農業気象
Online ISSN : 1881-0136
Print ISSN : 0021-8588
ISSN-L : 0021-8588
49 巻, 1 号
選択された号の論文の10件中1~10を表示しています
  • 川方 俊和, 矢島 正晴
    1993 年 49 巻 1 号 p. 3-9
    発行日: 1993/06/10
    公開日: 2010/02/25
    ジャーナル フリー
    Many studies concerning photoperiodic sensitivity of rice plants have been conducted under constant daylength. However, since daylength fluctuates periodically during the year, we examined photoperiodically sensitive rice under natural daylength (and constant air temperature) to predict heading time using meteorological data.
    Six cultivars of rice plants were sown at two-week intervals for one year in a green house. Air temperature was maintained at a constant 24 degrees C during the year, but water temperature decreased during winter.
    Cultivars sown between August and February were nearly constant in number of days required from emergence to heading. However, cultivars sown between March and July required more time, and results among cultivars were in consistent.
    From these results, the authors propose the following equation:
    Σhi=1Ti-S=Σhi=a+1f(Li)
    where Ti is water temperature, Li is daylength on the i-th day, S is accumulated water temperature from emergence to heading under short daylength, a is the date on which rice plants start to sence daylength and h is heading date, f(L) was calculated by non-parametric DVR methods.
    In conclusion, this model can be transformed into the developmental index (DVI) which is the sum of the developmental rates (DVR). And the developmental rate was constant when daylength was shorter than critical one. Over this critical value, however, the developmental rate decreased in direct proportion to daylength.
  • 黒瀬 義孝, 林 陽生
    1993 年 49 巻 1 号 p. 11-17
    発行日: 1993/06/10
    公開日: 2010/02/25
    ジャーナル フリー
    Using the thermal images offered by the infra-red thermometer and the LANDSAT, the air temperature distribution over mountainous regions were estimated under conditions of nocturnal radiative cooling in the winter season. The thermal image analyses by using an infra-red thermometer and the micrometeological observation were carried out around Zentsuji Kagawa prefecture. At the same time, the thermal image analyses were carried out by using the LANDSAT data. The LANDSAT data were taken on Dec. 7, 1984 and Dec. 5, 1989. The scenes covered the west part of Shikoku, southwest of Japan.
    The results were summarized as follows:
    Values of the surface temperature of trees, which were measured by an infra-red thermometer, were almost equal to the air temperature. On the other hand, DN values detected by LANDSAT over forest area were closely related with air temperature observed by AMeDAS. Therfore, it is possible to evaluate instantaneously a spatial distribution of the nocturnal air temperature from thermal image.
    The LANDSAT detect a surface temperature over Shikoku area only at 21:30. When radiative cooling was dominant, the thermal belt and the cold air lake were already formed on the mountain slopes at 21:30. Therfore, it is possible to estimate the characteristic of nocturnal temperature distribution by using LANDSAT data.
    It became clear that the temperature distribution estimated by thermal images offered by the infra-red thermometer and the LANDSAT was useful for the evaluation of rational land use for winter crops.
  • 塚本 修
    1993 年 49 巻 1 号 p. 19-25
    発行日: 1993/06/10
    公開日: 2010/02/25
    ジャーナル フリー
    Turbulent flux measurements were carried out over a paddy field to study the irrigation water effect. The ponding depth ranged from 0cm to 10cm with fine weather during a week. Upward sensible heat flux responded to the variation of water level with a maximum on no water condition. Downward carbon dioxide flux had a minimum value on no water condition. However, water vapor flux behavior is more complicated with a minimum on full water condition.
    The influences on the Bowen ratio and CWFR (Carbon dioxide Water Flux Ratio) were also studied.
  • 鈴木 晴雄, 大呂 肇
    1993 年 49 巻 1 号 p. 27-34
    発行日: 1993/06/10
    公開日: 2010/02/25
    ジャーナル フリー
    本実験では, 栽培畑におけるフィルムマルチ下同一深における地温測定値のバラツキを, 主に気象要因との関係から明らかにし, さらにマルチ区間の地温の比較方法について検討した。使用したフィルムは黒色有孔ポリエチレンフィルム (厚さ0.04mm, 植穴径8cm) であり, 植生としてダイズ (福獅子) を栽培した。実験区は, マルチと植生のない対照区である無植生無マルチ区 (Co), それに植生のある植生無マルチ区 (Cp), マルチがあり無植生状態の無植生マルチ区 (Mn), 植生のある植生マルチ区 (Mp) の計4区である。
    1) 10cm深の水平方向10点地温バラツキの日変化については, 夜間, 植生マルチ区 (Mp)>無植生マルチ区 (Mn)>植生無マルチ区 (Cp)≈無植生無マルチ区 (Co) の推移であり, マルチの区での植生は地温バラツキの増大化に作用した。また, 昼間は全区ともバラツキは上昇し, 夜間の場合より区間差は減少した。
    2) 地温バラツキに影響の大きい10点測定の土壌水分 (10cm深) は, 全般的に無マルチの2区よりマルチの2区で高く, さらにマルチ下では植生によって土壌水分バラツキが幾分大きくなった。
    3) 各区の地温比較について, t-検定によって2区間の高低判定を行い, 期間中 (計63日) を通じ連日求めた (Table 4)。比較は最低地温としての6時値と, 最高地温としての15時値である。両時刻を通じて97%以上の高い高低関係が得られたのは無植生の区間 (Mn-Co) であった。他の区間では必ずしもそうではなく, 特に植生のある区では生育に伴う区間差の減少が現れた。
    4) 期間中, 2区間の地温高低関係 (計3通り) を最多頻度め関係とそれ以外の関係の2グループに分け, 気象要因を説明変数とした判別関数により解析した。植生マルチ区 (Mp) と無植生無マルチ区 (Co) 間について行った結果, 同区間の2分類化には土壌水分とLAIによる影響の大きいことが得られた (式1)。
    5) マルチ下地温高低判定の九めの2区間の閾値 (地温差) を, 任意に設定して比較した。閾値の大きさによりマルチの地温効果は変化した。植生のある区との比較では, 植生の繁茂に応じた閾値設定の必要性が考えられた。
  • 狩野 敦, 永谷 奈々美
    1993 年 49 巻 1 号 p. 35-39
    発行日: 1993/06/10
    公開日: 2010/02/25
    ジャーナル フリー
    We have developed two CAI (Computer Aided Instruction) application software for the use of students at agricultural colleges. Hardware and software platforms for the applications are Macintosh SE (Apple Computer) and HyperCard ver. 1.2.1 (Apple Computer). The developed software (stacks) use graphical images, sounds, and animation techniques to keep users attracted to the screen. They also contain pop-up explanations of words and terms and mini-tests for understanding technical words and for self understanding user's achievement on the subjects, respectively.
    According to results of questionnaires answered by the test users, in general, the stacks were judged as easy to use and user friendly. However, the users indicated some points need to be improved. Future improvement on the user interface is necessary; at the same time, it is also necessary to keep the developmental environment simple for non-professional programmers.
  • 北村 修
    1993 年 49 巻 1 号 p. 41-47
    発行日: 1993/06/10
    公開日: 2010/02/25
    ジャーナル フリー
  • 変動気候下での緑資源と食糧生産に関する国際シンポジ
    1993 年 49 巻 1 号 p. 49-52
    発行日: 1993/06/10
    公開日: 2010/02/25
    ジャーナル フリー
  • 1993 年 49 巻 1 号 p. 80a
    発行日: 1993年
    公開日: 2010/02/25
    ジャーナル フリー
  • 1993 年 49 巻 1 号 p. 80b
    発行日: 1993年
    公開日: 2010/02/25
    ジャーナル フリー
  • 1993 年 49 巻 1 号 p. 80c
    発行日: 1993年
    公開日: 2010/02/25
    ジャーナル フリー
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