• 한국작물학회지
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• 제46권1호
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• pp.47-52
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• 2001

In order to develop more stable seedling stand method in wet direct rice seeding culture, the effect of making the drainage ditches was studied in both methods of broadcast seeding on floody paddy surface and puddled-soil drill seeding. In a broadcast seeding on floody paddy surface, the ditching after seeding using a tractor or small ditch maker improved the seedling stand, and reduced the floating seedling and herbicide injury by accelerating the drainage. Suitable ditching time was at 2 days after seeding (DAS) for the tractor and at 3 DAS for the ditch maker. In the puddled-soil drill rice seeding culture, the ditching before seeding with a ditch maker at 3 days after draining effectively improved the seedling stand due to quick draining through well formed the seeding furrows. In the puddled-soil drill seeding, seedling stand number showed higher in both ditching plots synchronized with seeding compared with both only draining treatment at 1 DAS without ditching and the flooding plot condition for 6 DAS. And the suitable ditching depth was 6 cm, as considered the ditching status and drained status. These results suggest that the ditching in wet direct rice seeding is an resonable practice for improving the seedling stand through the accelerating drainage of field.

• 한국작물학회지
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• 제44권3호
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• pp.225-229
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• 1999

Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA$_3$) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.

• 한국작물학회지
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• 제41권3호
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• pp.370-375
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• 1996

포승통의 미사질식양토인 간척지에서 벼 건답직파재배 가능성을 구명하고자 서안벼를 공시하고, 간이온실에서는 시용 및짚의 양과 토양수분조건을 달리 하여 파종심도별 벼의 출아율을 조사하고, 실제 포장 시험에서는 산파후 로타리 복토 유무에 따른 벼의 입모 및 수량성의 차리를 비교 검토한 결과는 다음과 같다. 1. 볏짚 처리(특히, 4ton, 6ton/ha)가 무처리보다 출아율이 높았다. 2. 헥타르 당 볏짚 4ton을 처리하고 파종심도가 얕을수록 출아율이 높았으며 초장도 현저히 커졌다. 3. 토양수분의 적습조건은 과습조건보다 출아율이 높았으며, 초장은 적습조건에서 파종심도가 얕을수록 커졌다. 4. 산파후 로타리 복토유무별 입모수는 로타리무복토(73개 /m$^2$)가 로타리복토(44개 /m$^2$)보다 많았다. 5. m$^2$ 당 수수는 로타리무복토가 로타리복토보다 많았고, 수량도 같은 경향을 보였다.

• 한국잡초학회지
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• 제12권3호
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• pp.200-222
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• 1992

The results of recent researches for improvement of seedling stand in direct seeded rice on the dry paddy in Korea were summarized as the following ; a variety to be cultivated should be chosen the characteristics of high percentage germination under low temperature, shorter period of shoot emergence, and better growth of the mesocotyl and shoots. Meanwhile, there was 40% increase in seedling stand at the treatment of removal of the seed awn under using the drill seeder. After seeding the rice seed covered with soil of 3cm depth was better seedling emergence and also there was the hightest seedling emergence at the 70% of moisture content of the soil. In addition, the application of the Release containing GA 10% enabled to increase the seedling stand and furthermore it was effective under deep seeding depth. The optimum seeding date should be seeded around May 10 when mean air temperature is above 12-13$^{\circ}C$ so that may establish more less 70% in seedling stand. Based on an appropriate seedling stand of 150/$m^2$, the optimum seeding rate was 5kg/10a. It was the best in seeding method using drill seeder and the most desirable recommended seeding method was the drill seeder in terms of seedling stand. In order to improve seedling stand water management was more effective in canal irrigation and in drainage at 6hr after irrigation following by the seeding process. On the other hand, for the increase of seedling stand under flooded condition a variety might have characters being better germination at low concentration of dissolved oxygen and vertically deeper growing of the crown root. Also, seedling stand was able to increase with the seed coating of $CaO_2$in the flooded soil. It was possible to be seeded on the early part of May being mean air temperature of avove 10$^{\circ}C$ and the optimum seeding rate was 5kg/10a. For an effective water management water would be flooded up to 3cm depth for 2-3 weeks after seeding. The rice plant grown under the direct seeded cultivation might be not so much strong in lodging resistance compared to that grown under the transplanting and moreover direct seeded rice cultivation under flooded condition would be more weak growth of the rice plant than that on dry paddy. Meanwhile, the lodging would be affected by the seeding rate, the soil depth after seeding. and seeding method even in the same variety. In particular, roots in the lodging pattern of direct seeded rice cultivation under flooded condition were largely distributed on the soil surface so that resulted easily in the lodging. In general, the lodging resistance would be greater as seeding rate and amount of N fertilizer application are lower and soil depth after seeding is higher. Among the introduction of different seeding method the high ridged drill seeding method on dry paddy soil resulted in the lowest in the lodging index and also it was lower in the drill seeding method than in the scattering seeding method under flooded condition. In case of more than 150 seedlings per $m^2$ there was a severe lodging due to high lodging index at the 3rd and 4th internodes. The effective lodging prevention was able to at the treatment of the Inabenfide at 45 days before heading and the Uniconazol at 15 days before heading which caused the shortage by 10-15cm in culm length. Also, fertilizer management using split application of nitrogen would be contributed the reduction of lodging at the rate of 20-30-20-20-10%(basal-5th leaf stage-7th leaf stage-panicle initiation stage-heading stage) on the dry paddy soil.

• 한국작물학회지
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• 제44권3호
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• pp.236-242
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• 1999

To examine the seedling stand and growth as affected by early seeding dates of dry direct seeded rice in the Honam plain area of Korea, Dongjinbyeo was seeded at six seeding dates from early March to late April in rice fields of silty loam soil(Jeonbuk series) at the National Honam Agricultural Experiment Station (NHAES) for two years, 1996 and 1998. Seedling stand decreased slightly. with an early seeding date, but it produced more than the optimum seedling number except for the seeding of 25 March in 1996. Days to emergence was significantly longer, as seeding date was earlier, and days to emergence by early seeding was shortened only by 8 days because the mean air temperature was lower in 1996 than average, while in 1998, the reduction effect was nine to twenty five days because the mean air temperature was higher than average. In early seeding, various weeds occurred at the emergence date of rice and dominant weeds were Alopecurus aequailis, Ludwigia prostata and Rorippa islandica. NH$_4$$^{+}$ -N content in the soil at the 5th leaf stage and maximum tillering stage were lower, as the seeding date was earlier when nitrogen was split applied as basal and top dressed in 1996, while it was not significantly different among seeding dates when nitrogen was intensively applied as a top dressing in 1998. Tiller number at the maximum tillering stage and panicle number/m$^2$ were more, as seeding date was earlier in 1996, while it was not different in 1998. Filled grain rate and 1,000 grain weight was not different among the seeding dates. Milled rice yield was significantly decreased in the seeding before the middle of March, but in the seeding after late March, it was not varied when compared with the normal seeding date in 1996, while in 1998, there was no difference among seeding dates. From the above results, in consideration of seedling stand, weed occurance, rice growth and milled rice yield, the critical optimum early seeding time in the southern plain area may lie in early April. But it was suggested that when soil moisture is proper for seeding practices, seeding amount is increased and nitrogen is applied after plumule emergence of rice, milled rice yield may not be reduced in the seeding of middle or late March, compared with the seeding in April.l.

• 한국작물학회지
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• 제41권3호
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• pp.295-301
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• 1996

벼 무논골뿌림 재배시 입모향상을 위한 기술체계를 확립하고자 1995년에 발아시험기에서 동진벼를 공시하여 최아장, 과산화석회 (CaO$_2$) 종자분의 및 파종(매몰)심도에 따른 출아, 입모 및 초기 생육을 검토한 바를 요약하면 다음과 같다. 1. 출아율 및 입모율은 최아장이 길수록 향상되었고 파종심도가 깊을수록 저하되었는데 입모율이 l0% 이하로 현저히 저하된 최아장별 파종심도는 무최아 0.5cm, 2mm 최아 1.0cm, 4mm 및 6mm 최아는 2.0cm이었다. 2. 최아장이 길수록, 파종심도가 말을수록 초장이 크고 건물중이 무거웠으며 입수도 많았다. 3. 최아장 6mm에서는 파종이 불균일하고 파종립수가 매우 적어 입모수 및 입모의 균일도가 매우 낮았으나 최아장 4mm에서는 파종이 균일하고 입모율 및 입모의 균일도가 높았다. 4. CaO$_2$종자분의로 출아율 및 입모율이 향상되었으며 CaO$_2$분의에 의한 입모향상 효과는 최아종자보다 무최아종자에서 컸다. 5. CaO$_2$ 처리로 입모율 50% 이상을 보인 파종심도는 무최아종자, 최아종자 모두 1.0cm까지이었으며 파종심도 3cm에서는 모든 처리 에서 전혀 입모되지 않았다. 이상의 결과로 보아 벼 무논골뿌림재배에 알맞는 최아장은 3~4mm라고 생각되며 CaO$_2$를 분의 하더라도 입모의 안정을 위하여는 종자가 출아전에 1cm 이상 매몰되지 않도록 파종 전후 물관리를 적절히 해야 할 것으로 생각된다.

• 한국작물학회지
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• 제52권2호
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• pp.204-207
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• 2007

서남부 간척지에서 벼 담수표면직파재배시 토양 염농도 별 파종전 후 합리적인 물관리 방법을 구명하고자 $2004{\sim}2005$년에 걸쳐 호남농업연구소 계화도출장소 시험포장인 세사양토(문포통)에서 남평벼를 공시하여 로타리 후 환수횟수와 파종 후 물관리 방법을 각기 달리하여 입모 및 쌀 수량등을 검토한 결과를 요약하면 다음과 같다. 1. 저염토양에서는 로타리 후 1회 환수, 파종 후에는 낙수 관리해 주어야 입모가 양호하고 쌀 수량이 감소되지 않았다. 2. 중염토양에서는 로타리 후 3회 환수, 파종 후에는 담수관리 하되 2일 간격으로 환수를 실시해 주어야 입모가 양호하고 쌀 수량감소가 적었다. 3. 따라서 서남부 간척지에서 벼 담수표면직파재배시 입모 및 쌀 수량 등을 고려할 때 저염답에서는 로타리 후 1회 환수, 파종 후에는 낙수관리, 중염답에서는 로타리 후 3회 환수, 파종 후에는 담수관리하되 2일 간격으로 환수하는 것이 유리하다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1989년도 추계 학술대회지
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• pp.18-19
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• 1989

• 현장농수산연구지
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• 제7권1호
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• pp.35-46
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• 2005

규산질비료이용 복토직파재배 개선을 위한 폿트시험 연구에서 얻어진 결과를 요약하면 다음과 같다. 본 연구에서 복토재료에 따른 초기 입모율차이는 무복토 55.0%에 비하여 복토처리로 90~100%의 높은 입모율을 보였다. 특히 파종직후 강우조건에서는 무복토 0%의 출아를 보인반면 복토처리에서는 65~100%의 입모율을 보였으며 강우 시에는 무복토 조건에서도 85%의 비교적 높은 입모율을 보였다. 특히 토양을 이용한 복토처리구에서는 강우로 인하여 20%의 매우 낮은 입모율을 보였는데 이는 수분에 의한 토양층 형성으로 산소공급 및 유모출아 조건이 불량하여 입모율이 극히 저조한 것으로 나타났다. 출수기 벼 생육은 무복토(비강우)처리구를 제외한 모든 처리구에서 비교적 양호한 벼 생육을 보였다. 벼 수량은 초기 입모 및 중간생육이 불량한 무복토(비강우) 및 토양 복토구(강우)에서 낮은 수량성을 각각 보였다.

• 한국작물학회지
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• 제43권4호
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• pp.214-222
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• 1998

These experiments were conducted to investigate water uptake, electrical conductivity, germination percentage, seedling growth, and seedling establishment rate in direct seeding cultivation of rice. The rice seeds of six japonica type varieties were coated with 12 kinds of polymers in a standard concentration of 0.2% using seed coating machine. The water absorption of the polymer-coated seeds under saturation conditions was not different among varieties, and was the highest in kulcel, maltrin, and waterlock on the polymer-coated seeds. The electrical conductivity with waterlock (55.0 $\mu scm^{-1}g^{-1}$) was higher than the control plot (45.6 $\mu scm^{-1}g^{-1}$) and other treatments. The germination of the polymer-coated seeds was 95.9% at control plot, 92.7% at low temperature and 35.7% at high temperature. The total dry weight of seed decreased in the order of low temperature, control plot, and high temperature, and was effective in pvp (polyvinyl pyrrolidone), opadry, and sacrust. The seedling establishment rate in direct seeding cultivation ranged from 74.9 to 81.0% in flooded paddy surface, and ranged from 64.7 to 76.6% in dry paddy. In both cases, it decreased in the order of early, medium and medium-late varieties, but was enhanced in daran 8600, sepirect, and sacrust. According to this study the recommended polymers for direct seeding cultivation of rice are daran 8600, sepirect, and sacrust.