• Title/Summary/Keyword: drill

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Effect of Seeding Method and Flooding Time After Seeding on Seedling Establishment and Growth in Direct Drill Seeding Culture of Rice in Puddled Soil (벼 무논골뿌림 재배에서 파종방법과 파종후 담수시기가 입모 및 생육에 미치는 영향)

  • Kim, Sang-Su;Choi, Min-Gyu;Seok, Soon-Jong;Lee, Seon-Yong;Park, Keun-Yong;Cho, Dong-Sam
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.39 no.5
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    • pp.495-501
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    • 1994

  • This experiment was carried out to investigate the proper seeding methed for direct seeding culture of rice in puddled soil at ill-drained paddy field. Mangeumbyeo was seeded on May 11 with drill seeder attached to cultivater, dibbling seeder attached to transplanter and power dust blower. And to determine the proper flooding time after seeding, Mangeumbyeo was seeded on May 7 and June 1 with drill seeder. Emergence ratio wasn't significantly different between drill seeder seeding and dibbling seeder seeding but emergence was very low with power dust blower. Working hour for seeding was shortened in the order of power dust blower, drill seeder and dibbling seeder, and these seeding methods saved the working hour remarkably compared with machine transplanting of infant seedling by omitting the procedures of raising seedling and transplanting. Lodging occurred slightly in all seeding methods. However, yield wasn't significantly different between machine transplanting of infant seeding and direct seeding culture in puddled soil except power dust blower. When field was flooded on seeding date, the emergence period was shortened, emergence ratio was increased and weed occurrence was decreased. Yield was highest when flooding was done on seeding date as the number of panicle per m$^2$ and the number of spikelets per m$^2$ were higher than any other flooding time.

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Case Study on the Characteristics of Vertical Bearing Capacity for Steel Pipe Pile Installed by PRD (PRD 강환 말뚝의 연직지지력 특성에 관한 사례 연구)

  • 최용규;정창규;정성기;김동철;정태만
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.225-232
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    • 1999

  • Construction case of PRD (Percussion Rotary Drill) pipe pile and matters to be attended in construction of PRD pile were reviewed. The compressive and uplifting static pile load tests for PRD piles were performed and, also, analysis by Pile Driving Analyzer was done. Based on these results, bearing components in each resisting part (that is: steel toe, external skin, and internal skin) were measured separately. The measured resisting force was compared to the value calculated by the estimated formula. The pile capacity was mobilized in steel toe area and the external skin friction and the internal friction were not produced. Thus, it could be considered that toe of PRD pile should be supported in hard bearing stratum (for example, the fresh soft rock).

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