• 현장농수산연구지
• /
• 제21권2호
• /
• pp.77-86
• /
• 2019

To determine none top soil covering in rice seedling nursery method for the sparse machine transplanting, four different sowing methods were tested. Shoot and root length, fresh weight, leaf number and color using leaf color chart(LCC) and SPAD were collected as the data comparison of methods. The seedling height showed the highest growth according to the conventional (230g seed rate of pre-emerged seeds and top-soil covering) > high sowing density 1 (290g seed rate of pre-emerged seeds and top-soil covering) ≥ high sowing density 2(290g seed rate of pre-emerged seeds and none top-soil covering) > high sowing density 3(290g seed rate of iron-coated seeds and none top-soil covering). There was any statistical difference between groups in root length, leaf number, LCC, and SPAD values. Thus, a high sowing density of 290g for rice nursery seedling box was recommended to the sparse machine transplanting in rice cultivation with the none top-soil covering method, enabling convenient handling in transportation and machine transplanting work.

• Plant Resources
• /
• 제3권3호
• /
• pp.194-199
• /
• 2000

The result of this experiment which are conducted, to improve the cultivation technology of Alisma plantago, to increase its quantity and to contribute for stable production with Yongiun local group by examining the optimal planting density and transplanting period of double cropping of Alisma plantago in the southern region. The characters of plant height, leaf width and length tend to be reduced as the seeding period is later by the order of the 10th, 20th and 30th of July. The period required for flowering is reduced as the transplanting period is later and dense planting is applied. Plant height, the number of leaves and yield of dry root have much quantity at the dense planting density of 20$\times$ 15cm as they are transplanted later in the 30th of August or the 10th of September, but they are rather less in sparse planting density of 20$\times$25cm or 20$\times$35cm.

• 한국작물학회지
• /
• 제11권
• /
• pp.1-9
• /
• 1972

본시험은 1971년에 품종진흥을 공시하여 묘대파종량을 3.3$m^2$(평)당 0.2ι, 0.4ι 및 0.6ι로, 본답 10a에 대한 묘대면적을 39.6$m^2$(12평), 49.5$m^2$(15평) 및 59.4$m^2$(18평)로 하여 4월 26일에 수묘대에 파종하고, 이앙기를 6월 5일(적기), 6월 25일 (만기) 및 7월 15일(극만기)로 하였는데, 본답의 재식밀도는 파종량과 묘답면적 각각의 조합에 따른 성묘수를 산출하여 이것을 주당 4묘식으로 주수를 결정하여 이앙하였으며 이앙전에 조사하고 이앙후 본답의 생육 및 수량을 검토하여 만앙대책으로서의 합리적 육묘를 위한 실용적 적정 묘대파종량과 묘대면적을 밝히고자 실시하였는데 그 결과를 요약하면 다음과 같다. 1. 묘대기간이 길수록 또한 박파묘일수록 묘의 초장, 출엽수, 건물중, 건물초장비 등은 뚜렷이 증가되었으나 묘의 분얼수, 생엽수등은 거의 증가되지 않았다. 2. 이앙기가 늦어질수록 간장, 수장은 짧아지고 출수기는 지연되었으나 이앙후 출수기까지의 일수는 심히 단축되었으며, 한편 80일묘를 이앙한 극만기재배에서는 심한 불시출수현상이 나타났다. 3. 따라서 만앙이 될 수록 수당경화수, 등열비율, 정조천입중 등이 감소되어 정조수량은 직선적으로 감소되었는데, 만앙에 의한 감수율은 6월 5일 이앙구에 비해 6월 25일, 7월 15일 이앙구에서 각각 15.6%, 41.3%로 나타났다. 그런데 극만앙구의 이렇게 뚜렷한 감수원인은 주로 수당경화수와 천입중의 현저한 감소에 있었다. 4. 파종량과 묘대면적이 증가할수록 재식주수가 증가되어 단위면적당 경수는 증가되었으나 간장, 수장 등은 감소되었다. 5. 따라서 후파묘 밀식구일수록 단위면적당 수수는 증가되었으나 수당경화수, 정조천입중 등이 감소되어 수량은 박파묘 소식구와 차이가 없었다. 그러나 7월 15일 이앙구에서는 후파묘 밀식구가 등열비율과 천입중의 현저한 감소로 수량이 떨어지는 경향이었다. 6. 극만앙 대책으로서의 적정 묘대파종량 및 본답 10a에 대한 묘대면적은 3.3$m^2$당 0.4ι 및 59.4$m^2$로 판단되었다.

• Journal of Biosystems Engineering
• /
• 제38권4호
• /
• pp.255-263
• /
• 2013

Purpose: It is not easy to drive a rice-transplanter avoiding underlapped or overlapped transplanting in paddy fields. An automated guidance system for the riding-type rice-transplanter would be necessary to operate the rice-transplanter autonomously or to assist the beginning drivers as a driving aid. Methods: A prototype of guidance system was composed of embedded computers, RTK-GPS, and a power-steering mechanism. Two Kalman filters were adopted to overcome sparse positioning data (1 Hz) from the RTK-GPS. A global Kalman filter estimated the posture of rice-transplanter every one second, and a local Kalman filter calculated the posture from every new estimation of the global Kalman filter with an interval of 200 ms. A PID controller was applied to the row-following mode control. A control method of U-turning mode was developed as well. A stepping motor with a reduction gear set was used to rotate the shaft of steering wheel. Results: Test trials for U-turning and row-following modes were done in a paddy field after some parameters have been tuned at the ground speed range of 0.3 ~ 1.2 m/s. The minimum RMS error of offset was 3.13 cm at the ground speed of 0.3 m/s while the maximum RMS error was 13.01 cm at 1.2 m/s. The offset RMS error tended to increase as the ground speed increased. The target point distance, LT also affected the system performance and PID controller parameters should be adjusted on different ground speeds. Conclusions: A target angle-based PID controller plus stationary steering angle controller made it possible for the rice-transplanter to steer autonomously by following a reference line accurately and even on U-turning mode. However, as condition in paddy fields is very complicated, the system should control the ground speed that prevents it from deviating too much due to ditch and slope.