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Volume 49 (2014)
- Issue 4 Pages 143-
- Issue 3 Pages 97-
- Issue 2 Pages 49-
- Issue 1 Pages 1-
Volume 49, Issue 2
Displaying 1-3 of 3 articles from this issue
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Original Paper
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Takayuki TSUKAMOTO, Satoshi YOSHINAGA, Masami FURUHATA, LOAN Nguyen Th ...2014 Volume 49 Issue 2 Pages 49-55
Published: June 20, 2014
Released on J-STAGE: December 26, 2014
JOURNAL FREE ACCESSAn air-assisted strip seeder was developed for the cost-effective and efficient seeding of paddy fields. The results of previous studies indicated that the seeding depth was too shallow, even though the hourly field capacity was high. The seeding depth is an important factor in preventing bird damage and lodging. We investigated a technique to increase the seeding depth of an air-assisted seeder. We investigated the base performance of the mechanism for blowing seeds, and examined two methods. The first method entailed increasing the airflow velocity to increase the seed velocity. The performance test results indicated that the airflow velocity has little effect on the seed velocity. In addition, the seed angle of descent increased with increasing airflow velocity. Moreover, the seeding rate decreased because the airflow velocity increased the pressure inside the tube under the grain hopper. The other method entailed the formation of grooves in the field surface before seeding. We developed an auxiliary airflow technique for forming grooves in the field surface. Field test results showed that the white part of seedlings was extended by 3 mm. This result suggests that the seeding depth can be increased.View full abstractDownload PDF (679K) -
Takeyoshi KAWAGUCHI, Hideki MINAMIDA, Yasunobu KAWAMOTO, Ayaka SATOU2014 Volume 49 Issue 2 Pages 57-67
Published: June 20, 2014
Released on J-STAGE: December 26, 2014
JOURNAL FREE ACCESSPlanting work for Allium × wakegi Araki bulbs, a specialty vegetable from Hiroshima Prefecture, is harsh to the body since it is performed manually in a squatting position. Therefore, a reduction in labor effort and an improvement in planting efficiency are needed. A new method of bulb planting was developed using a simple transplanting machine for Allium fistulosum L. The process for planting is as follows. First, the bulbs are loaded into a connected paper pot placed on a raising seedling box for rice, and filled with a culture medium. The connected paper pot is then immersed to dissolve the starch, loaded onto the transplanter and pulled. The authors conclude that the method is highly applicable to Allium × wakegi Araki, since the proportion of bulbs that can be loaded into the connected paper pot before planting is 94% of the cultivated bulbs. The immersion time to dissolve the starch was 22 minutes, during which the water temperature is approximately 30°C, 35 minutes, during which the water temperature is approximately 20°C and 43 minutes, during which the water temperature is approximately 10°C. High practicality was indicated, given that the growth and yield of Allium × wakegi Araki was the same as for those bulbs grown using a conventional method. However, such as an uneven planting depth, felled bulb upon planting, and tangling in the machine, were encountered upon planting the bulbs with available machines. Therefore, these problems were designated as points of concern in the development of a new type of machine that is adapted to bulb planting.View full abstractDownload PDF (1574K) -
Hiroshi SHIBUKAWA, Akihiro INOUE, Shuji HIMENO, Toshiya KOMATSU2014 Volume 49 Issue 2 Pages 69-78
Published: June 20, 2014
Released on J-STAGE: December 26, 2014
JOURNAL FREE ACCESSIn this study, we focused on the rice straw collection systems for co-digestion with sewage sludge at the Nagaoka Wastewater Treatment Plant. The collection period for rice straw in this area was between September and October, and rice straw was collected usually 6 to 8 times in that period. The amount of collectable rice straw in October was 68% of that in September, because the rice straw in October was stuck to the surface of paddy. In addition, the collection unit was generally composed of 3 participants. If the collection period was 2 days, then the amount of maximum collectable rice straw for the unit was about 24 Mg (water content, 20%), and the collection was accomplished using the “maximum collection system”. However, if the period was more than 2 days, the amount was 39.2 Mg (3 days) or 58.8 Mg (4 days), and the collection was accomplished using the “minimum farm machines system”. The reason was that collection at the first cite and turning over at the second cite were performed at same time in “minimum farm machines system”. At Nagaoka Wastewater Treatment Plant, 1916 Mg of rice straw (water content, 20%) is required for co-digestion with sewage sludge. The number of participants and farm machines for the collection of 1916 Mg of rice straw was as follows : 42 participants and 14-15 farm machines for the “minimum farm machines system” ; 36 participants, 14-15 farm machines, and 24 rakes for the “maximum collection system” ; and 57 participants and 19-20 farm machines for the “twice turning over system”.View full abstractDownload PDF (492K)
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