며 전북통에서 경도와 작토심과는 부의 상관을, 경도와 경반층 두께와는 정의 상관을 나타냈다. 경반층 경도는 전북통 $14.7kg\;cm^{-2}(25.3mm)$, 지산통 $8.7kg\;cm^{-2}(22.1mm)$ 이었고, 두께는 전북통 22.3 cm, 지산통 17.8 cm 이었으며 경반층 출현깊이는 전북통 15 cm, 지산통 20 cm에 있었다. 경반층 지온은 작토층과의 차이를 보면 전북통에서는 봄 $-2.0^{\circ}C$, 여름 $-2.5^{\circ}C$, 가을 $-1.0^{\circ}C$를 지산통은 봄 $-2.1^{\circ}C$, 여름 $-1.8^{\circ}C$, 가을 $-0.7^{\circ}C$를 나타냈고 전북통에서 산화환원전위차 변화는 작토층은 유수형성기부터 환원상태를 경반층은 출수후기까지 산화상태를 나타냈다. 토양물리성은 두 토양통 공히 경반층에서 용적밀도, 고상율이 높고 공극율, 기상율이 낮았다. 또한 토양화학성은 경반층에서 총질소가 낮았고, 유기물 및 유효 인산함량이 적은 반면에 pH가 높고, 유효규산, 치환성칼슘 및 마그네슘 함량이 많았다. 양이온치환용량은 전북통에서 작토층 및 경반층 비슷한 경향이었으나 지산통은 경반층에서 다소 낮은 경향을 나타냈다. 무기태질소 함량은 토양통 공히 작토층에서 많았고, 가용성 미량성분 함량은 경반층에서 많았으며 지산통에서 많은 경향을 나타냈다. 감수심은 전북통에서 심경구, 지산통 경운구는 로타리구보다 빠르고, 계절별 감수심 변화는 6월 하순까지는 감수심이 빨랐으나 7~8월에는 1~3 mm로 늦었으며 9월부터는 빠른 경향을 나타냈다. 벼 뿌리분포는 로타리 25 cm, 심경 30 cm, 경운 20 cm까지 신장하였고, 출수기 뿌리 건물중은 심경>로타리>경운 순으로 무거웠다.