• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.62-71
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• 2008

Soil quality standards (SQS) are necessary to protect the human health and soil biota from the exposure to soil pollutants. The current SQS in Korea contain only sixteen substances, and it is scheduled to expand the number of substances. Chemical ranking and scoring (CRS) system is very effective to screen the priority chemicals for the future SQS in terms of their toxicity and exposure potential. In this study, several CRS systems were extensively compared to propose the assessment factors that required for the screening of soil pollutants The CRS systems considered in this study include the CHEMS-1 (Chemical Hazard Evaluation for Management Strategies), SCRAM (Scoring and Ranking Assessment Model), EURAM (European Union Risk Ranking Method), ARET (Accelerated Reduction/Elimination of Toxics), CRSKorea, and other systems. The additional assessment factors of CRS suitable for soil pollutants were suggested. We suggest soil adsorption factor as an appropriate factor of CRS system to consider chemical transport from soil to groundwater. Other factors such as soil emission rate and cases of accident of soil pollutants were included. These results were reflected to screen the priority chemicals in Korea, as a part of the project entitled ‘Setting the Priority of Soil Contaminants'.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.18-28
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• 2009

Many countries have recently established legal regulations and soil quality standards for soil protection, This study investigated the role of soil quality standards in soil protection policy and methods of selecting standard substances from various types of chemicals. In most countries, soil quality standards act as guidance for further detail surveyor risk assessment from comparing soil concentration with the soil quality standards. Soil quality standards of Switzerland, Demark and Japan were used as enforcement tools. Priority substances for the standards were first selected from frequently detected chemicals in contaminated sites. Those substances were extensively evaluated for toxic effects, exposure potential and availability in chemical analysis.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.233-238
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• 1994

The experiment on sprouting and emergence properties of Eleocharis kuroguwai was conducted at laboratory and greenhouse conditions in 1993. Most of tubers had the apical dominance of buds at sprouting and had the competitive relationship for mesocotyl elongation. When pyrazosulfuron was applied on soil surface, all of apical buds were killed, but the first and second lateral buds survived to 50% and 90%, respectively, and the third lateral buds were almost at presprouted state. The tubers at 10-15cm deep soil emerged 1 week late and 35% low in emergence rate compared with the tubers at 2-5cm deep. As the plants emerged from the deep soil, the mesocotyl and the roots were distributed at deep soil more or less. Among the tubers buried at 10cm and 15cm deep soil, 25% and 30% respectively were not emergerd due to the suspension of mesocotyl elongation. Although the roots and shoots were removed from the tubers at the stage of 20cm high, all of mother tubers emerged again even 2 weeks late.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.351-363
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• 2007

The scientific articles using radio labelled insecticides performed by Korean researchers were reviewed. The research works were divided into 4 categories such as soil, plant, animal and insect. All researches used $^{14}C$-labelled chemicals, and the $^{14}C$-carbofuran was widely used among them. Fate of insecticides, bound-residues and metabolic process were staple concerning area in soil study. And the uptake and translocation, metabolism and metabolites also a major interests in plant study. As well as the degradation, metabolic pathway and metabolites, and distribution of chemicals in animal tissue were another point of consideration in animal study. And finally, the penetration ratio into body and resistant mechanism were the major concerning views of study with insects.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.10a
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• pp.125-139
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• 2000

The differential enhanced degradation of cis- and trans-1,3-D was observed in the previous two studies performed by Ou et al. (1995) and especially Chung et al. (1999). This study was initiated to investigate the involvement of microorganisms in the differential enhanced degradation of the chemicals. As expected, microorganisms were responsible for the enhanced degradation of the chemicals. A mixed bacterial culture capable of degrading 1,3-D was isolated from an enhanced soil sample collected from a site treated with 1,3-D. Similar to the enhanced soil, the mixed culture degraded trans-1,3-D faster than cis-1,3-D. This mixed culture could not utilize cis- and trans-1,3-D as a sole source of carbon for growth. Rather, a variety of second substrates were evaluated to stimulate the differential enhanced degradation of the two isomers. As a result, the mixed culture degraded cis- and trans-1,3-D only in the presence of a suitable second substrate. Second substrates that had the capacity to stimulate the degradation included soil leachate, tryptone, tryptophan, and alanine. Other substrates tested, including soil extract, glucose, yeast extract, and indole (ailed to stimulate the degradation of the two isomers. Therefore, it appeared that the degradation of cis- and trans-1,3-D was a cometabolic process. The mixed culture was composed of four morphologically distinctive bacterial colonies.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.568-573
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• 2001

The effects of foliar spray and soil drench application of triazole chemicals (diniconazole, myclobutanil, difenoconazole, tebuconazole, bitertanol, hexaconazole) on growth and flowering control in zinnia were investigated. For foliar spray application of tebuconazole, diniconazole and bitertanol on 'Dream Land Rose', plant height was decreased but tebuconazole gave the best result for dwarfing. Diameter, fresh and dry weights of flower were markably decreased at high concentration of tebuconazole. However, days to flowering was not affected by chemicals tested. For 'Dream Land Scarlet', plant height was decreased with all chemical treatments. Tebuconazole severely decreased plant height, in particulas. Diniconazole hastened flowering. For soil drench of 'Dream Land Rose', plant height was decreased by diniconazole and mycrobutanil, but diniconazole was more effective for plant height decrease. Flowering was hastened by diniconazole in both 'Dream Land Rose' and 'Dream Land Scarlet'. Plant height of 'Dream Land Scarlet' was decreased by all chemicals tested. Flowering was not occurred at $300mg{\cdot}L^{-1}$ myclobutanil with severe suppression of stem growth.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.368-374
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• 2016

The perennial edible wild plants such as Aster glehnii, Solidago virgaurea subsp. gigantean, Allium ochotense, Athyrium acutipinnulum, Aruncus dioicus var. kamtschaticus and Codonopsis lanceolata have cultivated as the main income crops introduced into the fields about 30 years ago in Ulleung island. Soil samples were collected from 190 fields and assessed the effects of management practices on soil chemical properties at wild edible plant fields under no-till system. The strong acidic soils of pH 5.4 or less were detected in 45% of the soil samples. The level of soil organic matter was being held at mean $63{\pm}28g\;kg^{-1}$, 2.7 times higher than upland soils in Korea. Available phosphate and exchangeable potassium showed more than recommended levels of upland crops as $680{\pm}489mg\;kg^{-1}$ and $1.94{\pm}1.7cmol_c\;kg^{-1}$, respectively. The fields of Solidago and Aster showing strong soil acidity and high level of available phosphate and water soluble $NO_3{^-}$ were distinguished from other crops in analysis of variance and principal component analysis of soil chemicals. These results suggested that high frequency of acidic soil and high levels of available $P_2O_5$, exchangeable $K_2O$ and water soluble $NO_3{^-}$ were accompanied with the use of urea and NPK-fertilizer based on nitrogen in the field. However, further research is needed to understand the appropriate management of fertilization and the prevention of soil acidification for wild edible plants.

• Korean Journal of Environmental Agriculture
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• v.2 no.2
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• pp.59-64
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• 1983

A study was undertaken to investigate the persistence of 2,4-D and MCPP in two different Suweon soils under field conditions. MCPP was extracted from soil with aqueous calcium hydroxide solution and then derivatized to pentafluorobenzyl ester to enhance the electron capture sensitivity. Total recovery of MCPP from soil was 85.6% and the detection limit for 20g sample was 0.02 ppm. Ethyl ester of 2,4-D applied to soil was rapidly hydrolysed to 2,4-D with the half-life of less than 1 day. Half-life of total 2,4-D ethyl ester, including 2,4-D, incorporated into soils at a rate of 0.045 ㎏ a.i./10a was $4{\sim}7$ days and that of under laboratory conditions was $7{\sim}8$ days. Half-life of MCPP applied at a rate of 0.25㎏ a.i./10a under field conditions was $9{\sim}12$ days and that of under laboratory conditions was $12{\sim}23$ days.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.13.1-13.5
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• 2013

Objectives: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. Methods: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals - di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)-were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. Results: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were $1.0{\times}10^{-4}$, $1.2{\times}10^{-5}$, $9.5{\times}10^{-3}$, and $5.3{\times}10^{-3}mg/L$ for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were $5.2{\times}10^{-3}$, $6.0{\times}10^{-4}$, $5.0{\times}10^{-1}$, and $2.7{\times}10^{-1}mg/kg$ for DEHP, DINP, Cd, and Pb, respectively. Conclusions: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.21-24
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• 1986

This experiment was conducted to find out the feasibility of foliar application of mixed solution of urea and agricultural chemicals. One to two percent urea solution and chemicals were combined for joint application and the degradation of mixed solution was tested and its phytotoxicity was evaluated on rice plant. There were no changes of pH and components of mixed solution of urea and chemicals. However, it led to phytotoxicity in rice plant and more severe in higher urea content. The yields of rice were slightly lower in the mixed solution plot than in check one, however, no significant statistical difference was observed. Due to phytotoxicity, the foliar application of mixed solution is not agronomically sound.