• 한국토양비료학회지
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• 제48권6호
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• pp.571-581
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• 2015

Soil moisture content is generally accepted as an important factor to understand the process of crop growth and is the basis of earth system models for analysis and prediction of the crop condition. To continuously monitor soil moisture changes at kilometer scale, it is demanded to create high resolution data from the current, several tens of kilometers. In this paper we described a downscaling method for Advanced Microwave Scanning Radiometer 2 (AMSR2) Soil Moisture Content (SMC) from 10 km to 30 m resolution using a soil texture and field measurements that have a high correlation with the SMC. As a result, the soil moisture variations of both data (before and after downscaling) were identical, and the Root Mean Square Error (RMSE) of SMC exhibited the low values. Also, time series analyses showed that three kinds of SMC data (field measurement, original AMSR2, and downscaled AMSR2) had very similar temporal variations. Our method can be applied to downscaling of other soil variables and can contribute to monitoring small-scale changes of soil moisture by providing high resolution data.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2019년도 하계 학술발표초록집
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• pp.232-233
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• 2019

• Carbon letters
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• 제16권4호
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• pp.265-269
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• 2015

• 한국토양비료학회지
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• 제50권4호
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• pp.306-317
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• 2017

Unmanned aerial vehicles (UAVs) became popular platforms for the collection of remotely sensed data in the last years. This study deals with the monitoring of multi-temporal onion growth with very high resolution by means of low-cost equipment. The concept of the monitoring was estimation of multi-temporal onion growth using normalized difference vegetation index (NDVI) and meteorological factors. For this study, UAV imagery was taken on the Changnyeong, Hapcheon and Muan regions eight times from early February to late June during the onion growing season. In precision agriculture frequent remote sensing on such scales during the vegetation period provided important spatial information on the crop status. Meanwhile, four plant growth parameters, plant height (P.H.), leaf number (L.N.), plant diameter (P.D.) and fresh weight (F.W.) were measured for about three hundred plants (twenty plants per plot) for each field campaign. Three meteorological factors included average temperature, rainfall and irradiation over an entire onion growth period. The multiple linear regression models were suggested by using stepwise regression in the extraction of independent variables. As a result, $NDVI_{UAV}$ and rainfall in the model explain 88% and 68% of the P.H. and F.W. with a root mean square error (RMSE) of 7.29 cm and 59.47 g, respectively. And $NDVI_{UAV}$ in the model explain 43% of the L.N. with a RMSE of 0.96. These lead to the result that the characteristics of variations in onion growth according to $NDVI_{UAV}$ and other meteorological factors were well reflected in the model.

• Nutrition Research and Practice
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• 제4권3호
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• pp.208-214
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• 2010

The objective of this research was to analyze nutritional status and food consumption of children participating in the Posyandu nutrition program. A total sample of 300 children under five years had been drawn. Sample was divided into two categories namely high participation and low participation in the Posyandu nutrition program. The sample was selected from two sub districts of Cianjur District, West Java. The districts were areas with a high proportion of poor people and many of them take the benefits of Posyandu nutrition program conducted by the government. The participation of children (under five years old) in visiting Posyandus was relatively good, namely, 92.4% (for the high participation group). However, for the low participation group, the number of participating children was relatively low (28.3%). The average consumption of energy for children under five years old was still below the recommended dietary allowance < 80% of RDA, whereas the protein consumption was already above the RDA. The prevalence of underweight, stunting, and wasting among children were respectively 30.0%, 43.7%, and 12.3%. The activities at Posyandus had a positive impact on the nutritional status of children under five years olds, measured in terms of weight for age (W/A) and weight for height (W/H). The more frequent the visit to Posyandus, the better the nutritional statuses would be.

• Journal of Crop Science and Biotechnology
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• 제11권3호
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• pp.193-198
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• 2008

To develop a natural re-seeding technology, the optimum soil incorporation time of Chinese milk vetch(CMV) plant residues, seed persistence in soil, biomass production and subsequent rice yield were determined from 2005 to 2007 in rice with CMV green manure in southern Korea. Generally, insufficient seedling stand was regenerated with CMV incorporation to the soil at 20 and 25 days after flowering(DAF), while high regeneration of greater than 400 seedlings per $m^2$ was observed at 35 and 40 DAF. High re-seeding stand of CMV incorporated at 35 DAF or later was related with high seed viability and heavy seed weight. Appreciable number of CMV seeds remained 4 month after burial in soil and a good number of CMV seedlings regenerated from this seed bank at rice harvest time in the fall. Based on the relationships among re-seeding number of CMV plants, seed weight and seed viability, CMV plants should be incorporated into the soil 35 DAF(May 30) or later when CMV seeds were sufficiently matured. The natural re-seeding stand for the 3-year trials was stable ranging from 437 to 700 plants per $m^2$ and the biomass production was sufficient to supply nitrogen for rice growth. The use of re-seeding CMV plant can produce similar rice yield like that of rice without CMV green manure.

• 한국농공학회논문집
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• 제61권5호
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• pp.33-47
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• 2019

The environmental ecological flow (EEF) of stream or river will be designated according to the enforcement of the Water Environment Preservation Act. Previous researches by Ministry of Environment have proposed agricultural reservoirs as alternative resources to secure river flow where multi-purpose dam does not exist. However, agricultural reservoirs are constructed for the supply of agricultural water, and in fact, there is not a sufficient amount of water to be supplied to rivers as EEF. Therefore, this study examines the economic feasibility of securing EEF through the remodeling or construction of agricultural reservoirs. We investigated water balance of reservoir through simulation of three types of water supply demands such as agricultural water, agricultural water and river maintenance flow, and agricultural water and environmental ecology flow. The economics analysis was conducted on water supply demands and corresponding remodeling or construction of reservoirs. As a result, it was found that the method of securing through heightening existing reservoir enhancement is economically feasible. However, it was not possible to secure all the amount of the EEF due to the size limitation of existing reservoirs or constrain of the watershed for newly built reservoir. Therefore, in order to secure all of the EEF, the utilization of other alternatives as well as agricultural reservoirs should be considered. This study demonstrated the method of economical feasibility study of securing river maintenace flow and EEF using agricultural reservoirs and other considerations.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.1013-1017
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• 2020

Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) harbor diverse microbial symbionts that play essential roles in host physiology, ecology, and evolution. In this study we aimed to reveal microbial communities associated with two different mealybugs, papaya mealybug (Paracoccus marginatus) and two-tailed mealybug (Ferrisia virgata) collected from the same host plant. Comparative analysis of microbial communities associated with these mealybugs revealed differences that appear to stem from phylogenetic associations and different nutritional requirements. This first report on both bacterial and fungal communities associated with these mealybugs provides a preliminary insight on factors affecting the endomicrobial communities.

• 한국응용곤충학회지
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• 제46권3호
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• pp.357-362
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• 2007

토양의 비옥도를 높여주는 분식성 곤충으로써 우리나라에 서식하고 있는 애기뿔소똥구리(Copris tripartitus)의 발육생태를 각 온도에서 관찰하였다. 대량증식 및 환경변화 모델 적용을 위해 15, 17.5, 20, 25, 27.5 및 $30^{\circ}C$(16L:8D)에서 발육실험을 한 결과 알에서 우화까지의 발육기간은 $17.5^{\circ}C$에서 118.0일이고, $27.5^{\circ}C$에서는 49.3일이었다. 온도가 높을수록 짧은 발육기간을 보였으며, 알, 유충, 용, 알에서 우화까지의 발육영점온도와 유효적산온도는 각각 12.1, 11.2, 12.1, $9.2^{\circ}C$, 그리고 82.7, 462.0, 225.7, 947.2일도이었다. 난 및 유충의 발육단계에서 사망률은 $25^{\circ}C$에서 가장 낮게 나타나 애기뿔소똥구리의 성장에 적합한 온도는 $25^{\circ}C$이었다.

• 한국토양비료학회지
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• 제39권1호
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• pp.38-45
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• 2006

질산태 질소의 이동에 대한 토양 특성과 경운의 영향을 구명하기 위하여 1993년부터 1994년까지 2년 동안 미국 일리노이주 중부지방의 몇 개 토양통이 다른 옥수수 포장에서 질산태 질소의 함량을 조사하였다. 1993년 포장에는 무수암모니아 $225kg\;ha^{-1}$을, 1994년 포장에는 URAN $115kg\;ha^{-1}$을 시용하였다. 1993년 초기 포장에 질산태질소의 함량은 토양 깊이 100 cm 까지 $20mg\;kg^{-1}$ 정도의 농도를 보였으나, 시용후 옥수수 재배 초기에는 질산태질소의 하향이동을 확인할 수 있었다. 또한 수확 후 토양중의 질산태질소의 함량은 유기물 함량이 보다 많은 Flanagan 및 Ipava 토양통에서 Saybrook 및 Catlin 토양통에 비해 높은 경향을 보였으나 유의적인 차이는 없었고, 무경운 포장에서 경운 포장에 비하여 질산태질소의 함량이 높게 나타났다. 이는 무경운에 의한 질산태질소의 지하수로의 용탈 감소를 의미한다.