• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.19-26
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• 1997

To find out the residual effect of phosphate fertilization on botanical composition, mineral contents and mineral nutrient deprivation of pasture plants, this experiment was arranged as a randomized complete block design with six treatments(0-0, 50-50, 100-65, 150-65, 200-65 and 250-65kg $P_2O_5$/ha), those were composed of three P,O, fertilization level(0, 50 and 65kg P,OJha) after phosphate fertilization trial with six treatments(0, 50, 100, 150, 200 and 250kg $P_2O_5$/ha) from 1989 to 1992, and conducted at hilly land in Kwangju, Kyonggi Province 60m 1993 to 1994. The results obtained are summarized as follows: The botanical composition of pasture plants without phosphate fertilization was very poor. With increasing available phosphate of soil, the percentage of grasses and legumes were remarkably increased and weeds was decreased. With 150-65kg $P_2O_5$/ha application for two years, the average DM yield was composed of 80.6% grasses, 15.4% legume and 4.0% weeds, the percentage was similar to that of 200-65kg $P_2O_5$/ha. As available phosphate of soil increase, P, K and Mg content of pasture plants were increased, but Ca/P ratio was lowed and the other mineral contents tended not to be regular. The mineral nutrient contents deprived by DM yield was increased as available phosphate of soil was increased, but those were not different between 150-65 and 250-65kg $P_2O_5$/ha. However, mineral nutrient of $P_2O_5$,$K_2O$ and MgO were higher in 200-65 and 250-65kg $P_2O_5$/ha. Most of applied mineral elements were accumulated at a subsurface(0-2.5cm) of grasslands, and mineral tended to be decrease than that of soil chemical analysis before the experiment of residual effect of phosphate fertilization.

• Resources Recycling
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• v.28 no.4
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• pp.15-22
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• 2019

Coal combustion products are generated during coal combustion and can be grouped into fly ash and bottom ash depending on collection methods. Fly ash and bottom ash can be recycled for various purposes based on their characteristics. Australia is the fourth largest coal production country in the world and reuses coal ash as cement, concrete, mine filler, and agricultural soil amendment. When fly ash is used as a supplement for cement and concrete, strength of the cement and the durability of the concrete can be improved. Use of coal combustion product for mine backfill stabilizes underground mine voids and stores a large amount of coal ash in the voids. Because of alkalinity of coal combustion products, it can neutralize acid mine drainage when used for mine backfill. In addition, it can be used as an agricultural soil amendment to improve acidity and physical properties of the soil and to supply plant nutrients. Recycling of fly ash in Australia will be further expanded because of its low trace element contents that can be toxic to plants and low radioactive element contents existing within soil background concentrations. The characteristics of coal combustion products are related to the characteristics of the coal used for combustion, and since Korea imports coal from Australia, Korean coal combustion products also can be recycled for various purposes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.381-387
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• 2003

Winter hairy vetch (HV) can be used as green manure with conventional tillage system (CT), in which chemical N fertilizer required for cultivation of sub-sequent com could be fully saved, or as cover crop with no-tillage system (NT) in which soil could be protected from erosion, control of weed, and the reduction of N fertilizer application. This experiment was carried out to compare the enrichment of soil mineral nitrogen (SMN) at corn root zone, and the changes of com growth and N uptake according to HV amounts (winter fallow, above-ground HV removed, intact HV, and HV added from aboveground HV removed) under two tillage systems in the upland field of National Crop Experiment Station, Suwon, Korea in 1996. HV cultivation during winter decreased SMN a little at com planting. HV incorporation with CT increased SMN rapidly during early growth stage according to rapid decomposition of Hv. SMN by HV cover with NT was increased slowly and its increase was higher in the surface soil (soil layer 0-7.5cm) compared to deep soil layer 7.5-22cm. Com growth and N status at corn silking stage, com yield and N uptake at harvest were increased in proportion to aboveground HV amounts regardless of tillage system. Average hairy vetch nitrogen (HV-N) uptake efficiency by com was 10% higher with CT than with NT in which average HV-N uptake efficiency was 43 %. Corn yields were not different between two tillage systems, but corn N uptake was increased by 33 kgN/ha more with CT than with NT due to the increase of corn N concentration. The increase of SMN and com N uptake from HV cover with NT could not be disregarded though those with CT were higher than with NT

• Journal of Soil and Groundwater Environment
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• v.21 no.1
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• pp.49-60
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• 2016

Distribution and behavior of baseline soil CO₂ were investigated in a candidate geologic CO₂ storage site in Pohang, with measuring CO₂ concentrations and carbon isotopes in the vadose zone as well as CO₂ fluxes and concentrations through ground surface. This investigation aimed to assess the baseline CO₂ levels and to build the CO₂ monitoring system before injecting CO₂. The gas in the vadose zone was collected using a peristaltic pump from the depth of 60 cm below ground surface, and stored at gas bags. Then the gas components (CO₂, O₂, N₂, CH₄) and δ¹³C_CO2 were analyzed using GC and CRDS (cavity ringdown spectroscopy) respectively in laboratory. CO₂ fluxes and CO₂ concentrations through ground surface were measured using Li-COR in field. In result, the median of the CO₂ concentrations in the vadose zone was about 3,000 ppm, and the δ¹³C_CO2 were in the wide range between −36.9‰ and −10.6‰. The results imply that the fate of CO₂ in the vadose zone was affected by soil property and vegetations. CO₂ in sandy or loamy soils originated from the respiration of microorganisms and the decomposition of C₃ plants. In gravel areas, the CO₂ concentrations decreased while the δ¹³C_CO2 increased because of the mixing with the atmospheric gas. In addition, the relation between O₂ and CO₂, N₂, and the relation between N₂/O₂ and CO₂ implied that the gases in the vadose zone dissolved in the infiltrating precipitation or the soil moisture. The median CO₂ flux through ground surface was 2.9 g/m²/d which is lower than the reported soil CO₂ fluxes in areas with temperate climates. CO₂ fluxes measured in sandy and loamy soil areas were higher (median 5.2 g/m²/d) than those in gravel areas (2.6 g/m²/d). The relationships between CO₂ fluxes and concentrations suggested that the transport of CO₂ from the vadose zone to ground surface was dominated by diffusion in the study area. In gravel areas, the mixing with atmospheric gases was significant. Based on this study result, a soil monitoring procedure has been established for a candidate geologic CO₂ storage site. Also, this study result provides ideas for innovating soil monitoring technologies.

• Animal cells and systems
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• v.4 no.1
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• pp.57-62
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• 2000

Soil samples were collected in thirteen Manitoba boreal forest sites. Spatial distribution of chytrids from diverse boreal forest microhabitats was investigated by baiting with jack pine pollen. After baiting, the pollen was surveyed for chytrids for 8 ten day period and individual species were counted. Total infestations of pollen by chytrids ranged from 5.8% to 90.2% from various soils. Each site with high infestation was characterized by litter with high needle content while mineral soil or soil with limited organic matter yielded low levels of pollen infestation. Species diversity tended to be higher in soils with higher pollen infestation and lower in soils with lower pollen infestation. Lower diversity was generally observed in mineral soils or soils with a limited organic horizon comprised, in part, of broad leaf litter. Based on coefficients of association and species in common among species across the collection sites, it was possible to relate dominant species assemblages in site groups. These species assemblages in the site groups suggest that the chytrids are distributed by litter and soil types. It can be concluded that the substratum characteristics of litter types and availability of litter may be important in describing chytrid distribution in boreal forest sites.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.265-273
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• 2011

Bacterial diversity based on the denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA gene sequences was determined for soil samples from two abandoned mine sites and the corresponding enrichment cultures using soil sample as key inoculum. Sequencing analysis of DGGE bands obtained from both the soil samples matched mostly with sequences of uncultured and newly described organisms, or organisms recently associated with the acid mine drainage environment. However, the enrichment of soil samples in ferrous sulfate and elemental sulfur media yielded sequences that were consistent with well-known iron- and sulfur-oxidizing acidophilic bacteria. Analysis of enrichment cultures of soil samples from Dalsung mine revealed abundant ${\gamma}$-$Proteobacteria$, whereas that of Gubong mine sample displayed acidophilic groups of ${\gamma}$-$Proteobacteria$, ${\alpha}$-$Proteobacteria$, $Actinobacteria$ and $Firmicutes$. Chemical elemental analysis of the mine samples indicated that the Dalsung site contained more iron and sulfate along with other toxic components as compared with those of the Gubong site. Biogeochemistry was believed to be the primary control on the acidophilic bacterial group in the enrichment samples.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.558-562
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• 2014

Cover cropping and liquid manure application are considered as effective ways to replace the use of chemical fertilizer in orchard. This study was conducted to investigate the effect of cover crop species and liquid manure application rate on green manure production, leaf mineral content, fruit quality and soil chemical properties in pear orchard. The treatments include rye and hairy vetch as cover crops, two liquid manure application levels based on N and $K_2O$ requirement on each cover crop species, and chemical fertilizer as control. Green manure production was higher in hairy vetch than in rye. K content of pear leaves and soil exchangeable K content increased in N based liquid manure application treatments. The yield was higher in rye + liquid manure and fertilizer treatments, and fruit quality was not different between the treatments. Taking all of these into account, rye + $K_2O$ requirement-based liquid manure application is recommended in pear orchard for not only sufficient nutrient supply but also prevention of any problem related with soil $K_2O$ accumulation in pear orchard in long-term perspective.

• Journal of Plant Biology
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• v.26 no.2
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• pp.53-71
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• 1983

Physicochemical properties of soil, mineral cyclings, production of plants, and relationship between sodium(Na) content and progresses of plant communities were studied in a coastal salt marsh in Incheon. Contents of Na, available phosphorus(A-P) and value of electric conductivity of soil decreased in order of Salicornia herbacea, Limonium tetragonum, Phragmites communis and Zoysia sinica communities, but contents of organic matter, total nitrogen(T-N) and calcium(Ca) of soil were vice versa. Specise diversity index decreased with increase of Na content of soil with correlation coefficient of -0.82. The aboveground biomass of plant communities were 2,981 g.dw/$m^2$ in P. communis, 1,471 g.dw/$m^2$ in Z. sinica, 189g.dw/$m^2$ in S. herbacea and 71 g.dw/$m^2$ L. tetragonum, respectively. Seasonal changes of contents of inorganic nutrients per unit land area coincided with those of biomass of plant communities, however, the maximum contents of K occured earlier than the maximum biomass. Amounts of inorganic nutrients absorbed by plant were directly proportion to its biomass and it was true to reverse in restored amounts of them to soil. In turnover times of nutrients of the communities, it took the shortest time for P but the longest for Ca and P. communis community took the shortest but L. tetragonum the longest. For example, in P. communis turover time of P took one year and that of Na 1,440 years. Lack of P element, therefore, was expected in this study area.

• Journal of Soil and Groundwater Environment
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• v.23 no.1
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• pp.63-73
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• 2018

Rice is a staple food source in Asian countries. In paddy field, rice plant can take up toxic elements through its roots from contaminated soils, and its leaves and grain can absorb the toxic elements deposited on the soil surface. A totla of 40 soil and polished rice samples were collected around four abandoned metal mines in Korea and analyzed for As, Cd, Cu, Pb and Zn by atomic absorption spectrophotometer (AAS). The average contents of As, Cd, Cu, Pb and Zn in rice grain grown on the contaminated soils were 0.247, 0.174, 4.694, 0.804 and 16.78 mg/kg, respectively. These levels are higher than worldwide average concentrations. Assuming the rice consumption of 169 g/day by overall households in Korea, the estimated daily intakes from the rices were found to be 33, 48, and 63% for As, Cd, and Pb, respectively, of the acceptable daily intake (ADI) suggested by the FAO/WHO Joint Food Additive and Contaminants Committee.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.1-8
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• 2018

In this study, formaldehyde and benzene were selected as the arbitrary chemicals in accidental leakage to environment, and their physicochemical and biological characteristics and toxicity were studied. Also, the fate of these chemicals in soil and groundwater was studied based on the results of previous studies. They can be released into the atmosphere as gas or vapor phase, which then can be photochemically degraded. Since they have relatively high water solubility, they are likely to have high mobility in water and soil. Volatilization of these chemicals from soil is affected by the soil moisture content. Biodegradation of formaldehyde and benzene is one of the important pathways as well. Therefore, it is necessary to study the environmental impacts of leakage accidents of flammable chemicals such as formaldehyde and benzene. Further research on the fate of flammable chemicals in the environment is needed to take appropriate response actions to leakage accidents of flammable chemicals, and this will contribute to the development of practical guidelines to cope with leakage accidents.