• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.256-260
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• 1995

This study was carried out to select economic-crops according to the improvement methods of newly-reclaimed soils. Silage corn, soybean, Job's tears and sweet potato were cultivated under 6 treatments including integrated improvement plot, control plot, compost plot, subsoiling plot, phosphate plot and lime plot on the Songjeong loam from 1985 to 1988. Crop yields and soil physical properties were investigated throughout the experiment. Soil porosity in the sweet potato plots were highest. In case of cultivated years, those of 4th year were lowest. Averaged yield increasing ratios of silage corn, soybean, job`s tears and sweet potato in the integrated improvement plots were 132%, 29%, 49% and 59%, respectively. And that of 5 soil improved treatments for 4 crops were 53%, 15%, 25% and 38%, respectively. After subtraction of the total expenses of soil conditioners, the economical efficiency of soil improvements were clear in the 4 crops except the compost plot of silage corn. That of sweet potato plot was the highest.

• Journal of Korea Foresty Energy
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• v.20 no.1
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• pp.1-5
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• 2001

In this study, it was examined the effect of carbonized wastewoods on soil improvement and effect of charcoal size on tree seedling growth Thuja accidentalis seedlings grow better in the charcoal-treated soil than in the non-treated soil. Especially Pinus koraiensis charcoal with good adsorption. brought the best growth result. The charcoal treatment also improved the height growth of transplanted Aesuculus turbinate seedling However charcoal sizes(i.e. powder and particle) did not affect the growth of the seedling. Also apple trees which had been suffering from rotten roots caused by root rot was recovered by application particle-sized charcoal.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.685-691
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• 1996

This experiment was conducted to investigate the effect of some soil conditioners, such as polyvinylalcohol(PVA), zeolite and perlite, on the changes of soil physical properties and on tobacco growth in paddy-upland rotated field. Soil conditioners were treated at the rates of 120kg in PVA, 500kg in zeolite and perlite per l0a, respectively. Ratio of soil aggregates formed from the treated plots tended to. be higher than those from the control in the order of PVA > perlite > zeolite. The wet aggregate stability, mean weight diameter, moisture retention and air permeability from the treated plots tended to be higher than those from the control. Amounts of water-stable aggregates of PV A-treated soil increased with higher soil moisture showing a peak at 50% of moisture content. But with respect to particle of size aggregate formed for crop growth and workability in field, it was presumed that 40% of soil moisture content would be most desirable. Visual characters of soil surface throughout the experiment clearly showed that treated soils were maintaining better surface roughness and porosity than control, but difference in water stable aggregates among treated plots tended to be narrowed. The growths of tobacco, espacially its root zone were better in conditioner treated plots than in non-treated plot showing best in PVA-treated soil.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.357-365
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• 2018

This study was carried out to evaluate the weight loss rates, carbon and nitrogen dynamics of wood stakes following soil amendment treatments (CLB: compound fertilizer + lime + biochar; LB: lime + biochar) in a post-fire restoration area, Ulsan Metropolitan city, southern Korea. Soil amendments in the fire-disturbed area were applied to two-times (Mar. and Jun. 2015, 2016) during the study period. Wood stakes on Mar. 2015 were buried at a top 15cm of mineral soil in two soil amendment and control treatments of Liriodendron tulipifera, Prunus yedoensis, Quercus acutissima, Pinus thunbergii plantations and an unplanted area in the post-fire restoration area. Wood stakes were collected at Oct. 2015, Mar. 2016 and Oct. 2016 to measure weight loss rates, organic carbon and nitrogen concentrations. Weight loss rates of wood stakes were not significantly affected by soil amendment treatments. However, remaining carbon of wood stakes were lowest in the control treatment (43.7%), followed by the CLB (71.3%) and the LB (71.6%) treatments. Remaining nitrogen of wood stakes was less in the control treatment (29.7%) compared with the LB treatment (52.6%). The results indicate that carbon and nitrogen mineralization of wood stakes in post-fire restoration area were delayed by soil amendment treatments.

• Korean Journal of Environment and Ecology
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• v.15 no.1
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• pp.69-78
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• 2001

본 연구는 지리산국립공원 아고산대 훼손지에서 식생복원 효과를 구명하기 위하여 야생풀포기심기, 개량토포설, 환경피해도 요인을 고려하여 입지환경이 다른 2개 대상지에 실험구를 설치한 후 4년(1997년~2000년) 동안 식생피복도와 종다양성을 조사. 분석하였다. 신림지대와 초원지대에서의 복원실험은 야생풀포기이식, 개량토포설, 환경피해도 요인간 상호작용효과는 없었으나, 야생풀포기이식 처리수준간에는 고도의 유의한 차이가 인정되었다. 국립공원 능선부 훼손지의 식생복원 실험 결과 토양이 습한 산림지대에서는 야생풀포기이식 15%피복 처리수준에서 2년안에 식생피복이 이루어졌고, 종다양성은 3년만에 복원되었다. 또한 무처리구에서 3년안에 식생피복이 이루어졌으나, 종다양성은 복원되지 않았다. 바람이 많고, 토양침식이 심한 능선부 초원지대에서는 3년후에 야행풀포기이식과 30% 피복 처리수준에서 식생피복이 양호하게 이루어졌으며, 종다양성은 복원되지 않았다.

• Journal of the Korean GEO-environmental Society
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• v.2 no.2
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• pp.59-64
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• 2001

Recently, the application of shallow mixing method using hardening agent has increased because of the advantage of securing trafficability, reducing the working period, solving environmental problems caused by dumped and replaced soil, etc. In this paper, three types of representative hardening agents in Korea are used to achieve the optimum of ground improvement. 1he unconfined compression tests are carried out with specimens under various mixing ratios and curing periods of hardening agent to assess the stabilizing ability. The unconfined strengths on site were estimated with various mixing ratios based on the results of the laboratory tests. It was estimated that the improved strength on site was higher than that of the required strength $5.0kgf/cm^2$.

• Asian Journal of Turfgrass Science
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• v.26 no.2
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• pp.110-115
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• 2012

Soil amendments have been used to improve the physical and chemical condition of turf soil, which might optimize turfgrass growth in golf courses. This study was to investigate the effect of inorganic soil amendment (ZC) established in USGA root zone system on growth of creeping bentgrass, cv. 'Penncross' carried out from May to Dec. in 2005 at the nursery on Sinwon Golf Course. To analyze the effects of inorganic soil amendment on pH, specific gravity, infiltration rate, water content, soil hardness, root length, tiller density and dry weight were measured. pH was 6.7-6.8, specific gravity of sand (S) 100% was 1.48 heavier than the other treatments (1.28-1.38). Infiltration rate with ZC 15% + peat moss (P) 5% + S 80% and ZC 10% + S 90% was faster than S 100%. Soil hardness of S 100% was the highest. Root length of creeping bentgrass of P 10% + S 90% (8.6-12.0 cm) was the longest. Tiller density with P 5% + S 95% was more 4-7 ea than other treatments in summer season. In growing season, however, ZC 10% + P 5% + S 85% was more 2-3 ea than others. Dry weight of creeping bentgrass treated by ZC 10% + P 5% + S 85% in summer season and P 5% + S 95% in growing season were heavier than other treatments. It is recommended to combine 5-15% inorganic soil amendment and peat moss 5% with sand in order to sustain soil balance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.500-506
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• 2011

The deep mixing method, which is generally considered as a method for improving soft ground, is assessed in terms of its applicability for urban construction. Using small equipment tailored to perform deep mixing in congested urban areas, deep mixing was performed to reinforce the foundation ground of a retaining wall in a redevelopment site in Seoul. Strengths characteristics, construction vibrations and displacements induced to an adjacent old masonry wall were evaluated by laboratory tests and field monitoring. The results indicate that the strength of ground was improved appropriately whilst the vibrations and displacements induced by deep mixing were slight enough to satisfy the general requirements for construction works in urban environments. Therefore, it is concluded that deep mixing method can be a practical option for foundation methods in urban construction works where minimizing noise and vibrations is an important concern.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.29-34
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• 1987

This experiment was designed to find out the effects of soil conditioner, Polyacrylamide (PAM) and Bitumen, on the changes of soil aggregate properties and crop yields. The soil conditioners were treated at the rates of 0.5% and 1% to sandy loam and silty clay loam soils. The aggregate stability, wetting angle, mean weight diameter and air permeability were analyzed. Pot experiments were carried out to investigate the soybean growths and soil property changes after the soil conditioners were sprayed to surface soils. Soil aggregate stability was increased remarkably by the soil conditioner, PAM and Bitumen, treatments. PAM was more effective in sandy loam than silty clay loam, but Bitumen was better in silty clay loam. Wetting angle of the soil was changed slightly by PAM treatment, but it was greatly changed to hydrophobic by Bitumen treatment. Air permeability, water infiltration rate and moisture retention of the soils were increased by surface application of soil conditioners, PAM and Bitumen. The growths of soybean in conditioner applicated pots were better than those of untreated pots from early stage, and the yields were increased 6-13%.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.7-14
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• 2008

The main objective of sewer rehabilitation is to improve its function while eliminating inflow/infiltration (I/I). If we can identify the amount of I/I for an individual pipe, it is possible to estimate the I/Is of sub-areas clearly. However, in real, the amount of I/I for an individual pipe is almost impossible to be obtained due to the limitation of cost and time. In this study, I/I occurrence of each sewer pipe is estimated using AHP (Analytic Hierarch Process) and RPDM (Rehabilitation Priority Decision Model for sewer system) was developed using the estimated I/I of each pipe to perform the efficient sewer rehabilitation. Based on the determined amount of I/I for an individual pipe, the RPDM determines the optimal rehabilitation priority (ORP) using a genetic algorithm for sub-areas in term of minimizing the amount of I/I occurring while the rehabilitation process is performed. The benefit obtained by implementing the ORP for rehabilitation of sub-areas is estimated by the only waste water treatment cost (WWTC) of I/I which occurs during the sewer rehabilitation period. The results of the ORP were compared with those of a numerical weighting method (NWM) which is the decision method for the rehabilitation priority in the general sewer rehabilitation practices and the worst order which are other methods to determine the rehabilitation order of sub-areas in field. The ORP reduced the WWTC by 22% compared to the NWM and by 40% compared to the worst order.