• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.375-380
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• 2006

Endocrine disrupting chemicals (EDC) have been emphasized due to their threats in human health. Waste incinerator emission has been emphasized as a source of EDC including polychlorinateddibenzofurans(PCDD/F) and other carcinogenic polycyclic aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene (1-OHP) has been used as an exposure biomarker for the PAHs. On the other hand, etheno-DNA adducts, e.g. 1, $N^6-ethenodeoxyadenosine({\varepsilon}dA)$, has been developed as an useful effective or response biomarker for carcinogenesis. Thus, I investigated association between urinary 1-OHP and ${\varepsilon}dA$ levels due to distance from an incinerator which was built more 10 years ago in the middle of a farm in P city. I designated the EDC-high and low exposed group due to distance from the incinerator, i.e. within 2.5km and $5.0{\sim}7.5km$ from the incinerator, respectively. The study subjects were age and sex-matched males and females (mean age, $61.3{\pm}9.6$ yrs; total 40 persons, male, 10; female, 10 for the each group). Urinary 1-OHP and ${\varepsilon}dA$ were analyzed with HPLC-FD and IP-HPLC-FD, respectively. As results, the distance from the incinerator was not associated with urinary 1-OHP nor ${\varepsilon}dA$ levels (p=0.43 and 0.82, respectively). On the other hand, urinary ${\varepsilon}dA$ levels were significantly higher in the hyperlipidemia group (N=10) than normal group (N=30). In conclusion, urinary 1-OHP nor ${\varepsilon}dA$ levels can not be suggested as an incinerator-related exposure nor effective biomarker. However, not only distance from the incinerator bot also systemic approaches including wind and soil contamination are required to assume exposure levels of incinerator-related EDC.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.31-37
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• 1987

A study has been conducted to investigate the behavior of carbofuran in a miniature paddy agrosystem simulated for paddy field. Carbofuran applied onto the paddy water was rapidly absorbed and translocated into rice plants. Carbofuran concentration in rice plant reached its maximum level between 1 to 3 days after treatment and gradually decreased thereafter. Half life of carbofuran concentration in paddy water was 4 days in both application rates of 0.12 and 0.24Kg a.i./10a. Carbofuran residue in paddy soil was gradually dissipated with the half life of 8 and 12 days in 0.12 and 0.24㎏ a.i./l0a respectively. Range of carbofuran residue in brown rice and rice straw harvested from the paddy agrosystem was 0.01∼0.02 ppm and 0.37∼0.57 ppm irrespective of the two application rates respectively.

• Korean Journal of Weed Science
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• v.13 no.1
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• pp.1-6
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• 1993

The experiments were conducted in order to find out the response of algae as affected by fertilizer and salinity, and to determine the chemical control method of algae in 1991. The higher the nitrogen fertilizer level, the more the occurrence of a blue-green alga Oscillatoria concerning with soil flakes. An increase in phosphorus fertilizer level stimulated the growth of green alga Hydrodictyon, whereas an increase in nitrogen level caused its abrupt reduction due to the harmful effect at high concentration of nitrogen, The high level of nitrogen fertilizer also reduced the growth of Euglena, although the detrimental effect was less compared with that of Hydrodictyon. A blue-green alga Oscillatoria, a green alga Cladophora and a diatom Navicula were tolerant to salinity. Piperophos/dimethametryn was highly effective in controlling various algae such as a green alga Hydrodictyon, suspended unicellular green algae and Euglena species. A fungicide propineb and copper sulfate also effectively controlled Hydrodictyon.

• Korean Journal Plant Pathology
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• v.2 no.3
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• pp.165-173
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• 1986

Accumulation of Pseudomonas sp., P. fluorescens and Erwinia carotovora in 60 min treatment was greater in extracts from soil, exudate from ginseng root and solutions than distilled water. In bacterial movement toward rubber tube soil from chamber, accumulation of P. fluorescens in response to soil supplemented with soil extracts, exudate and solutions was generally greater in soil extracts compared to control and other solutions, but Pseudomonas sp. and E. carotovora were not much response to supplemented extracts, exudate and solutions. Accumulation of the bacteria in capillaries containing various exudates from fungal propagules with not attracted to the exudates. For an accumulation of bacteria in rubber tubes containing soil inoculated with fungal propagules, the Pseudomonas sp. was not attracted in soil inoculated by the organisms as attractant but P. fluorescens and E. carotovora to fungi were attracted to F. solani, F. oxysporum and mixed organism Alternaria panax did not affect on bacterial movement except E. carotovora. The organic matter conten in Kangwha and Kimpo soil were low in diseased and healthy soil. The K content was especially high in Kimpo healthy soil. Bacterial population in Goesan and Kangwha were more abundant than other soil. The number actinomycetes was populated abundant in healthy soil of Goesan and diseased soil of Poonggi.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.115-124
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• 2016

The objectives of this study were to evaluate the soil fertility about plastic film house, upland, and orchard in Gyeongbuk Province, Korea. The surface chemical properties of soil samples were investigated every 4 year from 2000 year at upland, 2001 year at orchard, and 2002 year at plastic film house. During 12 year's monitoring, mean soil pH was increased by 0.7 and 0.8 pH unit from pH 5.7 in upland and orchard, respectively, 0.5 pH unit from pH 6.5 in plastic film house. About 50% of all the field samples occupied within the recommended pH range (pH 6-7). Although soil organic matter (SOM) was gradually increased by about $10g\;kg^{-1}$ for 12 years, 40% of orchard, 49% of plastic film house, and 77% of upland soil samples were still below the 3% SOM. The mean concentration of available phosphate for 12 years in upland, orchard, and plastic film house were 530, 600, and $760mg\;kg^{-1}$, respectively. The relative frequencies exceeding the recommended available phosphate range ($300-550mg\;kg^{-1}$) were 43%, 53%, and 66% at upland, orchard, and plastic film house soils, respectively. $NH_4OAc$ exchangeable $K^+$ of upland, orchard, and plastic film house in the last soil test were 0.8, 0.9, and $1.6cmol_c\;kg^{-1}$, respectively. The relative frequencies above the recommended K level were 56% and 70% of orchard and plastic film house soil samples, respectively. The levels of crop nutrients except exchangeable Ca and Mg in upland soil were tended to increase gradually in the three fields. Exchangeable Mg, EC, available phosphate, organic matter and soil pH could be used as principle components to differentiate the chemical properties of three land fields. This analysis revealed that the soil fertility was affected by cropping method and field management, although additional research is needed to assess the importance of management on soil chemical properties and many fields indicate an opportunity for improvement in fertilizer management.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.607-612
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• 2013

Soil ecological risk assessment requires terrestrial toxicity data based on trophic levels including plants, earthworms, nematodes, and springtails. To expand the trophic levels, it is needed to consider primary producer algae, nearly distributed in terrestrial environment, as representative terrestrial test species. In this study, we collected research cases focused on soil-related test species and exposure media from SCI papers, and analyzed exposure media, test species, test chemicals, and other test methods, for reviewing research trends of soil-related algal toxicity. Up to now, in the soil-related algal toxicity, test species were 8 cases (Pseudokirchneriella subcapitata, Chlorella vulgaris, Scenedesmus bijugatus, Chlorococcum infusionum, Scenedesmus subspicatus, Nostoc linckia, Synechococcus elongatus, and Chlorococcum sp.) and endpoints were cell count or photosynthetic pigment content. Also, 5 of exposure media were liquid medium, soil extracts, porewater, agar medium, and soil. Most of papers used algae isolated from natural soils or soil extracts. There were only one case for assessing algal toxicity in soil medium. More researches regarding algal toxicity in soil environments need to be conducted consistently.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.3
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• pp.38-45
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• 1998

Soil and water contamination caused by the abundant use of agricultural chemicals including herbicides and fertilizers draws public concerns since these chemicals may pollute the agricultural lands as well as the food products grown on these lands. As a method to reduce the use of agricultural chemicals mulching with thin plastic film has been commonly practised for many years. Although use of the plastic film for mulching is very effective in preventing the growth of weed, it is almost impossible to remove all of the plastic film from the agricultural land and the remaining film eventually contaminates the soils. Therefore, it is very imperative to develop a mulching material that decomposes completely to prevent soil pollution problems and to enhance the competitive edge of domestic agriculture. Mulch papers are believed to have many positive characteristics in preventing problems caused by the plastic mulch film since it decomposes completely after use. However, the basis weight of mulch papers needs to be reduced to improve its handling properties and to reduce the raw material costs of pulps. In this paper the possibilities of using domestic old corrugated containers in producing mulch papers were examined. Also use of unbleached softwood kraft pulps and dry strength additives were exploited along with two-layered sheet forming technology in decreasing the basis weight of the mulch paper. Results showed that reduction of 20g/$m^2$ of basis weight of mulch paper was possible by the appropriate raw material selection and application of strength resin. To use the mulch papers in paddy fields, however, further research to improve its durability should be pursued.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.1
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• pp.1-7
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• 2003

In spite water direct seeding cultivation of rice has advantages in terms of laborsaving and cost-down, it demonstrates uneven seedling establishment and difficult weed management. To select an applicable mat for mulching system of water seeded rice, weed occurrence, growth and yield performances of rice, and soil temperature were evaluated in several kinds of biodegradable mulching material. Field studies were conducted at the experimental farm of National Crop Experiment Station in 1999 and 2000. Among the mats tested in 1999, Safer-mat had the greatest effect on inhibiting weed occurrence and Lawn-mat demonstrated the least efficacy of weed control (EWC) value. In Safer-mat treatment, Ludwigia prostrata was the dominant weed species but Echinochloa crus-galli was not observed. Different kinds of mulching material from the mats studied in 1999 were tested in 2000. Biodegradable polyester (PES) coated on the recycled paper for newspaper press (RP) treatments showed similar or higher EWC values than non-mulched broadcast seed rice with 2 times of herbicide application (BC-herbicide) and Safer-mat that was the most effective mat on preventing weed appearance in 1999. Immediately after mat mulching on the surface of paddy soil, five pregerminated rice seeds were manually sown in each 3cm-hole formerly punctured at 30${\times}$14 cm spacing in 2000. All the 3 kinds of mulching material tested in 2000 had better seedling stand than BC-herbicide treatment. Rice yield in PES coated with 10 thickness on RP (PES10 $\mu\textrm{m}$＋RP) was a little higher than in BC-herbicide treatment but the former produced less panicles in unit land area than the latter. PES10 $\mu\textrm{m}$＋RP demonstrated a great effect on raising soil surface temperature than non-mulching treatment throughout the period of seedling establishment.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.413-421
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• 2014

This study was conducted into the effects of cover crops among the hairy vetch, red clover, rye, and hairy vetch+rye on the soil chemical and physical properties, and fruit yield in mature 'Fuyu' persimmon (Diospyros${\times}$kaki Thunb.) trees. The shallow-rooted red clover had poor dry matter production, resulting in the lowest coverage (66%) on the orchard floor. In contrast, the highest dry matter production observed in rye and hairy vetch+rye. Estimated N, P and K production from the cover crops were the highest on the hairy vetch+rye plots, increasing soil chemicals at a depth of 0-30 cm soil. Rye or hairy vetch+rye treatments decreased the soil bulk density and solid phase. As the hairy vetch+rye treatment increased fruit yield and sugar contents, it could be proposed as an suitable cover crop for improving productivity of persimmon trees.

• Advances in nano research
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• v.15 no.4
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• pp.355-366
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• 2023

Biological corrosion, a crucial aspect of metal degradation, has received limited attention despite its significance. It involves the deterioration of metals due to corrosion processes influenced by living organisms, including bacteria. Soil represents a substantial threat to pipeline corrosion as it contains chemical and microbial factors that cause severe damage to water, oil, and gas transmission projects. To combat fouling and corrosion, corrosion inhibitors are commonly used; however, their production often involves expensive and hazardous chemicals. Consequently, researchers are exploring natural and eco-friendly alternatives, specifically nano-sized products, as potent corrosion inhibitors. This study aims to environmentally synthesize silver nanoparticles using an extract from Lagoecia cuminoides L and evaluate their effectiveness in preventing biological corrosion of buried pipes in soil. The optimal experimental conditions were determined as follows: a volume of 4 ml for the extract, a volume of 4 ml for silver nitrate (AgNO3), pH 9, a duration of 60 minutes, and a temperature of 60 degrees Celsius. Analysis using transmission electron microscopy confirmed the formation of nanoparticles with an average size of approximately 28 nm, while X-ray diffraction patterns exhibited suitable peak intensities. By employing the Scherer equation, the average particle size was estimated to be around 30 nm. Furthermore, antibacterial studies revealed the potent antibacterial activity of the synthesized silver nanoparticles against both aerobic and anaerobic bacteria. This property effectively mitigates the biological corrosion caused by bacteria in steel pipes buried in soil.