• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.45-45
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• 2023

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.10a
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• pp.134-134
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• 2021

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.314-314
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• 2022

기후변화로 인해 집중호우 등 설계강우량을 초과하는 강우가 빈번하게 발생하고 있으며, 이에 따라 농촌유역의 홍수 및 침수의 발생빈도 및 강도가 증가하고 있다. 국내 농업용 저수지 약 17,500여개 중 약 70%는 70년 이상 경과된 노후시설로 분류되고 있으며, 특히 농어촌공사에서 관리하는 3,411개의 저수지를 제외한 시군관리 저수지는 체계적인 유지보수가 이루어지지 않고 있다. 이로 인해 홍수기 농업용 저수지의 월류 및 붕괴에 따른 하류지역 침수 피해가 빈번하게 일어나고 있다. 농촌유역 침수 피해 저감을 위한 대책을 수립하기 위해서는 먼저 정확한 침수 피해 평가가 수행되어야 하지만, 우리나라에는 현재 농촌유역에 특화된 침수 피해 평가 체계가 부족한 실정이다. 본 연구에서는 농촌유역의 맞춤형 침수 피해 평가 체계를 개발하고자 한다. 농촌유역의 농업용 저수지를 포함한 농업수리구조물의 붕괴 등에 따른 하류 침수 모의 기법을 개발하고, 농작물의 종류를 고려한 침수심 및 침수시간에 따른 침수피해 모의 체계를 개발하고자 한다. 본 연구에서 개발한 농촌유역 맞춤형 침수 피해 평가 체계는 향후 농촌유역의 체계적인 재난관리를 위한 정책 수립에 활용될 수 있을 것으로 기대된다.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.169-178
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• 2021

BACKGROUND: The Ministry of Agriculture, Food and Rural Affairs is promoting agri-environment conservation program to induce farmers to participate in agricultural environment improvement and conservation activities. However, assessment tools based on scientific evidence are needed to determine the effectiveness of the program objectively and quantitatively. Therefore, this study was performed to develop plant indicators in order to efficiently evaluate the effects of the agri-environment conservation program promoted by the Ministry of Agriculture, Food and Rural Affairs. METHODS AND RESULTS: The survey was conducted in five regions (Hampyeong, Boryeong, Mungyeong, Hongseong, and Sangju) participating in the agri-eonvironment conservation program. In each region, twenty paddy fields were investigated (ten paddy fields included in the program and ten paddy fields not included in the program). A total of 231 taxa vascular plants were identified in the paddy fields that were included in the agri-environment conservation program, and a total of 177 taxa were identified in the paddy fields that were not included. The average species number occurred on each field was 55.8 taxa in the fields included in the program, and 35.0 taxa in the fields not included in the program. The difference in occurring plants between two groups was found to be more higher in perennial plants than in annual plants. We selected the six groups as indicator plants through five criteria such as perennial plants and broadly occurring species, etc. to verify the effectiveness of the agri-environment conservation program: Taraxacum spp., Ixeris spp., Viola spp., Platago spp., Calystegia spp., and rare and endagered species. There was a high positive correlation between the score calculated using these indicator plants and the total number of plants species. CONCLUSION: This study suggests that it is possible to evaluate the agro-ecological environment by using indicator plants. The selected indicator plants can be effectively used to verify the effectiveness of projects such as agri-environmental conservation programs in the future.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.219-230
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• 2021

BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.297-304
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• 2020

BACKGROUND: Emission of nitrous oxide (N2O) from the soil is expected to depend on the types of nitrogen fertilizer used. Biochar has recently been proposed as a potential mitigation of climate change by reducing the N2O emission. Although laboratory studies reported that biochar applications could reduce N2O emission, the number of field-based studies is still limited. Therefore, a field experiment was conducted to investigate the effect of biochar on N2O emission when different nitrogen fertilizers were applied in corn cultivated field. METHODS AND RESULTS: The field experiment consisted of six treatments: urea fertilizer without biochar (U), ammonium sulfate fertilizer without biochar (A), oil cake fertilizer without biochar (O), urea fertilizer with biochar (U+B), ammonium sulfate fertilizer with biochar (A+B), and oil cake fertilizer with biochar (O+B). Biochar was applied at a rate of 10 t/ha. Greenhouse gas fluxes were measured during growing seasons using static vented chambers. The cumulative N2O emissions were 0.99 kg/ha in the U, 1.23 kg/ha in the A, 3.25 kg/ha in the O, 1.19 kg/ha in the U+B, 0.86 kg/ha in the A+B, and 1.55 kg/ha in the O+B. CONCLUSION: It was found that N2O emission was related to application of both nitrogen fertilizer type and biochar. In particular, the N2O reduction effect was the highest in the corn field incorporated with biochar when oil cake was applied to the soil.

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.245-257
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• 2021

Ulleungdo, a volcanic island, has different climate, soil, and topography characteristics from inland of the Korean Peninsula. Its agriculture also exhibits distinctive features. This study focused on floristic compositions and characteristics of crop lands in Ulleungdo. Flora surveys were conducted for 37 areas three times, one in May of 2016, one in July of 2020, and one in August of 2020. Results showed that vascular plants of crop lands in Ulleungdo included 186 taxa of 53 families, 132 genera, 160 species, 14 varieties, five subspecies, and five hybrids. Asteraceae had the most diverse species (33 taxa), followed by Poaceae (25 taxa), Fabaceae (12 taxa), Polygonaceae (11 taxa), and Liliaceae (nine taxa). The biological type of crop lands in Ulleungdo island was determined to be Th-R₅-D₄-e type. Rare plants were found for nine taxa: Athyrium acutipinnulum Kodama ex Nakai, Sedum takasimense Nakai, Rubus takesimensis Nakai, Dystaenia takesimana (Nakai) Kitag., Ligustrum foliosum Nakai, Aster pseudoglehni Y.Lim, Cirsium nipponicum (Maxim.) Makino, Lilium hansonii Leichtlin ex D.D.T.Moore, and Polygonatum robustum (Korsh.) Nakai. In addition, 45 taxa contained naturalized plants of 13 families, 33 genera, 44 species, and one variety. Urbanization and naturalization indices were 13.9%, and 24.2%, respectively.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1379-1391
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• 2020

UAV in the agricultural application are capable of collecting ultra-high resolution image. It is possible to obtain timeliness images for phenological phases of the crop. However, the UAV uses a variety of sensors and multi-temporal images according to the environment. Therefore, it is essential to use normalized image data for time series image application for crop monitoring. This study analyzed the variability of UAV reflectance and vegetation index according to Aviation Image Making Environment to utilize the UAV multispectral image for agricultural monitoring time series. The variability of the reflectance according to environmental factors such as altitude, direction, time, and cloud was very large, ranging from 8% to 11%, but the vegetation index variability was stable, ranging from 1% to 5%. This phenomenon is believed to have various causes such as the characteristics of the UAV multispectral sensor and the normalization of the post-processing program. In order to utilize the time series of unmanned aerial vehicles, it is recommended to use the same ratio function as the vegetation index, and it is recommended to minimize the variability of time series images by setting the same time, altitude and direction as possible.

• Korean Journal of Remote Sensing
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• v.36 no.6_2
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• pp.1523-1535
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• 2020

In order to produce crop information using remote sensing, we use classification and growth monitoring based on crop phenology. Therefore, time-series satellite images with a short period are required. However, there are limitations to acquiring time-series satellite data, so it is necessary to use fusion with other earth observation satellites. Before fusion of various satellite image data, it is necessary to overcome the inherent difference in radiometric characteristics of satellites. This study performed Korea Multi-Purpose Satellite-3 (KOMPSAT-3) cross calibration with Landsat-8 as the first step for fusion. Top of Atmosphere (TOA) Reflectance was compared by applying Spectral Band Adjustment Factor (SBAF) to each satellite using hyperspectral sensor band aggregation. As a result of cross calibration, KOMPSAT-3 and Landsat-8 satellites showed a difference in reflectance of less than 4% in Blue, Green, and Red bands, and 6% in NIR bands. KOMPSAT-3, without on-board calibrator, idicate lower radiometric stability compared to ladnsat-8. In the future, efforts are needed to produce normalized reflectance data through BRDF (Bidirectional reflectance distribution function) correction and SBAF application for spectral characteristics of agricultural land.

• Journal of Agricultural Extension & Community Development
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• v.19 no.4
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• pp.833-857
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• 2012

This study was carried out aiming to provide information and enhance the satisfaction of real-time smartphones users on Rural Amenity Resources Information Services. For this purpose, domestic and international discussions and surveys on technology developments and expert analysis smartphone technology were reviewed. And empirical data were collected from 600 people through structured questionnaires including smart-phone experience, smartphone usage behavior, the required content, service items, service quality, Through this information, the content of rural amenity resources, how to take advantage of smart phones. Service Plan and developed, and a rural village locations to target mobile phone technology, the content was established. Through the preference analysis of the collected data, we designed the contents of rural amenity resources information based on smart-phone. It will be helpful to enhance the interchange between urban and rural such as farmer's market and rural tourism.