Japanese Journal of Farm Work Research

» Vol. 47 (2012) | Vol. 46 (2011)

 

Vol. 47 (2012), No. 4

Release Date: June 20, 2013

  • Original Paper
    • Biomass production and nitrogen absorption in the rotational croppings of spring wheat and cover crops in Hokkaido
    Toshiyuki HIRATA, Takeshi NAGAYAMA, Hajime ARAKI
    Abstract: Cover crops have been used for maintenance of soil quality in wheat production systems for many years. Examined were biomass accumulation and nitrogen absorption in wheat production of four annual rotational croppings ; spring wheat and bare fallow, hairy vetch, bristle oat, and mixture of hairy vetch and bristle oat, in Hokkaido, with its cool season and snow cover region. The overview of results is as follows. 1) The yields of wheat were increased by cover croppings. It was not influenced by the species of cover crops used. 2) Yield of wheat in 2009 was 55.4% of that in 2008 in the bare fallow plot, while reduction rates of wheat yields from 2008 to 2009 were 36.7% and less in the plots where cover crops were produced. It was suggested that the yield stability of wheat was increased by rotational managements of cover crops. 3) From multiple linear regression analysis with nine explanatory variables ; three candidate nitrogen resources and their C/N ratio, two cover crop species and a tillage method, bristle oat production was found to have a negative effect on the nitrogen absorption of wheat. This result showed the effectiveness of hairy vetch cropping in the rotational production of spring wheat and cover crops. 4) The effect of spring tillage on wheat yield was not detected among cover crops. Nontillage seeding of spring wheat may provide an advantage in saving energy in the field in rotational cropping of spring wheat and cover crops.
  • Research Paper
    • Possibility for Advancing Harvest Time using CPPU on the Kiwifruit Cultivar ‘Rainbow Red’ (Actinidia chinensis)
    Satoru MURAKAMI
    Abstract: Fruit size enlargement and extension of selling period are assignments to be solved in the kiwifruit cultivar ‘Rainbow Red’. In order to solve these subjects, we investigated the practicability of forchlorfenuron (CPPU) treatments in this cultivar. Treatments by 4.0 ppm or below showed a tendency to increase fruit size, while fruit drop and fruit maturation were promoted. The possibility of hastening the harvesting time was suggested ; if the treatments were to be combined with no-treatments, expansion of harvesting period and selling period are expected. The green color of the pericarp became darker and the fruit apex enlarged by the treatments. Regulations of these undesirable effects are yet to be solved for the cultivation of kiwifruit ‘Rainbow Red’.

Vol. 47 (2012), No. 3

Release Date: March 20, 2013

  • Original Paper
    • Pseudostem Length as an Indicator of the Start of Internode Elongation in Wheat (Triticum aestivum)
    Masahiko TANIO, Teruo WATANABE, Koichiro FUKAMI, Yutaka SASAKI, Kunio TATEISHI
    Abstract: To develop a useful indicator of the start of internode elongation in wheat in the warmer regions of Japan, we analyzed the relationships between the apical development stage, stem length, and pseudostem length (from the ground to the lamina joint of the uppermost unfolded leaf) of the main shoot in wheat cultivar ‘Norin 61’. The time course of apical development differed with year and (greatly) with sowing time. Nevertheless, stem elongation was synchronized with apical development, and the internodes probably started to elongate at the floret differentiation stage. In addition, pseudostem length was highly correlated with the apical development stage (5.6 cm at the floret differentiation stage). These close relationships show that internode elongation began when the pseudostem length was ca. 5 cm. Therefore, pseudostem length could be useful as an indicator of the start of internode elongation for wheat cultivation in the warmer regions of Japan.
  • Research Paper
    • An Adaptability of Determinate Type Tomato Cultivar ‘Morioka 7’ for High-rise Hydroponics
    Yoko MIYAMA, Tatsuo SATO
    Abstract: For the purpose of developing a supplementary cropping during the summer for a high-rise hydroponic system of strawberries, the adaptability of a determinant tomato cultivar “Morioka 7” was evaluated. The seedlings were planted in May,and about 6 t/10a of marketable yield was harvested by the end of August. This cultivar showed a strong dwarf character, so no training or pruning was required. The total labor time was remarkably less than that for the indeterminate variety “House Momotaro”.
    　The highest yield was assumed when the Yamazaki nutrition formula nutrient solution was supplied at a concentration of EC 1.2 dS/m until the early stages of harvest and 2.4 dS/m thereafter.

Vol. 47 (2012), No. 2

Release Date: January 30, 2013

  • Original Papers
    • Evaluation of Growth of Summer Cover Crops and Their Function for Agro-ecosystems based on Multivariate Analysis
    Masakazu KOMATSUZAKI, Kasumi SUGANUMA, Hajime ARAKI
    Abstract: Summer cover crops are one of the most effective ways to improve the soil quality and agricultural environment because they offer many benefits to the agro-ecosystem, such as addition of organic matter, accumulation of nutrients, and contribution of nutrients to subsequent crops. However, the benefits are often not taken into account in farming systems because they are complex and differ depending on cover crop species and management. This research evaluated the growth of summer cover crops and their function for the agro-ecosystem based on multivariate analysis. The main results were as follows. 1) The accumulation of cover crop dry matter was significantly higher in oat and white mustard in June, but was the highest in sorghum in August. 2) The accumulation of cover crop nutrients increased as the accumulation of dry matter increased. 3) The yield of broccoli following summer cover crops was the highest after crotalaria and the lowest after mixed flowers. 4) Based on principle component analyses, summer cover crops were evaluated at each growth termination. These results suggested that the classification of summer cover crops were divided by their biomass accumulation and CN ratio. 5) Our results suggest which there is an appropriate selection of summer cover crops to establish a new farming system that maximizes the benefit of cover crops for agro-ecosystems.
    Effectiveness of Small-balloon Sensing in Field Survey— Case Study of Wheat Field Converted from Paddy Field —
    Toshifumi MURAKAMI, Masahiko MORI, Atsushi OYANAGI, Hideaki HISHINUMA
    Abstract: Because of recent technological development in digital camera miniaturization, it is now possible to acquire aerial photographs with a small balloon. However, there are few reports in Japan concerning such balloons and few field surveys of poor plant growth in wheat fields that were converted from paddy fields. Thus, we studied image analysis methods for aerial photography and examined the usefulness of the photography in the field survey and data analysis of wheat fields managed by a large-scale agricultural corporation. Aerial images were obtained with a compact digital camera attached to a small helium gas balloon measuring 1.8 m in length and 0.64 m3 in volume. Soil moisture content, leaf color index, plant height, ear number, and grain yield were determined. In the image analysis, topographical correction of aerial images, wheat vegetation rate, and areas with wet soil was conducted with graphics software. Birds’ eye view photographs acquired from a height of approximately 180 m facilitated the selection of fields to be studied because plant growth outline in a wide area could be compared. Vertical photographs of one field taken from a height of 117 m expedited the determination of sampling positions and enabled us to gain a perspective of the survey. The image analysis also simplified plant growth categorization and the analysis of the causes of poor plant growth. The causes were found to be high soil moisture content, increased soil hardness, and small relative field height. Soil color intensity in the aerial photographs enabled evaluation of the effectiveness of drainage measures. In conclusion, the small-balloon photography system is an effective tool to improve the precision of field survey and data analysis.

Vol. 47 (2012), No. 1

Release Date: September 20, 2012

  • Original Papers
    • Study on Developing a Drying Technique of Colored Sweet Potatoes
    Hideo FUKAZAWA, Ken-ichi YAKUSHIDO, Hisashi HOSOKAWA, Teruo WATANABE, Kei NAKAJI
    Abstract: Recently, production of sweet potatoes has tended to decline, but expansion of use for Shochu (Japanese distilled spirits) and processed food is in progress. Under these circumstances, ‘Ayamurasaki’ a new cultivar with a high anthocyanin content has been released and is expected to be useful as confectionary and food material. Steaming or boiling is conducted in conventional processing of colored sweet potatoes for primary food materials, resulting in alphanizing of starch. We developed a new drying technique of sweet potatoes by fine cutting before drying to retain betanized starch and useful natural pigments.
    1) We studied about the drying characteristics of fine cut sweet potato rhizomes and found a constant drying rate period. We also found out that the optimum air moisture ratio was 0.015 m3/s·kg (water).
    2) Retention of anthocyanin content was high(75 to 87% of before drying) when the drying air temperature was between 50 to 80°C, with the highest yield at 60°C, under an air flow rate of 0.015 m3/s·kg (water).
    3) Reducing the air temperature during drying was an effective method to retain anthocyanin content and betanized starch. Drying with an air temperature of 80°C until the cut raw sweet potatoes was heated, then gradually decreasing the temperature to end at 55°C showed a good performance.
    Changes in Structure and Mechanical Properties of Isahaya Bay Reclamation Soil by Agricultural Vehicle Traffic
    Tomohiro MIYAZAKI, Takashi OKAYASU, Satoshi SUGIMOTO, Eiji INOUE
    Abstract: Bulk density and three phases distribution of soil were measured before and after tractor running to evaluate soil compaction phenomena on the Isahaya reclaimed soil. Mechanical properties of reclaimed soil were also evaluated by soil tests. Results obtained from the study were as follows : 1) Soil compaction caused by the tractor running markedly occurred near the soil surface, due to decrease of the gaseous phase in soil with increase of the solid and liquid phases. This trend was more eminent with increase in frequency of tractor passes. 2) Water in the trampled soil was not drained immediately after trampling, but was gradually drained around the soil resulting in decrease of the water content and increase of the bulk density. 3) From the compaction test in a laboratory, the reclaimed soil showed a maximum dry density of 1.07 g/cm3 when the water content was 51.0%. This condition coincided well with the optimum condition for machinery operations. 4) The undrained triaxial compression tests showed that though undisturbed soil had higher strength than disturbed soil, an unstable mechanical behavior such as softening occurred. One of the reasons may be that a soil structure has been developed in the undisturbed soil. From this point of view, more detailed evaluation of soil structure is indispensable for practical assessment of reclaimed soil on polders.

Vol. 46 (2011), No. 4

Release Date: June 20, 2012

  • Original Paper
    • Improvement of Nitrogen Balance by Rotating Corn and Hairy Vetch
    Mohammad Zarif SHARIFI, Shoji MATSUMURA, Masahiro ITO, Tadashi HIRASAWA, Masakazu KOMATSUZAKI
    Abstract: To develop a cropping system for corn production without using N fertilizer, a crop rotation with hairy vetch (Vicia villosa Roth, HV) was examined over a 3-year period (2007-2009). The experiment consisted of four treatments (incorporation of HV biomass, mulching of HV biomass, fertilization with mineral fertilizer, and control without application of nutrient source) carried out in triplicate. The HV biomass was managed according to each treatment in May, followed by cultivation of silage corn in June. Corn dry weight and N uptake were measured during the growth season. The HV biomass accumulated 260-300 kg N ha-1 year-1, and approx. half of this N seemed to be available in an inorganic form to corn plants. In the second and third years, above ground biomass (AGB) in both HV-treated plots exceeded that of the control, which was almost equal to that of the fertilized plot. N uptake by corn was 330-400 kg N ha-1 when AGB reached 25 Mg ha-1. It was estimated that 40% of the N required to achieve this yield could be sup-plied by HV. The difference in N uptake between HV-treated and control plots was 20-25 kg N ha-1 in the first year, 100-140 kg N ha-1 in the second year, and 40-50 kg N ha-1 in the third year. Thus, HV was an important N source, in spite of the annual fluctuation. There was no difference in corn yield between the incorporation and the mulching treatments.
  • Research Paper
    • Study on a Rice Straw Collection Model using the System Dynamics Method
    Hitoshi KATO, Genta KANAI, Yuichi KOBAYASHI, Kazuhiro TAKEKURA, Kenichi YAKUSHIDO
    Abstract: A rice straw collection model using the system dynamics method was developed to analyze factors such as 1) number of working days when straw could be collected, 2) number of machinery-operating days, and 3) number of machines required, in warm and cold regions on Japan’s Pacific side (WP and CP, respectively) and in cold regions on the Sea of Japan side (CS). We used a model with six straw stocks : field-dried to three dryness levels, and wind rowed, baled, or collected;and four work flows : swath turning, rowing, baling, and transporting. The 10-year analysis (2000-2009) showed that in WP, during a 3.5-month work period, there were 61 workable days ; 39 were spent for packing and transporting field-dried straw to collection sites. Straw was collected in a stable manner but was exposed to rainfall for longer periods because of the extended collection period. In CP, during a 2.5-month work period, there were 38 workable days ; 23 were spent for packing and transporting. Because the collection period was short, in some high-rainfall years the amounts of straw collected were far below aimed. However, because the work was concentrated over a short period, the collected straw was generally exposed to rainfall for less time than in WP. In CS, during a 2.5-month work period, there were 26 workable days ; only 6 were spent packing and transporting. Collecting straw at high water content increased the number of packing and transporting days to 11 but reduced the number of machines required, except for transportation trucks.

Vol. 46 (2011), No. 3

Release Date: March 10, 2012

  • Original Paper
    • Development of the Computer Software for Farm Work Safety Instruction —Part 2 Production of the Safety Tractor Operations in Spring Cultivation—
    Satoshi YONEKAWA, Makoto NAKANO, Yutaka KIKUCHI, Ei SEKI, Shunsuke OKADA and Fumitake ISHIKAWA
    Abstract: Interactive multimedia agricultural work safety education software regarding springtime tilling by tractor was developed for use on a PC with mouse operation.
    The scenes in the main part of this software are classified into 5 groups, and are composed of 19 individual scenes with associated questions. In individual scenes with questions, 98 questions are presented with scores of 1 to 5 per question, on a total of 78 question-and-answer screens. The results are ranked in 5 levels based on the score and displayed as a comprehensive evaluation, and the user can verify his/her awareness level regarding work safety.
    To maintain the user’s motivation level, a variety of question and answer screens, such as multiple choice, image area selection, and specification of the correct sequence, were used. In addition, a total of 64 computer graphics (CG) movie clips with audio are played representing the contents of the answer, to increase the virtual reality experience and the feeling of being in a live situation. CG movie clips for wrong answers representing accidents intentionally used exaggerated expressions.
    The software is intended for use as a safety training material, and 80% of the user base consists of organizations, such as regional agricultural extension centers. However, the effect of safety education was not consistent across generations, and thus further improvements are necessary.
  • Research Papers
    • Questionnaire Survey of Injuries and Incidents during Bush Cutter Operations
    Kazuhiro MATSUMORI and Toshiyuki CHIDA
    Abstract: We conducted a questionnaire survey to the members of the “Agricultural Cooperative Kurikko” in Miyagi prefecture to collect reports of in-jury and incident experiences. Analyzed survey results will contribute to awareness activities designed to prevent injury during bush cutter operations.
    For injury prevention, operators should start working after confirming that they are dressed properly with protective clothing such as gloves and safety shoes. To raise their level of consciousness and work with a feeling of attentive caution, breaks should be taken some 30 min after starting work. The break duration should be set by their proactive consideration.
    When using back-pack type bush cutters, the function limiting the shaft rod return when kickback occurs, must be reviewed. Furthermore, the shape of the handgrip controlling the tool movement should be improved further. With shoulder-type units, we must investigate the effects of adjusting the belt length and loading attachments for stabilizing the cutting blade to prevent generation of shattered materials. For bush cutters of both types, operators appreciate the adjustability of the shape and the mounting position of the handgrip, which might alleviate fatigue, thereby reducing injury.
    Information sharing is necessary for reducing injury. Any organization making frequent contact with many users must assume a social mission of providing users with available attachments and options, and assume the mission of transferring users’ opinions to manu-facturers. Such organizations must raise aware-ness of health and safety of operators by explaining in such publications tentatively entitled as “Booklet for Prevention of Accidents.”
    High-Speed Seeding with an Inclined-plate Soybean Seeder —Development of the Inclined Cell Plate—
    Takuo KOKURYU
    Abstract: To achieve high-speed seeding using the conventional inclined-cell-plate soybean seeder now on the market, we need to improve the lling of the holes in the cell plate with seeds. A laboratory experiment showed that the seeding rate (the number of seeds that reached the ground through the holes) increases as the peripheral velocity (PV) of the circle of the seed holes decreases, i.e. as the distance from the center of the inclined-plate to the seed holes. Also, increasing the number of seed holes (to 20-mm intervals) helps to lessen the PV. Furthermore, to achieve a high seeding rate, the seed-hole diameter should be twice the minimum of the average diameters, or 3 to 4mm larger than the maximum of the average lengths, of 100 seeds. The optimum plate thickness was determined to be 1mm thinner than the average seed diameter for large seeds, and the same as the average for small seeds. On the basis of these results, an inclined-cell-plate with 16 holes was made for use with a high-speed double feeder for large seeds and tested in the field. The seeding rate remained high when the PV was below 20 to 25cm/s, achieving a seeder working speed of 1.5m/s. This was twice the speed of the conventional inclined-cell-plate soybean seeder available on the market. We concluded that the new inclined-cell-plate can be used to improve working effciency of the soybean seeder.

Vol. 46 (2011), No. 2

Release Date: December 20, 2011

  • Original Papers
    • Effects of Different Amounts of Inorganic Nitrogen and Phosphate Buffer Extractable Nitrogen on Nitrogen Use Efficiency in Cultivated Andosols
    Taku KATO, Masaharu IKEBA and Masayuki TANI
    Abstract: The purpose of this study was to clarify the influence of the amounts of inorganic nitrogen and degradable organic nitrogen on nitrogen use efficiency of chemical fertilizer. In this experiment, Chinese cabbage (Brassica rapa) and carrot (Daucus carota) were grown in Andosol soils, and the absorption of nitrogen by the plants was investigated using 15N tracer techniques. Positive correlations between chemical fertilizer 15N and the amount of 15N absorbed were observed in Chinese cabbage but not in carrot. 14N was absorbed together with 15N in Chinese cabbage ; however, this relation was not shown in carrot plants. Nitrogen use efficiency of chemical fertilizer were 53-88% and 4-57% for Chinese cabbage and carrot, respectively, showing wide range of fluctuation in both crops. There was no relationship between the nitrogen use efficiency of chemical fertilizer and the amounts of inorganic nitrogen or phosphate buffer exchangeable organic nitrogen in the soil. It became clear from these findings that the amount of inorganic nitrogen and phosphate buffer exchangeable organic nitrogen cannot serve as a predictor of the nitrogen use efficiency of chemical fertilizer.
    Labor Saving by Using a Transplanting Machine and Plug Seedlings for Short-Internode Squash 'TC2A'
    Hiroyuki TSUJI, Noriyuki MURAKAMI, Keita SUGIYAMA, Tomoko SUGITO, Daisuke KAMI and Yasuo OHSHITA
    Abstract: It is not necessary to pinch off the main stems of the short-internode squash cultivar 'TC2A' after planting. The fruit yield of densely planted 'TC2A' is higher than that of standard high-yielding cultivars. The objective of this study was to determine labor saving is possible by using a transplanting machine and plug seedlings for densely planted 'TC2A'.
    1) The labor hours for transplanting using plug seedlings with a hand planter was 5.92 hours per 10a, which was about 43% less than that required for transplanting using conventional pots.
    2) The labor hours for transplanting using plug seedlings with a transplanting machine was 3.85 hours per 10a, including 0.84 hours for transplanting, 0.34 hours for supplying seedlings and 2.59 hours for seedling adjustment.
    3) The fruit yield in the plot using plug seedlings and machinery transplanting was the same as that in the plot using conventional pot transplanting.
    4) Rates of vacant hills were less than 2% in the plot using machinery transplanting without seedling adjustment after transplanting. Increase of vacant hills reduced the number of harvested fruits, but the weight of harvested fruits in the plot with less than 10% vacant hills was not significantly decreased.
    5) In conclusion, transplanting using plug seedlings can save labor hours for 'TC2A' production. Labor hours were shortest when a transplanting machine was used, and seedling adjustment after transplanting was not necessary.
    Evaluation of Characteristics in Winter Squash Cultivars for Harvesting Operation
    Daisuke KAMI, Noriyuki MURAKAMI, Tomoko SUGITO, Keita SUGIYAMA and Hiroyuki TSUJI
    Abstract: To determine appropriate fruit and plant characteristics for harvesting winter squash, the time to pick fruits was measured in three cultivars representing different plant types. In 'Bush Buttercup' and 'TC2A', almost fruits were developed in 45cm distance from the base of a plant body. Especially, 'Bush Buttercup' has a short main stem and less lateral shoots as other two cultivars. This plant shape in 'Bush Buttercup' would make it possible that harvesting worker could find fruits easily and harvest those fruits in short time. Moreover, since the peduncle of 'Bush Buttercup' was thin, it was easier to separate the fruit from the plant. The results from this study indicate that improvements in breeding are necessary to stabilize the position of fruit set and the thickness of the peduncle for easy fruit harvest.

Vol. 46 (2011), No. 1

Release Date: September 20, 2011

  • Original Papers
    • Development and Physical Stress of Light Weight and Compact Chainsaw
    Yuu SUGISHITA and Jun YAMASHITA
    Abstract: The purpose of this research was to develop a chainsaw which is easy to handle, has good working efficiency, and gives less physical stress through the approach of ergonomics. First, we developed a light weight and compact chainsaw for limbing and pruning which displacement is 18.3ml, maximum power 0.65kW and weighs only 2.5kg (with bar and chain). We considered reduction of weight and the parts' layout, and in result we achieved approximately a 500g reduction in weight (with bar and chain), compared to the existing chainsaw which weighs 3.0kg (with bar and chain). The developed chainsaw showed sufficient performance in field monitoring, and cutting performance tests. Thus it was released into the market. After this, we evaluated in more detail its limbing and pruning performance at different heights of operation (100, 150cm). In result of analyzing the surface electromyograms and the volume of oxygen intake per cut, it was found that there was less physical stress in the arms due to the lighter weight, and also that work efficiency was influenced by the lighter weight, operating posture and the engine performance when operating over 150cm position. Thus, the developed chainsaw had an advantage of lighter weight was proven here also.
    Development of a Labor-saving Direct-mount Hiller for Taro Cultivation
    Mitsuho SUGIMOTO, Koichiro FUKAMI, Sasakazu IMAZONO and Eiji INOUE
    Abstract: In Miyazaki Prefecture, taro is cultivated in wide rows that allow for the use of tractors. We developed a labor-saving method for ridging work using a direct-mount-type hiller. This machine improves upon commercial up-cut rotary tillers in terms of the arrangement of the three rotary blades, the shape of the rotary cover, and the addition of a grass divider. The theoretical field capacity of this machine loaded on a 20-kW tractor is 0.16ha/h with the rotary tiller rotating at 316rpm and the machine running at 0.2m/s. For soil moisture contents of 35-59% and plowing depths of 51-166 mm, the plowing depth (x) and ridging thickness (y) were positively correlated (r=0.95), and the linear regression equation was y=1.03x-15.43. If soil contraction is considered, the required thickness of the ridges immediately after work is 135mm. The equation shows that a 149-mm plowing depth is necessary to obtain a 135-mm thickness. This study confirmed that the machine has sufficient capacity for ridging work for taro cultivation. The effective field capacity for supplemental application and ridging work by the machine was 2.9-3.6 times that of the traditional method. The yield equaled that of cultivation without ridging, and the quality of the product was higher than that of cultivation without ridging.
    Development of a Simple Pesticide-drift-preventing Curtain
    Yoshinori KUNIMOTO, Kimiyuki HIRONO, Koichiro TAIRA and Motokazu TANIKAWA
    Abstract: A pesticide-drift-preventing curtain composed of a net to prevent drifting of spray droplets, plastic line, iron pipes and spiral stakes was developed. The drift-preventingnet was hung from the plastic line with both ends fixed to a spiral stake. Then, the net was lifted with the props and the lower end of the net was fixed to each prop with clips. Thus, the curtain was set up without using a stepladder.
    The amounts of drift deposit on the net and the working hours spent to set up this simple curtain were compared with those for the conventional curtain based on the experience of 6 workers. The cost of the set up was also calculated.
    It took 606.5 seconds per 20m to set up the simple curtain. This was significantly shorter than the 938.2 seconds required for the conventional curtain. The dismantling time was also significantly shorter. There was no significant difference in the pulse rate of the workers when setting up and dismantling between the simple and conventional curtains. No significant difference was observed in the drift preventing effect between the two types of curtains. The simple curtain material cost 12,912 yen per 20m and the conventional curtain cost 17,320 yen per 20m. Thus the simple curtain was around 25% cheaper than the conventional one.
    When the simple curtain was set up, there were a few problems. The props were not strong enough to support the drift-preventing-net, and it was difficult to roll up the plastic line.
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