• Title/Summary/Keyword: Direct seeding

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A Study on the Automatic Level Measurement for Land Leveling (경지 균평 작업을 위한 자동 표고 측정에 관한 연구)

  • 김종안;김수현;곽윤근
    • Journal of Biosystems Engineering
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    • v.22 no.3
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    • pp.269-278
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    • 1997

  • An automatic level measurement system was developed to level the land fer direct seeding of rice. A laser transmitter/receiver set was used to measure land-level. The inclination error occurred in level measurement on irregular land surface could be compensated by attaching rotating mass. The level measuring experiments were performed on three kinds of different shapes(step, random, sine). This system could accurately measure step level of which amplitude was 40mm in 0.5s, random level change within $\pm$ 5mm maximum measurement error, and sine level change of which spatial frequency was 0.5m-1. To verify performance of the inclination error compensation system, frequency transfer function(acceleration input vs. inclination error) was computed by spectral analysis. The inclination error was decreased about 20㏈ by error compensation system.

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GENE TRANSFER BY MANIPULATION OF PRIMORDIAL GERM CELLS IN THE CHICKEN

  • Han, Jac Y.;Shoffner, R.N.;Guise, K.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.3
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    • pp.427-434
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    • 1994

  • The primordial germ cells (PGCs) were transfected in vitro and expressed the exogenous RSVLTR/${\beta}G2$ plasmid, suggesting thaI PGC is a possible vector for direct gene transfer into the germ line. Transfection efficiency of cell suspensions containing PGCs was 1.5% by liposome mediated DNA transfection. By microinjection of the transfected PGCs into the host germinal crescent, PGCs migrated via blood vessel to the future gonad and these transfected PGCs resulted in the RSVLTR/${\beta}G2$ expression in the gonad. The results from the seeding of PGCs on the chorioallantoic membrane were insufficient to test the hypothesis that PGCs can penetrate or invade the chorioallantoic membrane for transport via the circulatory system.

  • https://doi.org/10.5713/ajas.1994.427 인용 PDF

A study of influence factors on water requirement in paddy fields (논 감수심에 영향을 주는 요인에 관한 연구)

  • Yi, Sang-Bong;Jeon, Jong-Gil;Yun, Jin-Ha;Kang, Chang-Ho
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2005.10a
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    • pp.80-84
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    • 2005

  • The water requirement of transplanting culture(TC) consisting of 16 plots and direct seeding culture in a well-drained paddy field(DC) also having 15 plots were measured in order to clarify the influence factors on water requirement. Each plot was maintained under different cultivation conditions. Those varied cultivation conditions were classified into 7 items. Subsequently, the relationship between water requirement and 7 items were analyzed by evaluating the average water requirement in each condition to clarify the items influencing water requirement. From the analysis of the results, the water requirement of DC was determined to be 3.5 times of the TC. Furthermore, water requirement in DC and TC were influenced mainly by ponding depth and locational condition respectively.

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Chemical Control of Weed for Rapes ( Brassica napus L. ) (제초제에 의한 유채밭 잡초방제)

  • 안계수;권병선;김상곤;정동희
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.15 no.3
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    • pp.186-191
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    • 1995

  • This study was conducted to evaluate the effect of herbicides on weed control, growth characteristics and yield in rapes, after direct seeding it to the field. All herbicides treated had no effect on the emergence period, bolting rate of rapes. The major weeds were Cerastium holosteoides var. hallaisanense, Stellaria media Villars, Larnium ampleicaule L., Lobelia chinensis Lour., Geranium wilfordii Maxim. and Capsellu bursa-pastoris (L.) Medicus. Rapes yield were increased somewhat more with alachlor-G, herbicide than the other hehicides and by hand weeding. Alachlor-G and alachlor-Ec were had no i j u r y but butachlor- G and simajin-Wp were slightly harmful for the rapes with recommended concentration. On the other hand all hehicides were harmful in the double dosage level.

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