• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.3
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• pp.211-216
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• 2009

Approximately 43 million tons of livestock manure (LM) are produced each year on Korean farms. LM can be utilized as a valuable resource and/or it can contaminate water by runoff and leaching through the soil, when LM has been thoughtlessly applied to the land and directly discharged into the water. This experiment was carried out to investigate the effect of no-till system and LM application on dry matter (DM) yield of silage corn and $NO_3$-N concentration in leaching water of lysimeter installed in the experimental field. The treatments were replicated three times in split plot design. Main plots consisted of tillage systems, such as conventional tillage (CT) and no-tillage (NT). Sub plots consisted of the type of LM, such as chemical fertilizer (CF), composted cattle manure (CCM) and composted swine manure (CSM). The control plots were fertilized as commercial chemical fertilizer. DM yields of corn increased significantly in order to CF > CCM > CSM (p<0.05). DM yield of corn in CT increased as comparing with that of corn in NT. Plant height, ear height and stem diameter also increased in order to CF > CCM > CSM. In addition, the root weight in CT was increased as comparing with that of corn in NT. However, there was no interaction effects of between type of LM and tillage system. $NO_3$-N concentration in leaching water of LM application was less than 10 ppm, but $NO_3$-N concentration in CF exceeded 10 ppm which is safety level of drinking water during summer time (rainfall season).

• Horticultural Science & Technology
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• v.18 no.3
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• pp.334-341
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• 2000

To develop a nutrient solution for a closed hydroponic system in potato (Solanum tuberosum L.) 'Atlantic' and 'Superior' potatoes were grown with the nutrient solutions whose strengths were 0.25, 0.5, 1.0, and 1.5 of the concentration of the nutrient solution developed by the National Horticultural Experiment Station in Japan. The best results in potato growth and yield were obtained with 0.5 and 1.0 strength nutrient solutions, and nutrient compositions for potato were determined based on the 1.0 strength nutrient solution; $14.4me{\cdot}L^{-1}\;N,\;4.2me{\cdot}L^{-1}\;P,\;7.5me{\cdot}L^{-1}\;K,\;5.5me{\cdot}L^{-1}\;Ca$, and $3.5me{\cdot}L^{-1}\;Mg$ for stolon growth stage and $14.8me{\cdot}L^{-1}\;N,\;4.0me{\cdot}L^{-1}\;P,\;8.5me{\cdot}L^{-1}\;K,\;6.5me{\cdot}L^{-1}\;Ca$, and $3.0me{\cdot}L^{-1}\;Mg$ for tuber growth stage. To examine the suitability of the nutrient solutions developed for potato, the strengths of 1.0 (PS 1.0S), 0.75 (PS 0.75S), or 0.5 (PS 0.5S) were compared with half-strength of Japanese Horticultural Experiment Station' solution (JH 0.5S). Changes in pH, EC, and mineral concentrations in nutrient solutions depended more on solution strength and growth stage than on the type of nutrient solution. However, most elements in solution remained constant with plant age in PS 0.75S solution during stolon growth stage, and in PS 0.5S solution during tuber growth stage. The greatest growth and tuber yield was obtained in the standard strength solution (PS 1.0S), and potato solution developed in this experiment was recommended for hydroponic culture of potato in a closed system.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.2
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• pp.1937-1947
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• 1970

This experiment was conducted, making use of the 'NONG-RIM No, 6' a recommended variety of rice plant for the year of 1969. Main purpose of the experiment are to explore possibilities of; a) ways and means of saving irrigation water and, b) overcoming drought at the same time so that an increaded yield in rice production could be resulted in Specifically, it was tried to determine the effects of the Rotation Irrigation method combined with differentiated thickess of Lining upon the growth and Yield of rice production. Some of the major finding are summarized in the follows. 1) The Different thicknesses show a significant relationship with the weight of 1000 grains. In the case of 3cm Lined plot, the grain weight is 39.0 Grams, the heaviest. Next in order is 6 cm lined plnt, 5 day control plot, 6 day control plot. 2) In rice yield, it is found that there is a considerably moderate signicant relationship with both the different thickness of lining and the number of irrgation, as shown in the table No,7. 3) There is little or no difference among different plot in terms of; a) physical and chemical properties of soil, b) quality of irrgation water, c) climatic condition, and rainfalls. 4) It is found that there is no significant relationship between differences in the method of rotation irrgation and the number of ears per hill because of too much rainydays and low temperature during irrigation season. 5) In uyny1-treated plots, it is shown that there is on difference among different plots, but the irrigation water requirement saved as much as 1/2 to actual irrigation water compare to uncontroled plot. 6) The irrigation water requirement for 48 days is saved as much 67% compared to uncontroled plot, the order are; the 9cm lined plot, the plot of vinyl with no hole, the plot with a hole of $1cm/m^2$ as shows in fig 15. 7) The rate of percolation of 40-30mm/day is decreased to 30-20/day. It is found that the decreasad rate of percolation due to vinyl-cutoff in footpath. 8) The growing condition was fine, and there was no found that decease and lageing as always submerged plot. 9) It is found that it must be constructed irrigation and drainage system, inlet and outlet perpect, respectly, of which could be irrigation water saved and would be inereased the irrigation water temperature.

• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.699-708
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• 2017

The present study was to develop an approach for predicting soybean yield using a crop growth simulation model at the regional level where the detailed and site-specific information on cultivation management practices is not easily accessible for model input. CROPGRO-Soybean model included in Decision Support System for Agrotechnology Transfer (DSSAT) was employed for this study, and Illinois which is a major soybean production region of USA was selected as a study region. As a first step to predict soybean yield of Illinois using CROPGRO-Soybean model, genetic coefficients representative for each soybean maturity group (MG I~VI) were estimated through sowing date experiments using domestic and foreign cultivars with diverse maturity in Seoul National University Farm ($37.27^{\circ}N$, $126.99^{\circ}E$) for two years. The model using the representative genetic coefficients simulated the developmental stages of cultivars within each maturity group fairly well. Soybean yields for the grids of $10km{\times}10km$ in Illinois state were simulated from 2,000 to 2,011 with weather data under 18 simulation conditions including the combinations of three maturity groups, three seeding dates and two irrigation regimes. Planting dates and maturity groups were assigned differently to the three sub-regions divided longitudinally. The yearly state yields that were estimated by averaging all the grid yields simulated under non-irrigated and fully-Irrigated conditions showed a big difference from the statistical yields and did not explain the annual trend of yield increase due to the improved cultivation technologies. Using the grain yield data of 9 agricultural districts in Illinois observed and estimated from the simulated grid yield under 18 simulation conditions, a multiple regression model was constructed to estimate soybean yield at agricultural district level. In this model a year variable was also added to reflect the yearly yield trend. This model explained the yearly and district yield variation fairly well with a determination coefficients of $R^2=0.61$ (n = 108). Yearly state yields which were calculated by weighting the model-estimated yearly average agricultural district yield by the cultivation area of each agricultural district showed very close correspondence ($R^2=0.80$) to the yearly statistical state yields. Furthermore, the model predicted state yield fairly well in 2012 in which data were not used for the model construction and severe yield reduction was recorded due to drought.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.311-318
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• 2010

U. S. NRC Regulation Guide 1.52 regulating ESF ACS in nuclear power plants has been revised to revision 3. To apply reduction of operability test time, allowance of alternative challenge agents for in-place leak test of HEPA filters, and upgrade of Methyl Iodide penetration acceptance criterion in activated carbon performance test suggested in Reg. Guide 1.52(Rev.3) on Yonggwang units 5 and 6 ESF ACSes, technical feasibility study was carried out with on-site experiments as well as experiments with a lab-scale model. It was confirmed that the moisture in the system returned to the level before the test in 1 or 4 days even though the moisture was removed during the operability test lasting more than 10 hours. Therefore, it is appropriate to perform monthly operability test in 15 minutes just long enough to check the operability of equipment. To change challenge material for in-place HEPA filter leak test, size of aerosol, production rate, and leak detection capability were compared for DOP and PAO. It was concluded that PAO can be substituted for DOP in nuclear power plants. The upgrade of Methyl Iodide penetration acceptance criterion from 0.175 % to 0.5 % in active carbon filter bed deeper than 4 inches was to conform to the change of activated carbon performance test method to ASTM D3803(1989). It was confirmed that Methyl Iodide penetration acceptance criterion of 0.5 % under $30^{\circ}C$, relative humidity 95 % condition was conservatively good enough for testing performance of active carbon insitu. The licence change of Yonggwang units 5 and 6 has been completed based on this study.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.371-379
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• 2012

This study was designed to explore new nutraceutical and cosmetic resources possessing biological activities from the plant kingdom. To fulfill this purpose, we analyzed the anti-oxidative, anti-melanogenic, and anti-inflammatory activities of Zanthoxylum schinifolium extract (ZSE) and its solvent fractions using in vitro assays and cell culture model systems. Three kinds of ZSE treated with methanol, ethanol, and water exhibited potent anti-oxidative activities through DPPH radical scavenging capacity, and inhibited in vitro DOPA oxidation. Furthermore, Z. schinifolium methanol extract (ZSME) inhibited the ${\alpha}$-melanocyte stimulating hormone, which induces melanin contents in B16F10 cells. Its anti-melanogenic activity originates from the inhibition of tyrosinase enzyme activity and melanogenesis related protein expression. Moreover, lipopolysaccharide induced nitric oxide production in the RAW 264.7 cell line was also ameliorated by ZSME treatment in a dose dependent manner. Among the four solvent fractions of ZSME treated with dichloromethane, ethyl acetate, n-butanol, and water, three fractions, except water, showed significant anti-melanogenic and anti-inflammatory activities. Taken together, these results provide important new insights into Z. schinifolium, indicating that it possesses numerous biological activities such as anti-oxidative, anti-melanogenic, and anti-inflammatory activities. Therefore, it may well serve as a promising material in the field of nutraceuticals and cosmetics.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.484-489
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• 2010

The cultivation of green manure crops plays an important role in soil quality and sustainability of agricultural system. However, the incorporation of green manure crops may be of concern because it can lead to strongly reducing conditions in the submerged soil. This study was conducted to evaluate the effects of rice husk carbon on rice (Oryza sativa L.) cultivation using green manure mixtures (hairy vetch + rye) in rice paddy. Field experiments were conducted in rice paddy soil (Shinheung series, fine loamy, mixed, nonacid, mesic family of Aeric Fluventic Haplaquepts) at the National Institute of Crop Science (NICS), Korea from October 2007 to October 2008. The experiments consisted of three treatments: application or no application of carbonized rice husk, and conventional fertilization. These treatments were subdivided into whole incorporation and aboveground removal of green manure mixtures. The redox potential (Eh) was higher upon application of the carbonized rice husk when compared to no application at 8 and 37 days after transplanting (DAT). The ammonium-N ($NH_4$-N) in soil was highest upon the application of carbonized rice husk + whole green manure incorporation at 17 and 49 DAT. Plant height and tiller number of rice were similar to the $NH_4$-N concentration in soil. Rice yields of application and no application of carbonized rice husk treatment were not significant. However, application of carbonized rice husk improved the soil physical properties such as bulk density and porosity after rice harvest. Therefore, the results of this study suggest that carbonized rice husk could be used as soil amendment for environmentally-friendly rice production under a green manure mixture-rice cropping system.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.79-88
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• 2022

This study was conducted to evaluate the productivity of whole crop silage wheat utilizing the paddy fields during a couple of years from 2019 to 2021 in Suwon, Korea. This investigation was used the two maturity types of wheat cultivar 'Cheongwoo' (early) and 'Taeu' (late). The heading date of 2^nd year (Oct. 2020 to May. 2021) cultivation was delayed about 11 to 13 days by more than 1^st year (Oct. 2019 to May. 2020). The growth characteristics were shown that the plant height was increased in 2^nd cultivation, while the number of culms and the panicle part ratio were decreased. Moreover, the nutritive value of 'Cheongwoo' and 'Taeu' were also decreased in 2^nd cultivation. These changes have thought to a difference of the precipitation by cultivation years. Because, the precipitation during the period from the end of winter dormancy to the harvesting stage in 2^nd (337 mm) cultivation was more about twice than 1st (169.3 mm) cultivation. However, the dry matter yield of 'Cheongwoo' was not shown a statistical difference by cultivation years, while 'Taeu' was shown to decrease tendency. The total dry matter yield regardless of the cultivation years were higher in 'Cheongwoo' than 'Taeu', and especially 'Cheongwoo' was more 3 tons per hectare (15.3 t/ha) than 'Taeu' (12.6 t/ha) at 2^nd cultivation (p<0.01). The trend of dry weight in 'Cheongwoo', early mature type, showed a relatively high ratio of dry matter (p<0.05) was considered that due to a high panicle ratio by a fast heading and an adequate weight of panicles by a sufficient maturing. In conclusion, selecting the early maturity cultivars could achieve a higher and more stable total dry matter yield considering the cropping system in the central region. Furthermore, it also has the advantage of being able to double-cropping system with forage rice, which has considered the maximum whole-crop forage production year-round. These results suggest that the 'Cheongwoo' be optimum cultivar to produce the year-round forage on paddy fields in the central region.

• Journal of Practical Agriculture & Fisheries Research
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• v.10 no.1
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• pp.43-58
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• 2008

This research was conducted to determine the alternative tool of chemical spray for rice cultivation using the unmanned helicopter(Yamaha, R-Max Type 2G-remote controlled system) at farmer's field in Korea. The unmanned helicopter tested was introduced form Japan. In Korea the application of chemicals by machine sprayer for pest management in rice cultivation has been ordinarily used at the farmer's level. However, it involved a relatively high cost and laborious for the small scale of cultivation per farm household. Farm population has been highly decreased to 7.5% in 2002 and the population is expected to rapidly reduce by 3.5% in 2012. In Japan, pest control depending on unmanned helicopter has been increased by leaps and bounds. This was due in part to the materialization of the low-cost production technology under agricultural policy and demand environmentally friendly farm products. The practicability of the unmanned helicopter in terms of super efficiency and effectiveness has been proven, and the farmers have understood that the unmanned helicopter is indispensable in the future farming system that they visualized. Also, the unmanned helicopter has been applied to rice, wheat, soybean, vegetables, fruit trees, pine trees for spraying chemicals and/or fertilizers in Japan Effect of disease control by unmanned helicopter was partially approved against rice blast and sheath blight. However, the result was not satisfactory due to the weather conditions and cultural practices. The spray density was also determined in this experiment at 0, 15, 30, and 60cm height from the paddy soil surface and there was 968 spots at 0cm, 1,560 spots at 15cm, 1,923 spots at 30cm, and 2,999 spots at 60cm height. However, no significant difference was found among the treatments. At the same time, there was no phytotoxicity observed under the chemical stray using this unmanned helicopter, nor the rice plant itself was damaged by the wind during the operation.