• Journal of Korean Society of Environmental Engineers
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• v.34 no.2
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• pp.86-90
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• 2012

The gaseous product of nitrogen cycle, nitrous oxide ($N_2O$) is a potent greenhouse gas whose Global Warming Potential (GWP) is about 300 times greater than $CO_2$. The dynamics of $N_2O$ emission are controlled by such environments and soil conditions. The main aim of this study is to investigate variations of $N_2O$ emission and its controlling factors with different land-use patterns in Haean basin. A forest, a radish field and a rice paddy were selected as three different land-use patterns. Their $N_2O$ emissions were measured every month during a growing season. We also collected soil samples with seasons and analyzed soil characteristics including inorganic nitrogen content. $N_2O$ emission was greatest at the radish field likely due to anthropogenic nitrogen addition by fertilization. Soils of forest and rice paddy also contained inorganic nitrogen originated from organic matter. However, the spatial variation was great and it looks that nitrogen cycle and $N_2O$ production were slower than that of radish field. Intensive observation and control of fertilization would be requiredto adjust $N_2O$ emission from agriculture soils.

• Journal of Integrative Natural Science
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• v.3 no.3
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• pp.174-180
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• 2010

This study was conducted to investigate the major chemical components of dried Capsosiphon fulvescens. The proximate compositions of C. fulvescens as dry matter basis were the moisture content 6.27%, 27.66% of crude protein, 1.68% of crude fat, 10.69% of crude ash, and 53.70% of carbohydrate, respectively. Analysing total amino acids, 17 kinds of components isolated from C. fulvescens. The essential amino acid contained in C. fulvescens accounted for 42.33% of total amino acid, while the non-essential amino acid accounted for 57.67%. Fatty acids were of 13.34% of saturated fatty acids, 21.69% of monounsaturated fatty acids and 64.97% of polyunsaturated fatty acids. Linoleic acid, oleic acid, palmitic acid and linolenic acid were the major fatty acids among 14 fatty acids detected in dried C. fulvescens. Oxalic acid was the major organic acids. The contents of vitamin A and vitamin E were 0.021 mg% and 0.001 mg%, respectively. The mineral contents of dried C. fulvescens were greater in order of Mg

• Korean Journal of Weed Science
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• v.2 no.2
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• pp.114-121
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• 1982

Sagittaria pygmaea Miquel is widely infested and is the most dominant perennial weed in paddy field in Korea. This study was carried out in order to clarify the factors influencing tuber production and the competition ecology. The tuberization capacity in the paddy field transplanted with the small seedlings of rice was higher than in the paddy field transplanted with the vigor seedlings of rice. The stage which rice plants were most damaged by S. pygmaea plants was the period from 31 to 37 days after transplanting. According to the increasing of Eleocharis acicularis Roem. in the condition of rice cultivation, the number of S. pygmaea plants was remarkably reduced. Small size tubers planted within deep soil produced less tubers than large size tubers did. The number of plants and tubers were remarkably increased under the high levels of fertilization. Phosphorus was essential as well as nitrogen for tuberization. And the tuberization capapcity was different with the organic matter content in soil and with the soil moisture.

• Journal of the Korean Wood Science and Technology
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• v.16 no.2
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• pp.79-89
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• 1988

This experiment was carried out to investigate the difference of compositions between petroleum ether extract and its tall oil in Pinus rigida Mill. xylem and to obtain the basic data on effective extraction and its utilization of by-product, resin and fatty acid, when pulp making. After both petroleum ether extract from wood meal and its tall oil in pitch pine were separated to the resin and fatty acid by using DEAE-Sephadex and aluminum oxide column, these were analyzed with gas chromatograph. The results obtained were as follows: 1. Fatty acids contained as ester form in living trees were varied by peroxide of organic solvent in petroleum ehter extraction and cooking chemicals in cooking. 2. Pimaric-type acid was eluted earlier than abietic-type acid in resin acids and the fewer the carbons, the earlier the elution in fatty acids. 3. The retention time of SE-30 column was even smaller than that of OV-101 column but the relative retention time obtained by using methyl pimarate and methyl stearate as internal standard was nearly identical. 4. Both petroleum ether extract and tall oil mainly consisted of resin acids, expecially abietic-type acid. 5. Tall oil had more fatty acid but less resin acid than petroleum ether extract. Also, the content of unidentified materials was increased owing to the isomerization and the shift of double bond position in unsaturated fatty acids by high temperature and cooking chemicals when cooking.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.55-60
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• 1991

This study was carried out to obtain the effects of soil environment and characteristics on the growth and yield of young rice seedling. Twenty four rice fields were selected among the labor saving mechanization complex, and the growth statu s and various soil characteristics were investigated The young rice seedling planted soils were located at the range of elevation 5m to 210m, and the average water holding days was 5.1 days, and drainage class were mainly moderately well to imperfectly. The plant height on 30th day after machine transplanting were higher and the tiller numbers were smaller at the higher clay contents at moderately well and imperfectly drained soils. In case of sandy loam soils, the better the drainage class, the higher plant and more tillers. Soil hardness was lower in sandy loam, and the bulk densities of loam, silty clay loam and poorly drained soils were lower than the other fields. There were not differences of soil chemical properties between the soil textural groups but organic matter content were higher in poorly drained soils. The rice yields of young seedling planted fields were negatively correlated to soil bulk density and highly significantly correlated to the exchangeable calcium contents of the soils. The average yield of young rice seedlings was 487kg/10a, 2.5% higher than semi-adult rice seedling of 475kg/10a.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.396-402
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• 1996

This study was conducted to determine the effect of treatment with the plant-growth-promoting bacteria on the growth and yield of red pepper(Capsicum annuum L.) with different soil electrical conductivity(EC) levels. The mixed liquid culture was done pseudomonas P and saboraud dextrose medium. The isolated bacteria(IB) were inoculated by spray of 3.7ml at 1/2000a pot filled with different soil electrical conductivity level(2.9, 8.6, 11.5dS/m) every week, respectively, with mixed liquid culture (Pseudomonas P+Sabouraud dextrose) of eight strains. The plant height of red pepper with IBs treatment in different soil EC levels showed better growth than IBs nontreatment in the order of the 2.9>8.6>11.5 dS/m. The yield of pepper with IBs treatment in different soil EC level was higher in 13% than IBs nontreatment and chemical properties($P_2O_5$, K, Ca, Mg) of the soil after harvest in IBs treatment were slightly increased, while organic matter and EC of IBs treatment were slightly decreased than those of IBs nontreatment. Moisture content of the soil after the harvesting with IBs treatment was slightly increased than IBs nontreatment.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.20-25
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• 1996

This survey was conducted to investigate the chemical properties of soils cultivated medicinal plants. The soils were collected at 254 sites(Angelica gigas : 81, Astragalus membranceus : 38, Platycodn glandiflorum : 36, Paeonia albiflora : 34, Codonopsis lanoceolata : 32, Ligusticum chuanxiong : 17. Bupleurum falcatum : 16, respectively) throughout the country by 0-15cm depth. The chemical properties of soils were pH 5.6, O.M 3.0%. Av.$P_2O_5$ : 405 mg/kg, Ex.K : $0.67cmol^+/kg$, Ex.Ca : $6.3cmol^+/kg$, Ex.mg : $1.6cmol^+/kg$. The percentage distribution of pH on the basis of soil sample numbers were much more at the 5.1-6.0 range than any other ranges, especially those of below pH 6.0 were 83-91% for Angelica gigas, Platycodn glandiflorum and Codonopsis lanoceolata. The distribution of OM and Av.$P_2O_5$ in soils were much at the 2.1-4.0% and above 500mg/kg ranges, respectively. And the content of those in soils cultivated with Platycodn glandiflorum were lower than any other medicinal plants. The distribution of exchangeable cations in soils were much at the 0.2-0.8, 2.1-4.0 and $0.5-2.0cmol^+/kg$ of Ex.K. Ca and mg. respectively, and the contents were higher in soils cultivated Astragalus membranceus. and lower in soils cultivated Platycodn glandiflorum and Codonopsis lanoceolata than any other samples.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.8-14
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• 1996

Use of phosphate coated urea to decrease ammonia volatilization from directly seeded paddy under dryland condition at early stage was tested. Effect on urea hydrolysis was investigated through laboratory study comparing with use of thiourea, a urease inhibitor, under different water content. A field measurement of volitilized ammonia with phosphate-glycerol ammonia absorber was conducted for surface treated urea, phosphate coated urea, phosphate coated slow-release fertilizer and organic fertilizer. Through laboratory study, hydrolysis rate of phosphate coated urea at three days after treatment was lower than that of urea, however, the rate after one week was same. Thiourea addition retarted urea hydrolysis. By field measurement, ammonia volatilization was effectively reduced by use of phosphate coated urea.

• Food Science and Preservation
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• v.22 no.4
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• pp.490-497
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• 2015

This study was performed to improve the availability of reed and quality of traditional Yakju by using roasted reed. The pH of sprout Yakju was 3.43, whereas the pHs of other Yakjus were 3.57. No remarkable differences were observed in contents of total titratable acids and reducing sugars. Color changes were measured by Hunter's color value; L value decreased, whereas redness (+a) and yellowness (+b) increased during fermentation. Ethanol content of Yakjus prepared with sprout and root were 15.30% and 15.28%, respectively, which were lower than that of control Yakju (15.31%). However, there were obvious differences of ethanol contents in three types of Yakjus. The major free sugar and organic acid were glucose and lactic acid, respectively. The total polyphenol contents of sprout Yakju (4.26 mg%) and root Yakju (4.21 mg%) were much higher than that of control Yakju (2.56 mg%). The DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging activities of sprout Yakju and root Yakju were higher than those of control Yakju. Yakju prepared from 0.3% addition of sprout showed the highest score in overall preference from the sensory test.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.51-56
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• 1998

This study was carried out to evaluate environmental and ecological characteristics of natural habitat for cultivation of Epimedium koreanum. Habitat of E. koreanum was the slope foot of mountain descending gradually toward mostly northwest from top of mountain with slope of $2{\sim}20%$ and the altitude ranged from 60 to 400m above the sea level. Some physiochemical characteristics of habitat soil were as follows: pH, $4.1{\sim}5.8$, organic matters content, $4.9{\sim}6.6%$ and cation exchange capacity, $14.8{\sim}34.3\;me/100g$ soil, respectively. Habitats were shaded by deciduous broad-leaved tree mainly, and compared with those of naked area, relative photon flux density was $3.5{\sim}13.1%$ and relative luminance was $3.3{\sim}11.9%$ due to shading. Air temperature of habitat under shade was $4.3{\sim}6.5^{\circ}C$ lower than that of naked area. Habitat soil temperature was lower than that of naked area but temperature range was smaller than that of naked area. E. koreanum plants were growing with semishading plants under shade of tree leaf. From investigation of natural characteristics of habitat, it was concluded that E. koreanum plant would grow at place with a little change in temperature and moisture of soil which was caused by shading and mulching with litterfall of broad-leaved tree.