Japanese Journal of Farm Work Research

» Vol. 49 (2014) | Vol. 48 (2013)

 

Vol. 49 (2014), No. 4

Released: June 20, 2015

  • Research Paper
    • Effects of Soil Compression after Sowing Using a Shallow Rototiller Plus Seeding Machine Capable of Cutting Small Ditches
    Yutaka SASAKI, Teruo WATANABE, Yukimine NAKANISHI, Masahiko TANIO, Kunio TATEISHI, Koichiro FUKAMI
    Abstract: To support crop-rotation systems using rice, wheat, and soybean in paddy fields, we developed a sowing device that can be attached to a rototiller ; the device cuts small ditches on both sides of groups of rows of plants, while tilling to a depth of approximately 5 cm, planting seeds, and compressing the soil around the seeds. This device includes a pressurized roller which compacts the soil with sowing, and we examined the effect of this compaction on germination rate after seeding. The roller provides three settings : The setting of strong pressure is compressing the soil to the level of the original topsoil. The setting of weaker pressure is compressing to leave the tilled soil 1.5 cm above the original topsoil level. The non pressure setting does not apply pressure during seeding. The strong pressure produced a higher rice germination rate than the weaker pressure and the non pressure in March 2011, but did not affect rice yield. The weaker pressure produced higher germination and growth rates than with the strong pressure and non pressure settings for wheat. In a soybean, it was not able to be recognized which pressurized setting was higher a germination rate. The strong pressure increased soil volumetric water content in the surface layer to a depth of 5 cm layer from topsoil compared with the weaker pressure and non pressure. The setting of pressurized roller made contracting soil from topsoil to depth 6-8 cm, and this condition was retained after 3 months from sowing.
    Characteristic and Utilization for Mobile NDVI Sensor
    Futoshi SASAKI, Noriyuki MURAKAMI, Satoshi HAYASHI
    Abstract: GreenSeeker Handheld Crop Sensor (GHCS), which was recently introduced in Japan, provides the user with real-time normalized difference vegetation index (NDVI) data. In this experiment, GHCS values were compared with vegetation cover ratio and chlorophyll meter (SPAD) value for grass, wheat, and soybean to clarify the measurement characteristic. In the grass data, GHCS value showed high correlation between the vegetation cover ratio and SPAD value (R2=0.9595, 0.7748). In particular, the SPAD value under high vegetation cover ratio (more than 98%) was highly correlated with the GHCS value. The results suggested that it is possible to estimate the vegetation cover ratio and SPAD value from the GHCS value of grass. The GHCS value of wheat showed high correlation with either the vegetation cover ratio or the number of stems. On the other hand, for soybean, the correlations between the GHCS value and vegetation cover ratio and between the GHCS and SPAD values were lower than that of grass. Thus, in the experiments, the leaves of soybean showed different reflectance because of the different leaf types—light yellow, pubescent, and leaf that turned inside out.

 

Vol. 49 (2014), No. 3

Released: March 20, 2015

  • Research Paper
    • Influence of Black Locust Trees on Leaf Sheath Curvature in Welsh Onion Plant Plants and its Preventive Measures
    Kazuyoshi SATO, Yoshihiro KANETA
    Abstract: Leaf sheath curvature in Welsh onions (Allium fistulosum) has become an issue in the sand dune fields adjacent to black locust (Robinia pseudoacacia) windbreaks in the Kawatogawa district of Noshiro City, Akita Prefecture, Japan. Therefore, we aimed to elucidate the relationship between leaf sheath curvature in Welsh onions and the black locust, and then examined preventive measures. The field experiment results revealed that the incidence rates of leaf sheath curvature in Welsh onions tended to increase the closer they were planted to the black locust trees. The incidence rates of curvature were particularly high for Welsh onions planted within 5 m of the black locust trees, and the degree of curvature in these Welsh onions was also greater. Accordingly, when Welsh onions were grown in a field where the black locust trees had been cut down as a method to counter leaf sheath curvature, the percentage of Welsh onions with curvature decreased. Next, we grew Welsh onions in a pot where the base of the plants was covered with flowers or leaves collected from the black locust in order to elucidate the effect of fallen matters from the black locust on curvature in Welsh onions. We discovered that curvature occurs only in the areas covered with flowers. On the basis of this finding, a covering material was introduced to prevent direct contact of the flowers with the base of Welsh onions. The result obtained using this covering material showed that the incidence rates of curvature were low and also that the degree of curvature was small. The abovementioned findings indicate that, as a measure to counter leaf sheath curvature in Welsh onions, it is imperative to grow the onions more than 5 m away from black locust trees or to develop a Welsh onion planting system that does not coincide with the season when black locust flowers begin to fall from the trees.

 

Vol. 49 (2014), No. 2

Released: December 26, 2014

  • Original Paper
    • Development of Seeding-Depth-Increasing Systems for Air-Assisted Strip Seeder
    Takayuki TSUKAMOTO, Satoshi YOSHINAGA, Masami FURUHATA, LOAN Nguyen Thi Thanh, Tadashi CHOSA
    Abstract: An 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.
    Development of a Planting Method for Allium × wakegi Araki Bulbs using a Simplified Transplanter and its Practicality
    Takeyoshi KAWAGUCHI, Hideki MINAMIDA, Yasunobu KAWAMOTO, Ayaka SATOU
    Abstract: Planting 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.
    Examination of Rice Straw Collection and Transportation Systems for the Production of Biogas by Co-digestion with Sewage Sludge : A Case Study of the Nagaoka Region in Niigata Prefecture
    Hiroshi SHIBUKAWA, Akihiro INOUE, Shuji HIMENO, Toshiya KOMATSU
    Abstract: In 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”.

 

Vol. 49 (2014), No. 1

Released: September 20, 2014

  • Original Paper
    • Application of RothC Improved Model to Predict Soil Carbon Storage under Several Tillage and Cover Crop Managements in Andisol—Case study of Upland Rice and Soybean Production in North Kanto Region, Japan—
    Tatsuya HIGASHI, Masakazu KOMATSUZAKI, Yasuhito SHIRATO, Shigenori MIURA
    Abstract: Agricultural soil management may affect soil carbon storage. We predict soil carbon storage using the RothC model to determine the effects of cover crop and tillage system. The model used a customized version RothC improved model (Shirato, 2006) adjusted to Andisols. A long-term field experiment has been conducted in progress at the Field Science Center of Ibaraki University since 2002. This experiment combined three cover crop managements (fallow, hairy vetch and rye), three tillage systems (no-till, plowing and rotary) and two N fertilizations (100 kgN/ha for upland rice 20 kgN/ha for soybean, no fertilize) with four replications. Soil samples were collected at each depth (0-2.5, 2.5-7.5, 7.5-15 and 15-30 cm) twice a year. The RothC improved model has been applied to predict soil carbon storage based on the field data. The results of comparison between the actual data and the predictions of soil carbon storage indicate the model’s predictions were acceptable for notill and rotary not for plow system. Input organic matter was increased to incorporate in cover crop treatment. The model prediction suggests that rye cover crop will increase in soil carbon storage, and hairy vetch cover crop will be stable. On the other hands winter fallow will decrease soil carbon because there is very little plant residue incorporation in a year. These results strongly suggest that an appropriate farming system is necessary to maintain or improve soil carbon storage.
  • Research Paper
    • Effect of Forchlorfenuron on Fruit Ripening and Quality and its Varietal Difference in Kiwifruit
    Satoru MURAKAMI
    Abstract: The effect of CPPU (N1-(2-chloro-4-pyridyl)-N3-phenyulurea) application to eleven kiwi fruit varieties (six varieties of Actinidia chinensis, five varieties of A. deliciosa) were investigated. ‘Rainbow Red’ and ‘Kobayashi Sanzyuukyuu-gou’ showed promotion of fruit maturity by CPPU treatment. The treatment was effective in enhancing fruit enlargement in all varieties. Several varieties showed deepening of peel color, depression unevenness of fruits, furrowing of fruits, hypertrophy of the fruit apex, and fruit drop. These findings show great varietal differences in the effect of CPPU treatment. However, differences in effect of treatment between A. chinensis and A. deliciosa remained uncertain. Therefore, it is thought that further examinations remain necessary.
    Optimization of Rate and Times of Nitrogen Fertilizer Application for the Short-internode Squash Cultivar Cucurbita maxima ‘TC2A’ Grown in Drained Paddy Fields
    Tomoko SUGITO, Hiroyuki TSUJI, Noriyuki MURAKAMI, Keita SUGIYAMA, Daisuke KAMI, Masako TAKEBE, Takuro SHINANO
    Abstract: We investigated the effects of nitrogen fertilization rate and the timing of fertilization on the growth, fruit yield and fruit quality of the short-internode squash cultivar Cucurbita maxima Duchesne ‘TC2A’ based on experiments performed in an Andosol upland field converted from a paddy rice field in Hokkaido, Japan. Rice (Oryza satuva L.) was planted in the previous year and cattle manure composted with wheat straw at a rate of 1 t/10a was applied before ‘TC2A’ seedlings were transplanted in the experimental field. The treatment factor included in this experiment was the amount of nitrogen fertilization : 0, 4, 8 and 12 kg N/10a. Increasing the nitrogen application rate resulted in increases in both fruit yield and quality, but a rate of 12 kg N/10a failed to provide any further improvement over a rate of 8 kg N/10a. Basal fertilization plus topdressing, as compared with basal fertilization alone, enhanced foliage persistence and alleviated the decrease in quality caused by sunburn on the fruit surface and subsequent rotting. These results suggest that 4 kg N/10a basal fertilization plus 4 kg N/10a topdressing would be effective for ‘TC2A’ cultivation in upland fields converted from paddy fields in Hokkaido.
    Mixing Organic Fertilizer with Nursery Soil : Effect of Fallow Duration on Growth of Paddy Rice Seedlings
    Eiji ASATSUMA, Yukitsugu TAKAHASHI, Hideaki HIRAI
    Abstract: The present study aimed to develop a technique for raising middle rice seedlings under the pooled condition with organic fertilizer. We set up experimental plots in which rapeseed oil cake containing 1g nitrogen and ground fish containing 1g nitrogen were mixed with forest surface soil to prepare nursery soil. Plots were kept fallow for 0, 1, 2, or 4 weeks. All plots appeared to have satisfactory growth conditions for middle rice seedlings, but irregular seedling growth were observed in the nursery boxes of the 4-week plots.
    Effect of Tedding-less Operation during Sun Drying on Rice Straw Property for Bioethanol Production
    Motoi SEKINE, Yukiharu OGAWA, Nobuhiro MATSUOKA
    Abstract: We investigated the effect of tedding-less operation during sun drying process on yield, on collection efficiency for the rice straw, and on total cost of bioethanol production. The moisture content of tedding-less straw had fallen to around 20% by drying for 50 days, almost the same as that of tedded straw after rainfall during drying. Tedding accounted for 12% to 27% of the total operation time. In its absence, the cost of straw collection decreased with the yield, while the operation time was linearly increased with the yield. We concluded that the tedding could be omitted during straw drying in area like a tested field, Kanto district, Japan. The tedding-less operation can contribute to the reduction of total cost for the bioethanol production from straw.

 

Vol. 48 (2013), No. 4

Released: June 20, 2014

  • Original Paper
    • Using a Repellent to Suppress Spawning in Waterways by the Apple Snail Pomacea canaliculata (Lamarck)
    Kohei TASAKA, Takashi WADA, Yoichi YUSA, Kazuhiro YOSHIDA, Toshihiro ANDO, Shinori TSUCHIYA, Koichiro FUKAMI, Yutaka SASAKI
    Abstract: The apple snail, Pomacea canaliculata (Lamarck), was introduced to Japan from South America as food for humans about thirty years ago. It is now a threat to the spread of direct-sown rice in Kyushu, southern Japan. Here we studied the use of a newly developed repellent paint containing fine copper powder to control the spawning of apple snails living in waterways. First, the repel-lent paint was applied to a concrete wall of the waterway in a narrow band (10 cm in width) just above the water surface. However, it was not effective due to the fluctuations of the water level. Then, the repellent paint was applied in a broader band (50 cm in width), and the effect was tested for three years. No egg masses were laid on the concrete wall painted with the repellent, indicating that the repellent controlled the spawning of apple snails. However, the density of the apple snails in the areas where the repellent was applied did not decrease compared to the areas without the repellent. The main reason could be that the size of the repellent areas was so small that the snails moved across the areas.
    Utility of Salivary Biochemical Parameters for the Assessment of Mental Workload from Harvesting and Binding Work of Komatsuna as an Example of Farm Labor
    Akitsugu KOIZUMI, Yoko MIYAMA
    Abstract: In this study, the utility of salivary biochemical parameters that have been known to indicate mental workload in humans for assessing mental workload from farm labor was studied. The farm labor included harvesting and binding komatsuna (Brassica rapa L. Perviridis Group). Saliva samples were taken during a 120-minute period of labor and performed quantitative analysis of salivary α-amylase, cortisol, dehydroepiandrosterone and immunoglobulin A to identify the occurrence of any changes in these parameters with farm labor. It was found that α-amylase activity was increased significantly with farm work. These results suggest that α-amylase activity could serve as an effective evaluation index for assessing mental workload from farm labor.
    Development of Precision Two-tiered Belt Seeder
    Kentaro MATSUO, Mikio YASHIRO
    Abstract: A new seeder was designed and built to ease thinning by placing the seeds at correct intervals. The performance of this seeder was evaluated. The seeder consisted of 2 conveyor belts for transporting seeds, a chisel furrow opener, a covering plate and a ground-contact drive wheel. The 2 conveyor belts were stacked one on top of the other. A hole in the upper conveyor belt picked up one of the seeds, then transferred to a larger hole in the lower conveyor belt, and released at a low position. The laboratory experimental setup was as follows : the new seeder, a commercial belt seeder, and a commercial vacuum seeder were mounted on the motors that were fixed on stands. This setup was driven at a working speed of 0.56 m/s. For sowing pelleted carrot seeds by using the new seeder, the seed spacing interquartile range (IQR) was found to be 8.4 mm, which was lower than half the IQR for a commercial belt seeder. In case of spinach seeds, the new seeder showed an IQR of 8.6 mm, which was less than a third of the IQR displayed by both the commercial seeders. In case of Japanese radish seeds, the new seeder showed an IQR of 12.6 mm, which was also less than the IQR presented by both the commercial seeders. During field trials, while sowing 3 seed types, the new seeder showed an IQR less than the IQR displayed by both the commercial seeders.
  • Research Paper
    • Labor Saving Technology in Slas-Burn Method for Kanakabu Turnip
    Mitsuhiko KATAHIRA, Sei ITO
    Abstract: In this study, we evaluated the effects of labor saving technology on the cultivation of ‘Kanakabu’ turnip, a domestic variety cultivated using a slasburn method in Akita Prefecture. Power tillers were evaluated on a test field with a 10-meter elevation difference and a 14.0 degrees average gradient. Work rates were 47 h/10a in conventional blocks using a hoe and 6 h/10a in power farming blocks using power tillers, representing an 87% labor saving rate. The power-farming block showed increased germination of 36 hills/m2, compared to the conventional block. However, the power-farming block, with increased plant density, showed 28% lower yields, with a processing rate that was 22% lower than that of the conventional block. Power tiller 2, which has crawler-type wheels, has a longer tread than power tiller 1. Because of this, power tiller 2 was found to be more useful, maintaining a stable center of gravity on slopes of up to 30 degrees. The power-farming block showed a reduced workload on farmers : The workload was only 92% of that of the conventional block, which the reduction rate was greater than that on non-sloped fields. Working postures required for the power-farming block were 100% at AC1, which required no improvement of working posture. Farmers who participated in the study found the new power tiller to be as useful and as comfortable as the conventional power tiller. However, from the standpoint of work safety, both power-farming and conventional methods should be used in combination.

 

Vol. 48 (2013), No. 3

Released: March 20, 2014

  • Original Paper
    • Development of a Cutting Apparatus and Electric Planter for Direct Planting of Sweet Potato
    Yuko UEKA, Jun YAMASHITA, Kazunobu SATO
    Abstract: In this study, a cutting apparatus and an electric planter were developed for saving labor and energy during the direct planting of sweet potatoes, which is a raw material for bioethanol. The power consumption of the planter was examined for determining its suitability for use.
    　On the occasion of specification decision of cutting apparatus, the cutting angle and speed was considered about 9 degrees, 0.3-0.5 m/s in consideration of miniaturization of a device, and the promotion of efficiency of work. It took approximately 50 seconds to make eight pieces of seed sweet potatoes from one sweet potato by using cutting apparatus.
    　An electric planter equipped with a 1.5 kW motor showed significantly lower energy consumption compared to an unmodified gasoline engine. The electric power required for only the planting operation of the electric planter was about 20% of that required for the movement of the planter. Since much of the electric power is used for the movement of the planter, further energy savings can be expected if resistance to the movement is reduced.
    　The continuous operating time was 3.7 h for area coverage of 1300 m2 which amounts to a continuous operating time of 2.76 h per 1000 m2. Even if battery degradation is assumed to be 80%, a continuous operating time of 2.96 h for area coverage of 1000 m2, is possible. Thus, the planter can be adopted for practical use.
    Effects on Partially Shallow Tilling and Sowing Method on the Quality and Yield ofWheat (Triticum aestivum L.) and Labor-Saving Cultivation
    Yoshiteru KAWAMURA, Keiko NAKANO, Muneshi MITSUOKA, Eiji INOUE, Takashi OKAYASU
    Abstract: The study was conducted to evaluate the quality and yield of wheat when the partially shallow tilling and sowing (PSTS) method was used, and to survey the amount of time and fuel consumed in working. The results showed that PSTS method produced slightly higher yield of wheat grain than the usual method, and that both the bulk density and protein content of wheat in PSTS method increased compared with those of the grain in the usual method. In addition, it became clear that PSTS method could considerably reduce labor time and fuel consumption while working in tilling and sowing.
  • Research Paper
    • Development of an e-Learning System for Farm Work Safety and Estimation of Users’ Knowledge Level
    Ei SEKI, Shunsuke OKADA, Hirokatsu SHITO, Yutaka KIKUCHI, Makoto NAKANO, Satoshi YONEKAWA
    Abstract: Using information and communications tecnology, we have developed an e-learning system as a more efficient learning resource on farm work safety. We aimed to design it for a wide range of users to learn effectively by means of visuals such as movies, and so that users’ knowledge level can be estimated. The system was designed to be easily used and operated on wide range of personal computers without any need for registration or learning management systems. The developed system included seven learning items concerning four types of hig-accident-risk machinery. Each item comprised a scenario with questions, movies, etc., to ensure effective learning. The users’ knowledge level can be estimated by counting the page views of each file that comprised the system. After the release of the system, we estimated the users’ knowledge level on farm work safety. The ratios of correct answers were lower for questions on the stability of tractors and combine harvesters, and higher for questions on roll-over protective structures on tractors. As for power tillers, the ratio of correct answers was lower for questions on number of accidents and on the prevention of caught-between accidents when reversing. Concerning bush cutters, the ratio of correct answers was lower for questions on the most typical accidents and the causes of kickback. These results were similar to answers from farmers responding to a questionnaire about farm work that they felt was most risky, and the characteristics of the actual accidents. We concluded that these points should be more widely understood.

 

Vol. 48 (2013), No. 2

Released: December 20, 2013

  • Original Paper
    • Effects of Partially Shallow Tilling and Sowing Method on the Growth and the Yield of Soybean (Glicine max L.) in Upland Filed Converted from Paddy Field
    Yoshiteru KAWAMURA, Koji ODAWARA, Muneshi MITSUOKA, Eiji INOUE, Takashi OKAYASU
    Abstract: The study was conducted to establish the par-tially shallow tilling and sowing (PSTS) method by using the modified rotary in order to plow and sow under the highly humid soil conditions. The modified rotary was replaced rotary helloes of sowing parts of which with cultivator blades. The study evaluated the emergence rate, the growth and yield of soybean, when the PSTS method was used. The results showed that the emergence rate was higher in PSTS method re-gardless of how much or little it rains. In addi-tion, the main stem length was longer, the lowest podding position was higher, and yield was also higher with PSTS method than those with usual method.
    Improvement of a Mechanical Weeding Technique in a Paddy Field where a Large Number of Monochoria vaginalis and Schoenoplectus juncoides Emerged : Development of a Mechanical Weeding Technique for Intra-row Spaces
    Joe NAKAI, Satoshi TORITSUKA
    Abstract: Rice bran treatment of soil surfaces in paddy fields does not adequately control two weeds, Monochoria vaginalis (Pontederiaceae) and Schoenoplectus juncoides (Cyperaceae). After changing the arrangement of the rotor in a walking culti-vator, we examined the effect of weeding the intra-row spaces on the control of weeds in com-bination with rice bran treatment. In rice paddy fields where many of these residual weeds emerged after rice bran treatment, weeding the intra-row spaces twice reduced not only M. vaginalis and S. juncoides in the row spaces but also S. juncoides in the intra-row space. Compared to the weed-suppressive technique of rice bran treatment alone, the combination of rice bran treatment and weeding the intra-row space twice preserved paddy rice yields by more effectively controlling weeds.
    A Short Leaf Sheath Cultivation System for the Bunching Onion (Allium fistulosum L.) Cultivar ‘Shonan Ippon’
    Akitsugu KOIZUMI, Yoko MIYAMA
    Abstract: For the purposes of saving labor and adding hig- value to bunching onion production, a short leaf sheath cultivation system for the bunching onion (Allium fistulosum L.) cultivar ‘Shonan Ippon’ was evaluated in terms of working hours, growing period, and yield. It was found that the total working hours from planting until harvesting was 126.9 hours per 10a, which is 53% less than that for the conventional cultivation systems. With sowing between February 24 and May 23, the growing period was between 4.5 and 5.5 months, and it was possible to harvest continu-ously from early July. For each sowing time, a harvested yield of approximately 3000 kg/10a was obtained. In conclusion, the short leaf sheath cultivation system for the bunching onion cultivar ‘Shonan Ippon’ is considered to be an effective means of saving labor and adding hig-value to bunching onion production.

 

Vol. 48 (2013), No. 1

Released: September 20, 2013

  • Original Paper
    • Analysis of Causes of Lower Accuracy of Seeding with the Belt Type Planter
    Kentaro MATSUO, Mikio YASHIRO
    Abstract: The causes of lower accuracy of seeding when using a belt type planter were analyzed by a high-speed camera and were found to be the following.
    1) For radish seeds or spinach seeds, the standard deviation of the seed spacing just after the seeds have fallen is large (19 cm),whereas for coated carrot seeds, it is small (10 cm). 2) If the seeds are uneven in shape and size, the orientation is not even when the seeds enter the belt’s holes and so, the release points of the seeds vary. 3) The variation of the fall angle of the seeds is greater when the seeds drop from the curved portion of the belt. 4) As the angle of the wall of the guide pipe becomes more horizontal, the fall angle of the seeds after collision with the wall becomes large and uneven. 5) When radish seeds or spinach seeds pass through the guide pipe, about 80% of seeds struck the guide pipe. 6) When seeds pass through the guide pipe, the standard deviation in the seed spacing is approximately 2.5 times of that without the guide pipe. 7) When the rotation direction of the belt is opposite to the direction of motion of the planter, the seed spacing distribution varies greatly. 8) When the guide pipe is not used and the fall distance of the seeds is long, the probability of the seeds colliding with a tire and the furrow opener increases.
  • Research Paper
    • Effect of No-Tillage and Hairy Vetch Mulch on Soil Properties and Tomato Yield in Plastic Greenhouse
    Hajime ARAKI, Takashi FUJII
    Abstract: Effectiveness of the no-till and plant residue mulch of hairy vetch (HV) on soil properties and tomato (Lycopersicon esculentum Mill.) yield was examined in plastic greenhouse, andosol soil, in Muramatsu Station, Niigata University. HV was sown at the seeding density of 5 kg/10a on October 5, 1998 and mowed on May 13, 1999. Tomato plants ‘Momotaro T93’, grafted with ‘Kagemusha’, were planted in 4 types of field, conventionally tilled soil (Till), no-tilled soil (NT), tilled soil with HV mulch (NT-HV) and no-tilled soil with HV mulch (NT-HV) in a plastic greenhouse on May 14 and grown to September 30. Soil hardness in no-tilled soil was higher than that in tilled soils, however HV mulch decreased high soil hardness shown in NT and lightened the ratio-change in three-phases of soil during tomato production in the soil environment. Tomato yield in Till-HV was highest, following NT-HV, and that in NT was smallest. HV contributed high nitrate concentration in tomato plants in early growth period, and led to vigorous growth and fruit enlargement in tomato productivity.
    Current Design and Ergonomics of Agricultural Machinery and Its Suitability for Use by Elderly and Female Operators
    Muneki TOMITA, Keiko MINAGAWA, Takeshi HAJI, Yasuro SUGIURA, Shigeyoshi TSUKAMOTO, Yoshiyuki KAWASE
    Abstract: The growing number of elderly and female operators in agriculture is prompting the need for a revision of the Japanese safety standards for agricultural machinery. In this study, the physical attributes of elderly and female farm workers in relation to the operation of agricultural machinery were measured and compared with the dimensions of the safety equipment of machinery that complies with current standards. The items investigated were the height of the lowest step and grab bar, the adjustment range of the driver’s seat and the force needed to operate the brake pedals. The subjects of this study were 179 workers, including 48 elderly and 54 females in 14 prefectures. 56 tractors, 10 combine harvesters, 11 rice transplanters and 6 air blast sprayers were measured. Our results showed that the height of the lowest step on 96% of the measured machinery was greater than the upper quartile of female foot-lifting height. Grab bars on 3 tractors were higher than the upper quartile of female grasping height. The range of seat adjustment was insufficient to permit full braking by operators whose height was under 150 cm. The median of the pedal force applied by females was about the half of the upper limit of the standard, and the brake operating force in 87% of the measured machinery was lower than this median. All the equipment measured in this study would benefit from a revision of the standards, but a close examination of the costs of this change and its effects on general usability will be needed.
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