• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.270-274
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• 1992

This study was observed to find out the relationship of soil microorgaism physico-chemical properties and yields on the continuous cultivation of peanuts soil in the difference 20 farmes field located in Gochang, Chonbuk area. The results obtained was summarized as follows : 1. Soil hardness and volume of soild and liquid of peanut continuous cultivation soil were higher than those of one year cultuvation. 2. The exceeding optimum level of phosphorus and potassium appeared factors affecting and reduction of peanut continuous cultivation soil. 3. Number of microorgaisms in continuous cultivation soil was high but the ratio of bacteria/fungi (B/F) and actinomycetes/fungi (A/F) ratio were low. 4. The number of soil nematodes in continuous cultivation soil were higher than that of alternative cultivation soil.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.813-827
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• 2015

This study was conducted to evaluate the effect of organic inputs on soil properties in a newly reclaimed organic soils. The soil of the experiment site was very low in soil fertility and the physico-chemical properties were poor. Several organic input treatments with different source of nutrient were placed, including compost in combination with green manures for organic agricultural practices, chemical fertilizers for conventional agricultural practices, and control without fertilizer. The experiment was conducted with continuous cropping system during 3 years. The chemical properties concentration in compost+green manure treatment was increased continually compare to control and chemical fertilizer treatment, and closed to the recommended rate of fertilizer. The organic matter value for compost+green manure treatment was increased from 0.86~0.96% to 2.00~2.29% by continuous nutrient supply of compost and green manure. However, further investigation on increasing of organic matter value for 3 years is necessary to monitor carefully during the long-term because it will help to clarify the all mechanisms of organic matter on organic input application way. The available phosphate value for compost+green manure treatment was generally increased from 21.9~27.1 mg/kg to 182.0~394.1 mg/kg. In case of exchange cation, the concentration for compost+green manure treatment was increased during 2 years within the range to the recommended rate of fertilizer, however, it is expected to cause a rather over supply for 3 years.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.26-33
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• 1990

The pot experiment was conducted to compare the effects of BIO-COM (Organic fertilizer made from industrial by-product) with the compost and humic acid on the physico-chemical properties of soils and the yield of paddy rice (CV. Chucheong-byeo). The results obtained were as follows: 1. All the fertilizer treatments, except humic acid, increased rice yield compare to no fertilizer treatment, and Bio-Com was the highest among the fertilizer treatments. 2. Rice yields were increased with increasing BIO-COM only up to 4% but 2% with N.P.K. fertilizers. 3. Rice yield showed highly positive correlation with number of panicle per hill but negative correlation with 1000 grain weight. 4. BIO-COM application induced the noticeable increase of pH, EC, OM, T-N, Av-P, Ex-Ca, Ex-Mg, Ex-Na, and $Av-SiO_2$, contents in the soils after experiments, and there were highly significant positive correlation among them. 5. BIO-COM application was positively affected on plant height, number of tiller, and fresh weight and dry weight of rice plant throughout entire growing stages and these are positively correlated with rice yield. 6. BIO-COM application also induced the increase of chlorophyll, N, P, Ca, and Mg contents in rice plant 7. It is revealed that there were highly positive correlations between rice yields and pH, EC, OM, T-N, Ex-Ca, and Ex-Mg in the soils. 8. It was also shown the highly significant positive correlations between rice yields, and N and P contents in the rice plant at heading stages, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.123-131
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• 1999

To get the basic information for the improvement of the optimum levels of upland soil fertility and fertilizer application, the soil samples in two hundred fifteen site were collected from the major condiment vegetable cultivation areas such as red pepper, garlic and onion fields. Physico-chemical properties of the soil samples were investigated. Soil texture distribution of soil samples in red pepper, garlic and onion cultivation areas was in order of loam (L), sandy loam (SL), silt loam (SiL) and clay loam (CL) (35.4, 31.6, 14.9 and 7.0%, respectively). The average pH of soil in garlic and onion cultivation areas were over pH 6.0, whereas in red pepper was under pH 5.5. The frequency distribution of soil pH in total sampling sites were 58.7% in under pH 6.0 and 21.4% in below pH 5.0, in contrast to 10.3% in over pH 7.0. The organic matter contents were in the range of $20{\sim}30g\;kg^{-1}$, and the onion field soils was a little higher than those in red pepper or garlic. The available phosphate contents were in the range of $719{\sim}746mg\;kg^{-1}$ and were not different among in red pepper, garlic and onion. The frequency distribution of available phosphate in total sampling sites were found 62.8% of above $600mg\;kg^{-1}$, which was over the standard level for upland soil improvement, and then 22.3% was exceeded $1,000mg\;kg^{-1}$, especially. In the exchangeable cations, the K and Ca contents in garlic (1.27 and $9.11cmol\;kg^{-1}$) and onion (1.20 and $8.39cmol\;kg^{-1}$) were higher than in red pepper (0.96 and $5.87cmol\;kg^{-1}$), respectively. The Mg contents in garlic field soils ($2.17cmol\;kg^{-1}$) were higher than those in red pepper and onion (1.51 and $1.80cmol\;kg^{-1}$). This exchangeable K, Ca and Mg contents were higher than the standard level for upland soil improvement. The contents of microelement were ranged in $54.3{\sim}60.1mg\;kg^{-1}$ for Fe, $31.3{\sim}42.3mg\;kg^{-1}$ for Mn, $1.7{\sim}2.3mg\;kg^{-1}$ for Cu and $4.8{\sim}5.5mg\;kg^{-1}$ for Zn, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.296-300
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• 1989

This study was carried out to evaluate the effects of clay loam soil, zeolite, and high molecular organic compounds on the improvement of soil physico-chemical properties and soybean yield in a sandy loam soil. Soybean was cultivated from 1987 to 1988. CEC, moisture retention of soil were increased, but soil bulk density and hardness were decreased by soil conditioners. Clay loam soil addition enhanced the soybean yield by 5% at 10ton 10a plot, 7% at 20ton/10a plot. Also zeolite application increased the soybean yield by 6~10%. Effects of soil conditioner application of the 1rst year were greater than that of 2nd year. Some experiments were conducted in laboratory for the effect of soil conditioners on soil physical properties. The nutrient and water holding capacity were highest by K-SAM treatment, but the soil aggregates was most stable by AN-905SH and Primal treatments.

• 한국약용작물학회:학술대회논문집
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• 2011.04a
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• pp.434-435
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• 2011

• Microbiology and Biotechnology Letters
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• v.22 no.4
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• pp.382-388
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• 1994

In the course of screening for insecticidal metabolites from soil microorganisms, Actinomycetes isolate no.1166 was found to produce active metabolites against Musca domestca and Bombyx mori. Three active components from the metabolites were isolated by solvent extraction and chro- matographic techniques and examined their insecticidal activities on Bombyx mori (3rd larvae) by diet feeding bioassay methods. By UV and NMR data analyses, compound I and III were identified as bafilomycin A$_{2}$ and B$_{1}$, respectively and compound II was also estimated to belong to the bafilomycin family from its physico-chemical data and biological properties.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.306-313
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• 1995

The aim of the present study was to produce low molecular weight cathepsin B inhibitor. A strain of Streptomyces aburabiensis isolated from soil in Korea was selected and the optimum condition for the production of the inhibitor was evaluated. Glucose and soytone were selected as best carbon and nitrogen sources, respectively. From the kinetic analysis in batch fermentation, it was found that the specific cathepsin B inhibitor production rate (q$_{p}$) was linearly related to specific growh rate ($\mu$). The inhibitor in culture filtrate was purified by adsorption on activated charcoal, butanot extraction, silica gel chromatography, ion exchange chromatography using Dowex-1 (Cl form) and Amberlite IRC-50 (H$^{+}$ form), and preparative TLC. From the UV, IR, Mass spectroscopy and $^{1}$H-NMR, the inhibitor was thought to be a new inhibitor of which molecular weight was 199.

• Geomechanics and Engineering
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• v.1 no.4
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• pp.275-289
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• 2009

Electroosmosis (EO) is the movement of water in a porous medium under the influence of a direct current (dc). In past decades, electro-osmosis has been successfully employed in many soil improvement and other geotechnical engineering projects. Metal electrodes, such as steel, copper and aluminum have been used traditionally to conduct current. The shortcoming of these electrodes is that they corrode easily during an EO treatment, which results in reduced effectiveness and environmental concerns. More recently, conductive polymers are developed to replace metal electrodes in EO treatment. Electrical vertical drainages (EVDs) are one of these products under trial. The goal of this study is to assess the performance of EVDs for soil improvement and to further understand the scientific principle of the EO process, including the voltage drop at the soil-EVD interface, electrical current density, polarity reversal, and changes in soil physico-chemical properties generated by electroosmosis. It is found from the study that after 19 days of EO treatment with a constant applied dc electric field intensity of 133 V/m, the soil's moisture content decreased by 28%, the shear strength and pre-consolidation pressure increased more than 400%. It is also found that the current density required triggering the water flow in the soil tested, the Korean Yulchon marine clay, is 0.7 $A/m^2$. The project demonstrates that EVDs can serve as both electrodes and drains for soil improvement in short term. However, the EVDs, as tested, are not suitable for polarity reversal in EO treatment and their service life is limited to only 15 days.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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• pp.27-45
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• 2017

At the upper part of terrace deposits at Jeongdongjin area, there is a structure in which reddish brown and grayish white layers laying horizontally. Previous studies have reported the existence of these structures within the deposits and suggested the theoretical background related to the formation process. However, the analysis of physical properties and chemical composition such as particle size, classification, etc. of the materials constituting the reddish brown and grayish white layers is scarcely done. In this study, the physico - chemical properties of gray - white and reddish brown beds are investigated. The mean grain size of the particles was less than $4{\varphi}$ in both layers and the reddish brown layer was more coarse. The results shows that the sorting of the grayish white layer is better. The chemical composition of both layers shows that the average concentration of $SiO_2$, $Al_2O_3$ and $K_2O$ of the grayish white layer was higher than those of the reddish brown layer. The concentration of $Fe_2O_3$ of reddish brown lyaer was 3 times higher than those of the grayish white layer. The degree of chemical weathering (CIA) is 90 or so in both the reddish brown and grayish white layers, indicating a significant level of chemical weathering. In conclusion, reddish brown layers had been formed by the processes related to the migration of iron and the migration of water that induced aggregation after the formation of sediments (psudo-gleization). In this study area, a vertical layer of grayish white which cuts off horizontal reddish brown and grayish white color was found. The vertical layer or wedge similar to a ice-wedge or columnar structure that in a cold environment, and there is a difference in shape and size. The vertical layer appears to have occurred three or more cycles. The vertical layers begin to form at a certain height within the outcrop and descend downwards, which of course is difficult to see as directing certain times.