農業気象
Online ISSN : 1881-0136
Print ISSN : 0021-8588
ISSN-L : 0021-8588
16 巻, 3 号
選択された号の論文の7件中1~7を表示しています
  • 谷 信輝
    1960 年 16 巻 3 号 p. 89-93
    発行日: 1960/12/30
    公開日: 2010/02/25
    ジャーナル フリー
    Since 1951, wind profiles over the cultivated field were observed, and now some empirical results are obtained from these data.
    Six or ten small Robinson anemometers, and six aspiration type thermometers and psychrometers were used for the measurement of profiles. These instruments were installed between crop height and about 6m above the ground.
    Among many data, those obtained in September are selected.
    The wind profile over the paddy fields under the nearly neutral condition can be represented by
    U(z)=u*/k(lnz-d/z0+βz-d-z0/L) (1)
    where d is zero displacement, L stability length and β a constant (Ogura 1952, Monin and Obukhov 1954). It is known that d and z0 vary with wind speed U (Deacon 1949, Rider 1954). At first the observations made under almost neutral stability condition are selected, and d and z0 are determinded graphically. The relationship between wind speed at 1.5m above the ground and d is shown in Figure 1. It is divided into three regions as follows:
    A. (0-2m/s at z=1.5m)d decreases and z0 increases, because light wind bends only the top of leaves and ears and can not penetrate into the space under the ear layer.
    B. (2-4.5m/s) d increases and z0 decreases. Slightly stronger wind shakes leaves and stems of crop. The prevailing period of the fluctuating wind is close to the period of vibration of crop, and crops obstruct the penetration of wind.
    C. (above 4.5m/s) When the very strong wind blows, the crop bends deeply and effective height of crop decreases.
    The fact pointed by Deacon and Rider seems to corresponding to “B” region.
    β in equation (1) was given 0.6 by Monin and Obukhov. However, these observations give 5.30 as a mean value. (Table 1).
    Taking wind speed U, temperature θ, and absolute humidity χ at three height Z1=z1-d, Z2=z2-d, and Z4=z4-d, and 4Z1=2Z2=Z4, then β and L in equation (1) are eliminated and sensible heat flux F and vapour flux E can be obtained by following equations:
    F=-cpρk2/(ln2)2{2(U2-U1)-(U4-U2)}{2(θ21)-(θ42)} and E=-k2/(ln2)2{2(U2-U1)-(U4-U2)}{2(χ21)-(χ42)} The results calculated with these equations are shown in Figure. 2.
  • 第7報 柞蚕の化性と気象要素との関係
    西村 国男
    1960 年 16 巻 3 号 p. 94-98
    発行日: 1960/12/30
    公開日: 2010/02/25
    ジャーナル フリー
    柞蚕を累年飼育して, 2化性蛹を多数えた1948年, 1956年と1化性蛹を多数えた1949年との気象要素および繭質を比較検討してつぎの結論をえた。
    (1) 気温: 1化性蛹に変化した年は2化性蛹に変化した年に比べて卵期および幼虫第1令期は高温であり, 幼虫第2令~第5令期は低温, 蛹期は高温であつた。
    (2) 湿度: 1化性蛹に変化した年は2化性蛹に変化した年に比べて卵期および幼虫第1令期は寡湿であり, 幼虫第2令~第5令期は多湿, 蛹期は寡湿であつた。
    (3) 日照時数: 1化性蛹に変化した年は2化性蛹に変化した年に比べて卵期・蛹期は多く, 幼虫期は少なかつた。
    (4) 降水量: 1化性蛹に変化した年は2化性蛹に変化した年に比べて卵期幼虫期とも多雨であつた。
    (5) 繭質: 1化性繭は2化性繭に比べて繭重・繭層重が重く, 繭層歩合が高い。
  • 第1報 青森県における気象の地域性と水稲生育との関係
    阿部 亥三, 小野 清治, 鳥山 国士, 和田 純二
    1960 年 16 巻 3 号 p. 99-105
    発行日: 1960/12/30
    公開日: 2010/02/25
    ジャーナル フリー
    水稲の早期多収栽培の地域性を確立するために, 耕種条件を同一にした水稲ポットを上北郡ならびに上磯地帯を主対象として, 青森県下の23地点の水田に配置して気象の地域性と水稲生育との関連性について解明を行なつた。その結果, 次のことが判明した。
    1) 気象の地域的差異と水稲生育の地域性とは密接な関係があり, 気象の地域間差異の少ない昭和33年はやや冷涼気象を示した32年に比較して水稲生育の地域的差異も少ないことが認められた。
    また, 水稲の生育収量も大綱においては気象条件の良否と一致した。
    2) 水稲の生育型は海岸, 内陸, 高冷地の3つの型に大別された。
    3) 33年は6, 7月に例年のごとくに山背風が卓越せず高温を示したが, 海岸地帯の生育は内陸部に比べて劣つた。また, 高冷地帯は登熟障害によつて減収したが, 各地点とも総じて32年より生育が良好であつた。
  • 山川 寛
    1960 年 16 巻 3 号 p. 106-110
    発行日: 1960/12/30
    公開日: 2010/02/25
    ジャーナル フリー
    These observations were carried out in order to clarify the actual situation of the various temperatures (air, water and soil) in paddy field and to determine the effect of carbon black powder on the temperatures of water and soil, and on the growth of paddy plant, at Bukit Merah Paddy Experimental Station in Northern Malaya. The carbon black powder was dusted on the surface of water in paddy field to decrease the water and soil temperatures by intercepting the penetration of solar radiation into water. Results obtained are as follows:
    1. The water and soil temperatures varied according to the growth of paddy plant, but the air temperature at a height of 80cm from soil surface did not seem to be affected by paddy growth. The effect of paddy growth on the water and soil temperatures was negligible up to about two weeks before maximum tillering time, and these temperatures were similar to those before transplanting. Soon after passing that time, the effect of shading of leaves and stems of paddy plants on those temperatures was seen and those temperatures began to decrease gradually, reaching minimum temperatures approximately during heading time and increasing steadily towards harvesting time. Furthermore, the results obtained clearly indicated that the temperatures of water and soil were higher than the optimum temperature on the assumption that the optimum soil temperature for paddy plant is about 27°C, during the growth duration and particularly during the vegetative growth period.
    2, The temperatures in carbon black powder plot decreased in both water and soil as compared with control plot, particularly during the period from transplanting to heading. Furthermore, there was no sign of weeds growing in carbon black powder plot. Consequently the growth of plants in carbon black powder plot was excellent as compared with control plot and the yield of grain increased by 24% in comparison.
  • 羽生 寿郎, 小野 清治
    1960 年 16 巻 3 号 p. 111-118
    発行日: 1960/12/30
    公開日: 2010/02/25
    ジャーナル フリー
    This paper deals with the results of measurement of evapotranspiration from the paddy fieild at Kuroishi City situated in the cooler region of Japan, from 1953 to 1956.
    The amounts of transpiration were below 1mm/day in the early growth stage of rice plants and increased gradually with their growth (Fig. 1). But, the amount of evaporation decreased with their growth (Fig. 6).
    The evapo-transpiration rates to the evaporation E obtained from the meteorological observation field lay within about 1.0-1.3 in the early growth stage and increased after the young ear formation stage. But the rates decreased again from about the tenth day after heading (Fig. 7).
    Two peaks of the transpiration rates to E were found after the young ear formation stage and the heading stage. From the index of growth amount ln (l and n mean respectively the plant length and the number of stems per unit area), the transpiration rate t/E (t means the amounts of transpiration) and the seasonal changes of τ(τ means t/E/ln×104), it was presumed that two peaks for t/E during irrigation period would probably be found for the case of ln.
    Total evapo-transpiration amounts throughout the irrigation period varied annualy from 440mm to 553mm and were 493mm on the average, showing 1.22 times as much as E. The average transpiration amount was found to be 0.45 times as much as the evapo-transpiration. The annual changes for the average transpiration amount were larger than the cases of the evaporation amounts obtained from the paddy field.
  • 第4報 干ばつ
    日下部 正雄
    1960 年 16 巻 3 号 p. 119-120
    発行日: 1960/12/30
    公開日: 2010/02/25
    ジャーナル フリー
  • [IV] 霜害およびその防除法
    内島 善兵衛
    1960 年 16 巻 3 号 p. 121-126
    発行日: 1960/12/30
    公開日: 2010/02/25
    ジャーナル フリー
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