• 제목/요약/키워드: crops

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금강 수계에서 식물플랑크톤의 현존량에 관한 연구 (Standing Crops of Freshwater Phytoplankton in Kumgang River, Korea)

  • 이석구;부성민
    • 환경생물
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    • 제18권3호
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    • pp.347-353
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    • 2000
  • 금강 수계에서 식물플랑크톤 현존량 변화를 알기 위하여 현도, 마암, 장암, 나포에서 1998년 10월부터 1999년 9월까지 매월 1회 채수하여 식물플랑크톤 현존량을 조사하였다. 식물플랑크톤 현존량은 현도에서 7월에 $39.5{\times}10^3cells ml^{-1}, 마암에서 7월에 112.1{\times}10^3cells ml^{-1}, 장암에서 7월에 125.5{\times}10^3cells ml^{-1}, 나포에서 8월에 288.6{\times}10^3cells ml^{-1}로 최대였으며, 현도와 마암에서는 대부분의 시기에 5.0{\times}10^3Cells ml^{-1}이하였고, 나포에서는 5.0{\times}10^3Cells ml^{-1}$ 이상이었으며, 장암은 그 중간이었다. 각 조사 정점의 현존량은 마암이 현도보다 3배 이상 높았고, 장암이 마암보다 1.3배, 나포는 장암보다 2.1배 높아서, 중류에서 하류로 갈수록 급격하게 증가하였다. 현존량 조사 시점에 따라 차이가 있어서 봄부터 초여름까지는 장암의 현존량이 최대였고, 다른 계절에는 나포에서 가장 높았다. 현존량의 시공 분포 변화는 중심형의 소형 규조류 Cyclotella spp.와 Stephanodiscus spp. 및 사상 규조류 Aulacoseira spp.의 번무에 기인하였다.

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농작업 유해요인 노출평가를 위한 작목 및 작업분류에 관한 연구 (A Study of Categorization of Farm Types and Crops for Exposure Assessment in Agriculture)

  • 신소정;김효철;허진영;안민지;김경란;김경수;이민지
    • 한국산업보건학회지
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    • 제29권4호
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    • pp.500-507
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    • 2019
  • Objectives: The purpose of this study is to categorize farm types and analyze the cultivated area and labor input time for each crop over a year in order to decide farm type conducting for the hazard exposure assessment. Methods: Crops ranked within the top 45 by cultivated area in Korea were selected and 15 target crops that exposure assessment had been conducted for through the Rural Development Administration(RDA) pilot research projects were selected. Labor input time was based on data investigated through RDA research surveillance. If there was no data, data from Statistics Korea was used. Data from Statistics Korea was used for total cultivated area. Results: Crops were divided into 5 types: open field crops(Chinese cabbage, Corn, Ginger, Potato), fruits (Mandarin, Pear), green house crops(Cucumber, Lily, Oriental melon, Pumpkin, Tomato), livestock(Poultry), specialty crops(Ginseng, Oyster mushroom, Tobacco). The cultivated area for potato was the largest, and lily was the smallest among the crops. Labor input time over a year was the highest with oyster mushroom and the lowest with pear. Total labor input time by crops was the highest with mandarin and the lowest with Chinese cabbage. Conclusions: To evaluate hazard factors of farm work, it's essential that crops and tasks be classified based on the size of farmers and working hours by farm type. Therefore, the priority of management should be determined based on the cultivated area and total labor time, but the characteristics of tasks in each crop should also be considered.

리기다소나무 임상에 있어서의 Seedling 및 Sapling의 현존량에 관한 연구 (A Study on Standing Crops of Seedlings and Sapling in Pinus rigida Forest)

  • 방재욱
    • Journal of Plant Biology
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    • 제22권3호
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    • pp.59-62
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    • 1979
  • Distribution and standing crops of seedling and sapling as undergrowing tree were investigated in a Pinus rigida forest. The relative light intensity(RLI) on the ground level was 3.9∼59.3% which indicates a wide range. Under this range of RLI seedlings and saplings distribute well in the stand. Eight trees were selected from the stand, then measured dry weight of stem, branches and leaves using thestratified clip technique. A possible relationship between the diameter at the bottom of the tree (Do) and standing crops was investigated. As Do increased from 0.8cm (T1) to 7.2cm (T8), the standing crops also increased from 42.6g to 7,410.4g. Since semi-log values between Do and standing crops clearly indicates a straight line, there is close relationship between these two factors. Therefore it is possible to estimate the standing crops of seedling and sapling by measuring Do. Productive structure shows that phytosynthetic layer is located above the 1/2 height of the tree and maximum photosynthetic layer apperars on 2/3 level in height.

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영.호남 작부체계의 바이오에너지용 신품종 도입시 경제적 가치 비교분석 (The Comparative Analysis for the Economic Value of the Southern Part Cropping System Introducing New Bio-energy Crops.)

  • 김충실;이현근
    • 한국유기농업학회지
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    • 제17권1호
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    • pp.1-17
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    • 2009
  • The production of bio-energy crops is a major research project in the emphasizing the "low carbon green growth" strategy. For this, the possibility of the introduction of the new energy crops improve the agricultural income from fanning must be diagnosed. This study describes the level of agricultural income per unit area by cropping system based on the income of crops in the field. Especially, we have chosen the southern part attracting the attention in the possible area of the bio-energy crop production. This study consists of five chapters. Chapter I is the introduction. Chapter II is on the status of the southern part cropping system and the analysis of the economic value. Chapter III is on the economic value analysis introducing new bio-energy crops. Chapter IV is on the comparative analysis for the economic value of the croping system introducing new bio-energy crops. Chapter V is the conclusion.

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Investment beneficial analysis of rice alternative plants

  • Yi, Hyang-Mi;Goh, Jong-Tae;Lee, Jong-In
    • 농업과학연구
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    • 제40권2호
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    • pp.169-176
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    • 2013
  • The price and revenue of rice are expected to decrease due to increasing rice imports, decreasing consumption and the discontinuance of the government's rice procurement. This degenerating profitability is leading to a rise in the cultivation of upland-crops such as beans, fodder crops and fruits in paddy fields. However, there is a lack of research on the selection of rice substitute crops which are adaptable to the relevant region through profitability analysis. This research, therefore, analyzed investment profitability of rice substitute crops for Cheorwon-gun area in Kangwon province. The study applied net present value (NPV) and internal rate of return (IRR), which fit for mutually exclusive investments that make one selection to the exclusion of other crops. Target crops are green house plants in Cheorwon-gun area. Financial analysis showed paprika and cucumber have investment feasibility for automated vinyl greenhouses and conventional plastic greenhouses respectively.