• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.183-188
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• 2017

This study investigated the comparative growth characteristics, yield, chemical compositions, and nutritive yield of Italian ryegrass cultivars harvested in a paddy field. The experimental design was a randomized block design with three replicates. The treatments consisted of seven Italian ryegrass cultivars (Kogreen, Kowinmaster, Hwasan 101, Kowinnearly, Kospeed, Sahalie select, and Strike). The planting date was October 21, 2009 and the sample harvest was occurred on May 21, 2010. Dry matter yield was higher in Kowinnerary and Kogreen than in the other varieties (p<0.05). Crude protein and ether extract contents were highest in Hwasan 101 and lowest in Kospeed. The content of total digestible nutrients did not differ among the Italian ryegrass varieties. The amino acid contents were in the order Hwasan 101 > Strike > Kowinnearly > Kogreen > Sahalie select > Kospeed > Kowinnearly (p<0.05). Fructose content was highest in Kospeed, while glucose and sucrose contents were highest in Hwasan 101. The results of this study indicate that Kowinnearly, in terms of dry matter yield, and Hwasan 101, in terms of feed value (chemical composition and free sugar content), may be recommended for forage production in a paddy field.

• Journal of Conservation Science
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• v.25 no.3
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• pp.299-316
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• 2009

The Goryeo roof tiles from the Oegol site in Tangjeong, Asan are classified into three groups in color such as gray, red yellow and gray-yellow groups, respectively. While each group of tiles shows characteristic specific gravity, absorption ratio, LOI and vitrification degree, mineral content and distribution, and chemical composition are generally homogeneous among all groups of roof tiles. Also, all roof tiles and soils from the site show similar geochemical behavior of elements and clay-mineralization degree. This indicates that the soil from the site is probable to be a raw material of the roof tiles. Firing temperature of the roof tiles is estimated as 950 to $1,050^{\circ}C$ for the gray group, 800 to $900^{\circ}C$ for the red yellow group, and 900 to $950^{\circ}C$ for the gray-yellow group. In conclusion, roof tiles from the Oegol site is interpreted to be made of local clay without additive minerals, applying various firing conditions and standardized purifying process of raw clay materials.

• Asian Journal of Turfgrass Science
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• v.15 no.4
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• pp.157-168
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• 2001

This study was carried out to investigate the offsets of pyroligneous acid on the growth of ‘Penncross’Creeping Bentgrass (Agrostis palustris Huds.) and to propose the practical use for ecologically responsive management in Korean golf courses. In the plots affected by 300, 500, and 800 times diluted pyroligneous acid, the turfgrass growth increment and the visual quality were measured at fixed periods. The data were subjected to paired samples T-test. The results summarized are as follows； 1) In leaf growth increment, density, and root spread depth, turfgrass affected by 500 and 800 times diluted pyroligneous acid were superior to the control continually. It was reliable in the statistics. Especially, 500 times diluted solutions was superior to the others. 2) In color, texture, uniformity, and recuperative strength, the visual quality of turfgrass affected by 500 and 800 times diluted pyroligneous acid were superior to the control continually. It was reliable in the statistics except the recuperative strength. Espe-cially, 500 times diluted solutions tended to be superior to the others. 3) There was no symptom of a disease in all plots. The existing management was thought to be suitable in this golf course. 500 and 800 times diluted pyroligneous acid were not thought to trigger or promote a disease, 4) After investigating the effect of pyroligneous acid on turfgrass growth, the soils of all plots were analyzed. In all plots, the chemical properties of the soils were not changed obviously. 5) Considering the results mentioned above, the practical use of 500 and 800 times diluted solutions might decrease the amount of nutrients and agricultural chemicals used in golf courses as well as promote turfgrass growth in golf courses.

• Economic and Environmental Geology
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• v.48 no.4
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• pp.337-349
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• 2015

This study has focused on investigation of correlation for As and heavy metals in paddy soil and rice crops sampled in the vicinity of the abandoned Munmyung Au-Ag mine. Soil samples extracted by various methods including aqua regia, 1 M $MgCl_2$, 0.01 M $CaCl_2$ and 0.05 M EDTA were analyzed for As and heavy metals (Cd, Cu, Pb and Zn). Rice grain samples grown on the soils were also analyzed for the same elements to evaluate the relationships between soils and rice crops. According to soil extraction methods, As and heavy metal contents in the soils were decreased in the order of aqua regia > 0.01 M $CaCl_2$ > 1 M $MgCl_2$ > 0.05 M EDTA. In addition to correlation analysis, statistically significant correlation with the four extraction methods (p<0.01) were found in the soil and rice samples. As calculation of biological accumulation coefficients (BACs) of the rice crops for As and heavy metals, the BACs for Cd, Zn and Cu were relatively higher than those for As and Pb. This study also carried out a stepwise multiple linear regression analysis to identify the dominant factors influencing metal extraction rates of the paddy soils. Furthermore, daily intakes of As and heavy metals from regularly consumed the rice grain (287 g/day) grown on the contaminated soils by the mining activities were estimated, and found that Cd and As intakes from the rice reached up to 73.7% and 51.8% for maximum allowance levels of trace elements suggested by WHO, respectively. Therefore, long-term consumption of the rice poses potential health problems to residents around the mine, although no adverse health effects have yet been observed.

• Journal of Soil and Groundwater Environment
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• v.13 no.2
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• pp.62-69
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• 2008

In this study physicochemical characteristics and stability of various manganese coated sands (MCS) prepared with different methods were evaluated. In addition, removal efficiencies of As(III) by each MCS were compared. Four different MCSs were used; B-MCS prepared by baking method, W&D-MCS prepared by wetting and dry method, NMCS prepared during the water treatment process and Birm which is a commercial MCS widely used for the removal iron and manganese. The manganese content in each MCS was following order: Birm (63,120 mg/kg) > N-MCS (10,400 mg/kg) >W&D-MCS (5,080 mg/kg) > B-MCS (2,220 mg/kg). Birm showed the least solubility (% basis) in acidic conditions. As(III) oxidation efficiency of B-MCS was continuously increased as the solution pH decreased. While As(III) oxidation efficiency of N-MCS and Birm was minimum around neutral pH. The increased As(III) oxidation efficiency above neutral pH for N-MCS and Birm could be due to the competitive adsorption of $Mn^{2+}$, which was produced from reduction of $MnO_2$, onto the surface of aluminum and manganese oxides.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.61-67
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• 2019

The purpose of this research is to evaluate the salt tolerance of the Miscanthus sinensis and to characterize the content of pigments in the leachate in relation to calcium chloride ($CaCl_2$) deicing salt. Miscanthus sinensis were cultured at five different concentrations of calcium chloride deicing salt, 0, 1, 2, 5, and $10g{\cdot}L^{-1}$ (referred to Cont. C1, C2, C5, and C10) for four months. The salt tolerance and leachate while growing Miscanthus sinensis on soil which was artificially contaminated by calcium chloride deicing salt. Soil chemical properties (pH, E.C., $Ca^{2+}$, $Na^+$, $K^+$, and $Mg^{2+}$) and plant growth parameters (plant height, leaf length, leaf width, number of leaves, shoot fresh weight, root fresh weight, shoot dry weight, an root dry weight) were evaluated. Soil pH decreased, while electrical conductivity significantly decreased ($p{\leq}0.05$) with a higher concentration of deicing salt $0g{\cdot}L^{-1}$ (Cont.). The increase in the concentration of chloride-based exchangeable cations, along with the increase in the deicing salt treatments, were observed in $Ca^{2+}$ > $Na^+$ > $K^+$ > $Mg^{2+}$. Notably the $Ca^{2+}$ exchangeable cations were 83~90% higher than the others. The growth of Miscanthus sinensis significantly increased ($p{\leq}0.05$) with the concentration of deicing salt higher than $1g{\cdot}L^{-1}$ (C1) when compared to 0 g/L (Cont.), except for the $10g{\cdot}L^{-1}$ (C10) treatment. The results determined that the contamination of soil by deicing salt could negatively impact the soil and Miscanthus sinensis was a tolerant species for the deicing salts. Further research will be focused on soil improvement additives and the stable stimulated plant growth of Miscanthus sinensis and a formulation on that basis for the soil-plant continuum.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.25-35
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• 2005

This study analyzed total concentrations and existing forms of heavy metals in soils of Ulsan using a sequential extraction method. Soil samples were collected from 6 categorized areas including green, residential, heavy traffic, petrochemical industrial complex(IC), mechanical and shipbuilding IC, and non-ferrous metal IC areas. which represent different emission characteristics. The highest total concentrations of heavy metals by a sequential extraction analysis were observed in the soils collected from the non-ferrous metal IC area, followed by the mechanical and shipbuilding IC and heavy traffic areas. Dominant(> 50%) existing forms of Cd, Cr and Ni were residual forms followed by Fe and Mn oxides in almost areas. Residual fractions in the non-ferrous metal IC areas were relatively lower than those in other areas. However, the fractions of organic and sulphides in the IC areas were higher. The dominant farms of Cu were much different with the investigated areas. In most areas, the dominant forms of Pb and Zn were Fe and Mn oxides, followed by residual fraction for Pb. The exchangeable and carbonate fractions represent mobility of metallic elements in soils. They are also significantly affected by the environmental renditions, such as pHs of soil and rainfall. In this study the exchangeable and carbonate fractions were lower than other fractions. Because the total concentrations of heavy metals in the soils of the non-ferrous metal IC area were extremely high, however, the mobile fractions of heavy metals in the IC area would be significant. Thus a large amount of heavy metals can be released into plants, water bodies, and soils. Therefore, urgent measures, such as source control for soil remediation of heavy metals, in the non-ferrous metal IC areas are essentially required. Analysis results obtained from the sequential extraction and the aqua regia extraction showed a high correlation, whose determination coefficients(R2) of heavy metals except Cd approximately ranged from 0.7 to 0.9.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.83-105
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• 2003

Geochemical studies on the alluvial aquifer system near the Nakdong River were carried out for the basic investigation of the estimation of artificial recharge for the river bank filtration. In-situ data do not show any distinct difference between the pumping well and river. Most of waters belong to $_3$ and Ca-$SO_4$ types and show high Mn concentration. In the borehole installed with Multi-Ca-HCOPacker (MP) system, Na, Ca, Mg, $HCO_3$ contents of the groundwater are increased with depth increasing. Cl and $SO_4$ contents of the groundwater show the lowest values at the bottom level (18m depth) and Mn content is very high at the middle level (13.5 m depth) of MP system. There is no distinct difference in the ${\delta}^{18}O$ and D values and tritium content between MP, borehole and surface water samples. The sulfur isotope data indicate that the possible sulfur source is dissolution of sulfate mineral from sedimentary rock. Strontium isotope ratio shows a little differences between the pumping well and observation borehole samples. Nitrogen isotope data indicate that the nitrogen of water samples is originated from fertilizer or organic materials.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.55-59
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• 1984

An organic compound fertilizer was manufactured using wet oxidation human waste as principal source of phosphorus and organic matter. The waste was treated with sulfuric and glutamic acids to increase the available and water-soluble $P_2O_5$ contents. The treatment of 0.1 N sulfuric acid with 24 hours curing was best way in recovering the maximum percentage of $P_2O_5$ originally in the waste. The particle size distribution of trial product varied considerably in the amount of glutamic acid used for granulation. The number of relatively large fertilizer particles was increased as the amount of glutamic acid was increased. The granule crushing strength was generally high in large granules in which 12.5 weight percent of glutamic acid were used for granulation. The trial product showed high moisture absorption due to its porous structure and chemical makeup.

• Korean Journal of Medicinal Crop Science
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• v.18 no.4
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• pp.273-279
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• 2010

The study result survey platycodon cultivation regions of Jinju(2), Sacheon(4), Hapcheon(3), Haman(3), and Sancheong(3) of Gyongnam regarding chemical properties of soil, inorganic nitrogen phosphorus by type of composition is as follows: pH and EC value were highest where platycodon cultivated for under 3 years in soils. Content of O.M equal to or less than 25 mg $kg^{-1}$, the average value for platycodoncultivation in korea. Content of exchangeable calcium in soils were 12, 14 $cmol^+kg^{-1}$ in Hapcheon and Haman regions where platycodon was cultivated for two years which is 2~3 time higher level compared with the average upland soil of korea. Water solution boron confirmed approximated level of 3.0 mg $kg^{-1}$ in all survey regions, and the finding is about five times higher than average upland soil of korea which is 0.5 mg $kg^{-1}$. In the case of nitrogen, a significant difference was found depending on cultivation regions and continuous culture. Content of nitrogen in soils were difference according to cultivation area and continuous culture. The composition ratio according to the type of inorganic phosphorus showed the highest in order of Al-P > Ca-P > Fe-P > Saloid-P in all survey regions except for Hapcheon (five, seven years cultivated soils). The correlation showed high significance between available phosphate and inorganic phosphorus.