Japanese Journal of Farm Work Research

» Vol. 52 (2017)


Vol. 52 (2017), No. 2

Released: December 20, 2017

  • Research Paper
  • Development of a Precision Seeder to Shorten Thinning Labor Hours
    Kentaro Matsuo, Mikio Yashiro
    Abstract: The Two-row seeder has been developed to shorten thinning labor hours for direct seeding vegetable cultivation. In contrast to existing seeders, the Two-row seeder is able to sow seeds with narrow row distance arrangements. Performance tests for the Two-row seeder were conducted using Japanese radish. The effects of thinning labor hours and influence of the weight of crop on sowing of employing the Two-row seeder was evaluated. The seed spacing between the two rows of the Two-row seeder was 19 mm and the row distance of the Two-row seeder was 35 mm. These specifications, simplified and facilitated the seedling thinning process. The thinning labor hours of the Two-row seeder was 2.3 s/hill, 1.9 s/hill shorter than the thinning labor hours of a vacuum-type seeder. The root weight of Japanese radish as a result of using the Two-row seeder at harvest time was 1284 g, and was not found to yield no statistically significant difference to the root weight of other seeders. In conclusion the results demonstrate that the Tow-row seeder can shorten thinning labor hours without decreasing the yield of Japanese radish.
    Applicability of Dry Direct-seeding Rice Cultivation using Plowing and Compaction Based on Soil Conditions of Paddy Rice Fields
    Hideaki Kanmuri, Hiroyuki Sekiya, Ryuji Otani
    Abstract: Observations of soil condition, permeability of soil layers, and water-requirement rates of paddy fields were conducted at 20 paddy rice fields in 5 regions cultivated with compacted or non-compacted dry direct-seeding rice (DSR) cultivation methods to clarify applicable conditions of DSR cultivation using plowing and compaction. Three compacting conditions were set for these test fields: a low-compaction condition with 1 time compaction after seeding, a high-compaction condition with more than 2 compactions after seeding, and a non-compaction condition. Their influence on field water requirements was investigated under three compacting conditions with different degrees of soil layer permeability. Results clarify that DSR cultivation using plowing and compaction can be done easily in paddy fields with a gley soil layer because the water requirement can be reduced to less than the appropriate value of 20 mm/d under even a low-compaction condition. Consideration of the relation between saturated permeability at the soil samples of field surface layer, which were obtained at 3 cm or 5 cm below the field surface and at the deep layer and the water-requirement rate indicated that reduced permeability of the surface layer by high compaction can reduce the water-requirement rate in fields without a low permeability layer. Classification of paddy fields based on a 2×2 matrix diagram according to saturated permeability at a deeper layer and at the surface layer in the field can show the necessity for drainage improvement in a field or for compaction work on the field surface. Such classification presents useful information for the application of DSR in paddy fields, such as compaction work is necessary in fields with high permeability in the deep layer.


Vol. 52 (2017), No. 1

Released: September 20, 2017

  • Original Paper
  • Downsizing of Sugarcane Harvesting and Transportation System on Minami Daitojima and Kita Daitojima Islands in Okinawa Prefecture —Classifying and Estimating Current Effective Work Rate in Sugarcane Harvesting and Transportation—
    Tohru Akachi, Tohru Yoshihara, Kenjiro Maeda, Maro Tamaki, Morikuni Miyahira, Moriyuki Shoda, Masatatsu Aniya, Kenta Kameyama, Eiji Inoue
    Abstract: On the islands of Minami Daitojima and Kita Daitojima in Okinawa Prefecture, an initiative has been launched to replace aging sugarcane harvesters and trucks used for transportation. A variety of proposals have been put forward to downsize equipment and transition to large-scale mechanical systems. The authors set out to develop and formulate an efficient and sustainable model for harvesting and transportation sugarcane on the two islands, starting with organizing basic operational information to systematically classifying the main current systems, which combine harvesting and transportation. The results showed that eight types of harvesters are currently used on Minami Daitojima and Kita Daitojima—one type of large-sized harvester, six types of medium-sized harvesters, and one type of small-sized harvester. We also classified the different ways in which harvesting and transportation operations influence each other; for example, the use of trucks for escorting harvesters as well as for transportation. The effective work rate associated with each pattern was also clarified based on data received from sugar mills, resulting in 19.1-28.0 a/h with large-sized harvesters and 13.3-15.2 a/h with medium-sized harvesters. Our estimation method was verified by examining estimates of effective work rate calculated from real measurements of field work in time trials at sugarcane fields, taking into account the effective work rate measurements obtained from GPS-based analysis of the work performed by transportation trucks.
  • Research Paper
  • Workability of Summer-Autumn-Harvest Cherry Tomato in Open Field Culture Using Non-Training Cultivation with Net
    Satoru Motoki, Reiko Hojo, Miwa Someya, Takuya Fujio
    Abstract: The new cultivation method, which is referred to as the non-training culture with net (popular name: sauvage) method for the open-field cultivation of summer-autumn-harvest cherry tomato, is becoming popular across Japan, no studies have been conducted to compare the workability between the sauvage and traditional cultivation methods. The present study compared sauvage and traditional cultivation methods, focusing on the time required to perform each task, postures assumed to perform them, and yields, to establish the sauvage cultivation system. In sauvage cultivation, the time required to perform each task (training and chemical spraying in particular) was significantly shorter than in traditional cultivation methods, except for the time for harvest. However, the time required for the harvesting of cherry tomatoes in sauvage cultivation method accounted for 90% of the total time for all cultivation processes and the percentage was drastically higher than that of traditional cultivation methods. The yield per unit area in sauvage cultivation, in which the planting density was lower, was similar to or larger than the yield in traditional cultivation methods, and the growers were able to ship their crops in August to September when the plants would have been exposed to high temperatures and solar radiation level. Sauvage cultivation can be expected, as a new method for the open-field cultivation of summer-autumn-harvest cherry tomatoes to promote labor-saving in relation to their cultivation management. To reduce the time required to perform each task, improving harvest procedures accounted for majority of total time for all cultivation processes was considered to be necessary.
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