• 한국관개배수논문집
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• 제18권1호
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• pp.4-17
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• 2011

The standard design methodology was suggested to construct wetland system for reducing non-point source pollution from Saemangeum reclaimed paddy land. To set for the design flow and concentrations, runoff and water quality survey were conducted during the irrigation period in 2008 at Gyehwa reclaimed paddy land located at near Saemangeum lake. It is rational that 1ha is the optimum constructed wetland size. To meet this size, the moderate drainage area of reclaimed paddy field was 50ha under the conditions that rainfall is 30mm, average runoff coefficient is 0.83, and runoff capture ratio is 0.6. At these condition, the runoff volume from 50ha was 10,520 $m^3/d$ including base flow during irrigation period. To select the optimum wetland system, several case studies were conducted by focusing on the tidal reclaimed land areas having wetland systems in Seokmun. Pond-Wetland system was selected as the standard model because of showing the highest reduction efficiency. Single variable regression equation were delivered to estimate effluent water concentrations from the designed wetland by using long-term monitoring data from the Seokmun experiment site. The effluent concentration from the designed wetland using these equation were showed moderately range.

• 한국환경농학회지
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• 제27권4호
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• pp.464-473
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• 2008

Winter migratory birds gather in paddy rice fields to feed shed rice grains. The Korean Ministry of Environment has practiced a policy program Contract on Paddy Field Management (CPFM) during winter fallow since 2002. This program starts with a contract between local governments and farmers, and the government pays a differential subsidy to farmers who finish spreading rice straw, cultivating barley, letting the whole rice plant without harvest, and submerging paddy fields for winter migratory birds. As more local governments have operated CPFM program, the total area on the contract and subsidy budget has increased yearly since 2002. This program could have its stable position as a successful policy by giving profits to farmers. With the program extended, the population of winter migratory birds has been greatly. For the evaluation of environmental performance of a policy, we analyzed this CPFM program by introducing some indicators in the form of Driving Force-State-Response Framework. The indicators were composed of 3 categorized indicators; the area of paddy land contracted under this program as 'driving force' indicator, population of birds, the number of bird species and the amount of feces as 'state' indicators, and the size of monetary support, the number of farmers or local governments participating, and public perception as 'response' indicators. The contract area of paddy field under CPFM could be a good biodiversity indicator reflecting potential performance of this policy measure in the light of its linkage to the population of winter migratory birds. And the share of CPFM land of the whole agricultural land might also be used as a useful indicator of policy evaluation for improvement of wildlife diversity. The 'state' indicators such as population of birds and the number of bird species could be matched to 'driving force' indicator, but the total CPFM area of each site could not reflect the effect of areas under different management practices. However, the amount of bird feces could reflect differences in environmental performance with management practices as 'state' indicators. The development of indicators indicating 'response' such as farmers' behavior, public perception, and policy makers' willingness is also needed to support a successful implementation and improvement of this policy measure with the development of 'performance' indicators integrating all these indicators.

• 농촌계획
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• 제27권3호
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• pp.21-33
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• 2021

Rice straw management and winter crop cultivation are crucial components for the accurate estimation of paddy methane emissions. Field-based extensive investigation of paddy organic matter management requires enormous efforts however it becomes more feasible as drone technology advances. The objectives of this study were to identify paddy fields of straw application and winter crop cultivation using drone images and to apply for the estimation of yearly methane emission. Total 35 sites of over 150ha in area were selected nationwide as the study areas. Drone images of the study sites were taken twice during summer and winter in 2018 through 2019: Summer images were used to identify paddy cultivation areas, while winter images for straw and winter crop practices. Drone-image-based identification results were used to estimate paddy methane emission and compared with conventional method. As the result, mean areas for paddy, straw application and winter crop cultivation were 118.9ha, 12.0ha, and 11.3ha, respectively. Overall rice straw application rate were greater in Gyeonggi-do(20%) and Chungcheongnam-do(12%), while winter crop cultivation was greatest in Gyeongsangnam-do(30%) and Jeolla-do(27%). Yearly mean methane emission was estimated to be 226.2kg CH₄/ha/yr in this study and about 32% less when compared to 331.8kg CH₄/ha/yr estimated with the conventional method. This was primarily because of the lower rice straw application rate observed in this study, which was less than quarter the rate of 55.62% used for the conventional method. This indicates the necessity to use more accurate statistics of rice straw application as well as winter crop practices into paddy methane emission estimation. Thus it is recommended to further study to link drone technology with satellite image analysis in order to identify organic management practices at a paddy field level over extensive agricultural area.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.502-508
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• 2005

In order to assess the environmental risk of pesticides, information is usually required on the likelihood of exposure of organisms to the constituents of pesticides, expressed as a predicted environmental concentrations (PECs) and the likely effects of the constituents of pesticides on aquatic and terrestrial organisms, expressed as a predicted no-effect concentrations (PNECs). In this paper, the pesticide fate model, RICEWQ alone and coupled with the pesticide movement model, RIVWQ was used to simulate the potential for predicting the environmental concentrations of pesticides in paddy fields and adjacent surface water systems. The RICEWQ model was successfully calibrated against field data in poinding depth for paddy field. For the assessment of importance for water and pesticide management conditions and field scales, the integrated RICEWQ-RIVWQ model was simulated by the scenario analysis. The results of this study can be used as a basic information for assessing the environmental risk of pesticides.

• 한국농공학회논문집
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• 제53권6호
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• pp.51-58
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• 2011

The objective of this study is to identify whether or not the ground water level is decreasing. We suggest a method of estimating the change in groundwater level using newly developed groundwater pumping station data. The Goseong area located in Gyeongnam province was selected considering three factors. First, this area demands relatively large amount of irrigation water because most of the land is used as a paddy field and the proportion of the paddy field within total arable land is increasing. Second, groundwater level data in nearby area are available since these are monitored by Water Management Information System (WAMIS). Third, many groundwater pumping stations have been developed in this area in order to overcome droughts thus detail information for pumping stations are available. Regression results indicate groundwater level has been decreased for over 20 years. This decreasing trend is due to the shortage of surface irrigation water which was caused by the decrease in rainfall.

• 한국토양비료학회지
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• 제45권6호
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• pp.1194-1202
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• 2012

북한과 같이 접근이 힘들고 농업과 관련된 정보가 부족한 지역을 대상으로 RapidEye 위성영상의 판독 및 분류를 통하여 가장 기초적인 농업 현황과 생산 기반인 논 면적을 산정하였다. 291개의 RapidEye 영상을 이용하여 북한 전역을 대상으로 시기별로 논을 분류하기 위한 영상 판독 기준을 설정하였다. 5월 초에서 6월 말은 벼 이앙을 위해 관개를 하기 때문에 벼 이앙 전후에 물의 특성이 위성영상에서 잘 관측되기 때문에 영상이 어둡게 보이는 점을 이용하여 논과 다른 토지이용을 구분한다. 주요 벼 생육시기인 7월 초부터 9월 말에는 RapidEye 영상을 5:3:2 밴드조합으로 하여 영상을 판독하면 벼논의 색상과 질감의 차이를 이용하여 밭작물, 초지, 산림으로부터 논을 분류한다. 9월 말부터 10월 말은 벼 수확을 한 후로 논에 식생이 없는 시기로써 5:3:2 밴드 조합에서 회색빛이 나는 경지 형태를 대상을 논으로 판독한다. 그 결과 북한 전역에 대한 논 분포지도를 작성하였고 시도 행정구역별로 논 면적을 살펴보았다. 대부분의 논은 평안남북도와 황해남도가 위치한 서해안 평야지대에 전체 논 면적의 66% 정도인 $3,521km^2$가 분포하였고 함경남북도, 강원도, 나선시와 같이 동해에 인접한 지역의 논 면적은 $1,172km^2$로 전체 논 면적의 약 20%를 차지하는 것으로 나타났다. RapidEye 영상을 이용하여 분류한 논 면적은 2001년 및 2010년 FAO/WFP 북한 보고서와 비교할 때 각각 1% 이내의 면적 편차를 나타내었다. RapidEye 위성영상을 이용한 북한의 논 분류 결과는 농경지 이용 면적의 산정과 변화, 벼 수량 추정을 위한 마스킹 (masking) 자료로 활용될 수 있는 기본 자료로 의미가 매우 큰 것으로 판단된다. 향후에는 밭에 대한 분류 지도를 구축하고 나아가 옥수수와 같은 주요 밭작물에 대한 판독 방법에 대해서도 연구할 필요가 있을 것으로 생각된다.

• 한국작물학회지
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• 제60권1호
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• pp.33-40
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• 2015

재배환경에 따른 단백질 발현을 이차원전기영동을 이용하여 단백질 발현양상을 확인하고 이미지 분석을 통하여 단백질 발현 정도를 수치화하여 비교 분석한 결과, 재배환경에 따른 단백질 발현 양상은 전반적으로 매우 유사하였으며, 주요 단백질의 발현에는 차이가 없었다. 하지만 논과 밭, 즉 재배환경은 단백질의 발현 정도에는 영향을 미치는 것을 확인 할 수 있었다. 공시품종들 중에서 백천콩은 다른 세 품종과는 다르게 논에서 단백질 발현 정도가 밭에서의 단백질 발현 정도보다 높았다. 이 결과로 보아 품종마다 재배환경에 따른 단백질의 발현 정도에 차이가 있는 것으로 사료된다. 향후, 단백질 총 함량을 재배환경에 따라 비교하고 또한 질량분석을 통하여 증가 또는 감소되는 단백질의 기능을 확일 할 필요가 있다고 사료된다.

• 한국환경농학회지
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• 제30권4호
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• pp.377-381
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• 2011

본 연구는 논에서 돈분 액비 활용시 담수 시기에 따른 암모니아 휘산량을 평가하였다. 담수 상태에서 돈분 액비 시용은 142.0 mg/$m^2$ 의 암모니아 휘산량을 보인 반면, 돈분액비시용 1일 및 3일 후 담수시 암모니아 휘산량은 29.6, 25.4 mg/$m^2$ 였다. 그리고 담수 상태에서 돈분액비 시용이 돈분액비 시용 후 담수에 비해 높은 암모니아 휘산량을 보인 것은 암모니아가 토양교질에 흡착되지 않고 수중에 높은 농도로 존재하기 때문인 것으로 나타났다. 따라서 논에서 돈비 액비 활용시 암모니아 휘산량 저감에 의한 질소 이용도 향상을 위해서는 돈분액비 살포 최소 1일 후 담수하는 것이 좋을 것으로 판단된다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2004년도 학술발표논문집
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• pp.96-96
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• 2004

• 한국농공학회논문집
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• 제63권4호
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• pp.55-64
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• 2021

The expansion of upland crop cultivation in rice paddy fields is recommended by the Korean government to solve the problem of falling rice price and reduction of rice farmer's income due to oversupply of rice. However, water use efficiency is significantly influenced by the land use change from paddy field to upland. Therefore, this study aimed to evaluate the water budget of soybean grown in using APEX (Agricultural Policy and Environmental eXtender) model. The amount of runoff was measured in a test bed located in Iksan, Jeollabu-do and used to calibrate and validate the simulated runoff by APEX model. From 2019 to 2020, the water budget of soybean grown in uplands were estimated and compared with the one grown in paddy fields. The calibration result of AP EX model for runoff showed that R² (Coefficient of determination) and NSE (Nash-Sutcliffe efficiency) were 0.90 and 0.89, respectively. In addition, the validated results of R² and NSE were 0.81 and 0.62, respectively. The comparative study of each component in water budget showed that the amounts of evapotranspiration and percolation estimated by APEX model were 549.1 mm and 375.8mm, respectively. The direct runoff amount from upland was 390.1 mm, which was less than that from paddy fields. The average amount of irrigation water was 28.7 mm, which was very small compared to the one from paddy fields.