• 한국환경농학회지
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• 제27권1호
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• pp.10-17
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• 2008

The objective of this study was to estimate the pollutant loads from paddy fields by cultivation practices using a non-point-sources models. One of them is CREAMS-PADDY model that was developed considering the water balance and mass balance of paddy fields. The CREAMS-PADDY model was applied to provide basic data to reduce runoff loadings under various scenarios such as various water management control and various fertilizer condition. The model was verified against T-N, T-P and runoff flow data collected during cropping periods at 2000. The model results agreed well with the measured data in verification. The results showed that the model could be used for estimating the runoff loadings from irrigated paddy fields by cultivation practices was possible. Comparison of simulated the standard height and the sluice management of T-N and T-P runoff loadings from paddy fields were +32.4%, +10.3% in 10 mm below the standard height, -29.2%, -35.9% in 20 mm above the standard height, 52.6%, 59.0% in 40 mm above the standard height, respectively. Comparison of simulated the standard fertilizer and the fertilizer control of T-N and T-P runoff loadings from paddy fields were -1.3%, -21.7%in reduction of conventional fertilizer 30%, -1.0%, -12.5% in reduction of standard fertilizer 30%, respectively. Therefore, reducing nonpoint-sources nutrient loading by reducing fertilization may not work well in the range of normal paddy rice farming practices, and instead it could be achieved by reducing surface drainage outflow.

• 한국농공학회논문집
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• 제49권5호
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• pp.67-77
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• 2007

The images of MODerate resolution Imaging Spectroradiometer (MODIS) that provide wider swath and shorter revisit frequency than Land Satellite (Landsat) and Satellite Pour I' Observation de la Terre (SPOT) has been used fer land cover classification with better spatial resolution than National Oceanic and Atmosphere Administration/Advanced Very High Resolution Radiometer (NOAA/AVHRR)'s images. Due to the advantages of MODIS, several researches have conducted, however the results for the land cover classification using MODIS images have less accuracy of classification in small areas because of low spatial resolution. In this study, uncertainty of paddy fields classification using MODIS images was conducted in the region of Gyeonggi-do and the relation between this uncertainty of estimating paddy fields and topographical factors was also explained. The accuracy of classified paddy fields was compared with the land cover map of Environmental Geographic Information System (EGIS) in 2001 classified using Landsat images. Uncertainty of paddy fields classification was analyzed about the elevation and slope from the 30m resolution Digital Elevation Model (DEM) provided in EGIS. As a result of paddy classification, user's accuracy was about 41.5% and producer's accuracy was 57.6%. About 59% extracted paddy fields represented over 50 uncertainty in one hundred scale and about 18% extracted paddy fields showed 100 uncertainty. It is considered that several land covers mixed in a MODIS pixel influenced on extracted results and most classified paddy fields were distributed through elevation I, II and slope A region.

• 한국작물학회지
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• 제43권4호
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• pp.254-258
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• 1998

Distribution and occurrence of weedy rice in Kyonggi region were surveyed in 1996. Weedy rice was observed in 1368 fields (54.9%) of total 2490 fields. Almost two thirds of paddy fields in northern mountainous region were contaminated by weedy rice and more severe contamination, three forths of paddy fields, was observed in suburban regions. In those regions, occurrence of weedy rice was greater than those in north-eastern inland and south-western plain regions. The occurrence of weedy rice was higher in water seeding cultivation (66.7%) than other cultivation methods. The number of weedy rice per 10a was 756.7 plants in direct seeding on dry paddy and 379.4 plants in water seeding. The occurrence of weedy rice was higher in fields planted by farmer's seeds than that of paddy fields cultivated by certified seeds, and the longer the farmer's seeds being used, the more weedy rice occurred in paddy field.

• 한국환경복원기술학회지
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• 제16권5호
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• pp.19-26
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• 2013

This study was carried out to provide preliminary data for increasing biodiversity in agricultural ecosystem and investigate availability of using Tubificidae spp. for environment-friendly agriculture through the survey of growth of Tubificidae spp. in flooded paddy fields during winter. We estimated the number of Tubificidae spp. in rice paddy where had been flooded during the previous winter in Ganghwa-gun, Suwon-si, and Hwaseong-si (Bongdam-eup and Paltan-myeon) between March and April from 2010 to 2012. During growing period of rice, the number of Tubificidae spp. was compared between flooded and non-flooded paddy field in Ganghwa-gun. As results, mean density of Tubificidae spp. in winter flooded paddy field was 7,235.5 $ind./m^2$ in Ganghwa-gun, 14,347.5 $ind./m^2$ in Suwon-si, 59,989.9 $ind./m^2$ in Bongdam-eup, and 2,610.6 $ind./m^2$ in Paltan-myeon. Mean density of Tubificidae spp. was the highest in flooded paddy fields of Bongdam-eup that was kept wet until rice harvest time and had shallow water. While mean density was the lowest in Paltan-myeon where had deep water and later flooded paddy field than others. In Ganghwa-gun, during growing period of rice, mean density of Tubificidae spp. in flooded paddy fields (171,109.0 $ind./m^2$) and flooded fallow paddy fields (321,084.2 $ind./m^2$) was much higher than non-flooded paddy fields (1,006.6 $ind./m^2$). Flooded paddy field during winter can help increase the number of Tubificidae spp. which can control weeds and enhance biodiversity in paddy fields for environment-friendly agriculture. Early flooding and shallow water of paddy fields could be a good agriculture practice to encourage the growth of Tubificidae spp..

• 한국환경농학회지
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• 제13권1호
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• pp.98-110
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• 1994

논 주변에 서식하는 거미의 종류, 우점종, 월동상태, 증식상황, 이동상황, 년중 밀도변동상황 등을 파악하여 종합적 해충방제체계에 있어서 논거미의 보호 및 활용방안을 모색하고자, 경남 진주와 남해에서 1987년 12월부터 1988년 12월까지 논주변을 논둑, 보리밭, 휴한답, 본답 등으로 나누어 월 2${\sim}$4회 채집하고 종류와, 각 발육태별 밀도를 조사한 결과는 다음과 같다. 1. 거미는 총 10과 31속 34종이 채집되며, 논둑에서 34종, 보리밭에서 16종, 휴한답에서 17종, 본답에서 18종으로 나타나 논둑에서 종 구성이 다양하였다. 2. 진주와 남해의 각 채집장소별 논둑과 보리밭에서는 별늑대거미(Pardosa astrigera L. Koch), 휴한답에서는 황산적거미(Pirata subpiraticus (B. et S.)), 본답에서는 턱거미(Pachygnatha clercki Sunduvall)로 나타났다. 3. 논 주변 거미의 서식장소, 월동태, 거미줄 유무등 생태학적 특성과 과(科)(Family) 또는 속(屬)(Genera) 수준의 분류학적 특징으로 다음과 같은 9개의 거미군(Group)으로 분류할 수 있었다. Group 1 - 부이표늑대거미류(Pirata spp.); Group 2 - 턱거미류(Pachygnatha clercki); Group 3 - 소형정주성거미류(Theridiidae, Erigonidae, Linypiidae); Group 4 - 갈거미류(Tetragnatha spp.); Group 5 - 황닷거미류(Dolomedes surfureus); Group 6 - 긴마디늑대거미류(Pardosa spp.). Group 7 - 깡충거미류(Salticidae); Group 8 - 게거미류(Thomisidae); Group 9 - 염낭거미류(Clubionidae); 4. 9개 거미군 중 1-5군은 호습성 거미류로서 본 답기에 벼해충의 중요한 천적으로 여겨지며, 6-9군은 건조한 곳을 선호하는 거미류로서 논둑에서 월동중인 애멸구와 끝동매미충의 천적으로서 역할이 클 것으로 인식되었다.

• 한국토양비료학회지
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• 제49권3호
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• pp.275-281
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• 2016

The aim of this study was to examine the selected soil chemical properties of paddy fields in different topographic areas to efficiently manage nutrient valances of the paddy fields in Jeonbuk Province. Three-hundred soil sampling sites in paddy fields were selected from the different topographic areas in Jeonbuk Province. The soil samples were collected every four years from 1999 to 2015. Soil pH and exchangeable K and Mg concentrations declined during the experimental periods. However, almost all the chemical properties were within the proper levels for paddy soil, except exchangeable Mg concentration. Distributed areas of the paddy fields with soil pH below 5.5 continuously increased, but the paddy fields with lower concentrations of soil organic matter and available $P_2O_5$ than the proper levels declined after 2007. In addition, the paddy fields with available $SiO_2$ below the proper concentration decreased from 83.3% of the total paddy fields studied in 1999 to 61.0% of the total fields investigated in 2015. The paddy fields with lower exchangeable K and Mg than the proper levels increased after 2003 whereas the fields with lower exchangeable Ca concentration decreased. Dominant landform of coastal and plain areas was fluvio-marine plains that was distributed in 53.7% and 40.9%, respectively. Local valley and fans was a dominant landform of mountainous and middle-mountainous areas, which was 51.8% and 67.6%, respectively. Dominant soil textures distributed in coastal and plain areas were silty loam and loam. Those in mountainous and middle-mountainous areas were sandy loam and loam, respectively. Soil pH was relatively higher in coastal area and the comparatively higher content of soil organic matter was found in costal area than other areas. The concentrations of available $P_2O_5$, exchangeable Ca, and exchangeable Mg were generally higher in mountainous, coastal, plain areas, respectively, but available $SiO_2$ and exchangeable K concentrations were not significantly different among the different topographic areas.

• Ecology and Resilient Infrastructure
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• 제9권1호
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• pp.15-23
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• 2022

본 연구는 관행과 유기논에 서식하는 저서성대형무척추동물의 군집특성 및 군집안정성을 알아보고자 수행되었다. 조사는 2009년부터 2011년까지 수원, 안성, 보은, 군산, 김제, 함양 등 6개 지역의 유기논과 관행논을 대상으로 1년에 5회에 걸쳐 실시하였다. 전 지점에서 출현한 저서성대형무척추동추동물은 총 3문 6강 16목 47과 84종이었다. 서식기능군은 기어오르는무리 (Climbers), 헤엄치는무리 (Swimmers), 기는무리 (Sprawlers)가 대부분을 차지하였으며, 섭식기능군은 잡아먹는무리 (Predators)인 잠자리목 (Odonata), 딱정벌레목 (Coleoptera), 노린재목 (Hemiptera)이 대부분을 차지하는 것으로 나타났으나, 관행과 유기논에서 군집구조의 확연한 차이는 나타나지 않았다. 관행논과 유기논에서의 군집안정성 분석에서는 관행논에 비해 유기논에서 I 그룹에 속하는 종인 애물땡땡이 (Sternolophus rufipes), 잔물땡땡이 (Hydrochara affinis), 좀물땡땡이 (Helochares nipponicus) 등 이동성이 강한 종과 자연생태계에서 서식하는 고추잠자리 (Crocothemis servilia)가 비교적 중요한 종인 것으로 나타났다. 결론적으로 1차 소비자인 깔따구류 (Chironomidae spp.), 모기류 (Dixidae sp.) 등이 풍부한 유기논에서는 이를 먹이원으로 하는 딱정벌레류의 도입이 관행논보다 더 높은 것으로 나타났다.

• 한국작물학회지
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• 제23권1호
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• pp.60-63
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• 1978

우리나라 서 . 남해안 간척지의 매자기 분포상황을 알기 위해서 전간척지 면적의 약 29%에 해당하는지역에 대해 설간 및 현지조사를 실시하였다. 1. 매자기는 우리나라 중부의 경기도 강화군으로부터 남부인 전남의 양도, 고흥군에 이르기까지 전간척지에 분포되어 있다. 2. 전체 간척지의 평균 침입정도는 5 단계평가로 4.09에 이르고 있다. 3. 전체 조사지역중 73.04%가 평점 5및 4에 속하였다. 4. 전체 사사지역 어디에서나 매자기는 모내기 전과후 두차례에 걸쳐 발생하고 있었다.

• 한국농공학회지
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• 제44권5호
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• pp.106-115
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• 2002

The objective of this study was to evaluate the GLEAMS-PADDY model by applying it to estimate nutrients loading from paddy-field areas. Field data from Soro region of Chungbuk province during May to September 1999 were used for model application. Field data collected include the amounts of rainfall, irrigation water, drainage water, ET, and Percolation in hydrology Part. T-N and T-P concentrations in the rain water, irrigation water, ponded water, drainage water and percolated water were measured. The comparisons of observed and simulated water balance components and nutrient concentrations showed reasonably good agreements and the GLEAMS-PADDY model may be used to simulate nutrients loading from paddy fields. Futher research was suggested to include the erosion submodel in the GLEAMS-PADDY model to better simulate the nutrient behavior. In addition, the pesticide submodel also recommended to be included in order to simulate the various pesticide applied in paddy fields.

• 한국환경농학회지
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• 제40권4호
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• pp.295-312
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• 2021

BACKGROUND: Global warming is one of the most pressing environmental issues which concomitantly complicates global climate change. Methane emission is a balance between methanogenesis and methane consumption, both of which are driven by microbial actions in different ecosystems producing methane, one of the major greenhouse gases. Paddy fields are major sources of anthropogenic methane emissions and could be compounded by organic fertilization. METHODS AND RESULTS: Literature reviews were conducted to give an overview of the global warming conditions and to present the relationship of carbon and methane to greenhouse gas emissions, and the need to understand the underlying processes of methane emission. A more extensive review was done from studies on methane emission in paddy fields under organic fertilization with greater emphasis on long term amendments. Changes in paddy soils due to organic fertilization include alterations of the physicochemical properties and changes in biological components. There are diverse phylogenetic groups of methanogens and methane oxidizing bacteria involved in methane emission. Also, multiple factors influence methanogenesis and methane oxidation in rice paddy fields under organic fertilization and they should be greatly considered when developing mitigating steps in methane emission in paddy fields especially under long term organic fertilization. CONCLUSION(S): This review showed that organic fertilization, particularly for long term management practices, influenced both physicochemical and biological components of the paddy fields which could ultimately affect methanogenesis, methane oxidation, and methane emission. Understanding interrelated factors affecting methane emission helps create ways to mitigate their impact on global warming and climate change.