• 한국물환경학회지
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• 제39권2호
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• pp.162-174
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• 2023

In order to prevent water pollution caused by organic matter, Total Organic Carbon(TOC) has been adopted indicator and monitored. TOC can be divided into Dissolved Organic Carbon(DOC) and Particulate Organic Carbon(POC). POC is largely precipitated and removed during stream flow, which making DOC environmentally significant. However, there are lack of studies to define spatio-temporal distributions of DOC in stream affected by various land use. Therefore, it is necessary to estimate the past DOC concentration using other water quality indicators to evaluate status of watershed management. In this study, DOC was estimated by correlation and regression analysis using three different organic matter indicators monitored in mixed land-use watersheds. The results of correlation analysis showed that DOC has the highest correlation with TOC. Based on the results of the correlation analysis, the single- and multiple-regression models were developed using Biochemical Oxygen Demand(BOD), Chemical Oxygen Demand(COD), and TOC. The results of the prediction accuracy for three different regression models showed that the single-regression model with TOC was better than those of the other multiple-regression models. The trend analysis using extended average concentration DOC data shows that DOC tends to decrease reflecting watershed management. This study could contribute to assessment and management of organic water pollution in mixed land-use watershed by suggesting methods for assessment of unmeasured DOC concentration.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 국제학술회의
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• pp.114-115
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• 2005

• 신재생에너지
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• 제4권4호
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• pp.56-64
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• 2008

Anaerobic biodegradability (AB), which can be determined with the ultimate methane yield by the decomposition of organic materials, is one of the important parameters for the design and the operation of anaerobic digestion plant. In this study, Biochemical methane potential (BMP) test has been carried out to evaluate the methane yields of animal manures such as pig and cattle slurries, and different forage crops cultivated at the reclaimed tideland such as maize, sorghum, barley, rye, Italian ryegrass (IRG), rape, rush, and waste sludge produced from slaughterhouse wastewater treatment plant (SSWTP). In the ultimate methane yield and biodegradability of animal manure, those of pig slurry were 345 $mlCH_4/gVS_{fed}$ and 44.7% higher than 247 $mlCH_4/gVS_{fed}$ and 46.4% of cattle slurry (Cat. 2). The ultimate methane yield and biodegradability of spike-crop rye (Rye 1) were 442.36 $mlCH_4/gVS_{fed}$ and 86.5% the highest among different forage crops, those of the other forage crops ranged from 306.6 to 379 $mlCH_4/gVS_{fed}$ of methane yield with the AB having the range of about 60 to 77%. Therefore the forage crops could be used as a good substrate to increase the methane production and to improve the biodegradability in anaerobic co-digestion together with animal manure.

• 한국농공학회지
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• 제26권1호
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• pp.29-37
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• 1984

This study was made to find several significant relations among various physical and mechanical properties including cone penetration resistance. The alluvial clay samples were taken at the Daebul Reclaimed Tideland in Samhomyeon, Yeongamgun, Jeonranamdo. The results of the study are summarized as follows; 1.Most samples belong to medium or high plastic, inorganic, silty clay(clay contents;32-64%, silt contents; 36-68%, sand contents; 0-3%). The specific gravities range from 2.70 to 2.73, the unit weights from 1.45 to 1. 75g/cm$^3$, the natural moisture contents from 45 to 77%, the liquid limits from 32 to 56%. It is certain that the foundation is weak because the natural moisture contents are much higher than the liquid limits. 2.It is known from the shear tests that the unconfined compression strenghs vary from 0.09 to 0. 38kg/cm2, the cohesions from 0.05 to 0. 21kg/cm2, the internal friction angles from 0 to 3˚. 3.The consolidation tests show that the initial void ratios range from 1.25 to 2.28, the compression indeices from 0.43 to 0.84, the preconsolidation loads from 0.21 to 0.74kg/cm$^2$. 4.Cone penetration resistances are usually less than 5kg/cm$^2$ from ground surface to the depth of about 8m, and from S to l0kg/cm$^2$ in the layer below about 8m to hard layer. 5.The cohesion and cone penetration resistance are in proportion to the depth of soil layer. 6.The correlations between various physical and mechanical properties including cone penetration resistance for the alluvial clay samples are as follows; a) Wn=0.944C+ l2.733 (r=0.829) b) LL=0. 728Cy+6. 991 (r=0. 873) c) PI=0.659Cy-8.168 (r=0.860) d) rt=0. 0077(272-Wn) =2.092-0. 0077Wn (r=0. 859) e) 60=0. 035wn-0 447 (r=0. 893) f) C=0.380qw+0.031 (r=0.816) g) qu=0.0707qc+0.029 (r=0.810) h) C=0.018Z+0.055 (r=O.802) I) qc=0. 415Z+1, 438 (r=0. 943)

• 한국환경농학회지
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• 제38권2호
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• pp.69-75
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• 2019

BACKGROUND: Measurement of electrical conductivity of saturated soil paste ($EC_e$) for assessment of soil salinity is time-consuming, and thus conversion of EC of 1:5 soil-water extract ($EC_{1:5}$) to $EC_e$ using a dilution factor may be of help to monitor salinity of huge number of soil samples. This study was conducted to evaluate the dilution factor for reclaimed tideland (RTL) soils of South Korea. METHODS AND RESULTS: Soil samples (n=40) were collected from four RTLs, and analyzed for $EC_{1:5}$, $EC_e$, and cation compositions of 1:5 soil-water extract. The dilution factor (8.70) was estimated by regression analysis between $EC_{1:5}$ and $EC_e$, and the obtained dilution factor was validated by applying to an independent data set (n=96) of $EC_{1:5}$ and $EC_e$. The $EC_e$ measured and predicted was strongly correlated ($r^2=0.74$, P<0.001), but $EC_e$ was overestimated by 16% particularly for the soils with high clay content and low sodium adsorption ratio (SAR). CONCLUSION: This study suggests that using the dilution factor to convert $EC_{1:5}$ to $EC_e$ is feasible method to monitor changes in the soil salinity of the study RTL. However, overestimation of $EC_e$ should be cautioned for the soils with high clay content and low SAR.

• 한국농공학회지
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• 제34권4호
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• pp.80-96
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• 1992

This study was carried out in order to determin optimum irrigation requirements and water management practices for normal growth of dry field crops in reclaimed tidelands, and apply m planning of the irrigation projects. Desalinization experiments were performed by water management practices in the experimental field with high salt concentration, and growth experiments were conducted by irrigation point treatments using tomato and beet with relatively high salt tolerance. The results obtained from this study were summarized as follows : 1. Leaching or rinsing-leaching method was found to be effective in desalinizing the reclaimed tideland with rather high permeability. In this case, the water requirement for desalinizing the root zone layer of 40cm in depth, was estimated to be 1,200mm in depth. 2.The gypsum treatment in the desalinization of reclaimed tidelands, was ineffective in water requirements ; however, it could produce the desired effect in the facility of desalinization and the shortening of desalinization period with the sustaining permeability, in case of the desalinization by leaching method. 3.The optimum irrigation point which maintains the salt concentration within salt tolerance and maximizes the crop yield in reclaimed tidelands of silt loam soil, was found to be pF 1.6 in tomato and pF 1.8 in beet. The interval of irrigation date within 2 days was proved to he effective in both cases. 4.The optimum irrigation requirement and the water reguirement for the prevention of salt rise during the growing period after transplanting, were estimated to be 602mm(6.7mm/day) and 232mm for tomato, respectively. 5.The optimum irrigation requirement and the water requirement for the prevention of salt rise during the growing period after transplanting, were estimated to be 261mm(3.7mm/day) and 66mm for beet, respectively.

• 한국초지조사료학회지
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• 제27권2호
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• pp.117-122
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• 2007

본 시험은 1984년에 방조제가 완공된 충남 당진군에 위치한 대호간척지($37^{\circ}\;N,\;126.4^{\circ}\;E$)의 한국농촌공사 시험연구포장에서 2004년 3월부터 2006년 10월까지 3년간 수행하였다. 여름 작물에서 출현율은 수수${\times}$수단그라스 파종구에서 $23%{\sim}30%$로 매우 낮았다. 겨울작물에서는 총체 벼 재배후 이탈리안 라이그라스 파종구에서 가장 높았다. 월동율은 총체 벼 재배 후 이탈리안 라이그라스 파종구가 가장 높았으며, 수수${\times}$수단그라스 재배후 총체보리 파종구가 가장 낮았다. 하작물과 동작물을 연계한 작부체계에서 ha당 생초 및 건물수량은 총체 벼+이탈리안 라이그라스(50,807kg, 15,065kg) 작부체계가 가장 수량이 높았으며, 수수${\times}$수단그라스+총체보리(17,247kg, 5,209kg)으로 가장 낮았다. ha당 조단백질 생산량은 총체 벼+총체보리 작부체계가 가장 높았다. TDN 생산량에서는 총체 벼+이탈리안 라이그라스 작부체계가 가장 높았다.

• Weed & Turfgrass Science
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• 제6권2호
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• pp.124-129
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• 2017

사료용 피 직파재배시 적정 파종량 시험에서 입모수는 파종량이 증가할수록 많았으며, 입모율은 41-42% 정도였다. 경수도 파종량이 증가할수록 많았고, 초장은 파종량이 많을수록 증가하였으나 $50kg\;ha^{-1}$에서는 감소하였다. 파종량이 많았던 $50kg\;ha^{-1}$에서 도복지수가 3이었다. 건물중은 파종량 $40kg\;ha^{-1}$에서 가장 높았고, TDN 생산량은 파종량이 적을수록 높았다. 수량반응 곡선상 $36kg\;ha^{-1}$에서 최대수량 건물수량이 추정되었다. 변화 상태의 회귀식은 $Y=0.0098X^2+0.7030X+2.6267$으로 표시되었다. 출수기는 파종량이 많을수록 늦어지는 경향이었다. 사료용 피 직파 재배시 질소질 비료 $150-250kg\;ha^{-1}$ 시비에서 건초 수량의 차이는 없었으나, 무시용 대비 건초 수량은 200 및 $250kg\;ha^{-1}$ 시비에서 16.6톤 $ha^{-1}$ 및 16.9톤 $ha^{-1}$로 43% 및 45% 정도 높았다. 조단백질 수량(CP)은 건물수량과 비슷한 경향으로 무질소구에서 0.28톤 $ha^{-1}$이었던 것이 질소 $250kg\;ha^{-1}$ 시비구에서 0.54톤 $ha^{-1}$ 이었다.

• 한국관개배수논문집
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• 제4권1호
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• pp.10-21
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• 1997

지상관측위성에 탑재된 센서로부터 얻어진 자료는 지리정보데이터로 그 이용이 증가되고 있다. 이 연구에서는 신규간척지에서의 토지이용계획을 수립하기 위하여 위성자료를 이용한 원격탐사와 지리정보 체계를 종합하는 방법의 적용가능성을 다루고 있다. 현재 공사중인 간척사업지구를 커버하는 LANDSAT TM, MOS, SPOT 디지털데이터를 영상화하고, 영산강 3단계 사업지구 유역의 토지이용 현황을 분석하였으며, 신규간척지의 토지이용계획을 위하여 동원가능한 데이터를

• 농업과학연구
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• 제32권2호
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• pp.107-126
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• 2005

The most limited production resource in Korea is land. During the period from 1995 to 2002, annual farm land area of 17,600ha have been converted to urban and industrial land. The self-sufficiency rate of rice, Korean staple food, is expected to be decreased from 97.5% in 2003 to 60-70% in 2020. Under such conditions, this study is aimed at first identifying multi-functional benefits of the reclamation projects such as agricultural production, industrial water supply, urban land supply, transportation effects, sightseeing effects and environmental values with and without the projects. To carry out the objectives, three existing tideland reclamation projects such as Daeho, Kumgang and Yongsangang irrigation project stage II were evaluated and Saemangeum tideland reclamation project which was jointly revaluated by environmental NGO and Govn't appointed specialists in 2000 was reviewed. According to this study results, tide land reclamation projects were showed financially and economically feasible and environmentally sustainable. The joint cost like estuary dam should be allocated based on the multi-functional benefits of the projects. To allocate the joint cost, legal and institutional improvement should adapt the joint cost allocation method as the specific cost-remaining benefit method. Korea has more than 402,000 ha of tidal flat of which 76,396ha have been reclaimed in 2003. To meet food security and to cope with shortage of land, phil-environmental reclamation projects should be continuously implemented and necessary tidal flats for protecting environmental ecosystem should be remained according to the detail survey results of reclaimable resources.