• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.73-80
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• 2023

This study was conducted to analyze changes of irrigation water and soil volumetric water content by irrigation method of field soil in Saemangeum reclaimed tideland. The main test irrigation methods was surface drip irrigation, sprinkler irrigation, and sub drip irrigation. In addition, the correlation between irrigation amounts and crop yield by irrigation method was investigated. For soil volumetric water contents increases by 25%, surface drip irrigation took 1.5 hour, sprinkler irrigation took 2.0 hours, and sub drip irrigation took 3.0 hours. As a result of analyzing the irrigation amounts according to the yield, the surface drip irrigation was 2.66 mm/day in the seedling stages, 3.31 mm/day in the vegetative growth stages, and 5.09 mm/day in the flowering stages. Sprinkler irrigation was 2.90 mm/day in the seedling stages, 3.87 mm/day in the vegetative growth stages, and 7.11 mm/day in the flowering stages. Sub drip irrigation was 2.42 mm/day in the seedling stages, 3.09 mm/day in the vegetative growth stages, and 4.87 mm/day in the flowering stages. It was analyzed that there was a statistically significant difference in irrigation amounts by fresh weight and irrigation method (F=4.002, p=0.022), and irrigation amounts by dry weight and irrigation method (F=3.499 p=0.034). Surface drip irrigation was judged to be more appropriate than sprinkler irrigation or sub drip irrigation for field crops in Saemangeum reclaimed land.

• Journal of Radiation Protection and Research
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• v.36 no.4
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• pp.209-215
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• 2011

In order to investigate the soil-to-plant transfer factor (TF) of $^{99}Tc$ for Korean major upland crops (soybean, radish and Chinese cabbage), pot experiments were performed in a greenhouse. Soils were collected from four upland fields (two for soybean and two for radish and Chinese cabbage) around Gyeongju radioactive-waste disposal site. Three to four weeks before sowing, dried soils were mixed with a $^{99}Tc$ solution and the mixtures were put into pots and irrigated. TF values were expressed as the ratios of the $^{99}Tc$ concentrations in plants (Bq $kg^{-1}$-dry or fresh) to those in soils (Bq $kg^{-1}$-dry). There was no great difference in the TF value between soils. The TF values for soybean seeds were extremely lower than those for the straws, indicating a very low mobility of $^{99}Tc$ to seeds. As representative TF values of $^{99}Tc$, $1.8{\times}10^{-1}$, $1.2{\times}10^1$, $3.2{\times}10^2$ and $1.3{\times}10^2$ (for dry plants), arithmetic means for two soils, were proposed for soybean seeds, radish roots, radish leaves and Chinese cabbage leaves, respectively. In the case of the vegetables, proposals for fresh plants were also made. The proposed values are not sufficiently representative so successive updates are needed.

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.481-488
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• 2007

This study covers the relationship between land use and water quality items. The kinds of land used in this study were almost agricultural areas with paddy fields and mountains. We set up zones at intervals of 200 m along 48 watersheds all over the country. The analysis showed high relationship between the water quality and the land use specially on the areas in the 400 m radius from the stream so that the areas needed to have strict managements. In the cases of residential area and upland, the positive correlation had a tendency to be lower when they were farther away from the stream. It depended on the increase of rainfall during July and August which affected on the water quality of reservoirs. The correlation analysis of paddy fields resulted in negative relationship, which indicated that paddy fields did not have negative effect on the quality of the stream. Through adequate irrigation and Management, paddy fields may be led to have positive effect on the quality of the reservoirs. In the case of forest, it also resulted in negative correlation so it was concerned as a positive factor which helped to improve water quality. Furthermore more than 00% of the land used in this study is comprised of forest so that it would have a positive effect on the reservoir management.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.913-917
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• 2006

K-WEAP은 수자원 지속적 확보기술개발사업의 일환으로 개발된 프로그램으로 용수이용에 대한 정책 시나리오 설정과 용수관리가 용이하게 설계되어 사용자와 정책결정자가 이해할 수 있는 일반적인 과정과 합리적인 결과를 제공한다. 본 연구에서는 경상북도 성주군에 위치한 성주댐 유역을 대상으로 각 수요처의 용수수급요인을 데이터베이스로 구축하고 증발산량, 유효우량, 토양수분 등 실제 현장의 여러 여건을 고려한 농업용수 산정 값과 용수수요 및 공급에 영향을 주는 경제, 인구 등의 시나리오 구성 구동인자를 K-WEAP에 적용하여 2002년${\sim}$2011년까지 총 10개년 대상유역의 수요-공급량의 변화를 모의 분석하였다. 그 결과 성주댐 유역의 모든 수요처는 약 98.45%의 용수충족률이 나타났으며, 이 결과가 밭용수의 공급원을 지하수가 아닌 성주댐으로하여 K-WEAP에 적용하였음을 감안할 때 각 대상 수요처에서 만족된 용수충족률이 100% 가능한 것으로 분석되었다. 또한 K-WEAP에 적용한 기준시나리오에 새로운 수요처의 추가와 하천유지용수의 증가 등 수요관리에 변화를 주어 10개년 대상유역의 물수지 변화를 모의.분석하였으며, 그 결과 각 대상 수요처들은 수원공인 성주댐으로부터 충분한 용수공급이 가능한 것으로 분석되었다.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.2
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• pp.3-12
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• 2005

The objective of this study is securement of upland irrigation water using storage level management of small dams. However, it is not new development of water resources but securement of water using storage level management of existing dam. This study has enhanced the water utilization coefficient of dam, after extra available water had been calculated by application of periodical management storage level and this water is used to other water like the upland irrigation water demand. As the result of application, it can secure extra available water except the water requirement. Minimum extra available water except flood is about $20,000,000\;m^3$ and crop irrigation water demand of 10yr frequency is about $2,033,000\;m^3$ in Seongju. The utilization of crop irrigation water can be possible. And extra available water is about $3,102,000\;m^3$ in 2000, $1,959,000\;m^3$ in 2001 except flood period and crop irrigation water demand of 10yr frequency is about $2,272,000\;m^3$ in Donghwa. It is judged that extra available water cannot be used to crop irrigation water during the dry season in Dongwha. Consequently, when management storage level is determined and more efficient use of water is gotten like this study, water utilization coefficient will be enhanced.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.363-363
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• 2017

각 기관에서는 가뭄상황을 모니터링하기 위해서 기관의 역할에 맞는 방식으로 가뭄지수를 산정하여 표출하고 있다. 국민안전처에서는 2016년 3월부터 부처간 협동으로 우리나라의 가뭄 상황을 기상학적 가뭄, 농업적 가뭄, 수문학적 가뭄으로 구분하여 행정구역단위로 주의, 심각, 매우심각의 3단계로 표출하여 활용하고 있다. 저류시설 등을 고려하여 가뭄지수를 도출하고 가뭄을 세가지 속성으로 나누어서 표출하는 것은 타당하지만, 동일한 행정구역 상에서 각 가뭄속성을 표현하는 것은 실제적인 가뭄상황의 판단과 적절한 전략적 대응을 위해서는 개선될 필요가 있다. 본 연구에서는 토지이용도를 기반으로 용수 이용 상황과 용수공급을 위한 사회기반시설을 고려해서 가뭄상황의 표현을 위한 구역의 재설정과 각 구역별로 적절한 가뭄지수의 적용 및 상황파악에 도움을 줄 수 있는 통계적 지표를 동시에 제공할 수 있는 프레임워크를 설계하고 이를 테스트베드를 대상으로 시범적으로 구현하였다. 산림이나 초지 지역, 관개시설에 의한 용수공급을 받는 논지역, 강수의존형 논지역과 밭지역, 광역상수도나 지방상수도에 의한 공급지역, 기타 생공용수 공급지역 등으로 구분하여 기상학적 가뭄, 농업적 가뭄, 수문학적 가뭄 상황이 동일 행정구역내에서도 서로 다른 값을 가질 수 있도록 하였다.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1203-1210
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• 2012

As the area of upland crops increase, it is become more important for farmers to understand status of soil water at their own fields due to key role of proper irrigation. In order to estimate daily water balance and soil water content with simple weather data and irrigation records, we have developed the model for estimating water balance and soil water content, called AFKAE0.5, and verified its simulated results comparing with daily change of soil water content observed by soil profile moisture sensors. AFKAE0.5 has two hypothesis before establishing its system. The first is the soil in the model has 300 mm in depth with soil texture. And the second is to simplify water movement between the subjected soil and beneath soil dividing 3 categories which is defined by soil water potential. AFKAE0.5 characterized with determining the amount of upward and downward water between the subjected soil and beneath soil. As a result of simulation of AFKAE0.5 at Gongju region with red pepper cultivation in 2005, the water balance with input minus output is recorded as - 88 mm. the amount of input water as precipitation, irrigation, and upward water is annually 1,043, 0, and 207 mm, on the other, output as evapotranspiration, run-off, and percolation is 831, 309, and 161 mm, respectively.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.220-226
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• 2007

For the analysis of hazard factors and the development of GAP (Good Agricultural Practices) Ginseng, 10 ginseng cultural farms wished certified GAP were selected at Geumsan-gun area, a representative site of ginseng cultivation in Korea. In order to verify the safety of GAP ginseng, possible contamination of pesticide and heavy metal residues, and microbial hazard were analyzed. Soil and water around ginseng cultivation field, and ginseng were investigated. Eighty-one pesticides including carbendazim were used as typical pesticide against plant pathogens and insect pests of ginseng plant and general crops. There was no excess the maximum residue limit (MRL) in residue figure of the soil. Including the residue figure of the arsenic (0.81 ml/kg) and 7 other heavy metals was also suitable to cultivate the ginseng plant. The irrigation water and dilution water for pesticide application were also safety level for GAP. Fresh ginsengs from the farms were sampled and investigated pesticide residues and contaminations of bacteria. Among 23 pesticides tested, we didn't detect any kinds of pesticide residues, but tolclofos-methyl was frequently found in the other ginseng field. On the investigation of microorganism hazards, 2 gram negative bacteria and 1 gram positive bacterium were found in the fresh ginseng. Number of total bacteria was $1.5{\times}10^3$ cfu/ml, which was less than the other agriculture products. At these results, 10 selected ginseng farms were good cultural places for GAP ginseng production and the ginseng cultured from Geumsan-gun area were a good safe far human.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.204-213
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• 2012

The objectives of this research were to estimate nitrogen budgets in agriculture and livestock in 2010, and to evaluate nitrous oxide ($N_2O$) emission by a local government. Input-output budgets for nitrogen were categorized into two sections including agriculture and livestock. Fertilizer, deposition, fixation, compost, irrigation, and feed were used as the nitrogen inputs while crop production, crop uptake, denitrification, volatilization, leaching, compost, and ocean disposal were used as the nitrogen outputs. Annual nitrogen input and output for agriculture and livestock were 1,148,848 N ton/yr and 610,380 N ton/yr respectively indicating the decrease of the nitrogen input and output, compared to our previous researches in 2005 and 2008. Total nitrogen input in 16 local government was estimated resulting that $N_2O$ emission was the highest for Jeonnam (2,574 ton/yr) and the lowest for Seoul (7 ton/yr).

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.492-499
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• 2009

Effect of drip irrigation on soil salinity control and growth of vegetable crops was studied in the three reclaimed lands of Korea in 2007. Drip irrigation was done one or two times per month for reduction of salt stress by using vinyl hose with tiny holes laid on ridge surface under black plastic film mulch during growing season of cabbage and chinese cabbage. It was observed that drip irrigation was generally effective to soil salinity control, but soil salinity variation of some place was not fully solved to lower down under level of free salt stress. It is also considered that high salinity of runoff water spilled out from cultivation ridge plays another key role for soil salinity management. Consequentially, this soil salinity variation might be one of factors brought low average yield and low commercial ratio of agricultural products. Relation between soil salinity and head growth of cabbage and chinese cabbage was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the heaviest head can be estimated was $6.1dS^{\circ}{\S}m^{-1}$ for cabbage and $5.7dS\;m^{-1}$ for chinese cabbage transplanted at optimum season.