• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.4
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• pp.98-109
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• 2004

This study was conducted to develop revegetation methods for the restoration of the steep slopes by recycling of bark compost and mushroom media. In general, bark compost and mushroom media can be used as soil media for the restoration works, because they can increase infiltration of rainfall and give enough porous to breathe and elongate for the root growth as well as environmental value. This experiment was carried out to know the effect of soil media composed by different ratio of mushroom media for the restoration of steep rock-exposed slopes, and to certificate how soil media(PEC) will be effective to germinate and grow for native plants. The main results of the study are summarized as follows; 1. In percent coverage, the soil media PEC1 is more valuable than PEC2. The seed mixtures recommended by Government of Transportation and Construction can be used at PEC1 and PEC2, but it will be more useful if the total amount of seed are reduced and seed mixtures are altered in a direction of native plants. 2. The soil media is under 20 mm tested by Yamanaka Hardiness Tester which is available for the seed germination and growth. 3. The surface cracks are not occurred in PEC1 and PEC2, but more than 30 cracks per 1 square meter are occurred at soil media which is constructed by normal soil-seed-fertilizer hydro-seeding methods. 4. The soil moisture contents are over 20 percent level during 15 day. Such moisture content in soil media will be effective for the plant growth. By using Terra-Control, PEC can maintain enough soil moisture. 5. The eroded soils from $60^{\circ}$ slopes by artificial rainfall with the intensity of 20 mm/hr in one day after seeding are estimated under 1%. By the results of erosion test, it comes to the conclusion that soil media of PEC can be adapted at steep rock exposed slopes.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.61-70
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• 2018

This study was carried out to review and compare crop cultivations upon chemical properties of paddy soil and qualitative characteristics of rice in Sejong-city from a point of view of farming extension to rice farmers and to utilize the result of the study as a basic guideline for precise agricultural practice. The pH in soils of Sejong was about 6.1-6.6 and had no difference with an average pH of paddy soils in Chung-Nam with pH 6.1. However, the average of organic matter, calcium (Ca) and available silicate in Sejong was lower than the average of them in Chung-Nam. The yields of rice were higher in 2010 than in 2011 and 2012, and the protein contents of rice were the highest in 2011 while the lowest water contents of rice in 2011. The protein contents upon regions were the highest in 2011 with 6.1%, and the amylose contents were the highest in Yeondong-myun, Jeoneu-myun, and Yeonseo-myun in 2010 while Kumnam-myun and Jeondong-myun were the highest in 2012. With the increase of precipitation, the protein content level in rice was increased while the amylose content level tended to decrease. Correlations between the chemical properties of paddy soil and the quality of rice and between level of organic matter in soil and amylose contents were negative (r = -0.507), and the correlation between the moisture contents and amylose contents (r = 0.419) and between the water contents and whiteness (r = 0.485) were positive. Because the quantity and quality of rice yield is determined by the soil characteristics, the consultation to farmers for the proactive soil analysis and for the maintenance of stable level of pH, organic matter and available silicate based on historical results of analysis is highly recommended. Also, the analysis on the effect of the weather and the soil characteristics affecting the quality and quantity of rice would be another good way.

• Korean Journal of Environmental Agriculture
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• v.20 no.5
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• pp.317-324
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• 2001

Short-term effect of phosphogypsum on soil properties including acidification, salinity and metal availability were investigated under laboratory and field conditions. Phosphogypsum and mixtures of phosphogypsum and compost were added to soil and incubated in a laboratory condition with 15% moisture content. Phosphogypsum treatments were 2.5 and 5.0 g/kg soil and in the treatments of phosphogypsum and compost mixture 10 g of compost was added additionally. After the 30 days of incubation, an additional phosphogypsum and/or compost were added to the remaining soils at the same rates of the first treatments. pH, electrical conductivity, and available hazardous elements were measured periodically during the incubation. Field experiment was conducted in a plastic film house of mellon with four treatments of phosphogypsum and compost mixtures - 25+125, 50+125, 50+250 and 100+250 kg/165 $m^2$. pH, electrical conductivity, and hazardous elements in soil and total hazardous elements in leaf were measured. In the laboratory experiment, after 30 days of the first phosphogypsum application, soil pHs were lowered by 0.7-0.8 units. After the second treatment of phosphogypsum 0.2 units of additional acidification occurred. However, acidification was not observed in the soils treated with mixtures of phosphogypsum and compost. In the laboratory experiment, phosphogypsum treatments increased electrical conductivity very significantly. In field experiment, pH and electrical conductivity of soils treated with phosphogypsum were nearly the same as those of soil not treated with phosphogypsum. Since soil condition in the field study was an open system, the free acids and salts derived from phosphogypsum could be diffused down with water leaching through the soil profile and then any significant acidification or salt accumulation in the topsoil could not be observed. In both laboratory and field experiments, levels of available hazardous elements in soils treated with phosphogypsum were quite low and not different from the levels found in the control soil. Results obtained from this study suggest that application of phosphogypsum at appropriate rates on agricultural land appears of no concern in terms of acidity, salinity and hazardous element content of soil.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.279-291
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• 2015

This study analyzed the growth characteristics of multi-layer planted trees through their growth analysis and attempted to present a management strategy. The subject of research is the Citizen's Forest Area of Seoul Forest Park located in Seoul City. Field surveys were conducted three times over eight years from 2005 when the Seoul Forest Park was created through 2013. Labels were attached to all trees in the target area, and their species, height and DBH were investigated. To identify the growth differences by trees in each area, a detailed tree location map was drawn up for use in the analysis. To check soil health, soil organic matter, soil pH and soil microbial activities were analyzed. It turned out that the growth of the multi-layer planted trees in the target area of research was higher than that of the trees in existing urban parks, and that it was similar to that of trees in natural forests. Through a field survey in the area with a remarkably low growth, high-density planting problem, soil was found to have excess-moisture and there was the problem of Pueraria lobata covering. As a result of the analysis of the soil, it was found that its organic content in the soil was lower; soil pH was higher; and microbial activities in the soil were lower when compared to that of natural forests.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.788-791
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• 2001

An improved double-cylinder hammer-driven sampling device was designed to extract undisturbed soil cores. The improvements consist of 1) separation of hammer from the driving head, 2) a split inside cylinder, and 3) a plastic sample holder. Pushing the sampler deep into the soil before hammering would result in less compression of the sample. Core samples should be taken in soils of medium moisture content. The improved soil core sampler provides sufficiently accurate volumetric soil samples with original soil layers and soil cores of 40cm in length and 5cm in diameter.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.5
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• pp.373-383
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• 2020

The purpose of this study was to evaluate the corrosion damage of large diameter metallic pipes buried in reclaimed land due to the corrosion effect by soil, and to propose a method of installing metal pipes in the reclaimed land. The results are as follow. First, the soil of the reclaimed land was gray clay, the soil specific resistance indicating soil corrosiveness was at least 120 Ω-cm, the pH was weakly acidic(5.04 to 5.60), the redox potential was at least 62 mV, the moisture content was at most 48.8%, and chlorine ions and sulfate ions were up to 4,706.1 mg/kg and 420 mg/kg. Therefore, the overall soil corrosivity score was up to 19, and the external corrosion effect seems to be very large. Second, the condition of straight part of pipes was in good condition, but most of KP joints were affected by corrosion at a severe level. The reason for this seems to be that KP joints accelerated corrosion due to stress and crevice corrosion in addition to galvanic corrosion in the same environment. Third, as a result of evaluating correlations of each item that affects the corrosion on the external part, the lower the soil resistivity and redox potential, the greater the effect on the KP joints corrosion, and the moisture content, chloride ion, and sulfate ion, the higher the value, the greater the effect on the corrosion of KP joints. In addition, among soil corrosion items, the coefficient of determination of soil resistivity with corrosion of KP joints was the highest with 0.6439~0.7672. Fourth, when installing metal pipes or other accessories because the soil of the reclaimed land is highly corrosive, it is necessary to apply a corrosion preventive method to extend the life of pipes and prevent leakage accidents caused by corrosion damage to the joint.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.206-213
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• 2008

We observed the physical and chemical properties of a soil on pine mushroom picking areas where were located in the most upper and lower parts showing a comparative climatic characteristics in Korea. The slope gradients within the investigation areas which were divided into 100 quadrates of $1m^2$ ranged from $5.7{\sim}8.6{\beta}$ to $24{\sim}22.7{\beta}$ (left to right) and $4.5{\sim}6.8{\beta}$ to $13.5{\sim}17.8{\beta}$ (top to bottom) for Ponghwa and Gansung, respectively. The amount of clay and thickness of organic matter were significantly decreased with increasing slope gradient, resulting in decrease of the soil moisture content around a fairly ring-colony of Tricholoma matsutake which was observed under the relatively thicker organic matter layer beyond 3 cm depth. Soil pHswere weak acid and average EC was $0.44dS\;m^{-1}$ in both areas. The cations were in the order of Fe K > Na > Mg > Ca and Fe > K > Na > Ca > Mg for the upper(Gansung) and the lower (Ponghwa) part. And the amount of Fe was approximately $80dS\;m^{-1}$ or greater in the pine mushroom picking soil. From this, we could assume that the growth of the pine mushroom was closely related not only with iron but also soil moisture content.

• Korean Journal of Remote Sensing
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• v.29 no.1
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• pp.35-43
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• 2013

We analyzed the relationships between backscattering coefficients of wheat measured by COSMO-SkyMed SAR and biophysical measurements such as biomass, vegetation water content, and soil moisture over an entire wheat growth period. Backscattering coefficients increased until DOY 129 and then decreased along with fresh weight, dry weight, and vegetation water content. Correlation analysis between backscattering and wheat growth parameters revealed that backscatter correlated well with fresh weight (r=0.88), vegetation water content (r=0.87), and dry weight (r=0.80), while backscatter did not correlated with soil moisture (r=0.18). Prediction equations for estimation of wheat growth parameters from the backscattering coefficients were developed.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.315-320
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• 2015

Burcucumber (Sicyos angulatus) is an annual invasive plant species originated from North America. This species grows by twining around tree trunks, and blocks other plants from photosynthesis. Thus, it has caused the destruction of the ecosystem and biological diversity by threatening native plants. This study was performed to find out the effect of different soil water content (20%, 13%, 10%, 3%) and various shading degrees (0%, 60%, 80%) on the growth and photosynthesis-related activity of burcucumber. In the responses of burcucumber to soil water content, plant height (PH), leaf length (LL), leaf width (LW) and photosynthetic efficiency (PE) were lower at 20% water content than 10% reflecting that burcucumber plant grow well in the less dry soil and shows poor growth under wet soil condition. In shading experiment, PH, LL, LW and PE were lower at 80% than 60% shading and in general, the growth characteristics were lowered as the shading intensity increased. The improved growth of burcucumber under highly or moderately shaded condition implies that the plant can grow well without growth retardation and can be adapted to shading condition with other tall plant species including tree. Further study on the combination effects of above factors should be conducted in future for effective ecological control of burcucumber.

• Journal of the Korean Geotechnical Society
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• v.40 no.3
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• pp.93-100
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• 2024

Pore water freezes in low-temperature compaction, which leads to different compaction characteristics compared to room temperature conditions. In regions like Alberta, Canada, where organic soils are prevalent, compaction performance is influenced by the high water retention and compressibility of organic soils, as well as their sensitivity to freezing and thawing. Alberta's strict environmental regulations demand the reuse of excavated soil for backfill, and the long winter season creates challenging conditions for civil engineering projects. In this study, a laboratory compaction test was conducted to evaluate the low-temperature compaction characteristics of organic soils with varying organic content. The results indicate that the optimum moisture content increases as the organic content increases, and the maximum dry unit weight decreases by up to 21.9%. In addition, under temperature conditions below -4℃, no optimum moisture content was observed, and the dry unit weight decreased as the moisture content increased.