• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.99-106
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• 2008

A synthetic aperture radar (SAR) system is of great interest in many fields of civil and military applications because of all-weather and luminance free imaging capability. SAR image quality parameters such as spatial resolution, peak to sidelobe ratio (PSLR), and integrated sidelobe ratio (ISLR) can be normally estimated by modeling of impulse response function (IRF) which is obtained from various system design parameters such as altitude, operational frequency, PRF, etc. In modeling of IRF, however, background clutter environment surrounding the IRF is generally neglected. In this paper, analysis method for SAR mage quality is proposed in the real background clutter environment. First of all, SAR raw data of a point scatterer is generated based on various system parameters. Secondly, the generated raw data can be focused to ideal IRF by range Doppler algorithm (RDA). Finally, background clutter obtained from image of currently operating SAR system is applied to IRF. In addition, image quality is precisely analyzed by zooming and interpolation method for effective extraction of IRF, and then the effect of proposed methodology is presented with several simulation results under the assumption of estimation error of Doppler rate.

• Ecology and Resilient Infrastructure
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• v.9 no.1
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• pp.15-23
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• 2022

This study was conducted to investigate in relation to characteristic of macroinvertebrates in conventional and organic paddy fields. The investigation was conducted five times a year for Suwon, Ansung, Boeun, Gunsan, Gimje, Hamyang, divide into conventional paddy fields and organic paddy fields from 2009 to 2011. The macroinvertebrates collected from the surveyed between conventional and organic paddy fields belonged to 84 species, 47 families, 16 orders, and 6 classes in 3 phyla. In the habitat orientied groups, climbers, swimmers and sprawlers were considerably occupied in conventional and organic paddy fields. In relation to the functional feeding groups, predators such as Odonata, Coleoptera, and Hemiptera were only the highest in paddy field ecosystem, regardless of cultivation method. As a result of community stability analysis, orgainc paddy fields has been identified much as species high resistance and resilience to environmental change in paddy field ecosystem. Species belonging to the I groups is considered to be important in organic paddy field such as Sternolophus rufipes, Hydrochara affinis, Helochares nipponicus, which has high mobility. In conclusion, it was found that the introduction of coleoptera as a food source was higher than that of conventional paddy fields in organic paddy field where primary consumers were abundant such as Chironomidae spp. and Dixidae sp..

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.247-253
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• 1997

Development of soybean cultivars with great nodulation and high nitrogen fixation activity, derived mostly from mutagenesis, may decrease inputs of chemical fertilizer nitrogen into the soil-plant system. Soybean seeds (cv. Jangyupkong, Hwanggeumkong, and Geomjungkong 1) were treated with three different levels of EMS (ethyl methanesulfonate) concentration(30, 50, and 70mM). Increasing the doses of EMS resulted in decreased field emergence rate of seeds, whereas it did not increase M$_2$ mutation frequencies. This indicated that the most efficient concentration of EMS was 30mM for generating mutants. Extensive mutagenesis of Sinpaldalkong 2 with 30mM EMS was undertaken to isolate soybean mutants with greater nodulation. Approximately 8, 200 M$_2$ families were screened for greater nodulation on 5 mM nitrate after inoculation with Bradyrhizobium japonicum strain YCK213-KFCC-10728. Mutant SS-2 nodulated more than the wild type. Comparison of supernodulation between SS-2 and two nts mutants(nts 1007 and nts 1116) revealed that SS-2 showed the supernodulation character at an earlier growth stage than the two nts mutants. Further studies should be needed to characterize the difference in timing of nodulation between SS-2 and nts mutants.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.705-715
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• 2010

The adoption of carbon foot print system is being activated mostly in the developed countries as one of the long-term response towards tightened up regulations and standards on carbon emission in the agricultural sector. The Korean Ministry of Environment excluded the primary agricultural products from the carbon foot print system due to lack of LCI (life cycle inventory) database in agriculture. Therefore, the research on and establishment of LCI database in the agriculture for adoption of carbon foot print system is urgent. Development of LCA (life cycle assessment) methodology for application of LCA to agricultural environment in Korea is also very important. Application of LCA methodology to agricultural environment in Korea is an early stage. Therefore, this study was carried out to find out the effect of lettuce cultivation on agricultural environment by establishing LCA methodology. Data collection of agricultural input and output for establishing LCI was carried out by collecting statistical data and documents on income from agro and livestock products prepared by RDA. LCA methodology for agriculture was reviewed by investigating LCA methodology and LCA applications of foreign countries. Results based on 1 kg of lettuce production showed that inputs including N, P, organic fertilizers, compound fertilizers and crop protectants were the main sources of major emission factor during lettuce cropping process. The amount of inputs considering the amount of active ingredients was required to estimate the actual quantity of the inputs used. Major emissions due to agricultural activities were $N_2O$ (emission to air) and ${NO_3}^-$/${PO_4}^-$ (emission to water) from fertilizers, organic compounds from pesticides and air pollutants from fossil fuel combustion in using agricultural machines. The softwares for LCIA (life cycle impact assessment) and LCA used in Korea are 'PASS' and 'TOTAL' which have been developed by the Ministry of Knowledge Economy and the Ministry of Environment. However, the models used for the softwares are the ones developed in foreign countries. In the future, development of models and optimization of factors for characterization, normalization and weighting suitable to Korean agricultural environment need to be done for more precise LCA analysis in the agricultural area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.245-252
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• 2010

The objective of this study was to obtain the basic informations on variability of germplasm and cultivation practice for the production of biodiesel in sunflower. A total of 275 accessions obtained from the National Agrobiodiversity Center (34 landraces from Korea, 219 and 22 introductions from America and other countries, respectively) were screened to evaluate variations of seed characteristics, oil content and fatty acid composition. Seed types were classified into 4 types (broad ovoid, narrow ovoid, rounded and elongated). The broad ovoid type was the highest proportion of 40.4%, while the elongated type was the lowest proportion of 5.0% among accessions. Also, the seed colors were classified into 4 colors (gray, brown, black and white). Gray and brown seed color showed the highest distribution and white seed color showed the lowest among accessions, respectively. Hundred and one liter seed weight ranged 2.9~15.5g and 178~439g with averages of 6.3g and 322.0g, respectively. Oil content ranged from 11.7% to 45.6% with an average of 25.5%. The frequency distribution of oil content showed the highest in range of 22~28% and the lowest in range of over 40%. Three promising accessions with higher oil content than 40.0% were IT031967, IT031970 and IT031965 introduced from America. Palmitic and stearic acid contents, saturated fatty acid, ranged 3.1~7.6% and 1.3~4.1% with averages of 4.7% and 2.2%, respectively, and a total content of saturated fatty acid ranged 5.4~9.4% with an average of 6.9%. Oleic and linoleic acid contents, unsaturated fatty acid, ranged 18.1~75.7% and 18.1~74.1% with averages of 55.2% and 38.0%, respectively. Five accessions, IT031831, IT031669, IT031895, IT031938 and IT031694, showed higher oleic acid content than 70%. A total content of unsaturated fatty acid ranged 89.6~94.8% with an average of 93.0%.

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.137-145
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• 2012

BACKGROUND: Along with the surplus rice production, introduction of upland crop cultivations into newly reclaimed tidal areas has gained public attentions in terms of farming diversification and farmers income increase. However, its impacts on the surroundings have not been well studied yet, especially associated with nutrient balance from reclaimed upland cultivation. The objective of this study was to investigate water and nutrient balance during winter barley cultivation as affected different fertilization methods. METHODS AND RESULTS: TN and TP balance for three different plots treated by livestock compost, chemical fertilizer, and no application were monitored during winter green barley cultivation (2010-2011) at the NICS Kyehwa experimental field in Jeonbuk, Korea. Nutrient content in soil and pore water near soil surface appeared to increase, while sub-soil layer remained similar with no fertilization plot. Livestock compost application appeared to increase organic matter content in surface soil compared to chemical fertilization. Crop yield was the greatest with livestock compost application (10.6 t/ha) followed by chemical fertilization (6.9 t/ha) and no application (1.8 t/ha). The nitrogen uptake rate was also greater with livestock compost (52.4%) than chemical fertilizer (48.1%). Phosphorus uptake rate was much smaller (about 7.0%) compared to nitrogen. Nutrient loss by surface and subsurface runoff seemed to be minimal primarily due to small rainfall amount during the winter season. Most of the remaining nutrients, particularly phosphate seemed to be stored in soil layer. Phosphate accumulation appeared to be more phenomenal in the plot applied by livestock compost with higher phosphorus content. CONCLUSION: This study demonstrated that livestock compost application to tidal upland may increase barley crop production and also improve soil fertility by supplying organic content. However, excessive phosphorus supply with livestock compost seems likely to cause a phosphate accumulation problem, unless the nitrogen-based fertilization practice is adjusted.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.53-61
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• 1986

The races of soybean cyst nematode, Heterodera glycines were investigated at 13 localities in Kyungpook, Chungpook and Cheonnam provinces for the resistant soybean variety selection to soybean cyst nematode. Race C, 1, and 5 were distributed and among them race 5 was dominant in Korea. Native soybean 203 lines and 25 introduced soybean varieties were investigated in field where soybean cyst nematode race 5 infested. As the result, the reproduction of soybean cyst nematode in native soybean lines decreased on entry number 18, 21, 36, 38, 41, 42, 43, 45, 55, 59, 68, 72, 75, 93, 94, 95, 98, 123, 131, 136, 146, 170, 174, 187, 190, 191 than others. And then, in pot experiment, entry number 170 showed moderately resistant with 10 cysts per root, while entry number 55 was decreased reproduction a little and the other 25 line appeared susceptibility. In introduced soybean varieties, Peking, Illsoy and PI90763 showed resistance and not reproduction in field and pot experiment. But Custer, Delmar, Dyer and Jackson represented moderately resistant under 10 cysts, while the other 18 varieties were susceptible. In yield analysis, native soybean line 170 showed the same tendency as Peking and PI90763 known for resistant varieties in decreased rate of branch number, pod number, pod weight per plant and weight of 100 grains. Peking and PI90763 decreased at the rate of under 1.6% in branch number, pod number, pod weight per plant and weight of 100 grains, while Illsoy showed a little higher decreased rate of 3.8% in pod number and 3.4% in pod weight per plant. Custer, Delmar, Dyer and Jackson represented a little higher decreased rate in yield.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.253-259
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• 2018

This study set out to select a system to realize an optimal environment for strawberry cultivation greenhouses based on data about the growth and development of strawberry and its environment and to provide basic data for the research of its improved productivity. For these purposes, the investigator conducted a field survey with greenhouses for strawberry cultivation in western Gyeongnam. The findings show that farmers in their fifties and sixties accounted for the biggest part in the age groups of strawberry farmers. While those who were under 50 were accounted for approximately 67.5%, those who were 60 or older accounted for 32.5%. As for cultivation experiences, the majority of the farmers had ten years of cultivation experiences or less with some having 30 years of cultivation experiences or more. All the farmers built an arch type single span greenhouse. Those who used nutrient solutions were about 75.0%, being more than those who used soil. All of the farmers that used a nutrient solution adopted an elevated hydroponic system. The single span greenhouses were in the range of 7.5~8.5m, 1.3~1.8m and 2.5~3.5m for width, eaves, and ridge height, respectively, regardless of survey areas. The rafters interval was about 0.7~0.8m. In elevated hydroponic cultivation, the width, height, and interval of the beds were about 0.25m, 1.2m and 1.0m, respectively. As for the strawberry varieties, the domestic ones accounted for approximately 97.5% with Seolhyang being the most favorite one at about 65.0%. As for the internal environment factors of greenhouses, 38 farmers measured only temperature and relatively humidity. As for hydroponics, the farmers used a hydroponics control system. Except for the farmers that introduced a smart farm system for temperature and humidity control, approximately 85.0% controlled temperature and humidity only with a control panel for side windows and ventilation fans. As for heating and heat insulation, all of the farmers were using water curtains with many farmers using an oil or electric boiler, radiating lamp or non-woven fabric, as well, when necessary.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.321-326
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• 2014

The aim of this study was to investigate which hydroponic system is the optimum for growth and photosynthetic characteristics of Angelica gigas during experiment. Angelica gigas 'Manchu' were sowed and managed under a growth room chamber. The environmental conditions (temperature $22^{\circ}C/18^{\circ}C$ (day/night), relative humidity 50-70%, photosynthetic photon flux density (PPFD) $120{\pm}6{\mu}mol\;m^{-2}s^{-1}$) were maintained for 3 weeks. Forty eight seedlings with 4-5 leaves were transplanted in deep flow technique (DFT), substrate, and spray culture systems [culture bed: 800 (L) ${\times}$ 800 (W) ${\times}$ 400 mm(H)] under $150{\pm}5{\mu}mol\;m^{-2}s^{-1}$ PPFD provided with fluorescence lamps and cultivated for 11 weeks. At the end of the experiment, fresh and dry weights, leaf lenghth and width, SPAD, root fresh, and dry weights, and root volume of Anglica gigas were measured. Photosynthetic rate of Anglica gigas were measured with portable photosynthesis systems to investigate optimum PPFD, $CO_2$ concentration, and air temperature conditions. Fresh and dry weights of Anglica gigas grown in substrate were significantly greater than DFT-treated, but there were not significant with spray treatment. Leaf photosynthesis of Anglica gigas showed the tendency to sharply increase as PPFD was increased from 50 to $200{\mu}mol\;m^{-2}s^{-1}$. Though $CO_2$ saturation point was around $1000-1200{\mu}mol\;mol^{-1}$, increase in air temperature from 16 to $26^{\circ}C$ did not quite affect photosynthesis of Anglica gigas. In conclusion, Anglica gigas may be optimally cultivated with a spray culture system as air temperature, PPFD, and $CO_2$ concentration for environment are controlled at $20{\pm}3^{\circ}C$, $150{\mu}mol\;m^{-2}s^{-1}$, and around $1000{\mu}mol\;mol^{-1}$ for mass production.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.474-481
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• 2011

Potato late blight caused by the fungus Phytophthora infestans is one of the most vital diseases damaging the potato plant. It is for this reason that breeding potato cultivars resistant to late blight is now becoming a major concern around the world. The B3C1 clones has been introduced by the Highland Agriculture Research Center, RDA. The clones which came from International Potato Center in 2005 have a durable resistance to late blight. The clones were bred under a short-day condition in Peru. However, there was still no report on the adaptability of these clones to the long-day condition in Korea. Therefore, this study was conducted to evaluate the late blight resistance and major agronomic characteristics of B3C1 clones under Korea's long-day condition. This study was also done to generate genetic resources for developing new varieties resistant to late blight. In this study it was found out that in naturally infested field with P. infestans, AUDPC (area under disease progress curve) values of all B3C1 clones were significantly lower than those of the control varieties, 'Superior', 'Atlantic', and 'Haryeong'. It was found out that B3C1 clones had a high level of resistance to late blight and that they could be used as genetic resources to breed potato varieties with late blight resistance. However, several undesirable characteristics such as extremely late maturity, excessive growth of stems and stolons, and production of tubers that cannot easily be removed from the stolons were also observed. Among the twenty B3C1 clones, two clones, LB-8 (CIP393077.159) and LB-11 (CIP393371.159), were selected for cultivating at the highland area of Korea. Two B3C1 clones were crossed with Korean breeding lines and clonal selection for the progenies is still in progress.