• Title/Summary/Keyword: Greenhouses

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Investment beneficial analysis of rice alternative plants

  • Yi, Hyang-Mi;Goh, Jong-Tae;Lee, Jong-In
    • Korean Journal of Agricultural Science
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    • v.40 no.2
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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.

Actual State of Practical Use and Thermal Environment of Greenhouses in Summer Season (하절기 온실의 활용실태 및 열환경분석)

  • 남상운;김문기
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1999.10c
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    • pp.418-423
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    • 1999
  • This study was performed to find an efficient method to overcome extremely high temperature within greehhouse in summer season. The actual states of practical use for greenhouse in hot summer season were investigated. About 21.6% of the investigated greenhouse farms were no cultivation, and most greenhouse farms were cultivating under the very inferior environment . To examine thermal enviornment of greenhouse according to cooling or assistant cooling , greenhouses were treated with natural ventilation, shading, roof sprinkling , and evaporative cooling with air cool fan. Shading and operating air col fan showed a drop in temperature of 3.8∼4.2$^{\circ}C$ as compared with natural ventilation, and most greenhouse air temperatures were maintained below 35$^{\circ}C$.

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Energy Generating Self-cooling Greenhouse (열-전기 병합 에너지 생산 겸 자체 냉각 온실)

  • Kleinwachter, Jurgen;Chung, Mo;Kim, Jong-Sung
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.584-587
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    • 2006
  • An energy generating greenhouse based on fluoropolymer envelope and fresnel lens is proposed. The outstanding properties of the fluoropolymer films make them very suitable for large scale solar applications. Extremely high optical transmission over the whole solar spectrum, combined with mechanical strength, and durability allows us to design a highly optimized greenhouses for both plant growing and energy generation. Systems such as photovoltaic triple junction cells are especially attractive since they have up to 35% efficiency with much less cell material when the sun beam is focused with concentrators such as fresnel lenses. Cooling such devices will enhance the efficiency and provide useful thermal energy that could be further utilized for various applications depending on the local demands. This article introduces the basic ideas and principles of the energy generating greenhouses as a first step towards the actual deployment of such systems under Korean environment.

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Effects of Sowing Density and Thinning Treatment on Growth Characteristics and Yield of 3-Year-Old Ginseng Cultivated in a Greenhouse (인삼 하우스 직파재배 시 파종밀도 및 솎음처리가 3 년근 인삼의 생육과 수량에 미치는 영향)

  • Suh, Su Jeoung;Jang, In Bae;Yu, Jin;Jang, In Bok;Hyun, Dong Yun;Park, Hong Woo;Kweon, Ki Bum
    • Korean Journal of Medicinal Crop Science
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    • v.26 no.1
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    • pp.64-71
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    • 2018
  • Background: The cultivation of ginseng (Panax ginseng C. A. Meyer) in greenhouses could reduce the use of pesticides and result in higher yield; however, construction costs are problematic. The adaptation of direct-sowing culture in greenhouses could reduce the cost of ginseng production. Methods and Results: To improve seedling establishment in direct-sowing culture, effects of sowing density (SD), number of seeds sown per hole (SN), and thinning (TH) treatment on the root yield were investigated after 3 years of seeding. The emergence rate was significantly influenced by SD, but not by SN or TH. Damping-off and rusty roots increased with an increase in SN with diminishing effects of SN on seedling establishment. Root weight and diameter were affected by SD, SN, and TH, however, there were no statistical significances. The total number of roots harvested per unit area increased with increasing SD and SN, and the weight of roots was affected by SD, but not by SN or TH. Conclusions: Multi-seed sowing per hole and/or thinning might not be an efficient method for the direct-sowing culture of ginseng. The SD for direct seeding culture in greenhouses should be approximately $33-42seeds/m^2$ for an optimum yield of 3-year-old ginseng.