• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.20-26
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• 1997

This paper examines the influences of mining activities on the concentrations of heavy metals in soils in the vicinity of the Dalsung Cu-W mine, Korea. Geochemical surveys were undertaken in the Dalsung mine area and sampling of surface and subsurface soils was carried out. Samples were prepared using 0.1 N HCI, HNO$_3$-HClO$_4$, and aqua regia, and analyzed for Cd, Cu, Pb and Zn by Atomic Absorption Spectrometry. In addition, soil samples were sequentially extracted to investigate the chemical speciation of heavy metals in soils. Heavy metals are highly contaminated in soils in the vicinity of mining area ranging up to 28 $\mu\textrm{g}$/g Cd, 5000 $\mu\textrm{g}$/g Cu, 2390 $\mu\textrm{g}$/g Pb and 930 $\mu\textrm{g}$/g Zn by the method using HNO$_3$-HClO$_4$. The pollution indices calculated with the permissible levels are up to 49 in surface and subsurface soils, which are considered sufficient to raise environmental problems. However, the heavy metal levels by the method using 0.1 N HCl are not higher than Korean standard for soil contamination. It suggests that analytical methods and soil standard should be re-examined. From the results of the sequential extraction methods for metal speciation, total Cu, Pb and Zn concentrations may be determined by analytical methods using HNO$_3$-HClO$_4$ or aqua regia, and exchangeable phase of those metals by the method using 0.1 N HCl.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.351-357
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• 2000

This study was carried out to find out characteristics and contamination status of the urban-forest soils. Both topsoil (0-20 cm) and subsoil (40-60 cm) samples were collected from Namsan, Changdeok-palace, Seongjusan and Odaesan (control). The samples were analyzed for physicochemical properties, heavy metal (Cd, Cu, Pb, Zn) and anion $(NO_3\;^-,\;SO_4\;^{2-})$ contents. Soil pH of Odaesan was the highest followed by Namsan, Changdeok-palace and Seongjusan. The anion concentrations of the soil samples were in the order of Namsan, Seongjusan > Changdeok-palace > Odaesan. The relationships between soil pH and the anion concentrations showed highly significant negative correlation, which indicated acidification of soil due to air pollutants such as $NO_3\;^-$ and $SO_4\;^{2-}$ was going on. The heavy metal contents of the soils of urban-forest were higher than those of control. Heavy metal contents in the topsoil were higher than those in the subsoil. Since urban-forest soils were quite vulnerable to acidification and heavy metal accumulation due to chronic exposure to air pollutants such as automobile exhaust, a comprehensive countermeasure not to deteriorate urban-forest ecology must be prepared in the near future.

• The Journal of Engineering Geology
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• v.19 no.1
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• pp.33-41
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• 2009

In this study, some changes of soil characteristics in a field were analyzed to investigate the effect of heavy rainfall during rainy season. The heavy rainfalls were often induced geohazards like landslides. To do this, the reaching rainfall in the ground surface was investigated according to a condition of vegetation, and the change of soil characteristics induced by infiltrating rainfall was analyzed. The study site is a natural terrain located in Daedeok Science Complex. This site has same geology and soil condition whereas it has different vegetable condition. The rainfall records during the rainy season of 2006 and 2007 were selected. The rainfall records are based on the measuring date from Daejeon Regional Meteorological Administration adjacent to the study site. Also, the rainfall records according to the condition of vegetation were measured using rainfall measuring device made by ourselves. The soil tests were carried out about soil specimen sampled before and after rainfall, and then the change of soil characteristics related to rainfall and vegetation were analyzed. As the result, the density of vegetation was influenced by reaching rainfall quantity in the ground surface, and its influence intensity was decreased with rainfall intensity and rainfall duration. Also, it shows that degree of saturations, water contents, liquidities and shear resistances are directly influenced by heavy rainfalls.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.637-643
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• 2010

For enhancement of apple productivity, the calcium fertilizers to increase the calcium content of fruit, and reduce the incidence of bitter pit in apples are applied. Crushed oyster shell contains a plenty of calcium carbonate, and a very small amount of boron, ferrous, and manganese. A field study was conducted to determine the optimum level of crushed oyster shell for soil nutrient management, and its effect on the induction of bitter pit in cultivar 'Gamhong' apple. The application of crushed oyster shell increased organic matter, available phosphate, and exchangeable cation concentration in soil. We found a significant positive correlation between soil pH, and application level of crushed oyster shell in both top, and subsoils. The incidence of bitter pit in apple fruit at the harvest stage was significantly higher in non treatment and calciummagnesium carbonate treatment than on over applications 4 Mg $ha^{-1}$ for crushed oyster shell. However, the optimum level of crushed oyster shell was 2 Mg $ha^{-1}$, especially considering the soil Ca content, soil pH, fruits weight, and yield. Our results show that the crushed oyster shell can be effective in restoring the soil nutrient balance, and inducing the bitter pit in apple fruit.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.189-194
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• 1994

This experiment was conducted to obtain basic information on the improved methods of soil physico-chemical properties and sweet potato yield cultivated on a newly-reclaimed land, a Songjeong loam soil. The crop was cultivated under the six different treatments for 4years since 1985 in the field conditions. Annual changes of soil properties and sweet potato yield were investigated and analyzed. Soil bulk density increased from the second year, and also soil hardness of topsoil increased, but that of subsoil had not tendency. Average yield of sweet potato for 4years in the integrated improvement plot was 32.68ton/ha, which is increased by 59% in comparison to that of the control plot. Crop yield was in order of integrated improvement>phosphate>subsoiling>lime>compost>control plots. The soil properties of the topsoil which showed high correlation coefficient to sweet potato yield were bulk density, hardness and cation exchange capacity(CEC), and those of the subsoil were bulk density, soil moisture and CEC. Ratios of changes of soil properties except organic matter content showed high significancy to sweet potato yield. Soil physico-chemical properties of the 4th year without soil conditioners application were worse than those of 3rd year.

• Asian Journal of Turfgrass Science
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• v.16 no.1
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• pp.11-18
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• 2002

This research was designed to know optimize soil sampling time, soil sampling depth and fertilizers according to season and soil condition in the golf course. One of the results was revealed that sampling point and depth have to be consistent for much fluctuation by sampling. Especially, Soil pH is decreased by soil depth remarkably. Top soil (0-5 cm depth) pH is higher than the sub soils (5-10 cm, 10-15 cm depth). It was confirmed that soil pH would increase when the state of soil is appropriate to H$^{+}$ ion concentration. Therefore, Soil pH modification is always not determined by lime content rather than soil conditions, i.e., Organic matter content, moisture content, and soil air content. More effective fertilizing time according to soil pH correction is the middle of october, and it's quantity is 100 g/$m^2$ silicate and 200 g/$m^2$ lime (Pel-Lime Mini) in this experiment. Recommended soil sampling method for acidity measurement is dividing by soil depth into each 5 cm respectively, rather than mixing 15 cm total soil.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.11
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• pp.619-630
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• 2015

This study was conducted to propose the methodology of human risk assessment specialized to domestic mine areas and to quantify the human risk of heavy metal (As, Cd, Cu, Pb, and Zn) contamination around two abandoned metal mines. To attain the goals, we established a relevant exposure scenario, including 7 exposure pathways and extracted a variety of exposure factors reflecting the characteristics of inhabitants around abandoned metal mine areas. Finally, carcinogenic and non-carcinogenic risks were compared between two areas, exposure pathways, heavy metal contaminants, and receptors. The total excess carcinogenic risks of two mine areas of concern were calculated to be larger than the acceptable carcinogenic risk ($1{\times}10^{-6}$), indicating those two areas are not safe for carcinogenic hazard. In addition, the hazard indices of two areas were computed to be higher than unit risk (1), suggesting that the areas of concern have non-carcinogenic risk. Ingestion of crop and intake of groundwater were evaluated to be main exposure pathways contributing to carcinogenic and non-carcinogenic risks within the areas. Also, the results show that carcinogenic and non-carcinogenic hazards were mostly attributed to As and As, Cd, and Pb, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.424-431
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• 1996

This study was carried out to provide information for establishing counter measures of soil pollution through analysis of Cd. Cu, Pb, and Zn in paddy soils and brown rice. Cadmium, Cu, Pb, and Zn contents in soils were analyzed and distribution maps for these heavy metals were prepared. Heavy metal contents in brown rice were also measured. Average contents of Cd, Cu, Pb, and Zn in surface paddy soils extracted with 0.1 N HCl were 7.4, 35.8, 98.9, and $118.8mg\;kg^{-1}$, respectively. These were 9 times (Cu) to 50 times (Cd) higher than the background level of heavy metals in unpolluted paddy soils in Korea. The contents of Pb and Zn were lower than those measured in 1980, whereas Cd content did not decrease. The levels of heavy metal contamination in paddy soils may not affect growth or yield of rice plant, however, Cd contents indicated a level of serious concern to humans. The average contents of Cd, Cu, Pb, and Zn in brown rice were 0.38, 2.38, 1.31 and $22.31mg\;kg^{-1}$, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.40-44
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• 2009

This study was carried for the understanding of infiltration and percolation characteristics of water in agricultural land filled with rock-dust (Technosols). The experiment was performed at two sites (A, B), and soil horizons of the sites were classified with 4 layers, respectively. The soil texture of all soil horizons was analyzed with silt loam (SiL) except for the soil texture, which was loamy sand (LS), at the lowest horizon of measurement site A. The bulk densities at each horizon of two soils were mostly over $1.49g{\cdot}cm^{-3}$, which is very higher than $1.25g{\cdot}cm^{-3}$ of typical medium-textured mineral soil, except for the surface of site A measured immediately after tillage. The concentrations of $P_2O_5$ at surface of two soils s were 1962 (A), 1613 (B) $mg{\cdot}kg^{-1}$, respectively. These concentrations are 3.2~6.5 times of $300{\sim}500mg{\cdot}kg^{-1}$, which is the optimum concentration for crop growth. Infiltration rates at surface of the soils were 3.54 (A), 2.85 (B) cm $hr^{-1}$, but percolation rates at soil horizons under the surface were below 0.3 (A), below 0.003 (B) cm $hr^{-1}$. These results would be because the surface soils were managed by tillage and crop planting etc., but soils under surface were formed with structural problems occurred at the formation time of agricultural land accumulated with rock-dust or a compaction by farm machines.

• Korean Journal of Agricultural Science
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• v.6 no.2
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• pp.125-133
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• 1979

The characteristics of landslides occurred in August 5, 1979 in pyeongchangkun were surveyed and indentified as follows. 1. Deep limestone regions. Distinct differences in soil texture between A1 and B horizon could be observed on soil profile, which is attributed to the clay illuviation. The clay illuvial horizon is supposed to be an important cause of large scale mudflows on middle slopes by the lubricant action of ground water flowing between top soil and subsoil. 2. Shallow limestone regions. Very shallow top soils (less than 50cm) laid on tilted bedrock stratification provide a proper condition of mass soil movement if the top soil is saturated and ground water flows between top soil and bedrock when concentrated heavy rainfalls shower. 3. Granite regions. Weathering granitic bedrock produces very coarse textured top soils which are very cohesionless and have many pores. Therefore, the soil has high infiltration ratio and is easy to be saturated by water and to be detached from the bedrock. The landslides abrase very severely both sides of gully with high potential energy when they flow down. The following methods for landslide prevention can be recommended. 1. The original parts of landslides on top of the gully must be treated by intensive planting of deep rooting species and check dams. 2. Clear-cutting and crop planting on steep slope (more than 25 degrees) should be controlled and prohibited. 3. Establishment of landslide prevention forest should be practised on proper site.