Japanese Journal of Farm Work Research

» Vol. 53 (2018) | Vol. 52 (2017)


Vol. 53 (2018), No. 2

Released: December 24, 2018

  • Research Paper
  • Yield and Quality of Tomato (Solanum lycopersicum L.) Cultured in Bittern-Supplemented Hydroponic Solution
    Songying Zhou, Mioko Yoshino, Keisuke Maejima, Hiromitsu Odani, Ani Widiastuti, Isao Yamoto, Mitsutake Unuma, Hideyuki Misu, Yumi Eguchi, Haruna Kamoda, Maki Shinohara, Tomofumi Watanabe, Tatsuo Sato
    Abstract: Increasing the electric conductivity (EC) of the nutrient solution for growing hydroponic tomatoes (Solanum lycopersicum L.) is an effective way to increase fruit sugar content. The potential of bittern and coarse salt (NaCl) to cause high-EC stress, thereby improving fruit yield and quality in tomato plants under single- or double-truss cultivation were compared. Bittern is a by-product of the salt manufacturing process; it is easy to use and inexpensive. In particular, bittern is more convenient than common salt for high-EC treatment, because it is distributed as a solution, whereas common salt must be dissolved to very high concentration. The experiments reported herein were conducted during two growing seasons: spring and autumn. High-EC stress treatments (bittern or coarse salt) started when the largest fruit on the first truss was 4 cm in diameter. Fruit yield and Brix sugar content in the bittern treatment were similar or higher than in the salt treatment under both cultivation schemes. The EC of the bittern-added nutrient solution increased faster than that of the solution with added coarse salt. This trend was probably caused by the different ion compositions of bittern and coarse salt. There were no differences in tomato growth among treatments. Thus, bittern is a practical and effective additive for hydroponic single-truss tomato cultivation.
    Using a Water Nozzle for Disbudding Satsuma Mandarins
    Hiromichi Ichinokiyama, Hitoshi Okuda
    Abstract: A new disbudding method using a water jet nozzle was developed. An experiment was conducted on 32-year-old satsuma mandarin trees (cv. Okitsu wase) bearing many fruits. The disbudding treatment was applied to selected lateral shoots 1 day after budding (March 31, transverse bud diameter: 1.24 mm), 7 days after budding (April 6, transverse bud diameter: 2.30 mm), 16 days after budding (April 15, transverse bud diameter: 2.86 mm), or 24 days after budding (April 23, transverse bud diameter: 4.99 mm). Two types of nozzles with different discharge volumes (WJN1: 43.8 mL/s; WJN2: 29.3 mL/s) were considered for the bud removal rate and time required. As a result, NNZO12 was more successful for removing buds. When the nozzle with the higher discharge volume (WJN1) was used 1 day after budding, the time required was 49.5% of that needed for manual disbudding, and the removal rate was 96%. Because the peduncle became thick with time, the time required to remove buds increased; from these findings, it was considered that the treatment up to 7 days after the sprouting (bud diameter 2.3 mm) was effective for disbudding using the water jet nozzle. No significant difference was found in the required time when the treatment was applied more than 7 days after budding. The development of new shoots could be damaged if the water jet disbudding was applied to very small buds just after sprouting.
    Accumulation Characteristics of Carbon and Nitrogen in Growth Stages of Sunflower and Uses of Crop Residue
    Seishu Tojo, Tadashi Chosa, Kaoruko Sunaga
    Abstract: Sunflowers are grown as oilseed crops in every region of Japan, though the residues left after harvesting are seldom utilized. Recently, sunflowers have received a lot of attention for their use as landscape crops for tourist attractions and/or catch crops to perform the uptake of excess plant nutrients in the soil. This research aims to clarify the accumulation characteristics of carbon and nitrogen in sunflowers at each growth stage, and the reuse of crop residues after harvesting is discussed. Sunflowers were cultivated in 3×3 m plots with varying planting densities and the fertilizer conditions at the university farm. Growth changes in the sunflowers were observed and samples were obtained at three growth stages, namely, flowering, just after flowering, and harvesting. Dry matter, calorific value, and carbon and nitrogen content were measured and analyzed for each sunflower region. As a result, the following was revealed: the calorific value of stems and leaves was nearly equal that of seeds, sunflower biomass increased in regions with a higher planting density, and one third of the total nitrogen uptake was accumulated in seeds during grain filling.


Vol. 53 (2018), No. 1

Released: September 20, 2018

  • Original Paper
  • Land Cover Change in Bamyan, Afghanistan from 1990 to 2015
    Abdul Aziz Mohibbi, Hasi Bagan, Motoko Inatomi, Tsuguki Kinoshita
    Abstract: Lack of management and years of conflict have resulted substantial stress over natural and seminatural ecosystem in Bamyan, Afghanistan. In this study, we evaluated the spatio-temporal changes in land cover in Bamyan from 1990 to 2015 and lack of land management issues. To achieve the objective a comprehensive field work survey was conducted with 97 local people and farmars with a framed questionnaire. 88 local people and farmars stated that land cover has changed with 30 years. Both respondent groups specified the reasons as population increase, overuse of resources, overgrazing, shrub collection, drought and mismanagement. The result of interview with governmental organizations and NGOs demonstrated, land degradation is acute problem due to vegetation cover removal, overgrazing, dependency on natural resources, fodder collection and cultivations on steep slopes. Moreover, we applied the Maximum Likelihood Classification method to produce land-cover maps using Landsat images of 1990, 1999, 2008, and 2015. Defining grid cells with unique cell IDs allowed us to quantify spatio-temporal changes in land-cover classes. Rangeland decreased from 60.2% to 37.9%, accompanied by rapid increases in bare soil and built-up classes. This suggests the extension of anthropogenic influence into surrounding natural and semi-natural ecosystems. Statistical comparison of the land-cover changes in 0.81 km2 grid square cells showed that the decrease in rangeland was strongly negatively correlated with that of bare soil. Furthermore, around Bamyan city, the expansion of builtup areas was strongly positively correlated with that of plantation areas, and negatively correlated with bare soil increases. This is due to the rapid socio-economic changes between 1999 and 2015. The result indicates that years of conflict, absence of management, and socio-economic change caused land cover change in Bamyan between 1990 and 2015.
  • Research Paper
  • Effects of Spinach Cultivars and Cultivation Conditions on Leaf Yield and Appearance Quality in Ratoon Cropping for Processing Use
    Takayuki Suzuki, Erika Kamada, Takanori Ishii, Katsuki Adachi, Hiroshi Niimi
    Abstract: The mechanical har vesting of spinach for processing use is becoming common in Japan. We investigated the effects of cultivars and cultivation conditions, including the supplemental application of fertilizer after first harvesting and the time of first harvesting, on leaf yield and appearance quality in ratoon cropping, which utilizes regrowth of spinach foliage, in Miyazaki Prefecture, which is the largest spinach producing center in Japan. Regarding whole plant weight at harvest, there was no significant difference between cultivars, but the ratio of foliage weight cut at harvest to whole plant weight was consistently higher in the upright cultivar‘ Kuronosu’ than in‘ Sapuraizu7’ in both the first and second cropping (ratoon cropping) with supplemental fertilizer application. In‘ Kuronosu’ cropping, the supplemental fertilizer application after first harvesting increased the foliage weight at the second harvest and percentage of good leaves for products. In addition, the longer growing period increased the foliage weight at the second harvest. Therefore, in a mechanical harvesting system with ratoon cropping, the following measures are recommended: upright cultivars should be grown; when the plant length reaches approximately 40 cm, spinach should be initially harvested to ensure adequate growth period for the second harvesting; and supplemental fertilizer should be applied after first harvesting.
    Effects of Biculture of Guinea Grass (Panicum maximum Jacq.) and Crotalaria (Crotalaria spectabilis Roth.) on Biomass Production and Soil Nitrogen Dynamics
    Akira Iwasaki, Masakazu Komatsuzaki
    Abstract: Gramineae and Leguminosae are used as summer cover crops in monoculture; however, their biculture system has not been studied well. This study compared the effects of biculture of summer cover crops on biomass production and nitrogen leaching in the fields of the Field Science Education Center, Ibaraki University. The fields were seeded using different seeding ratios of guinea grass (Panicum maximum Jacq. cv. Natsukaze) and crotalaria (Crotalaria spectabilis Roth. cv. Nemaclean). We prepared six combinations of the biculture in the following seeding ratios: 100:0 (guinea grass monoculture) , 75:25, 50:50, 25:75, 0:100 (crotalaria monoculture) , and 0:0 (bare). In 2016, the aboveground biomass of the cover crop, the C / N ratio, and the amount of absorbed carbon were highest in the harvested guinea grass monoculture crop compared with the other seeding ratios. In 2017, the aboveground biomass in the guinea grass monoculture crop and in the 75:25 biculture crops were almost similar, while it was lowest for crotalaria monoculture crop. On the other hand, the C / N ratio was the highest in the crotalaria monoculture crop. The concentration of nitrate in the soil decreased significantly due to the cover crop uptake in the both years. The results of these two years showed that it is possible to increase the decomposability of the residue and promote the supply of organic matter necessary for agricultural productivity of the land, securing biomass production, by lowering the C / N ratio.


Vol. 52 (2017), No. 4

Released: June 20, 2018

  • Original Paper
  • Development of a Fertilizer Application Device Capable of Producing and Pouring Liquid Fertilizer in Paddy Fields
    Takuya Mori, Shuhei Makabe, Tomohiro Iijima, Masatoshi Hirata, Shuich Yokota, Kazuto Shigeta
    Abstract: We have developed a liquid fertilizer application device that, utilizing irrigation water and inexpensive urea, can produce and apply the liquid fertilizer necessary for use in paddy fields onto the crop in a highly accurate manner. The drop flow rate of the fertilizer, and the nitrogen concentration rate, remained almost constant throughout field demonstration tests. After the fertilizer was applied, the leaf color, rice yield (calculated by crop cutting surveys) were the same as those achieved when a conventional fertilization method was used, namely, application of ammonium sulfate using a backpack-type spreader. In order to ensure accurate fertilizer application using irrigation water, it was necessary to first completely drain the field to expose the paddy, and to stop the flow of irrigation water after the application was complete.
  • Research Paper
  • Formulation of the Process and Estimating of the Energy Required for Harvesting and Drying of the Shelled Corn in the Paddy Field Areas
    Ichiro Inano, Kota Ishii, Yoshiaki Kimura, Hideyuki Takenaka
    Abstract: The energy required for harvesting and drying of shelled corn was estimated using the potential workable number of days for a grain-maize combine harvester predicated on the drying rate and the rate of harvesting in the paddy field areas. A harvester with an attached maize header and far-infrared radiation grain dryer for 14.4 m3 of shelled corn drying were used. The results of the simulation show that the moisture content of the shelled corn alters the duration of the process from 2 days to 1 day with 3 driers owned by a corporate farm versus 4 driers owned by 4 family farms. From the relationship between the moisture content at the start of the harvest of the corn and the total energy consumption, the energy required in the harvesting and drying processes increase when the moisture content of the shelled corn decreases below 30%. However, it was found that the energy required in the harvesting and drying processes decrease when the period of the process changes from 2 days to 1 day.
    Selecting Suitable Grape Varieties for a Rural Work Experience Program with a Container Growing System
    Akihiro Hosomi
    Abstract: This study was designed to select grape varieties suitable for cultivation by beginners in a rural work experience program. Five grape varieties, ‘Campbell Early’, ‘Red Port’, ‘Steuben’, ‘Muscat Bailey A’, and ‘Neo Muscat’, were compared for ease of cultivation and fruit productivity. The vines were grown in 10-liter containers during the 1st year and in 50-liter containers during the 2nd–3rd years, under condition of shelter from rain. They were trained by unilateral horizontal cordon training with spur pruning. The uniform shoot growth of ‘Red Port’ and ‘Steuben’ was well suited to pattern working. The weaker shoot growth of ‘Muscat Bailey A’ meant that less labor was needed for shoot management. After 2nd year the shoots of all varieties, apart from ‘Neo Muscat’, bore flower clusters. The greater berry setting proportion of ‘Steuben’ gave rise to compact and well-regulated clusters. More insect pests attacked ‘Campbell Early’, ‘Red Port’ and ‘Steuben’, and it was necessary to control them. More diseases occurred in ‘Muscat Berry A’ and ‘Neo Muscat’, but were unimportant and no action was needed. Laborsaving plant protection is likely to be needed for ‘Muscat Berry A’ and ‘Neo Muscat’, if grow under rain shelter to inhibit disease. It emerged that, ‘Steuben’ and ‘Muscat Bailey A’ were the varieties of grape best suited to cultivation by beginners.


Vol. 52 (2017), No. 3

Released: March 20, 2018

  • Original Paper
  • Characteristics of Seedbed Preparation Work Using a Chisel Plow and Power Harrow and Rice Plant Growth on Non-Puddling Direct Rice Seeding Cultivation in Flooded Paddy Field Soil
    Hayato Shindo, Masanori Saito, Keiji Sasaki, Yuko Sato, Mitsuhiko Katahira
    Abstract: We studied non-puddling direct rice seeding into flooded paddy field soil, which uses a seedbed produced with a chisel plow and a power harrow, with seeding by a precision direct drill seeder. Those methods apparently improve spring work related to rice direct seeding, such as tillage, harrowing, and puddling. Therefore, we investigated the work rate and fuel consumption of spring work, rice growth, yield, and brown rice quality. These data of non-puddling direct rice seeding cultivation (NP) compiled during 4 years were compared with those obtained from conventional tillage cultivation (CT). Seedbed preparation work using a chisel plow and power harrow achieved 63.4–73.5% soil pulverization ratios. The precision direct seeder can sow into non-puddled soil 3–4 days after flooding softens the soil. Seedbed preparation work time and fuel consumption in the NP block were decreased respectively by 41% and 26% compared to the CT block. The NP block seeding establishment rate was 71.7% on average, which was higher than that of CT block. These test blocks showed sufficient seeding establishment. The NP block showed faster midseason drainage for soil moisture, with a higher percentage of the productive culms and lower generation of non-productive tillers, with an equal or greater number of panicles than the CT block.
  • Research Paper
  • Reduction in Nitrogen Fertilizer Application by Introduction of Hairy Vetch Cultivation in Two Cropping Systems of Spring Wheat in Central Hokkaido
    Toshiyuki Hirata, Daisuke Noguchi, Hajime Araki
    Abstract: This study examined how hairy vetch seeding affects reduction of nitrogen (N) fertilizer application to the continuous cropping of spring wheat in Central Hokkaido, in 2015 and 2016. The spring wheat cultivar, ‘Haruyutaka’, was cultivated using two cropping systems, namely, a conventional system wherein spring wheat was sown in early April and an early winter seeding system wherein spring wheat was sown just before snowfall. Hairy vetch was grown until just before the spring wheat seeding was completed in the conventional system. In contrast, in the early winter seeding system, hairy vetch was incorporated in late October. N fertilizer application after snow melting was reduced to half the recommended level in the cropping systems employing hairy vetch. Growth and dry matter production in spring wheat were estimated in 2015 and 2016, by comparatively evaluating these results with the conventional and the early winter seeding systems without hairy vetch application. Dry weight of hairy vetch ranged from 250.1 g m-2 in the conventional system in 2014 to 50.1 g m-2 in the early winter seeding system in 2015. The grain dry matter weight was higher in the early winter seeding system in only 2015, but there was no difference between hairy vetch application treatments in both systems in 2015 and 2016. N content in wheat grain ranged from 2.29% to 2.52%, which was sufficient to ensure seed quality of spring wheat. The plant length was suppressed at the late growth stage in the early winter seeding system employing hairy vetch in 2016. This results suggest that N deficiency occurred at the ripening stage of wheat in this system. The present study shows the potential to reduce spring N fertilizer to half of the recommended level by introduction of hairy vetch during the previous autumn season.


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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