• Journal of Forest and Environmental Science
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• v.39 no.1
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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.

• Journal of Environmental Science International
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• v.22 no.11
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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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.

• Economic and Environmental Geology
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• v.5 no.4
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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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• v.47 no.3
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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.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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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.

• Journal of Korea Soil Environment Society
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• v.2 no.2
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• pp.25-33
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• 1997

To investigate the effects of cow manure compost(CMC) on soil and water environment as non-point source, the elution patterns of anions were determined in muti-layered soil columns which were consisted of one top and one bottom in combination. The top soil columns were uniformly packed with Ap horizon soils amended with air-dried CMC at different ratios(0, 2, 4, 6%, wt/wt), the bottom ones were packed with of B horizon soils of 15, 30, and 45cm in length. After saturating the each soil column, the leachate were collected from the bottom of the column while the double-ionized water was applied from the surface of the column by constant head method. From the hydraulic conductivity and anion eluted were measured in the leachate. Each saturated hydraulic conductivities for top and the bottom soils were 3$\times$$10^{-4}$sec and 1.6$\times$$10^{-3}$cm/sec. Most of water soluble chloride and sulfate, having non-specific adsorption characteristics onto the soil particles, were eluted within 1 PV, showing that there was no apparent retardation of anion movement with increasing CMC contents in the top soils. The effect of soil depths on anion movement were similar to the results of CMC contents. Sulfate of having both of non-specific and specific adsorption characteristics was also recovered in the effluent within 1 PV, while the elution curves were slightly skewed to the right showing that the CMC affected the movement of sulfate. Phosphate of specific adsorption characteristics was hardly eluted within 5 PV.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.572-577
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• 2010

Field monitoring was performed to evaluate the soil chemical properties of 31 sweet persimmon orchard soil samples every two months from April to October in 2008 at Gyeongnam Province. Soil chemical properties such as pH, organic matter, available phosphate, exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable sodium, ammonium nitrogen, and nitrate nitrogen were analyzed. The soil chemical properties of both top soil, and subsoil showed that soil pH was significantly increased whereas ammonium nitrogen, and nitrate nitrogen were significantly decreased. The insufficient levels of nutrients in top soil, and subsoil were higher in 69.4%, and 84.7% for pH, 63.7%, and 84.7% for organic matter compared to optimum range. Meanwhile, the excessive levels of available phosphate showed 70.2% in top soil, and 46.8% in subsoil compared to optimum range. The experimental results showed that the optimum fertilization based on soil testing was the most important thing in soil nutrients management for sweet persimmon.

• The Korean Journal of Ecology
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• v.21 no.5_1
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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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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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.