• Journal of Forest and Environmental Science
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• 제39권1호
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• pp.13-19
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• 2023

We investigated Soil respiration in Bluepine forest of western Bhutan, in relation to soil temperature, moisture content and soil pH and it was aimed at establishing variability in space and time. The Bluepine forest thrives in the typical shallow dry valleys in the inter-montane Bhutan Himalaya, which is formed by ascending wind from the valley bottom, which carries moisture from the river away to the mountain ridges. Stratified random sampling was applied and the study site was classified into top, mid, low slope and further randomized sample of n=20 from 30 m×30 m from each altitude. The overall soil respiration mean for the forest was found 2248.17 CO₂ g yr^-1 and it is ~613.58 C g yr^-1. The RS from three sites showed a marginal variation amongst sites, lower slope (2,309 m) was 4.64 μ mol m^-2 s^-1, mid slope (2,631 m) was 6.78 μ mol m^-2 s^-1 and top slope (3,027 m) was 6.33 μ mol m^-2 s^-1 and mean of 5.92 μ mol m^-2 s^-1, SE=0.25 for the forest. Temporal distribution and variations were observed more pronounced than in the space variation. Soil respiration was found highest during March and lowest in September. Soil temperature had almost inverse trend against soil respiration and dropped a low in February and peak in July. The moisture in the soil changed across months with precipitation and pH remained almost consistent across the period. The soil respiration and soil temperature had significant relationship R²=-0.61, p=0.027 and other variables were found insignificant. Similar relationship are reported for dry season in a tropical forest soil respiration. Soil temperature was found to have most pronounced effect on the soil respiration of the forest under study.

• 한국환경과학회지
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• 제22권11호
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• pp.1443-1449
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• 2013

This was an experimental study to evaluate temperature reduction and evapotranspiration of extensive green roof. Three test cells with a dimension of $1.2(W){\times}1.2(D){\times}1.0(H)$ meters were built using 4-inch concrete blocks. Ten-centimeter concrete slab was installed on top of each cell. The first cell was control cell with no green roof installed. The second and third cells were covered with medium-leaf type Zoysiagrass (Zoysia japonica) above a layer of soil. Soil thickness on the second cell was 10cm and that on the third cell was 20cm. Air temperature, relative humidity and solar irradiance were measured using AWS (automatic weather system). Temperature on top surface and ceiling of the control cell and temperature on top surface, below soil and ceiling of green roof cells was measured. Evapotranspiration of the green roof cells were measured using weight changes. Compared with temperature difference on the control cell, temperature difference was greater on green roof cells. Between two green roof cells, the temperature difference was greater on the third cell with a thicker soil layer. Temperature differences below soil and on ceilings of green roof cells were found greater than those of the control cell. Between the green roof cells, there was no difference in the temperature reduction effects below soil and on ceilings based on substrate depth. In summary, green roof was found effective in temperature reduction due to evapotranspiration and shading effect.

• 한국초지조사료학회지
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• 제18권1호
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• pp.55-60
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• 1998

This study was conducted to investigate the effects of the pasture types and the leveling methods of winding slope land for seedbed on the runoff, soil loss, botanical composition, dry matter yield of forage and economical value at the Experimental Field of Grassland and Forage Crops Division, National Livestock Research Institute, Suweon, from 1994 to 1995. The results obtained are summarized as follows: 1. Runoff of the improved land was higher than that of the unimproved land in the top grass and bottom grass. 2. Soil loss of the improved land was higher than that of the unimproved land in the top and bottom grasses in the first year. However, it was slightly higher in the unimproved land, and all of it were greatly decreased in the second year. 3. The percentage of grasses coverage was increased with the improved land in the first year, and it was not different between the improved land and unimproved land in the second year. Also, it was slightly increased in the bottom grasses. 4. Dry matter yield of grasses was increased with improved land at the top and bottom grasses. DM yield of grasses was increased in the top grasses in the first year and bottom grasses in the second year, respectively. 5. The establishment cost of grasses was decreased with wages decrement, and the management cost was saved about 1,116,000 won per ha with improved land. The results demonstrated that although soil loss was increased by leveling methods of improved land irrespective of pasture types in the first year, it was decreased with time little by little. Also, improved land was very good for grasses coverage, dry matter(DM) yield and economical value.

• 자원환경지질
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• 제5권4호
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• pp.221-229
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• 1972

Through the series of study on the above subjects, the following were founded. 1. Soluble silica in paddy top-soil (xppm) and maxium possible yield (y) is expressed as following equatic $y=63.97+0.425x-0.00114x^2$ It is known that soluble silica in paddy top-soil in South Korea is limited as 130ppm. 2. Gnder the present Korean condition 90% of paddy-top-soil is estimated to be short in available silica content and the country average to only 78ppm. 3. The total area of Korean paddy-top-soil is about 1,036,710 ha. All requirements of wollastonite in South Korea estimated from the equation $Y=0.94-0.033{\times}$are about 2 million M/T 4. Silicates fertilizer minerals are Bentonite, Zeolite, Wollastonite, Serpentine, and Chlorite. But Wollastonite is most economic and can be supplied to using Korea. 5. Wollastonite is formed in contact metomorphic deposits. Limestone is the country rock of wollastonite. Limestone in Korea is in Ryunchcon system, (Pre-cambrian) Okcheon system, (unknown), Great limestone series (paleozoic), Hongjum series (Paleozoic) and Kyungsang system (mesozoic) so that the zones of these limestone and igneous rock are the possible area which wollastonite can be produced. 6. According to the published geologic map (scale 1/5000), about 25 provinces will be possible area which wollastonite can be produced. In future, I believe that many possible area will be increased. 7. According to this survey at Danyang, total wollastonite resources are about 179,000 M/T and average of soluble $SiO_2$ is 29.84%. 8. According to this survey at Daijeon, total resources are about 57,600 M/T and average of soluble $SiO_2$ is 21.53%. 9. Total wollastonite resources including Danyang, Yangduk, and Daijeon are about 1,172,200 M/T. Considering possible resources, it will be over 20 million M/T and I can say that it is possible to be supply for a score.

• Applied Microscopy
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• 제47권3호
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• pp.148-156
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• 2017

The wide distribution of redox-sensitive elements (RSE) as arsenic (As), cadmium (Cd), selenium (Se), and strontium (Sr) in the top soil of Siwaqa area are related to the weathering action of alkaline surface and groundwater on the parent rocks. The bioavailability, distribution, sorption, and ecotoxicity of As, Cd, Se, and Sr, of the wild plants and top soils in the study area were investigated. A total number of 23 surface soil samples and 23 plant samples were collected and analyzed for the most toxic elements. The uptake of elements by plants was dependent on the plant species and the concentration of elements in the soil. For example, Sr was the highest concentration in soil samples and plants, while Se was the lowest concentration in soil samples and pants. For the plants, the results showed that Bellevalia sp. had the highest elements uptake, while Allium rothii had the lowest elements uptake. The results of this work provide a valuable knowledge for understanding the bioavailability of some toxic elements in the soil and plants of Central Jordan. The results are expected to be of great help for the Jordanian Uranium Mining Company during their environmental risk assessments.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1315-1323
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• 2010

This paper deals with a case study on a unique slope failure in a liner system of a municipal solid waste containment facility during construction because the sliding interface is not the geomembrane/compacted low permeability soil liner (LPSL) but a soil/soil interface within the LPSL. From the case study, it is concluded that compaction of the LPSL should ensure that each lift is kneaded into the lower lift so a weak interface is not created in the LPSL, and the LPSL moisture content should be controlled so it does not exceed the specified value, .e.g., 3% - 4% wet of optimum, because it can lead to a weak interface in the LPSL. In addition, drainage materials should be placed over the geomembrane from the slope toe to the top to reduce the shear stresses applied to the weakest interface, and equipment should not move laterally across the slope if it is unsupported but along the slope while placing the cover soil from bottom to top.

• 한국토양환경학회지
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• 제2권2호
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• pp.25-33
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• 1997

비점오염원으로 토양과 수환경에 영향을 미치는 우분퇴비의 영향을 조사하기 위하여 상부와 하부에 연결한 다층토양칼럼을 가지고 음이온의 토양으로부터 용출경향을 조사하였다. 상부 칼럼은 건조 우분 퇴비를 0, 2,4, 6%의 비율로 Ap토양에 처리한후 균일하게 채웠고 하부칼럼은 15, 30, 45cm의 길이의 아크릴칼럼에 B층 토양을 용적비중 1.3g/$\textrm{cm}^3$으로 채운 후 결합하였다. 이렇게 조합된 칼럼을 충분히 포화시킨 후 증류수를 칼럼의 상부에서 일정 수두높이를 유지하면서 칼럼의 하부에서 수집되는 용출수의 수리전도도와 용출된 음이온의 농도를 조사하였다. 상부와 하부의 각각의 수리전도도는 3$\times$$10^{-4}$cm/sec 와 1.6$\times$$10^{-3}$cm/sec 이었고 비특정흡착특성을 지니는 대부분의 수용성 염소와 황산이온은 90%가 0.2 공극수량에서 그리고 대부분의 음이온은 1 공극수량이내에 용출되는 경향을 보였는데 이는 이들 이온이 토양에 가해진 유기물에 의해 이동에 영향을 받지 않았음을 보여주는 것이다. 또한 이들 음이온이 통과하는 토양의 깊이도 이들 음이온의 이동에 영향을 주지 않았음을 알 수 있었다. 그러나 비특정과 특정 모두의 흡착특성을 가지는 황산이온의 경우 용출곡선이 오른쪽으로 약간 이동하여 용출이 지연되는 경향을 보여주고 있다. 그리고 인산이온의 경우 조사된 5 공극수량 이내에서 전혀 용출되지 않았다.

• 한국토양비료학회지
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• 제43권5호
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• pp.572-577
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• 2010

경남지역 단감 재배 토양의 양분관리를 위한 기초 자료를 제공하고자 창원 7, 마산 1, 진주 6, 사천 3, 김해 5, 밀양 2, 함안 2, 창녕 1, 하동 3, 산청 1 등 31개 지점을 선정하였고 4월부터 10월까지 2개월 단위로 4회 조사하였다. 표토와 심토의 pH 값은 4월에 비해6월 이후 유의적인 증가를 나타냈으며 적정수준인 6.0-6.5 보다 낮았다. 반면, 암모니아태 질소 함량과 질산태 질소 함량은 4월 보다 6월 이후 유의적인 감소를 나타냈다. 표토와 심토의 pH는 적정수준인 6.0-6.5 보다 부족한 비율이 각각 69.4%와 84.7%로 매우 높게 나타나 경남지역 단감 재배 토양의 pH 교정을 위해 토양개량제 공급이 시급한 것으로 판단되었다. 토양 유기물 함량도 적정수준인 25-35 g $kg^{-1}$ 분포비율은 표토 13.7%, 심토 4.0%로 매우 낮았으며 부족한 비율이 각각 63.7% 및 84.7%로 매우 높아 적절한 유기물 공급이 필수적인 것으로 나타났다. 유효인산 함량은 적정수준인 200-300 mg $kg^{-1}$보다 초과된 비율은 표토 70.2%, 심토 46.8% 였으며 토양 유기물 함량 (r=0.339, $p{\leq}0.001$)과 고도의 유의적인 정의상관을 보여 가축분 퇴비 과다 시용에 대한 주의가 필요한 것으로 나타났다.

• The Korean Journal of Ecology
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• 제21권5_1호
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• pp.457.1-463
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• 1998

the research has been made for alkali and metal element concentrations in top soils and plants from the abandoned coal mine, Keumsan, Chungnam Province. Samples of the top soil and plant (Miscanthus sinensis and Pinus rigida) were collected from the mine area in which was divided into t재 regions the polluted region influenced by the coal mining and the non-polluted region. pH of the top soils was 3.16-4.33 in the polluted region. Ca, Sr and P concentrations were high in the polluted soils, and Al and Ba concentrations were high in the non-polluted soils. No differences were found in K, Na and Ti concentrations. M. sinensis was higher in the element concentrations than P. rigida. In the average concentration of the alkali and metal element, M. sinensis showed high Cs and Na in the polluted region, and high Ba, Ca, K, Sr and concentrations in the non-polluted region. P. rigida had high Cs, Na and Rb concentrations in the polluted region. M. sinensis and P. rigida were higher in the root than above-ground part in the most element, but Ca and K. Ca, K and Na concentrations within both plants had higher than those of soils.

• 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.