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Volume 36 (2001)
- Issue 4 Pages 179-
- Issue 3 Pages 131-
- Issue 2 Pages 49-
- Issue 1 Pages 3-
Volume 36, Issue 4
Displaying 1-5 of 5 articles from this issue
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Tatsushi TOGASHI, Kunji SHIMOTSUBO, Satoshi YOSHINAGA2001 Volume 36 Issue 4 Pages 179-186
Published: December 20, 2001
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSWe developed a seed-shooting seeder of rice combined with a tractor-mounted paddy harrow. Seeding is carried out simultaneously with the last puddling operation in a paddy field.
The seeder unit has a saw-toothed disc which revolves 100 to 1500rpm. The disc shoots seeds coated with calcium peroxide (CaO2) onto the soil surface of a paddy field. The seeds are fed by the seed roller. Disc and the roller are driven by direct current motor (40W and 130W) with tractor battery. Using high speed camera, some basic room tests related to seeding depth was performed. The results were as follows:
1) The seeds velocity (CV=15%) right after shooting was about 0% to 10% higher than the peripheral velocity of the saw-toothed disc.
2) When the coated seed was shot into water, the seed velocity rapidly decreased and seed motion virtually came to a stop. The distance of the stopping point from the water surface was about 40mm (CV=27%).
3) When the seed was shot into agar (its viscosity was 50dPa·s), the sowing depth was in proportion to the seeds velocity, and CV of the sowing depth was 36% to 38%.View full abstractDownload PDF (1319K) -
Tatsushi TOGASHI, Kunji SHIMOTSUBO, Satoshi YOSHINAGA2001 Volume 36 Issue 4 Pages 187-194
Published: December 20, 2001
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSPreviously, we developed seed-shooting seeder of rice and the machine was able to get some seeds to be hill-seeded along rows. We developed a new cell roller and investigated some factors which influenced the form of the hill-seeding spots.
The results were as follows:
1) The new cell roller was developed to discharge the CaO2 powder of the seed coat in the cell.
2) The new cell roller remodeled successfully performed hill-seeding, i. e., it was able to release several seeds intermittently.
3) The form dimensions of the hill-seeded spot (ellipse in shape), which was obtained during paddy field and laboratory tests, were 7 to 12cm (longer diameter) and 3 to 6cm (shorter one).
4) Test results clearly showed that the factors influencing the form of hill-seeded spot were as follows: (a) the timing of seeds release, (b) the timing of providing or delivering seeds to the saw-toothed disc, (c) the traveling speed of the tractor, and (d) viscosity of puddled soil and other soil conditions.View full abstractDownload PDF (926K) -
Tatsushi TOGASHI, Kunji SHIMOTSUBO, Satoshi YOSHINAGA2001 Volume 36 Issue 4 Pages 195-203
Published: December 20, 2001
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSPerformance test of the seed-shooting seeder of rice was carried out in some soil conditions of paddy field and the growth characteristics of rice were investigated.
The results were as follows:
1) Soil viscosity and seeds velocity just shot onto soil surface seemed to influence the germination depth of rice. The depth was 5-20mm in the case that seeds were shot into submerged soil (viscosity: 50-150dPa·s) of a paddy field.
2) The form dimensions of the hill-seeded spot (ellipse in shape) which was obtained in a paddy field was 6-10cm (longer diameter) and 3-5cm (shorter one).
3) Work efficiency of the seeder was 0.4ha/h (working width=2.4m). It was generally equal to one of rotary type transplanter of rice.
4) Lodging tolerance of the hill-seeded rice was nearly equal to one of the transplanted rice and was superior to one of the broadcasted rice.
5) Yield of the hill-seeded rice was about 10% inferior to one of the transplanted rice.View full abstractDownload PDF (2627K) -
Takahiro FUJIWARA, Hiroshi YOSHIOKA, Fumio SATO2001 Volume 36 Issue 4 Pages 205-209
Published: December 20, 2001
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSWe devised a process of refilling plug trays with cabbage seedlings after first removing defective seedlings and then using a modified vacuum cleaner to remove the soil from the empty cells. We compared the efficiencies of this process and the process of replanting seedlings in the field.
1) We classified the process of refilling plug trays for uniform seedling production into the following 4 steps: (a) initial removal of defective seedlings; (b) second removal of defective seedlings; (c) vacuum removal of soil from unoccupied cells; and (d) filling of empty cells with fresh seedlings.
2) To compare the efficiencies of this process and the replanting of seedlings in the field, we made a seed quality model.
3) We decided on a standard for seedlings to be removed.
4) We made a vacuum machine for the trial.
5) We then used the seed quality model to clarify the working efficiency of each step in the process of refilling trays.
6) In the comparison of the overall efficiencies of refilling trays by our process in the greenhouse and replanting seedlings in the field, our process was faster than the replanting work by 100min/10a.
7) Our system of refilling trays with nursery seedlings by removing unoccupied soil by vacuum is very efficient and would therefore save on labor costs.View full abstractDownload PDF (968K) -
Junji TAKENAGA2001 Volume 36 Issue 4 Pages 211-220
Published: December 20, 2001
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSDownload PDF (3612K)
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