JSFWR -Journal Vol. 42 (2007)

Japanese Journal of Farm Work Research

» Vol. 43 (2008) | Vol. 42 (2007)

Vol. 43 (2008), No. 4

Release Date: June 25, 2009

Original Papers

Shortening of the Weed-Free Maintenance Period for Soybean Production with Wheat as a Living Mulch Hiroyuki TSUJI, Yasuo OHSHITA, Kenji KIMIWADA and Shizuko ISHIKAWA: Abstract: The effectiveness of the use of living mulch for shortening the weed-free maintenance period for soybean production was examined for the weed species black nightshade, barnyard grass, Persicaria lapathifolia (L.) S.F. Gray and common purslane. Living mulch greatly reduced both plant height and maximum shoot length of all weed species. The weed-free maintenance period was calculated from the rate of increase in plant height based on the assumption that relative illuminance on the ground reaches less than 10% on July 30 and August 5 and that plant height at that time point was less than 350mm. The results of calculation showed that using living mulch cropping system reduced the periods for weed-free maintenance by about 15 days for barnyard grass and by about 20 days for Persicaria lapathifolia (L.) S.F. Gray compared to the periods in conventional cropping system. The same calculation for black nightshade showed that the period for weed-free maintenance was reduced by about 35 days compared with that in conventional cropping. However, the results of field investigation of suppression of weed growth and production of fruit, which is the source of stain of soybean grain, showed that the actual reduction of the weed-free maintenance period for black nightshade is thought to be about 20 days. The growth of common purslane was almost completely suppressed by the use of living mulch. The results suggest that the weed-free maintenance period for soybean production using living mulch in Hokkaido is less than 30 days.

Absorption of Nitrogen Decomposed from Rat Tail Fescue Residue in Satsuma Mandarin Orchard with Sod Management Kei ISHIKAWA and Hideya KIMURA: Abstract: The nitrogen dynamics in a sod culture of the satsuma mandarin orchard were determined by using ¹⁵N-labeled rat tail fescue (Vulpia myuros). ¹⁵N-labeled rat tail fescue plants were applied to the soil surface in an orchard and pot experiments. The satsuma mandarin trees began to absorb the nitrogen decomposed from the dead rat tail fescue 80 days after application. The absorbed nitrogen was translocated to current various organs of the satsuma mandarin trees and even to newly developed organs to the following spring. Similarly, newly reseeded rat tail fescue also absorbed the nitrogen. The satsuma mandarin trees and the reseeded rat tail fescue absorbed nearly the same amount of derived nitrogen from the dead rat tail fescue. The ¹⁵N content was high in newly developed organs, one-year-old leaves and fine roots of the satsuma mandarin trees but low in fruit. The rate of nitrogen occupied by supplied nitrogen was much greater in the reseeded rat tail fescue than the satsuma mandarin trees. Besides, the under-ground parts of reseeded rat tail fescue showed the greater level than the above-ground parts. The utilization efficiency of nitrogen decomposed from the dead rat tail fescue was 5.5% and 5.4% in satsuma mandarin trees and reseeded rat tail fescue, respectively. It was estimated that about 11% nitrogen was utilized from application in May to following next spring.

Mitigation of Wind Erosion Adopting Grass Cover Crops in Chinese Cabbage Production Masakazu KOMATSUZAKI and Kotaro SUZUKI: Abstract: Soil wind erosion is a serious issue in upland fields, because winter fallow treatments produce awful erosions in Kato area, Japan. This research evaluated the abilities of cover crops that planted at inter row spaces in Chinese cabbage (Brassica rapa var. glabra) production on their growths, crop yields, and reduction of wind speeds. Main results were followings.
There was little crop yields differences between uni-culture of Chinese cabbage and bi- culture of that with grass cover crops. Dry matter accumulations of cover crops were significantly different depending on their species and planting time. Cereal rye (Secale cereale L.) showed high dry matter accumulation compare with oat (Avena sativa L.). planting time of cover crops also showed significant difference, October and early November planting time showed high dry matter accumulation although late November and December planting time showed low dry mater accumulations due to delay of germination in the fields.
The significant difference was observed between cover crop biomass and the reduction of wind speed at the soil surface, 50g/m² oat dry matter showed significant reduction of wind speed although rye needs over the 100g/m² to reduce the wind speeds. Because of the difference of their growth type between standing type for oat and spreading type for rye.
Adopting cover crops in Chinese cabbage production may contribute to cope with both maintaining crop production and mitigation of wind erosion. In addition cover crops also recommend in the view points of sustainable agro ecosystem because their abilities that add organic matter to the soil is significant.

Research Papers

Growth and Yield of Middle Seedling Grown Rice in Paddy with Hairy Vetch Sakae HORIMOTO, Yoshiharu FUJII and Hajime ARAKI: Abstract: Hairy vetch (HV) was sown (4kg/10a) in paddy December fast, 2001 and was incorporated or mulched before transplanting of rice, May 17th, 2002. The effect of the middle seedlings was estimated for overcoming delayed growth and low yield of rice in the paddy with incorporated or mulched hairy vetch, comparing with young seedlings. Nitrogen contents of leaves of middle seedling-planted rice in HV-incorporated (3.8%) and HV-mulched (3.6%) paddy were higher than that of young seedling-planted rice in conventional paddy (3.5%), tilled and no HV, 28 days after transplanting, June 20. Plant length of middle seedling-planted rice was higher than that of young seedling-planted rice in paddies with or without hairy vetch 56 days after transplanting (July 18). The tiller number of middle seedling-planted rice was increased to 9.7 in the HV-incorporated paddy, whereas, it reduced to 6.8 in the HV-mulched paddy, compared with tiller number (8.0) of young seedling-panted rice in the conventional paddy. Similar LAI in middle seedling-planted rice in incorporated and mulched paddy was shown to that in young seedling-planted rice in conventional paddy 78 days after transplanting, August 10. Grain yield of young seedling-planted rice in the paddy with HV was 62.6% to 67.3% of conventional paddy, however it increased to 81.4% to 85.6% by transplanting of middle seedling in the paddy with HV. From these observations, possibility to overcome the delayed growth and low yield by middle seedling-planting was shown in the HV-incorporated and HV-mulched paddy.

Relationship between Winter Cereal Cultivars as Living Mulch and Weed Control in Soybean Cultivation Shigenori MIURA and Hiroyuki KOBAYASHI: Abstract: Weed control and soybean yield were used as measures of the efficacy of eighteen winter cereal cultivars as living mulch. Each cereal cultivar grew well until the beginning of July, and then gradually died off. Shading of the soil surface differed by cultivar, but only cvs. Shinjyuboshi and Benkeimugi provided shade in excess of 90%, a level which has been reported to strongly suppress weed growth. The degree of shading correlated with cereal dry matter and the cereal multiplied dominance ratio (MDR). Weed dry matter at the beginning of August was negatively correlated with cereal plant height and MDR. These results indicate that MDR is an appropriate index for estimating weed control with cereals as living mulches. Soybean yields from field plots with living mulch were lower than from conventional cultivation plots, likely because of imperfect control of barnyardgrass and ladysthumb, which are comparatively shade tolerant.

Vol. 43 (2008), No. 3

Release Date: March 31, 2009

Original Papers

Apple Harvesting by a Backpack Shaker and a Tractor-Mounted Shaker Akira AKASE, Hiroshi SUZUKI, Hideharu HONMA and Kazuhiro BIZEN: Abstract: Mechanical apple harvesting experiments were conducted using a backpack shaker and a tractor-mounted shaker. The shaken fruits were collected by a 2.7m by 2.7m catching frame laid on the ground. The resistance force required to remove a fruit from its bearing shoot and the storability of harvested fruits were investigated. The main results were as follows :
(1) When a fruit was pulled perpendicular to the peduncle, the removal force was 1/5 of that when pulled parallel to it. All fruits pulled perpendicularly retained their peduncles.
(2) In the vibration test, frequencies of at least 6.7, 5.0, 3.3, and 3.3Hz were needed in amplitudes of 1, 2, 3, and 4cm respectively in order to shake off apples from the bearing shoots within 3 seconds.
(3) The percentage of fruits removed from a limb from the point of attachment of the shaker clamp to the tip was 90%. The catching frame collected nearly 100% of the shaken fruits.
(4) The amplitude of limb movement produced by the backpack shaker was 1.4 to 3.3cm and that by the tractor-mounted shaker was 3.8 to 3.9cm.
(5) The shaker-harvested fruits had bruises, cuts and punctures. Sixty% of the fruits showed no skin damage after storage for 2.5 months.
(6) Fruits dropped from a height of 2m onto urethane foam 10cm thick were not damaged.

Additional Profits by an Introduction of Polyculturing into Monoculturing at Paddy Field Naoki SAKAI, Kumi NEZU and Hisayoshi HAYASHI: Abstract: To investigate the additional profits by an introduced complexity of cropping into rice monoculturing at an usual paddy field, the serial experiments were carried out in 2004.
1) In the experiment to confirm the possibility of using water hyacinth (Eichhornia crassipes, WH) as green manure, we selected the two experimental factors which were nitrogen applied by basal chemical fertilizer and nitrogen applied by WH grown at the previous cropping. Rice yield reduced with an increment of applied quantity of WH at 0gN/m², but rice yield at 2.5gN/m² (1/2 plot) were almost as same as 5.0gN/m² at the conventional plot, so we could estimate the effect of applied fertilizer level on rice yield. It was also estimated to be nitrogen starvation in the soil.
2) In the experiment to confirm the possibility of distribution to rice growth preferentially by the side dressing and controlled release fertilizer in place of uniform application of fertilizer to top soil with the shift of transplanting time between rice and WH, it was not observed the effects of chemical fertilizer type and co-existence of WH on preferential growth of rice.
3) In the experiment to confirm the reduction of methane production from a paddy field by an introduction of co-existence crop, differences between plots were observed in methane fluxes and Eh values, but the difference of total methane production during growing season was not significant among plots and the difference between treatment plots and conventional plots.
4) It was estimated that competition between rice and WH was happened at some severe conditions only. In the future studies, it is important to collect more fundamental data on precise decomposition rate of WH in soil and maintenance at an optimum nutritional condition to solve a nitrogen starvation at the various practical cases.

Research Papers

Development of Automatic Attachment for Shaft Tillage Cultivation and Transplanting Kiyoshi TAJIMA, Junya TATSUNO, Masayoshi KATO, Yutaka SASAKI, Heita KAWASHIMA, Tadashi ISHII, Yasuhiro MIYAUCHI and Eiichiro KINOSHITA: Abstract: We propose a photovoltaic powered farming robot system that consists of a delivery vehicle and a working vehicle. The proposed system is designed based on a newly proposed farming method called shaft tillage cultivation. As such, we have developed two automatic vehicles, as well as a 2-D localization method for the positioning of the working vehicle. In addition, we have developed an attachment for shaft tillage and transplanting, which is derived from commercially available transplanting machines. In this paper, we introduce the mechanism and control method of the developed attachment. In addition, we experimentally examined the transplanting performance and measured power consumption. In the transplanting experiment, we found that approximately 96% of seedlings were automatically transplanted when using developed attachment. Total power consumption for one cycle was found to be approximately 1kJ, two-thirds of which was consumed during shaft tillage. Although the fundamental performance of the developed attachment can be predicted based on these experimental results, several problems need to be solved before a fully automatic system can be constructed. Specifically, sensing functions for judging whether seedlings have been extracted from the cell tray as well as the budding condition of seedlings in the cell tray, and a method for examining the power consumption associated with shaft tillage cultivation of a test field covered with live weeds need to be implemented.

Effects of Reduction of Amount of Seedlings Picked off from Seedling Mat by Rice Planter and Enlargement of Hill Distance on Growth and Yield of Paddy Rice―Sparse Planting for Reduction in Labor of Raising of Seedling and Seedling Transportation in Rice― Tetsuro KAWASAKI, Youko MORISIGE, Eiji SUGIYAMA, Hirosi KIMURA and Hideki SUGIMOTO: Abstract: In the paper, the effects of amount of seedlings which are picked off from seedling mat by rice planter and enlargement of hill distance on growth and yield of paddy rice were investigated for the case of 30cm row distance, and the possibility of reduction of the number of nursery box was discussed.
As the results, in a general hill distance, no effects on the yield were found even if amount of seedlings picked off from seedling mat by rice planter was the minimum. And the number of nursery box was reduced to less than 60%.
Still, if we accept a little decrease in yield or we do supplemental planting in the culture of a good transplanting season, the number of nursery box is reduced to less than 30% in culture by enlargement of hill distance and reduction of amount of seedlings picked off from seedling mat by rice planter.

An Automatically Controlled Lactic Acid Bacillus Sprayer for Rice Whole Crop Harvester Kota MOTOBAYASHI and Tomoyuki YUKAWA: Abstract: Compared to other crops, such as wheat, barley and soybeans, rice whole-crop-silage (WCS) conserves the functionality of paddy fields such as the irrigation systems and soil conditions, and it can also provide high-quality roughage for cattle feed. The production of rice WCS has thus been increasing significantly in Japan. Spraying a solution of lactic acid bacilli onto the rice plants prior to their being ensiled improves the fermentation and preserves the quality of wrapped silage. However, a device for spraying such a solution with high efficiency and high controllability has not been available on the market.
We have developed a lactic acid bacillus sprayer for use with a rice whole-crop harvester. It has a simple control system with three sensors and a simple control circuit for automatically switching the spraying on and off. This automatic control stops the spraying whenever the machine is not processing rice plants, so solution wastage is reduced. Moreover, it eliminates the troublesome manual switching operation. Work time simulation and field-testing showed that the amount of lactic acid bacilli needed was reduced by about 37%.

Vol. 43 (2008), No. 2

Release Date: March 31, 2009

Original Paper

Absorption of Fall-Applied Nitrogen in Satsuma Mandarin Orchard with Rat Tail Fescue as Cover Crop Kei ISHIKAWA and Hideya KIMURA: Abstract: A¹⁵N-tracer method was used to study the absorption of nitrogen applied in the fall to satsuma mandarin trees and Rat tail fescue, Vulpia myuros, in a pot test in which a satsuma mandarin tree was grown with the grass (Rat tail fescue) as a cover crop. Nitrogen absorption by the trees in a plot covered with Rat tail fescue was about 41% of that in the plot without cover crop. The difference of the nitrogen distribution was particularly observed in new leaves and fine roots. The absolute amount of nitrogen absorbed by the grass in a sod culture plot was about twice that absorbed by the trees in the plot, and the absorbed nitrogen was distributed in the aboveground parts in Rat tail fescue. The trees utilized 19.5% of the fall-applied nitrogen in the plot with Rat tail fescue and 48.1% in the plot without cover crop. However, total utilization (trees+grass) in the sod culture plot reached 60.9%, which was about 1.3 times the rate in the plot without a cover crop.

Research Papers

Survey of Riding Tractor Operating Comfort in Nueva Ecija, Philippines Masafumi MITARAI, Julius Caesar V. SICAT, Osamu KINOSHITA and Yukio TOYOMITSU: Abstract: The body measurements of 76 riding tractor operators as well as the mechanical problems and operating comfort associated with their profession were investigated at the Science City of Mun~oz, Nueva Ecija, Philippines in 2001-2003. As a result, the characteristic and detailed body measurements of the typical riding tractor operator in the aforementioned area in the Philippines was established. The study likewise revealed that 100% of the riding tractor operators were male with an average riding tractor operation experience of 3.3 years. The most widely used riding tractor brands were the Kubota and Iseki tractors which accounted for 63.2% and 21.1% of the total units surveyed. The average engine size was 16.6kW. The most prevalent problems mentioned by the riding tractor operators were excessive engine heat conduction, implement workmanship/durability and the need for operator cover with 86.8%, 85.5% and 59.2% ratings, respectively. Ergonomic related problems were top billed by excessive engine heat convection (86.8%), need for operator cover/protection from unfavorable weather (59.2%), and better seat design (47.4%).

Improvement of the Catch Efficiency of the Apple Snail, Pomacea canaliculata (Lamarck) (Gastropoda : Ampullariidae) by the Trap Crop Yoshinori KUNIMOTO and Manabu NISHIKAWA: Abstract: We compared the efficiency of catching the apple snail by hand with and without trap crops. Except in the paddy rice field where there were few snails, it took over two hours per 10a to handpick the snails when a trap crop was not used. In the longest case, it took about 536 minutes per 10a. The number of snails hand picked without a trap crops was only 68.3% of the total number of snails caught. The number of snails after the first hand picking was above the control threshold for the apple snail in transplanting rice. Hand picking had to be repeated three more times to reduce the number of snails below the control threshold.
In contrast, when there were trap crops in the paddy field, it took 418 minutes per 10a to catch the snails. The number of snails remaining was much smaller than the control threshold. When trap crops were placed around a paddy field, the number of snails remaining in the paddy field after repeated picking 13 times was under the control threshold, and it took about 116 minutes per 10a. These results suggested that this method of handpicking using trap crops was easy and most efficient.

Vol. 43 (2008), No. 1

Release Date: December 16, 2008

Original Papers

Protection of Citrus from Bird Damage by a Dog Hiromichi ICHINOKIYAMA and Masami TAKEUCHI: Abstract: Effectiveness of a dog (Canis lupus familiaris) for protecting citrus fruits from bird damage was investigated using a citrus orchard (5.8a in area) in the harvest season. In Exp. 1, a Border collie shepherd (male) was tied to a wire extended along oneside of the square orchard to allow him to run along the inner side of the orchard. This watchdog system was effective in reducing fruit damage by birds (mainly brown-eared bulbul) only in the citrus tree row nearest to the dog runway. In Exp. 2, the orchard was enclosed with a tall chain-link fence and the same dog was allowed to move freely in the orchard. In this case, he persevered in chasing birds until they flew away from the orchard. This watchdog system effectively reduced bird damage to citrus fruits all over the orchard, resulting in an increase of crop yield by about 17.5kga-1 per day. Further study is needed on the optimum number of dogs released per unit orchard area and the effectiveness of the watchdog system in case when this bird control system is spread to all orchards in the citrus-growing area.

Responses of Crop Growth by an Introduction of Polyculturing into Monoculturing at Paddy Field Naoki SAKAI, Kumi NEZU and Hisayoshi HAYASHI: Abstract: At a paddy field with introduction of some complexities based on biodiversity, we investigated the effect of plant population of water hyacinth (Eichhornia crassipes, WH), selected as a covering model plant for water-surface and a companion plant to rice plant, on responses of crop growth. The plant population of rice plant was constant, and plant population of WH was only changed as follows ; 22.2, 16.7, 11.1, 5.6, 0hill/m² and WH without rice plant (11.1hill/m²). Experimental plots were arranged with randomized design including three repetitions. Although yield of rice decreased with the increment of plant population of WH, height of WH increased. As an extinction coefficient decreased, light competition between rice plant and WH increased. As LAI of rice plant decreased, nutrition competition also observed. With the increment of plant population of WH, panicle number per m², final brown rice yield decreased as a result of decrease of glumaceous flower number per head. Although paddy yield decreased with the increment of plant population of WH, total fixation rates of carbon and nitrogen surely increased by the contribution of WH. If we are prepared to decrease the paddy yield, we obtained some useful data in order to propose a new cropping systems based on environmental conservation and biodiversity in future.

Research Papers

Effects of Different Rootstocks on Quality of Seedless Berries in the Grape 'Fujiminori' Kazunori ISHIKAWA and Tadashi BABA: Abstract: This study was conducted to evaluate the effects of rootstocks on characteristics of seedless berries in the grape ‘Fujiminori’. Growth and quality of seedless berries induced by gibberellin (GA) and streptomycin (SM) were determined using 15-year-old vines on volcanic ash soil, grafted on 4 different rootstocks, ‘Teleki 5BB’, ‘SO.4’, ‘3309’ and ‘101-14’. There was a marked increase in berry and rachis weight grafted on ‘Teleki 5BB’. Brix was higher in seedless berries induced by GA and SM on ‘Teleki 5BB’ and ‘3309’ than those on ‘SO.4’ and ‘101-14’.
In conclusion, ‘Teleki 5BB’ was the most desirable rootstock for the seedless berries in the grape ‘Fujiminori’.

Effects of Enlargement of Hill Distance on Growth and Yield of Normal Season Cultured Rice―Sparse Planting for Reduction in Labor of Raising of Seedling and Seedling Transportation in Rice― Tetsuro KAWASAKI, Youko MORISIGE, Eiji SUGIYAMA, Hirosi KIMURA and Hideki SUGIMOTO: Abstract: In the paper, the effects of enlargement of hill distance on growth and yield of paddy rice in normal season culture were investigated for the case of 30cm row distance.
As the results, no effect on the yield were found in the varieties of ‘Koigokoro’ and ‘Hinohikari’ which were transplanted from the beginning to the middle of June with hill distance from 18cm to 36cm or 45cm ; and in the variety of ‘Himenomai’ which was transplanted from the beginning to the end of June with hill distance from 18cm to 36cm.
These results suggest a drastic labor saving of seedling culture and seedling transportation by reduction of the number of nursery box with sparse planting.

Vol. 42 (2007), No. 4

Release Date: March 31, 2009

Original Papers

An Evaluation Method for Various Recycled Organic Materials Using a Self-Organizing Map Seishu TOJO, Shiho OCHIAI, Haruo TANAKA, Sohzoh SUZUKI and Kengo WATANABE: Abstract: Recently there has been promotion of the recycling of various kinds of organic wastes after their recovery. Excess amounts of recycled organic materials are often applied to fields because the decomposition and mineralization go on very slowly and little effect appears in terms of nutrients for crops. In this paper, for various recycled organic materials, an evaluation and representation method are described to show comprehensively, through crop cultivation tests and the analysis of components, the features and properties obtained. As recycled organic material test fertilizers, cattle excrement compost, sludge compost and sludge pyrolysate were compared with ordinary chemical fertilizer. In terms of nutrient rate of application in the cultivation test plots, 1 times to 4 times the rate of nitrogen were set for each test fertilizer, on the standard basis of chemical fertilizers of Kanto district, considering the degradation rate and the fertilizer effect. The nutrient components of harvested crops and remaining growth soil were analyzed with a standard chemical method. The map of principal component scores by principal component analysis shows the effect of the trial fertilizer. Utilization of the self-organizing map presented more visually the similarities and tendencies of the recycled organic materials on crop cultivation and environmental loading.

Effects of Rootstock Diameter on Successful Union and Growth of Highbush Blueberry Grafts by Grafted Cutting Kazunori ISHIKAWA and Tadashi BABA: Abstract: Scions of highbush blueberry cultivar ‘Jersey’ and ‘Spartan’ were grafted on rootstocks of rabbiteye blueberry cultivar ‘Tifblue’ to determine the effects of rootstock diameter (4, 6 and 8mm) on the successful union, rooting and growth of grafts.
1) Current shoots of the thinner rootstocks terminated earlier. The thicker rootstocks showed earlier resprouting.
2) ‘Jersey’ scions grafted on 6- or 8-mm-diameter of ‘Tifblue’ rootstocks had long, vigorous and heavy current shoots.
3) The rate of rooting was higher in ‘Jersey’ scions grafted on 6- or 8-mm-diameter ‘Tifblue’ rootstocks. The plants of ‘Spartan’ scions grafted on ‘Tifblue’ rootstocks showed a lower rate of successful union and formed callous tissue at the end of the cutting.
4) Grafts by grafted cuttings required a nursery period of more than 3 months, which is sufficient for ungrafted cuttings to root.
In conclusion, grafted highbush blueberry plants on 6-mm-diameter rabbiteye rootstocks tended to perform better for the successful union and growth of grafts.

Research Paper

Effects of Stock-scion Combination and Timing of Grafting on Successful Union, Rooting and Growth of Blueberry Grafts by Grafted Cutting Kazunori ISHIKAWA and Tadashi BABA: Abstract: Inter- and intraspecific blueberry grafting by grafted cutting was conducted to determine the effects of stock-scion combination and timing of grafting on successful union, rooting and growth of grafts.
1. In a trial grafting highbush cultivar ‘Berkeley’ scions on to four different rootstocks, rabbiteye cultivars ‘Homebell’ and ‘Woodard’ and highbush cultivars ‘Jersey’ and ‘Spartan’, successful union was greater than 70%. However, grafting ‘Spartan’ scions on to ‘Spartan’ rootstocks gave only 37% successful union. Among tested combinations, the rate of rooting was significantly higher in ‘Jersey’ rootstock, and the length of current shoots was significantly shorter in ‘Woodard’ rootstock. Current shoots of all tested stock-scion combinations terminated until late April and resprouted from mid May.
2. Although the rate of rooting was low for the combination of highbush cultivar ‘Spartan’ scions grafted on to rabbiteye cultivar ‘Homebell’, the storage period after grafting and the time of cutting back of rootstock base influenced the rate of successful union : grafts grafted in mid January with cutting back of rootstock base, and storage in a refrigerator for 2 months had better rates of successful union than grafts grafted in February and March and storage in a refrigerator for a month and several days, respectively.
In conclusion, all tested combinations except ‘Spartan’ scions grafted on ‘Spartan’ were successfully intergrafted by grafted cutting, and the grafts grafted with cutting back of rootstock base in mid January and storage in a refrigerator for 2 months gave the best successful union results.

Vol. 42 (2007), No. 3

Release Date: March 31, 2009

Research Paper

Development of Pulling Sprayer for Herbicides Ryuichi SAGO: Abstract: Herbicides, bush cutters and other tools are used for weed management in orchards and border areas on arable land. However, weed management involves heavy labor and thus it is necessary to develop a labor-saving sprayer for the efficient use of herbicides. So, a pulling herbicide sprayer was developed based on the wheel pump sprayer.
This sprayer has no engine, but operates the pump by rotation of a wheel. A nozzle has been built in a form spray nozzle for low volume (25L per 10a) and for coarser spray. The application rate of herbicides is linked with the application speed, so if operator walks at a speed of 2Kmper hour, the sprayer will work at a volume of 25L per 10a exactly. A built-in pressure relief valve prevents the sprayer from developing excessive pressure. Herbicides do not drift towards the operator since the operator moves ahead of the sprayer in the direction of the application.
This sprayer has a highly prospective value as a new model, low-volume herbicide sprayer.

Special Edition

Development of Vegetables Grafting in China Gu SONG and Jiang KAI: Abstract: It has been said that plant grafting technology was invented 3,000 years ago in China for fruit trees, however it was firstly applied for actual vegetable cultivation in Japan. China started investigations on vegetables grafting in 1960s. In 1980s vegetable grafting was disseminated to vegetable cultivation in order to control the soil sickness induced by continuous cropping, because vegetable production had extended with development of sunlight greenhouses. Meanwhile significant increase in cropping area of water melon in China promoted grafting technology to water melon production also for control the soil sickness. Grafting cultivation has been used in every vegetable production in China after 2000, as an important cultivation method. The Chinese Agricultural Ministry promulgated a non- pollution cultivation standard of vegetables in 2002. To realize the non-pollution cultivation, grafting technology for vegetables is also one of the promising supporting technologies. However, current production capacity cannot meet the demand of grafting seedlings from farmers, some Chinese universities has started development of automatic or semi-automatic grafting machines.

Vol. 42 (2007), No. 2

Release Date: January 30, 2009

Original Papers

The Estimation of Absorbed Nitrogen Using Increased Leaf Number in Drip-fertigated Spring Cucumber Tatsuo SATO, Kyoko MATSUURA, Jiro NARIMATSU and Yutaka YONEYAMA: Abstract: Destructive analysis was used to estimate the half-monthly nitrogen content and related growth parameters of drip-fertigated spring cucumber.
Three fertilizing treatments were compared. The amount of nitrogen applied half-monthly varied independently, but the total amount was same. There was little difference in the growth and yield of cucumber among nitrogen application patterns, which suggests that soil has a buffering capacity on cucumber yield even if the amount of nitrogen fertilizer changed. Destructive analysis including three all treatments found a significant correlation between nitrogen content of cucumber plant and the number of increased leaves (absorbed nitrogen (g/m²/14 days)=increased leaves (no./m²/14 days)×0.0441+2.189). This relationship will lead to reduce nitrogen application through counting of leaves twice a month.

Nutrient Evaluation of Winter Cover Crop Subsequently Produced after Rice Cultivation Masakazu KOMATSUZAKI, Yoshiteru KAI and Yutaka NAKAMURA: Abstract: Cover crops subsequently produced rice culture in the paddy field, were evaluated the nutrient values as feed for livestocks including dry matter (DM) accumulation, metabolizable energy (ME), and chemical composition or digestible nutrients as a nutrient source of livestock. Main results were as follows.
1) There were significant differences in nutrients of cover crops among their growth termination and used species. Soil residual N, however, had little effect on their nutrient values of cover crops.
2) In all cover crop species, both of extract concentration and crude protein concentration were higher in March than those in April. On the other hand, crude fiber concentration was significantly lower in March than in April.
3) Across the growth termination, the order of concentartion of ether extract, crude protein, and crude fiber was rye>oat=triticale>wheat. The ash concentration, however, showed triticale≥wheat≥oat>rye.
4) Higher DM yield of cover crop were shown when soil residual nitrogen was high. At all the soil nitrogen levels, the order of DM accumulation, crude protein accumulation and ME yield showed rye>triticale>=oat=wheat in 2001 and wheat>rye=triticale=oat in 2002.
5) Nitrate concentrations in cover crop that was harvested in April, ranged from 75.6 to 282ppm in DM. These values were appropriate level for livestock feeds.
6) Rye showed high dry matter accumulation, protein content was approximately 7% and fiber concentration was 23∼27% in April. It was recognized rye harvested in April had same digestible chemical qualities compared with commercial timothy. These results suggested that rye had a great potential for livestock feeds to establish a crop-livestock using paddy fields.

Improvement of the Work Efficiency by the Half Size Square Bale to 2 Steps Load System Noritoshi SUMIDA, Atsushi SAWAMURA and Nobuhiro ITOKAWA: Abstract: The purpose of this research presents the efficient work system of new square big baler that the stack of 2 square bales system and used the handling system for the wrap silo.
1) The stack of 2 square bales system is composed of the fixation fulcrum with a push arm, plate, turn fulcrum, the roller and demonstrate a function by attaching to the lift arm of bale wrapper for round baler. The improvement and wrap film of comparative work efficiency of it was conceivable that the effect is connected to the improvement of the silage quality that is related to wind and stabilize to work conventionally.
2) We can attach the handling system for a wrap silo to the front loader or forklift that are composed of a mast, upper part control arm, lower part control arm, arm stopper, the roller, oil pressure cylinder and fixed to the tractor. The square wrap silo that tightly seals and covers it with a stretch film without producing the loss and the opening that adjoined and the film is nonexistent the corner form wrap silo loading, cargo were lowered and was able to do such handling operation.

Ergonomic Study on the Process of Mastering Reversible Plow Operation using Ride-on Tractor M. Faiz SYUAIB, Shoji MORIIZUMI and Hiroshi SHIMIZU: Abstract: This research was mainly conducted to obtain basic ergonomic data about tractor operator performance and to analyze the mastering process of tractor operation, especially reversible moldboard-plowing using a ride-on tractor. This paper mainly deals with the analysis of learning curve patterns of beginners to assess the necessary expertise level through a comparison with skillful operators. Comparative analyses between beginners who do and do not have automobile-driving experience are also discussed. Suggestions for the minimum account of practice and instructional attentions are also given.
It was proven that the automobile-driving capability of beginners was cognitively advantageous for the learning tractor operation. Compared to the skillful operators, almost, no significant difference in physiological burden was recognized in the beginners, except at the beginning of practical experience of the non-driverslicensed beginners. The tillage straightness was clearly the most difficult task to be mastered. In this regard, a minimum working (learning) time of about 64 and 67 hours is recommended for DL and NDL beginners, respectively, to reach the necessary level of performance. From the various results, the mastering process of reversible plow tillage may be divided into the first and second steps. Depending on the situation, the practice of second step (DL-beginners : after 3 hours, NDL-beginners : after 43 hours) is considered that it may be made to be the self-training.

Application of Yield-Monitoring Combine to Test Cultivations for Paddy Rice to Compare their Grain Yields Koichi SHOJI, Nobuya KOBAYASHI, Hisashi HORIO and Tsuneo KAWAMURA: Abstract: Procedures have been presented to utilize a yield-monitoring combine for test cultivations of paddy rice. As an example, grain yields were compared at two blocks of sparse (30cm×30cm) and controlled (23cm×30cm) transplanting treatments allocated in a paddy field of 0.5ha. Data obtained from the yield-monitoring combine was assumed to represent the populations themselves, and methods were discussed to compare the grain yields between the treatments.
1) To maintain the size of the populations and the normality of their distribution, an appropriate size of the plots to generate the yield data was 5m×6m or 10m×3m for the experimental field employed.
2) Higher grain yields were observed at lower elevations of the field. For the comparison of the grain yields between the treatments within the same field, it was necessary to incorporate the effect of the micro-elevation into a regression model, or to create populations within a limited range of the micro-elevation. The optimum range of the micro-elevation was ±15mm for the same reason as discussed in 1) above.
3) Difference in the grain yields between the sparse and the controlled treatments was not concluded to be significant under the comparison of the populations specified in 1) and 2) above.

Original Papers

Biomass Production and Weed Control in Some Winter Cover Crops in Hokuriku District Hajime ARAKI, Yoshifumi HATANO, Sakae HORIMOTO, Yoshiharu FUJII and Michiaki ITO: Abstract: For the purpose of introduction cover crops into summer crop production in the Hokuriku district, grass (wheat, barley, rye and bristle oat), legume (hairy vetch, HV ; common vetch, CV ; milk vetch, MV ; crimson clover, CC) and Brassica (rape) cover crops were sown in October of 1998 and 1999, and above-ground biomass (AGB) in the following spring and weed control effect were observed at the University Farm of Niigata University. A large amount of AGB (646kg·DW and 591kg·DW per 10a in rye and in HV, respectively) was provided as organic matter to the field. In particular, nitrogen content of HV was 4.2% (DW) and approximately 24kg/10a organic N was supplied to the field grown HV. After mowing, although HV residue covered the ground surface completely, ground surface cover by residue of other cover crops was insufficient. Suckering occurred from the stubble of rye, and living mulch was formed by seed germination on the ground surface in wheat, barley and CC. These cover crops should be mowed earlier for residue mulch formation. There was little difference in AGB between 1999 and 2000 ; however, HV-AGB obtained in 2000 was reduced compared to that in 1999 because of long period of snow cover in 2000. Emergence and growth of weed in the grass residue mulch were smaller or the same compared with the tilled field for control. In the HV residue mulch field, weed emergence was smaller but final weed DW was larger than the tilled field and grass mulch fields. DW of lettuce grown in HV, CV and bristle oat mulch was larger than those in tilled or other mulch fields. From these observations, HV and rye will be promising cover crops in the Hokuriku district because of the large AGB production. However, it is necessary to establish cropping techniques so that seedlings can overwinter in the snow cover region in HV and suckering will be suppressed after mowing in rye.

Simulation of Harvesting and Wrapping Forage Rice using a Rice Whole Crop Harvester and a Bale Wrapper Kota MOTOBAYASHI, Tomoyuki YUKAWA and Ryouji SASAKI: Abstract: Much attention is being focused on growing rice not for human consumption but for cattle feed as whole-crop silage (WCS) in Japan. Rice WCS is a wholesome cattle feed that meets demands for safe feed from domestic sources. Furthermore, growing rice for WCS in paddy fields helps preserves them and satisfies the rice production adjustment policy.
A self-propelled rice whole crop harvester and a self-propelled bale wrapper are preferred for harvesting and ensiling the crop, because of their higher adaptabilities to wet soil conditions, rather than conventional tractor-mounted forage-harvesting implements. But, on the other hand, work efficiencies of these machines are lower than those of tractor-mounted implements.
A simulation model of these machines working in a field was developed to analyze the total working time, which depends on the harvesting path plan and the allocation of the machines to convey specific bales. In case all bales are to be conveyed to the entrance side of the field, an optimum sharing line of the allocation can be calculated, with bales on the entrance side of the line being conveyed by the bale wrapper and bales on the other side being conveyed by the harvester. In a 1-ha field (125×80m), the optimum sharing line was calculated to be 84m from the entrance side of the field, which improved field capacity by 33% over other working methods. The results can be used to optimize the work allocation between the two machines, increasing work efficiency.

Vol. 42 (2007), No. 1

Release Date: 2010/02/09

Original Papers

Nitrogen Fertilization Method on the Number of Leaves in Cultivation of Spring Cucumber by the Drip-Fertigation Technique Tatsuo SATO, Kyoko MATSUURA, Rika TAKAYANAGI and Yutaka YONEYAMA: Abstract: he adaptability of a formula for estimating the amount of nitrogen absorbed (absorbed nitrogen (g/m²/14 days)=increased leaves (no./m²/14 days)×0.0441+2.189) in autumn cucumber, cultivated using drip tubes, was tested as a fertilization index. The amount of nitrogen applied was reduced to 31.9g/m², which constituted a saving of 24% over conventional fertilization methods, without reducing the yield.
The adaptability of this formula was tested, using five training methods, with different leaf appearance patterns. Although the yields differed, the amount of nitrogen fertilizer differed only slightly, in the range from 27.6 to 29.2g/m², which amounts to 63 to 51% of the 46.2g/m² used in conventional fertilization
In conclusion, this formula for estimating the amount of nitrogen absorbed can be applied to save fertilizer in the cultivation of autumn cucumber, grown using drip tubes.

Effects of Cover Cropping and Tillage System on Soil Physical Characters in Upland Rice Cultivation Yinghui MU, Masakazu KOMATSUZAKI, Shoji MORIIZUMI, Song GU, Masaaki ARAKI, Hajime ARAKI and Toshiyuki HIRATA: Abstract: We investigated the changes in soil physical properties, such as soil cone index (SCI), soil bulk density (SBD) and soil water content (SWC) in upland rice (Oryza sativa L.) production following rye (Secale cereale L.), hairy vetch (Vicia villosa Roth) and fallow (no cover crop) under different tillage systems (plowing, rotary and minimum tillage) with 4 replications. Field experiments were conducted at the Experimental Farm of Ibaraki University on a Humic Allophane soil (Haplic Andsolos) from Aug. 2002 to Dec. 2004. The main results obtained from these 2 years of field research were as follows:
1) The tillage system significantly affected soil water content, with minimum tillage having the greatest effect. Cover crop types also showed significant effects on soil water content, especially for minimum tillage with rye treatment.
2) The tillage system also had a significant effect on soil bulk density, with minimum tillage having the greatest compare with other tillage treatment. Cover crop types, however, showed little effect on soil bulk density.
3) The tillage system also affected soil hard-ness significantly during the dry paddy rice growing season. SCI was the highest for no. -till treatment, and the lowest for plow tillage treatment. With all the tillage systems, cover crop types also showed significant effects on reducing SCI. SCI showed the lowest value for rye and the highest for fallow.
4) These results suggest that cover cropping has some potential for reducing soil hardness without tillage treatment; consequently, cover crops may be effective tools to optimize soil hard-ness in minimum tillage systems.

Characteristics of Soil Fertility in Organic Rice Cultivation Ryuichi SAGO and Hisashi KOBAYASHI: Abstract: A common definition of organic agriculture is farming without synthetic pesticides or chemical fertilizers. It has been pointed out that it is extremely difficult to apply sufficient nutrients by organic practices alone. The objective of this research is to assess the differences of the following soil fertility components between organic and conventional farming practices: total soil carbon (C), total soil nitrogen (N) and inorganic nitrogen (NH4-N, NO3-N), exchangeable potassium (K), available phosphorus (P), available magnesium (Mg), available calcium (Ca), manganese (Mn), copper (Cu), and zinc (Zn). In 2004, soil was collected from 19 paddy fields on working organic and conventional farms in the Kanto district.
We found no significant differences in the total soil carbon (C), the total soil nitrogen (N), and C/N ratio among the farming systems. Available soil N (NH4-N and NO3-N) declined significantly as total soil N rose with the use of organic practices. Ca and Mg rose with the use of organic practices, but K, P, Cu, Mn and Zn did not exhibit differences in farming systems in any of the analyzed fields. Inorganic N in conventional farming soil and Ca and Mg in organic farming soil reached a level that could be an environmental risk if soils are not managed carefully. In the future, we should control the amount of fertility component by soil analysis data.

Effect of the Dispersion of Fields Concentrated to a Sugarcane Agricultural Production Corporation on Agricultural Productivity―Analysis by the Geographical Information System― Takeshi SHIKANAI, Takayuki MINAMI, Senlin GUAN and Masami UENO: Abstract: Although sugarcane agricultural production corporations have been established as the leaders of regional farmers to avoid cultivation abandonment, the sugarcane yield of these agricultural production corporations is low and the leased fields managed by these corporations are scattered. Because of the scattered leased fields, the workers of these corporations have to move from field to field for work and thus farm work becomes inefficient. Thus, it is considered that inefficient work results in a rather low yield of sugarcane for these corporations as compared to the average yield in Okinawa. This study aims to ascertain the correlation between the dispersion of farmlands and productivity by investigating the relation between the unit crop yields and some factors of the evaluation of the geographic condition of the dispersion obtained by the GIS. We proposed three factors of the evaluation of the geographical condition; that is, the area of the farmland, distance of the corporation office, and area of the surrounding farmlands. The area of the surrounding farmlands shows a positive correlation with the unit yields, while the distance of the corporation office shows an inverse correlation with the unit yields. The result shows that the dispersion of the accumulated fields could have some impact on the unit sugarcane yield of the agricultural production corporations.

Amount of Fertility Components Applied and Soil Fertility in Pear Orchards in Southern Ibaraki Ryuichi SAGO, Chihiro SUGIMORI and Hisashi KOBYASHI: Abstract: The Japanese pear grows abundantly in southern and western parts of Ibaraki Prefecture. In particular, the production of 'Ko-sui' pear is the highest in Japan.
Yields and growth rates of trees have decreased, and the amount and number of fertilizer applications have increased over the years. We investigated the plan for fertilizer application and the soil fertility of ten pear orchards in southern Ibaraki Prefecture.
The average of 'Ko-sui' pear tree was 28 years old, and the average of 'Ho-sui' pear tree was 26.5 years old in investigated orchards. The amount of fertilizer applied exceeded the recommendations in Ibaraki. Most farmers consider the soil modification function of organic fertilizer, but they do not consider its nutrient function. As a result, they apply organic fertilizer in addition to chemical fertilizer.
The pear yields were unrelated to the amount of fertilizer applied. Soil fertility also exceeded the standard of soil nutrients for pear orchards. Furthermore, the available phosphoric acid and exchangeable potassium in the soil was related to the amount of phosphoric acid and potassium applied with organic fertilizer, but inorganic nitrogen in soil was not related to the amount of nitrogen applied. This indicates that the available phosphoric acid and the exchangeable potassium were held in the soil, but the inorganic nitrogen runs off with soil water.
In order to protect the environment, nutrient recommendations in Ibaraki must indicate the presumable method of the available nutrient on organic fertilizer. We should regulate the amount of organic fertilizer applied based on the nutrient recommendation.

Study on Organic Sweet Corn Production and Marketing for Agro-Industry Thawansak PHAOSANG and Opal SUWUNNAMEK: Abstract: Though major organic products in Thailand are rice, grains, fruits and vegetables, organic sweet corn has been demanded commercially in the market. This paper introduced the first empirical study on the production and marketing of organic sweet corn "ATS-5" developed by "KU Fresh" of Kasetsart University, in collaboration with the food processing company, Malee Samphran Public Company Limited. The results of trials indicated that downy mildew, corn stem borer, and corn earworm were controlled, harvest period was significantly shorten, harvested corn size was as same as the conventional, and percentage of husk weight was significantly reduced as well. Price per kilogram at the farm gate was 2.50 times higher than that of the conventional. In addition, sensory test by the company showed higher average scores of organic "ATS-5" on 5 sensory characteristics compared with the chemical. Direct transportation from farm to the customer was recommended to keep the sweetness.

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