• 한국수산과학회지
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• 제56권4호
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• pp.462-472
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• 2023

We investigated the physio-chemical and geochemical parameters in the spraying shellfish aquacultures (Yeoja and Gangjin Bay) to establish the systematic strategy for effective environmental management. Spatial variation of each parameter showed partially significant difference (P<0.05) between Yeoja and Ganjin Bay, inferring the discriminative progress (i.e., accumulation and degradation) of the autochthonous organic matter within the aquaculture environments. We additionally integrated various properties (e.g., water/sediment quality, natural hazard, and biological health) which may affect the biological growth within the aquaculture habitats based on the biogeochemical cycles related to environmental components and aquaculture species. We used a screening approach (i.e., one out-all out; OOAO) which can permit the assessment of the health levels of aquaculture species, the scoring for other parameters (seawater, sediment, and natural hazard) as three levels (excellent, moderate and poor) depending on the complex interactive properties occurring in the aquaculture environments. Actual, discriminative scores obtained via our case studies may confirm that these stepwise processes are effectively evaluated for optimal health conditions within the aquaculture habitats. Thus, this approach may provide valuable insights for effective environmental management and sustainable growth of aquaculture operation.

• 한국환경농학회지
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• 제35권2호
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• pp.143-147
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• 2016

BACKGROUND: Rice fields are one of the most important habitats for various bird species. The list of bird species occurred in rice fields in Korean peninsula have been documented. However, information of listed bird species is included not only rice fields but also other wetland habitats such as lakes, tidal flats and rivers. Therefore, the study was conducted to clarify the status of bird observed in rice fields of Korea.METHODS AND RESULTS: Birds using rice fields defined as birds which forage or rest on rice paddies, levees, ditches and farming roads. Birds using rice fields recorded as total 124 species belonging to 40 families. Anatidae and Scolopacidae were the best represented family, followed by Ardeidae, Accipitridae, Motacillidae and Emberizidae; 50% of species belonged to these six families. 18 of 124 endangered wild species, which designated threatened at the national scale, found in this study regions.CONCLUSION: Despite interest in birds using rice fields of Korean peninsula, knowledge of birds and rice fields there is extremely limited. We need more studies to understand and conserve for birds in rice fields of Korea.

• 한국해양환경ㆍ에너지학회지
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• 제6권4호
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• pp.24-36
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• 2003

본 연구는 무안반도 주변 연안수질의 계절별, 조석별 변동과 방조제의 수문개방시 시간에 따른 수질에 미치는 영향을 평가하였다. 주요 수질인자 중 용존산소는 하계의 대부분 정점과 추계 썰물시 저층에서 불포화상태를 나타내었지만, 다른 조사시기에서는 대부분 포화상태를 나타내었는데, 광합성에 의한 영향보다는 기후변동에 크게 영향을 받는 것으로 사료되었으나 생물성장에는 악 영향을 미치지 않는 범위였다. 화학적 산소요구량은 춘계 밀물시와 추계의 밀물과 썰물시에 표층과 저층 모두 평균 2㎎/L이상의 고농도를 나타내고 있어 해역수질환경 기준 II등급을 초과하였는데, 이것은 이 지역이 매우 낮은 Chl. a농도로 보아서 식물플랑크톤에 의한 유기물보다는 이 시기에 증가된 저층교란에 의한 부유물질과 담수유입의 영향이라 판단되었다 용존무기질소는 전 조사기간에 걸쳐 0.11~8.63㎍-at/L의 변동범위로 하계와 추계에서 다소 높고, 조석별 차는 뚜렷하지 않았으며 저층에서 놀게 나타났다. 용존무기인은 ND~2.08㎍-at/L의 변동범위를 보였으며 춘계를 제외하고는 평균 0.30㎍-at/L이상의 다소 높은 값을 보였다. N/P비는 대부분 16이하로 조사해역은 질소가 식물플랑크톤 등의 기초생산자에 대한 성장을 제한하고 있는 것으로 판단되었다. 부영양화 지수는 대부분 1이하였으나, 추계에는 밀물시 방조제 지선 주변해역에서 1이상의 부영양화 현상을 나타내었고 썰물시에는 남부해역에서 부영양화 현상을 나타내었다. 추계 강우시 방조제 수문을 약 12분 동안 개방으로 인해 담수가 방류된 후 조석류에 따라서 방조제와 지선 주변해역에서 COD, DIN, DIP 등의 농도가 1시간 내지 2시간 안에 일시적으로 급증하였으나 그 후 다시 감소하여 방류전의 농도로 회복하는 특성을 보여 주었다. 따라서 본 해역의 지속적 건강성을 위해서는 간석지 매립에 의해 조성된 방조제를 통한 방류량 및 오염부하량을 효과적으로 관리해야 하는 것으로 평가되었다.

• 한국토양비료학회지
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• 제11권4호
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• pp.213-233
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• 1979

장기적(長期的)으로 2000년대(年代)를 전망(展望)할 때 인구(人口)의 증가에 따른 우리나라 국민의 주곡(主穀) 수요량(需要量)은 계속 크게 증가 될 것이고 특히(特) 경제성장이 지속되고 국민의 소득(所得)이 향상(向上)됨에 따라 육류(肉類), 우유, 계란 등(等) 축산물(畜産物) 수요량(需要量)이 급증할 것이며 이와 상응하여 옥수수, 밀, 콩, 과수(果樹), 채소(菜蔬) 등(等)의 수요량(需要量)이 점진적(漸進的)으로 증가할 것이다. 이와같이 수요량(需要量)은 크게 증가할 전망(展望)에 있는 반면(反面) 작물(作物)의 재배기지(栽培基地)인 농경지(農耕地)는 공업화(工業化) 과정(過程)에 따른 기존(旣存) 농경지(農耕地)의 잠식 및 전용은 점차 심화할 것이므로 현재와 같은 추세(趨勢)로 큰 전환없는 실정이 그대로 1991년(年)까지 이어진다면 식량(食糧)의 자급도(自給度)는 현재(現在)의 79%에서 62% 정도(程度)의 수준(水準)으로 감소(減少)될 것으로 예상된다. 이에 대처 국내식량, 축산물(畜産物), 채소(菜蔬), 과수(果樹) 등(等)의 자급도(自給度)를 높이는 길은 기존 농경지(農耕地)의 전용억제와 경지이용도제고(耕地利用度提高) 등(等) 시책(施策)을 계속 강력히 추진(推進)해야 할 것이며 특(特)히 무엇보다도 주요(主要)한 것은 산지(山地)의 대대적(大大的) 개간이용(開墾利用)과 간척지(干拓地)의 개발 등(等) 농경지(農耕地)의 외연적(外延的) 확대를 서둘러 농경지(農耕地) 신규소요면적(新規所要面積)을 확대 확보(確保)해야 할 것이다. 산지(山地)의 개간이용(開墾利用)에 있어서는 합리적(合理的) 개간공법(開墾工法)의 도입(導入), 토양(土壤)의 유실방지(流失防止), 토양(土壤)의 물리화학적 특성(特性)에 바탕을 둔 이화학적 개량(改良), 농업지대(農業地帶)의 구분설정, 입지적(立地的) 조건을 감안한 적지적작(適地適作) 지정(指定), 개간지(開墾地)의 경제성 조사(調査) 등(等)이 긴요(緊要)하며 또한 산지개간(山地開墾)에 있어서 농로관개(農路灌漑), 토양보전처리, 배수(排水) 등(等) 기간시설(基幹施設)의 정부지원(政府支援)으로 농민(農民)의 산지개발의욕을 고취(鼓吹)시키고 안전영농을 도모하여 개발된 땅이 단수제고(段收提高)와 소득증대로 연결(連結)될 수 있도록 뒷받침하여 우리나라 국민의 식량(食糧) 수요량(需要量)을 안정적(安定的)으로 생산공급(生産供給)할 수 있도록 하여야 할 것이다.

• 한국지역지리학회지
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• 제3권2호
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• pp.37-87
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• 1997

만경강유역을 하나의 연장선상에 놓고 연구한 결과, 그 공간상에서 역사와 더불어 형성발달해온 시공연속체를 확인할 수 있었다. 만경강상류에서 하류 하구연안에 이르는 면장공간상에서의 개간과정은 여말에서 부터 시작되어 오늘에 이른 것으로 볼 수 있다. [기원지-지향지] 지향가설에서 본 개간과정에서 개간의 기원지는 만경강상류 산간계곡의 지류곡지 개간을 효시로 하여 기원지가 이루어지고, 조선조 중기까지는 수방대책의 발달과 더불어 하천 중류까지 진출하고, 하천 본류에 대한 하류지역의 계간은 하천의 규모와 유수량의 증가로 인한 하안의 홍수와 범람을 극복할 수 있는 인공제방을 축조할 수 있는 기술수준에 이른 1920년대에 들어서야 본격화되고, 그후 연이어 하구연안의 간석지 개간도 시행되어 개간의 개척첨단이 이들 지향지인 해안간석지일대에 형성되는 것을 볼 수 있다. 시간의 흐름과 더불어 각 시기마다 공간의 변화도 수반되어 시공연속체가 발달하는 것을 볼 수 있다. 취락의 경우 개간과정에 따라 산간계곡 산록일대에서는 주변입지적 집촌, 하천중류와 하류에서는 중앙입지적 집촌, 하천하구 간석지에서는 중앙입지적 열촌형태가 우세하게 나타났다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.8-9
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• 2017

Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

• 농업과학연구
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• 제26권2호
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• pp.77-93
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• 1999

This study is aiming at identifying the foreward and backward lingkage effects of the farm land base development project. Korean Government has continuously carried out farmland base development projets including the integrated agricultural development projects. large and medium scale irrigation projects and the comprehensive development of the four big river basin including tidal land reclamation and estuary dam construction for the all weather farming since 1962. the starting year of the five year economic development plans. Consequently the irrigation rate of paddy fields in Korea reached to 75% in 1998 and to escalate the irrigation rate, the Government had procured heavy investment fund from IBRD. IMF and OECF etc. To cope with the agricultural problems like trade liberalization in accordance with WTO policy, the government has tried to solve such problems as new farmland base development policy, preservation of the farmland and expansion of farmland to meet self-sufficiency of foods in the future. Especially, farmland base development projects have been challanged to environmental and ecological problems in evaluating economic benefits and costs where the value of non-market goods have not been included in those. Up to data, in evaluating benefits and costs of the projects, farmland base development projects have been confined to direct incremental value of farm products and it's related costs. Therefore the projects'efficiency as a decision making criteria has shown the low level of economic efficiencies. In estimating economic efficiencies including Leontiefs input-output analysis of the projects could not be founded in Korea at present. Accordingly this study is aimed at achieving and identifying the following objectives. (1) To identify the problems related to the financial supports of the Government in implementing the proposed projects. (2) To estimated backward and foreward linkage effects of the proposed project from the view point of national economy as a whole. To achieve the objectives, Hwangrak benefited area with reservoir which is located in Seosan-haemi Disticts, Chungnam Province were selected as a case study. The main results of the study are summarized as follows : a. The present value of investment and O & M cost were amounted to 3,510million won and the present value of the value added in related industries was estimated at 5.913million won for the period of economic life of 70 years. b. The total discounted value of farm products in the concerned industries derived by the project was estimated at 10,495million won and the foreward and backward linkage effects of the project were amounted to 6,760 and 5,126million won respectively. c. The total number of employment opportunities derived from the related industries for the period of project life were 3,136 man/year. d. Farmland base development projects were showed that the backward linkage effects estimated by index of the sensitivity dispersion were larger than the forward linkage effect estimated by index of the power of dispersion. On the other hand, the forward linkage effect of rice production value during project life was larger than the backward linkage effect e. The rate of creation of new job opportunity by means of implementing civil engineering works were shown high in itself rather than any other fields. and the linkage effects of production of the project investment were mainly derived from the metal and non-metal fields. f. According to the industrial linkage effect analysis, farmland base development projects were identified economically feasible from the view point of national economy as a whole even though the economic efficiencies of the project was outstandingly decreased owing to delaying construction period and increasing project costs.