• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.15-15
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• 2017

본 연구는 필드 작업 시 작업조건에 따른 정식기의 PTO 부하를 측정하고, 이를 이용하여 작업조건에 따른 안전율 시뮬레이션을 목적으로 수행하였다. 부하 계측 시스템은 PTO 축의 부하를 측정하기 위한 토크 센서, 토크 센서에서 발생한 신호를 수집하기 위한 데이터 수집장치, 노트북에 전원을 공급하기 위한 파워 컨트롤러로 구성하였다. 토크센서에서 입력된 부하 데이터를 처리하기 위한 소프트웨어는 Labview(Version 2011, National Instrument, USA)를 사용하였다. 포장시험은 유사한 토양 조건에서 4회 반복 시험을 수행하였으며, 작업속도 고속 조건에서 4개의 주간거리(26, 35, 43, 80cm)와 3개의 식부깊이 (85, 105, 136mm)에 대하여 수행하였다. 안전율 시뮬레이션을 위한 소프트웨어는 KISSsoft(Version 2016, Kissling & Co. AG, Switzerland)를 사용하였다. 식부깊이 85mm에서 주간거리 26, 35, 43, 80cm일 때 작업시 각각 굽힘 안전율은 2.2874, 2.4507, 2.7139, 2.8064로 나타났으며 접촉 안전율은 1.1787, 1.2799, 1.3205, 1.3275로 나타났다. 식부깊이 105mm에서 주간거리 26, 35, 43, 80cm일 때 작업 시 각각 굽힘 안전율은 2.1261, 2.2781, 2.4879, 2.5866로 나타났으며 접촉 안전율은 1.1296, 1.1425, 1.2710, 1.2507로 나타났다. 식부깊이 136mm에서 주간거리 26, 35, 43, 80cm일 때 작업 시 각각 굽힘 안전율은 1.6587, 1.6651, 1.7824, 2.2198로 나타났으며 접촉 안전율은 1.0030, 1.0104, 1.0450, 1.1931로 나타났다. 주간거리에 따른 식부깊이의 굽힘 안전율과 접촉 안전율은 가장 차이가 큰 주간거리 80cm에서 식부깊이가 85, 105, 136mm일 때 작업 시 각각 굽힘 안전율은 2.8064, 2.5866, 2.2198로 나타났으며 접촉 안전율은 1.3275, 1.2507, 1.1931로 나타났다. 시뮬레이션 결과 정식기 베벨기어의 안전율은 주간거리가 짧을수록, 식부깊이가 깊을수록 더 낮게 나타났다. 그러므로 정식 작업 시 정식기의 부하와 내구성을 고려하여 적절한 작업조건을 선정해야 함을 알 수 있다. 또한 향후 다양한 토양 조건 및 작업 단수 등에 따른 포장시험을 추가로 진행하여 여러 조건에서의 안전율 시뮬레이션을 수행할 예정이다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.192-197
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• 2009

This study was conducted to investigate the effect of site-specific variable fertilization following digital fertility map generated from soil analysis on rice growth and yield. The site-specific application of fertilizer was implemented by using rice transplanter equipped with side dressing applicator and global positioning system (GPS). Coefficient of variation (C.V.) of soil nitrogen content was reduced after the experiment, and spatial variation of semivariogram was reduced. Rice growth from tillering to ripening stage, plant height, tiller and panicle number increased at site-specific variable fertilization treatment, and coefficient variation (C.V.) of each growth characteristics was lower than those of conventional fertilization treatment. As a result, fertility in the rice field was more uniform become of site-specific fertilizer application. Head rice yield of site-specific application plot increased by 9% (i.e., to from 450 kg/10a to 492 kg/10a of the control plot) and its CV was significantly reduced to 3.5 compared to 7.8 of the control plot. In addition, there was no significant difference in amylose, protein contents and whiteness of milled rice, but its CV was reduced.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.261-266
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• 2014

Purpose: This study was conducted to serve as a basis for strengthening policy support and R&D to improve the domestic and international competitiveness of domestic agricultural machinery. Levels of satisfaction among farmers and service engineers were analyzed regarding the current quality of agricultural machinery and the primary consumers' propensity for replacement purchases. Methods: A survey was carried out targeting farmers in over 150 townships and 300 villages in South Korea who collectively used 711 tractors, 286 rice transplanters, and 221 combine harvesters. Furthermore, agricultural machinery service engineers from 20 different after-services were surveyed regarding the quality of main components in domestic agricultural machinery versus those in imported agricultural machinery. Results: The farmers' overall quality satisfaction ratings for tractors, rice transplanters, and combine harvesters ranged from 57.1% to 62.6% in consideration of operating performance, failure rate, and durability. Compared with imports, satisfaction ratings for domestic agricultural machinery were 19.1%p to 38.1%p lower for quality. Regarding engines, transmissions, hydraulics, planters, reapers, threshers, and electrical components, only 5.3% to 25.0% of service engineers indicated that domestic agricultural machinery was higher in quality compared with imports. By contrast, 33.3% to 78.9% of those surveyed indicated that domestic components were lower in quality compared with imports. Intent to purchase replacement agricultural machinery at the end of their respective products' lifecycles was indicated that they planned to purchase imported tractors, rice transplanters, and combine harvesters comprised 25.2%, 46.9%, and 43.9%, respectively. This clearly shows that a very high percentage of farmers were satisfied, particularly for transplanters and combine harvesters. Conclusions: The level of desire for purchasing imported agricultural machinery was very high among those who expressed intent to purchase replacement machinery. Therefore, strong policy support and R&D for domestic agricultural machinery is critical for improving competitiveness on the domestic and foreign markets.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.25-30
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• 1984

Rice seedlings were raised in seedling box for rice transplanter at the temperatures of 32$^{\circ}C$ (day/1$0^{\circ}C$(night) and $25^{\circ}C$/1$0^{\circ}C$ in a phytotron. The endosperm materials were consumed more rapidly at the high temperature (32/1$0^{\circ}C$) than at the low temperature (25/1$0^{\circ}C$) and thus the leaf development was proloted at the high temperature for 15 days from the sowing. But at 35 days after sowing more leaves were developed at the low temperature than the high temperature. The short cotyledon length(5mm) before sowing was more available for the leaf development than the long cotyledon(20mm) because the endosperm materials of the former were consumed slowly. The residual of 10% endsoperm materials, when seedling age was of 2.0 to 2.1, promoted the regrowth of seedlings after machine transplanting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.256-264
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• 2021

Rapeseed (Brassica napus L.) is generally sown in late autumn and harvested in early summer in Korea, however, spring cultivation has also been attempted in some areas because frequent climate changes induce reducing productivity. Therefore, there is a need for a transplanting technology that is relatively easy to control of cropping season according to changes in cultivation conditions. In this study, to find out the optimal characteristics of seedlings for machine transplanting of spring cultivation, seedling morphological characteristics were investigated according to the seedling age of three varieties for 2020 and 2021. The hypocotyl length was less than 2 cm in both years and the 40-day-old seedling was the shortest among all seedling ages. The number and size of leaf were increased with longer seedling age in both years. To evaluate seedling quality, total seedling length, seedling weight, and impact resistance were measured before transplanting. Total seedling length was the longest in 40-day-old seedlings and the shortest in 25-day-old seedlings in both years. In the case of seedling weight, no significant differences were observed depending on the seedling age and the impact resistance increased with increasing seedling age. Finally, 'Jungmo7001', 'Naehan', and 'Tamla' showed a high transplanting rate in seedlings grown for more than 30 days, 35 days, and 40 days, respectively, in the field using a general transplanter. These results suggest that the proper seedling age for transplanting is limited depending on the rapeseed varieties. The suitable seedling cultivation method can be selected for different cultivation environments.