• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.76-82
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• 1986

A laboratory experiment was conducted to find out the denitrification rate upon the levels of nitrogen and source of organic matter in submerged sandy and sandy loam soil. The results obtained were sumarized as follows; 1. Evolution of nitrous oxide was increased at 1st and 10 days after incubation. And dinitrogen was increased at 1st and 30 days after incubation. Applications of green manure was enhanced the evolution of nitrous oxide ($N_2O$) and dinitrogen ($N_2$). 2. The cumulative denitrification rates at 50 days was high in Gyuam sandy loam soil (O-M: 1.52%) than that of Hamchang sandy soil (O-M: 3.81%). On the other hand, the cumulative emission of dinitrogen was high in Gyuam sandy loam soil while nitrous oxide was high in Hamchang sandy soil. The total mount of denitrification rate was high in order of green manure > rice straw > compost > control soil. 3. Increases of fertilizer nitrogen was enhanced the rate of emission of dinitrogen and nitrous oxide during the incubation time. 4. According to Michaelis-Menten kinetic equation, denitrification rates and reaction efficiency were remarkably increased by application of readily decomposable organic matter with in higher organic matter content of soil. 5. The negative relationship was observed between the evolution of dinitrogen and carbon ($CO_2+CH_4$) while the nitrous oxide with carbon was positive. 6. Under the this experiment conditions 1 mg of carbon was required for production of 4 mg N as $N_2O$ and 3 mg of N as $N_2$, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.315-322
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• 1997

Sixteen cultivars of corn(Zea mays L.) hybrids have been recommended as the government recommended corn hybrids since 1984, however, their forage performances have been mostly tested at two locations, such as Suweon and Sunghwan in the Middle parts of Korea. Therefore, the objective of this experiment was to retest the agronomic characteristics and yield of eleven of sixteen government recommended corn hybrids at five scattered locations, such as Icheon, Suweon, Sunghwan, Keonpan and Kwangju in 1993 and 1995 with the intention of improving recommendations to dairy farmers. Among the corn hybrids tested, 'Suweon 19' was susceptible to foliar diseases and poor stay green at all locations in 1993 and 1995. Generally, all hybrids have less lodging and infection rate of rice black streaked dwarf virus(RBSDV) varied by location but mostly not exceed 10%. Infection rate at Sunghwan and Kwangju among locations was the highest as 13.5 and 15.3% respectively. Among the corn hybrids tested, 'Suweon 19' was the highest RBSDV infection rate, but that of 'Kwanganok' and '3282' was lower than other hybrids. At all locations, '3352' and '3394' were the earliest in growth stage, but 'Kwanganok', '3282', 'DK729', 'G4624' and 'DK713' were the latest among the corn hybrids. Ear percentage in total DM of '3352', '3394' and 'G4624' was higher than other hybrids, but that of 'DK713' was the lowest among the corn hybrids. '3352' and '3394' showed the most suitable DM content for silage production at harvest. Among the corn hybrids tested, 'Suweon 19' and '3282' were the lowest DM yield at all locations in 1993 and 1995, but the highest DM yield varied by location. At Icheon, '3144W' and 'G4743', at Suweon, '3352' and '3144W, at Sunghwan, 'DK729' and '3144W', at Keongsan, '3352' and 'DK729', and at Kwangju, '3352' and 'DK689' were the highest DM yield in 1993 and 1995, respectively. Then, '3394' was higher than other hybrids at all locations in 1995. The government recommended corn hybrids tested were generally adapted across the country. However, in forage production situations where wrn should be harvested before the rainy season in late summer, earlymedium maturing corn hybrids, '3352' and '3394' might be preferred.

• Korean journal of food and cookery science
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• v.24 no.3
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• pp.340-348
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• 2008

The purpose of this study was to develop new method for the manufacture of Yukwa, a Korean oil-puffed rice snack with a soft texture, using a far infrared ray electric roaster. The Yukwa base is traditionally expanded using oil, but the Yukwa base tends to develop unpleasant rancid odors or off-flavors during storage. In this study, the DPPH radical scavenging activity of mugwort powder was evaluated. Baked and fried Yukwa samples were added with 0.5, 1.0, 1.5, and 2.0% of mugwort powder and left untreated as a control, and then tested for moisture content, expansion rate, color, hardness, and sensory evaluations. The samples with higher concentrations of mugwort powder, evidenced a more profound tendency toward DPPH radical scavenging activity. The moisture content of Yukwa dough tended to increase with the addition of mugwort powder. As the mugwort powder content increased, the moisture contents of the Yukwa base and the Baked Yukwa increased. The moisture content and expansion rates of the fried Yukwa did not differ significantly. The samples containing the mugwort power evidenced a lower expansion rate than was observed in the control group. The lightness of the baked and fried Yukwa was reduced with increased mugwort powder content. The greenness of the baked and fried Yukwa was at a minimum upon the addition of 2.0% mugwort powder. The yellowness of the baked Yukwa did not differ significantly between the samples. As the mugwort powder content increased, the yellowness of the fried Yukwa increased. The hardness of the baked and fried Yukwa tended to increase with the addition of mugwort powder. In the sensory evaluations, the baked Yukwa scored higher than the fried Yukwa, and all of the sensory characteristics of baked Yukwa scored highest in the samples without mugwort powder, but also scored fairly well with 1.0 and 1.5% mugwort powder. In conclusion, these results demonstrated that 1.0～1.5% of mugwort powder should be added to Yukwa baked in a far infrared ray electrical roaster in order to optimize physiological functions and keep overall acceptability reasonably high.

• The Korean Journal of Quaternary Research
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• v.20 no.2
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• pp.1-10
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• 2006

Flooding hazard caused by natural and artificial environmental changes is closely associated with change in river bed configuration. This study is aimed at explaining a river-bed change related to soil erosion in the Keum river basin using GIS and RS. The USLE was used to compute soil erosion rate on the basis of GIS. River-bed profiles stretching from Kongju to Ippo were measured to construct a 3D-geomorphological map. The river-bed change was also detected by remote sensing images using Landsat TM during the period of 1982 to 2000 for the Keum river. The result shows that USLE indicates a mean soil erosion rate of $1.8\;kg/m^2/year$, and a net increase of a river-bed change at a rate of $+5\;cm/m^2$/year in the Kangkyeong area. The change in river-bed is interpreted to have been caused by soil erosion in the downstream of the Keum river basin. In addition river-bed change mainly occurred on the downstream of the confluence where tributaries and the main channel meet. Other possible river-bed change is caused by a removal of fluvial sand aggregates, which might have resulted in a net decrease of exposed area of sediment distribution between 1991 and 1995, while a construction of underwater structures, including a bridge, a reclamation of sand bars for rice fields and dikes, resulted in an increase of the exposed area of river-bed due to sediment accumulation.

• Journal of the Korean Home Economics Association
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• v.26 no.3
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• pp.53-68
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• 1988

This article concerned with the nutritional status and the taste of the lunch box of 311 middle school girls in Kwangju City from May 18 to June 12 in 1987. The purpose of this research was making materials to show direction of the education about nutrition by checking relationships among the nutritional status for the lunch box, the taste of food and the environmental factors. The results observed in the study were as follows: 1. The intake of nutrition from the lunch box and the ratio between the recommended dietary allowance and the contained nutrients in the lunch box as follows. Calorie(603 Kcal, 78.6%), protein (21.7g, 93.1%) Animal protein (10.3g, 132.1%) calcium (151.7 g, 56.9%) Ferrum 93.1 mg, 51.7%), Vitamin a (129.3 RE, 55.4%) Vitamin B1 (0.29 mg, 72.5%), Vitamin B (0.26 mg, 55.3%) Niacin (4.7 mg, 94.0%), Vitamin C 913.2 mg, 79.0%). Except animal protein, all the recommended dietary allowance. 2. According to the intake of calorie, the ratio of taken carbohydrate, protein and fat was 77.7 : 15.5 : 6.8. The intake of protein was desirable but most of calorie depended on carbohydrate. Among the total intake of protein, the ratio of animal protein was 47.5%, which was a high rate. 3. Most of calorie (75%), was taken from staples, protein (41.5%), vitamin B1 (48.3%) were taken at the same rate from staples and side dishes. Most of fat, calcium, ferrum, vitamin A, vitamin B, and vitamin C, was taken from side dishes. 4. In taking among the five basic food groups, proportion of the grain fourth food group was the highest, light color vegetable the third food groups, proportion of the grain fourth food group was the highest, light color vegetable the third food group was second, and Calcium food the second food group was the lowest. 5. As the staples, students liked tchajangmyon, mandu and ttokkuk as written order. They disliked Kongbap and Patpap. As the side dishes for the lunch box, they liked kimchi, ham, sausage, cuttlefish, dried slices of filefish, eggs and green seaweed as written order. As a side dishes they liked Laver, Cucumber, Squid, lettuce, Potatoes. They disliked pork fat, cow's intestines, cow's liver, Crussian carp, pickled fish. The favorite snack was fruits, ice cream, hamburger, Chocolate and milk. 6. In taking condition of the principal food, rice rate (65.6%) was the most, and mixed food was 5 or 10%. 7. Favorite cooking was frying, roasting and kimch. But disagreeable cooking was pickling. 8. Favorite food was what was pungent but disagreeable food was what was salty. 9. the higher parents educational background was, the higher their income was. Also the more various the information about the nutrition was, the better the intake of nutrition was. 10. The preference tendency influenced in choosing the side dish of the Lunch box. The higher the preference tendency of the girl students became, the better their nutrition condition became.

• Korean Journal of Community Nutrition
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• v.19 no.2
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• pp.198-211
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• 2014

Objectives: To investigate the use frequency and amount of food sources of sodium and knowledge requirement, and job satisfaction with school food services according to the school types in Busan. Methods: A total of 98 schools were surveyed and knowledge requirement and job satisfaction were assessed using a questionnaire. In addition, the use frequency and amount of food sources of sodium for 10 school days were examined. Results: The response rate of the most difficult area among dietitians' tasks was significantly high in 'nutrition education and counseling' for elementary schools and 'hygiene management' for high schools (p < .05). The response rate of the factors to be considered in meal planning was significantly high in 'energy and nutrients requirement' for elementary schools and 'menu/taste preference of students' for middle and high schools (p < .05). The response rate of whether school food services affect health and eating habits of students or not was significant high in 'very helpful' for elementary schools (p < .001). The average sodium contents in the meals of elementary, middle and high schools was 1981.4 mg/meal/person/day, 1867.3 mg/meal/person/day and 1,329.9 mg/meal/person/day, respectively. For foods in highest sodium, Kimchi, Oribulgogi, and Kare rice were ranked 1st, 2nd and 3rd respectively. The main reason for not providing the fruits was 'price' among all groups. The knowledge requirement such as 'nutrition and menu management', 'nutrition education', and 'nutrition counseling' was significantly higher in elementary school compared with middle and high school (p < .001, p < .01, and p < .01 respectively). The dietitians and nutrition teachers of elementary schools have a higher job satisfaction compared with those of middle schools (p < .01). The job satisfaction was positively correlated with knowledge requirement of dietitians and nutrition teachers of elementary and middle schools. Conclusions: The results suggest that developing dietitians' education program about knowledge requirement contribute to increasing the school food service and job satisfaction in elementary and middle schools.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.66-71
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• 2008

Phosphorus transfer from agricultural soils to surface waters is an important environmental issue. Fly ash and phospho-gypsum which are industrial by-product were investigated as a means of reducing dissolved phosphorus in arable soil. To determine the optimum mixing ratio of fly ash(FA) and phospho-gypsum(PG) for reducing dissolved reactive P(DRP) in soil, various mixture ratio of FA and PG were mixed with two soil. The DRP content and pH in soils were analysed after 3 weeks incubation under flooding condition. Although DRP content in soils was significantly decreased by FA-PG mixture compared with control, there were no significant difference among the FA and PG mixture ratio of 75:25, 50:50, and 25:75. The mixture of 75% FA and 25% PG was selected for field test. A field experiment was carried out to evaluate the reducing DRP content in paddy soil to which 0(NPK), 20(FG 20), 40(FG 40), and 60(FG 60) Mg $ha^{-1}$ of the mixture were applied. The DRP content was reduced by 31% at the application rate of 60 Mg $ha^{-1}$. In contrast to deceasing DRP, Ca-P content increased significantly with the mixture application rate. After rice harvesting, available $SiO_2$, P, and exchangeable Ca content in soil increased significantly with application rate due to high content of Si, P, and Ca in the mixture. Mixtures of fly ash and gypsum should reduce P loss from paddy soil and increase soil fertility.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.570-576
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• 1995

The new sixteen herbicidal N-2-(1-hydroxy-2-fluoroethyl)-6-substituted(X)-benzenesulfonyl-N'-4,6-dimethoxypyrimidinyl-2-yl urea derivatives(S) were synthesized and thier herbicidal activities$(pI_{50})$ in vivo against rice(Orysa Sativa L.), Barnyard grass(Echninochloa orizicola) and Bulrush(Scirpus juncoides) were measured by the pot test under paddy conditions. The structure activity relationship(SAR) were studied using the physicochemical parameters of ortho-substituents(X) and hydrolysis rate constant(logk) and herbicidal activities by the multiple regression technique. The SAR suggested that the herbicidal activities were more dependant on the hydrolysis rate constant(logk>0) than the steric constants $(Es, small width($B_4$) and length($L_1$). Among them, halogens(2 & 5), methyl(15) and non(H) substituent(1) showed higher herbicidal activity for weeds which was not tolerent to rise and weeds. The herbicidal activity was increased and the persistency in aqueous solution was decreased by electron donating(${\sigma}0<0$) groups as ortho-substituent(X). From the relationship equation between herbicidal activity and hydrolysis rate constant, it was assumed that the both reactions would be proceeds with similar process. And the conditions on the ortho substituents to show higher herbicidal activity and the persistency in aqueous solution were also discussed.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.207-215
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• 2012

In this study, we performed to select the high growth potential agri-products in Ulsan City, Korea. For this, we carried out the location quotient and the regional growth rate differential analyses using the cultivated area data and the agricultural output data in 2000, 2005 and 2007. The location quotient analysis revealed that rice, pear and persimmon were classified as specialized agri-products. These results would be useful to reflect on a short-term policy in support for the agricultural activities of the local farmers because the specialized agri-products occupy a relatively high proportion in the region. In addition, the regional growth rate differential analysis showed that strawberries, persimmon, potatoes, corn and sweet potato are classified as growing agri-products whereas pear is classified as a competitive agri-product in the analysis based on agricultural output from 2000 to 2007. Based on cultivated area, strawberries, potatoes and corn are classified as growing agri-products whereas sweet potato is classified as a competitive agri-product. These results would be beneficial to establish a long-term agricultural policy in Ulsan City because these agri-products are further supported by the time series analysis, considering the nationwide trends and the production activities reflecting the preferences of consumers and the willingness of producers.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.205-205
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• 2022

Sorghum (Sorghum bicolor L.) is a major cereal grain crop of the world and It can be cultivated under high temperature and dry condition with high adaptability to the adverse environment. It is usually eaten with rice in korea and most of domestic sorghum cultivars have been developed by pure line selection and cross breeding. In prior studies, Hybrid cultivar (F1 seed) was known to improve 30-40% in yield and resist to disease and pest than pure line varieties due to hybrid vigor. Therefore, study on the hybrid sorghum is continuously necessary. In korea, hybrid sorghum cultivar have been developed, so we need to find methods seed production technology for supply and commercialization of hybrid seed cultivar. Female inbred line(A-line) and male inbred line(R-line) are needed for hybrid seed production. This study was carried out to investigate growth characteristics and yield of hybrid sorghum according to the seedling period and planting rate between female inbred line(YSA1) and male inbred line (Sodamchal, Miryang 19). When the flowering period of two inbred groups in the process of hybrid seed production is coincides, hybrid seed production is increase. The female inbred line and male inbred lines were cultivated at Daegu in 2021. Two inbred lines were sown at intervals of 3 days and 7days and were evaluated flowering period. As a result, the flowering period of the female inbred line and male inbred lines were matched at the 7days interval. To find out optimal planting rate, two inbred lines were cultivated under different plating rate (4:2, 5:2, 6:2). Yield of YSA1/Sodamchal(F1) was the highest 130(kg/10a) in the 4:2 ratio and yield of YSA1/Miryang 19 was the highest quantity of 139(kg/10a) in the 6:2 ratio. The results of this study could be helpful for hybrid Sorghum seeds production.