巻号一覧
35 巻 (2000)
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35 巻, 1 号
選択された号の論文の5件中1～5を表示しています
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酒井 憲司, 市村 香織, 笹尾 彰, 澁澤 栄, アスティカ イワヤン2000 年 35 巻 1 号 p. 1-6
発行日: 2000/03/08
公開日: 2010/02/09
ジャーナル フリーThis paper develops a model of white clover-weed community competition. Field experiments were conducted to obtain the growth data of white clover and weed. The conventional Lotka-Volterra type competition model was modified to describe the clover-weed community competition.
Field experiments were set up on three plots of different density, 2kg/10a, 4kg/10a and 10kg/10a. White clover was seeded among the three plots. Seeding was done on 24 September 1996. The weed emergence rate was more restrained at the higher density plot during the following autumn and winter. However, weeds finally disappeared for all three plots until the following summer. The yield of white clover was saturated with clover seeding density of 4kg/10a. The model of the density effect of white clover was found to be 1/Wc=0.104+0.0011 Nc from the results of the field experiments.
The parameters of the modified Lotka-Volterra type competition model were determined by a Genetic Algorithm and the model successfully described qualitatively the characteristics of clover-weed competition.抄録全体を表示PDF形式でダウンロード (586K) -
石束 宣明, 宮崎 昌宏2000 年 35 巻 1 号 p. 7-16
発行日: 2000/03/08
公開日: 2010/02/09
ジャーナル フリーOrdinarily citrus orchards in Shikoku are located on a steep sloping land. Such topographical condition being suitable for production of high quality fruits demands hard works in sloping orchards because the use of farm machines is difficult. Therefore, it is advocated to construct narrow paths with 1 to 1.3m width on the sloping land and some small machines have been developed for use on the paths.
This report shows the comparison between two types of transporters carrying different numbers of containers, 6 and 10, for harvesting. They are used on a narrow path in a steep sloping orchard in order to improve the harvesting operation.
Since the harvesting operation of fruits is a complex system influenced by the capacity of the transporter, the transporting distance, and the number of workers, we applied a systems analysis method of building a computer model and simulating the operation. The model was programmed by Visual Smalltalk, which is known as an object-oriented programming environment.
The results of the computer simulation were summarized as follows.
(1) The bigger type transporter with 10 containers does not have higher efficiency than the one with 6, in case of a 20a field lot with a wide road enough for a light truck in a common sloping orchard.
(2) In the case, which requires long transportation over 100m to a light truck, the bigger type transporter gives a slightly higher efficiency.
(3) Introduction of additional labors brings a drastic reduction in harvesting time.抄録全体を表示PDF形式でダウンロード (904K) -
吉村 正敬, 田島 淳, 牧 恒雄2000 年 35 巻 1 号 p. 17-24
発行日: 2000/03/08
公開日: 2010/02/09
ジャーナル フリーThe disposal of the prunings is a difficult problem especially in municipal areas in Japan. Typically the prunings are decomposed, however the process takes around six months until it is done with several well-experienced skills, such as chipping branches, turning operation and adjusting of moisture content during the composting.
In this study effects of the aeration during a composting with starter composts were examined to investigate an effective composting method. The fermenting process, the ending timing of composting, and effects of turning and aeration in composting period were observed in 1m3 detachable reactors equipped with air pipes. The condition of reactors were the no-aeration, the 5L/min. and the 10L/min. reactors. The turning intervals were 10-20 days and the moisture content was adjusted to 60% (w. b.). Duration of the composting examination was 105 days.
Results of the examination were followings:
1) With 60% of moisture content the composting process was completed in 90 days.
2) The aeration after the turning was effective to rise the temperature rapidly. The temperature reached to the suitable range for fermentation within 2 to 3 days with both aeration conditions.
3) The aeration reduced moisture content of the chips. Therefore the additional water must have been added to the chips at the turning operations.
4) The total additional water was 112L in 1m3 of tree chips.
5) The higher in aeration required higher amount of additional water.
In conclusion, the aeration with turning operation was effective to reduce the time and to simplify the processes.抄録全体を表示PDF形式でダウンロード (917K) -
藤原 隆広, 吉岡 宏, 佐藤 文生2000 年 35 巻 1 号 p. 25-32
発行日: 2000/03/08
公開日: 2010/02/09
ジャーナル フリーWe investigated the effects of the position of band-applied fertilizer on the uniformity of cabbage growth and the occurrence of weed. Placing the fertilizer directly under transplants gave uniform cabbage growth and controlled weed growth.
Major findings:
1) The temperature of the ridge slopes differed with the azimuth of the Sun: the temperature of the eastern sides rose more than that of the western sides, causing a range in soil temperatures on fine days.
2) Because of this range in temperatures, placing the fertilizer off-center in the rows reduced the uniformity of cabbage growth.
3) Regardless of fertilizer placement in the row, rootlet-bundles developed like surrounding the fertilizer.
4) The placement of the fertilizer did not influence the total quantity or generation number of weeds on the ridge, although weeds growing directly above the fertilizer initially grew vigorously.
5) Placing the fertilizer directly under the center of the ridge finally reduced the amount of weed emergence.抄録全体を表示PDF形式でダウンロード (1277K) -
川村 恒夫2000 年 35 巻 1 号 p. 33-38
発行日: 2000/03/08
公開日: 2010/02/09
ジャーナル フリーIn this study, the relationship between the skin color measured by the L*a*b* color system and the maturity of Japanese pear (Housui) was clarified. The parameters of maturity were mass, equatorial diameter, polar diameter, volume, and sugar content of fruit. The skin color and color charts were measured with a color meter of a D65 standard light source (color temperature is 6504K). All samples were classified into unripe (20 samples), ripe (30 samples), and over ripe (20 samples).
From the measurement of color chart, the value of a*, b*, and L* increased with maturity. It shows that the skin color changes from dark green to light reddish green with maturity.
From the analysis of skin color, there is a difference between every 2 maturity with 1% significance as for the value of a* and b*, but there is no difference of L*.
According to the correlation analysis between the sugar content and the other parameters, the value of b* of skin color has a highly correlation to the sugar content with 1% significance. Thus, it is able to select the maturity of Japanese pear by the value of b* of skin color.抄録全体を表示PDF形式でダウンロード (587K)
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