• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.43-49
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• 2015

The production of high quality seedlings is a very important phase in silvicultural systems for successful reforestation or restoration. The purpose of this study was to quantitatively measure both growth performances and nutrient responses of Fraxinus rhynchophylla, Pinus densiflora, and Pinus koraiensis seedlings, which are commercially planted in Korea, according to the different types of soil improvement treatments. We applied soil brought (hereafter 'brought'), subsoil inversion (hereafter 'subsoil'), and mixture of brought soil with soil on nursery bed (hereafter 'mixing') in a permanent national nursery. Silt and clay contents were the highest at the subsoil treatment and organic material, soil nitrogen and phosphorus concentrations were the lowest at the brought treatment. The growth of F. rhynchophylla was the lowest at the subsoil treatment, but there were no significant differences among treatments. There were significant differences in only root nutrient concentrations of F. rhynchophylla among treatments: nitrogen, phosphorus, and potassium concentrations were the lowest at the subsoil or brought treatment. Mixing treatment increased N contents with deduction of N concentrations ('dilution') because of more dry weight increase compared with the amount of N uptake. This study suggested mix of brought soil with soil on a nursery bed in a permanently used nursery can economically be an effective technique to improve soil quality.

• Journal of the Korean GEO-environmental Society
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• v.20 no.12
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• pp.33-39
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• 2019

The upsurge of population, internal migration, economic activities and developmental works has brought significant land use and land cover (LULC) change over the period of 1990 and 2010 in the Bagmati basin of Nepal. Along with alteration on various other ecosystem services like water yield, water quality, soil loss etc. carbon sequestration is also altered. This study thus primary deals with evaluation of LULC change and its impact on the soil carbon storage for the period 1990 to 2010. For the evaluation, InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) Carbon model is used. Residential and several other infrastructural development activities were prevalent on the study period and as a result in 2010 major soil carbon reserve like forest area is decreased by 7.17% of its original coverage in 1990. This decrement has brought about a subsequent decrement of 1.39 million tons of carbon in the basin. Conversion from barren land, water bodies and built up areas to higher carbon reserve like forest and agriculture land has slightly increased soil carbon storage but still, net reduction is higher. Thus, the spatial output of the model in the form of maps is expected to help in decision making for future land use planning and for restoration policies.

• KIEAE Journal
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• v.13 no.2
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• pp.33-38
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• 2013

Limited resources for construction material in the Mae-Hae region, a remote Northern Thailand, acted as an impetus to introduce a new way for constructing their dwellings. The new construction material brought new construction methodology, namely, using earth and bamboo which are indigenous materials, readily available for them to use. Using indigenous material at Mae-Hae region was most ecological and logical method for establishing sustainable dwellings both in terms of monetary and ecological reasons. Prior to the construction at Mae-Hae, Thailand, series of experimental tests on the strength of rammed earth were performed off site at our university and also brought soil samples from the actual job site at Mae-Hae for detailed soil analysis. Through the tests, integrity of the earth and characteristics of the soil were established to build a small senior citizen center as an example. This appropriate technology is expected to contribute to the sustainable construction at Mae-Hae.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.57-63
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• 1976

The lecturer pointed the agriculture in change brought about population bomb and economic development, and he appealed the scientists of soil and fertilizer to make proposals for establishing their constructive attitudes toward the situations of agriculture. The points emphasised by the lecturer for the improvement of future food situation were: fox example the elucidation of the ancient agricultural technology of Korea which is a important attempt for development of agricultural technology of Korea and Japan, and soil improvement with special attention to the efficiencies of phosphate, silicate, cations and trace elements. He showed some Japanese examples of natural pollution as both of a sufferer and an assailant of agriculture which are resulted from the high economic development, and some methods of solution, for example active application of legumes capable for fixing atmospheric nitrogen to wasted soils. He also pointed the need of lower consumption of energy and resources, and new understanding of wild plant species for the future agriculture. Some methods of other fields of sciences were emphasised for developing the soil and fertilizer researches.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.2
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• pp.149-154
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• 1971

To elucidate the effects of calcium carbonate applied under upland and flooded conditions on the changes of soil pH, an incubation study of a soil was carried out. The experiment was conducted under the conditions with and without ground rice straw application. The results of the experiment are summarized as follows: 1. The incubation under the upland moisture condition after the application of calcium carbonate raised soil pH as high as calcium hydroxide did, whereas incubation with calos treatment under the flooded condition showed a low pH. 2. Reduction of a soil brought about by the application of ground rice straw has a significant effect on the rise of soil pH. The high pH of a soil thus brought about or raised by the use of lime is gradually reduced as the accumulation of bicarbonate ions and carbon dioxide increases in the soil solution. It may, however, be possible to keep the high pH of a flooded soil by practicing intermittent drainage or cultivation which reduces the content of bicarbonate and $CO_2$ pressure in soil solution. 3. Carbonate and bicarbonate salts which may be produced in flooded and reduced soil increases the buffering capacity of the soil.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.88-96
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• 2007

Organic farming systems based on ecological concepts have the potential to produce sustainable crop yields with no decline in soil and environmental qualities. Recent expansion of sustainable agricultural systems, including organic farming, has brought about need for development of sustainable farming systems based on value judgments for key properties of importance for farming. Chemical and microbiological properties were chosen as indicators of soil quality and measured at soil depth intervals of 5-20 and 20-35 cm in conventional and organic-based apple orchards located in Yeongchun, Gyeongbuk. The orchards were two adjacent fields to ensure the same pedological conditions except management system. Soil pH in organic farming was around 7.5, whereas below 6.0 in conventional farming. Organic farming resulted in significant increases in organic matter and Kjeldahl-N contents compared to those found with conventional management. Microbial populations, biomass C, and enzyme activities (except acid phosphatase) in apple orchard soil of organic farming were higher than those found in conventional farming. Higher microbial quotient ($C_{mic}/C_{org}$ ratio) and lower microbial metabolic quotient for $CO_2(qCO_2)$ in organic farming confirmed that organic farming better conserves soil organic carbon. Biological soil quality indicators showed significant positive correlations with soil organic matter content. These results indicate organic-based farming positively affected soil organic matter content, thus improving soil chemical and biological qualities.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.3
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• pp.286-293
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• 1983

The glucose application remarkably increased the heterotrophic acetylene reducing activities during one month incubation. The amount of the increases varied between the soils. Application of rice straw brought about the significant increases during incubation time. Compost contained the largest amount of available-N among the C-sources, and thereby brought the smallest increase in all soils. The cumulative fixed nitrogen with application of rice straw at 30 days incubation in the three experimented soils were highest in Hwadong clay soil, i.e, $2.2mg^N/100g$, intermediate in Ratchaburi soil $0.85mg^N$, and least in Konosu soil $0.80mg^N/100g$. On the other hand, nitrogen fixing heterotrophic, bacteria, such as Clostridia, aerobes and anaerobes, were remarkably increased by application of rice straw while Azotobacter and Beijerinkia were not. The cumulative fixed nitrogen was more pronounced in the clay soil than in the coarse loamy soil. More pronounced nitrogen fixing activities in light condition(heterotrophic + photosynthetic) than that in dark(heterotrophic) condition have been observed both in the coarse loamy and clay soils. The nitrogen fixing ability of photosynthetic microbes in paddy soil is probably higher in coarse loamy soil than in clay soil.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.1
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• pp.3-10
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• 1988

A laboratory study was carried out to investigate the effects of application level of soil amendments, mixing method of soil amendments, and compost treatment on desalinization by examining the changes in hydraulic conductivity and chemical properties of effluent of the soil during desalinization. 1. The treatment of soil amendments brought about the increase in hydraulic conductivity. 2. The higher the application level of a soil amendment, the higher the hydraulic conductivity and the shorter the time elapsed to complete the desalinization. 3. Complete mixing of calcium compounds was more effective for desalinization than surface mixing. 4. The compost treatment induced the rise in pH and therefore brought about the remarkable drop in hydraulic conductivity. 5. During the desalinization, the changes in physical and chemical properties of the soil were influenced by the kind and application level of soil amendments, mixing method of soil amendment, and compost treatment.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.40-48
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• 2010

Saemangeum reclaimed area is needed to construct much green zone to make high-quality multi-functional land such as tide embankment, lake dike, industrial complex, environmental spaces, etc. However, growth of plants is somewhat difficult because a salinity of Saemangeum soil is very high and a soil fertility, water content of soil are low. Therefore, it is essential to initial desalination of soil and continuous management for planting base. It is recommended that a group of grassland to raise the efficiency of covering should be made in the first stage and a forest by improvement of vegetation should be made in the mid and long term stage. It is recommended that the construction of vegetation base should be made with a regular thickness of soil of good quality in multi-functional area such as a shrub and wood. In case of construction of a windbreak forest, it is necessary to make a wood base of suitable depth using soil brought from another place or filling of soil. Also, it is necessary to keep a maintenance of woods in early stage. Saemangeum reclaimed land will be brand-named worldwide tourist attractions due to construction of much green zone having high quality multi-functional facilities.

• Journal of Plant Biology
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• v.17 no.1
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• pp.15-21
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• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.