著者

高見 晋一

出版者

日本農業気象学会

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.62, no.4, pp.119-125, 2006 (Released:2007-06-06)

参考文献数

20

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The law of the minimum, reputedly originally conceived by Justus von Liebig more than one hundred fifty years ago, is a powerful tool in understanding processes with unknown details. The objective of this study was to provide a rationale and some evidence for such a claim. To do so, I assume that the law of the minimum is to be specified as the linear response and plateau (LRP) model: Y = min {X, U}, where X is the limiting variable when it is smaller than U, and U the limiting variable when it is smaller than X. These variables may be either stocks or flows. The study shows that the law thus specified has nothing to do with empiricism but is purely a form of thinking that can be intuitively or logically understood by anyone. As such, it can be applied not only to biological, chemical, and physical processes of academic interests, but also to various processes in our daily lives. In this article, the following examples were given: (ii) the dry-matter partition associated with crop production, (i) crop growth in an environment of abundant resources, and (iii) evapotranspiration in relation to precipitation and net radiation. The law of the minimum is also shown to be useful in analyzing the relationship between sink and source variables to identify the limiting factor.

著者

坂上 務

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.15, no.2, pp.59-63, 1959-09-15 (Released:2010-02-25)

被引用文献数

1 1

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The author investigated the microclimate on the waste heap from the forest point of view. That is, the slopes were favourable to the sliding down of cold air and the rising of warm air, on the slopes, the layer of air near the ground had the peculiar meteorological properties.Like a skin of air it clothes and determined the climatic habitate of the plants growing thereon. There were 10 observation points located on the slopes of different direction and high degree.The sketch map (Fig. 1) shows by the configuration of the contours how regular the cone is on all sides, and it lies at an average inclination of 30°. All the points of maximum and minimum temperature readings were taken at a height of 30cm in winter, and vertical distribution of temperature and humidity readings were taken at o-150cm height in spring & summer. Fig. 6-9.Fig. 1-Fig. 4 show the distribution of maximum and minimum temperature on the waste heap on average for winter days.It was to be found that the lowest temperature and maximum temperature range would be found on the south slope, and results of humidity measurement on the south slope, had dry air layer, so the plants did not easy grow there.

著者

小元 敬男 青野 靖之

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.45, no.1, pp.25-31, 1989-06-10 (Released:2010-02-25)

参考文献数

21

被引用文献数

22 15

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An attempt is made to estimate blooming dates of Prunus yedoensis for 21 meteorological stations in Japan by using DTS (the number of days transformed to standard temperature). The starting date for computation at each station is determined by correlation analysis. At many stations the date lies between 40 and 55th day from January 1st.The number of days transformed to a standard temperature (in this study 25°C is used) at each station is computed by adding characteristic temperature of each day from a starting date to blooming date for various temperature characteristic (Ea). The estimated blooming date is the date when accumulated value of DTS reached at that of mean observed blooming date for the site.It is found that 17kcal mol-1 for Ea gives minimum error when averaged over all sites. Using this Ea and D2 which is the starting date determined from error analysis, computations are made to estimate blooming dates at each station between 1961 and 1985. It is shown that at stations in Hokkaido and Tohoku districts, RMS errors between the observed and the calculated blooming dates fall between 1 and 2 days. At stations in other areas, the errors range between 2 and 3, except for Hachijo where it becomes 6.7 days. The large error at this southernmost station seemed to be attributed to year to year change of degrees of rest completion of Prunus yedoensis, which affect effectiveness of temperature just before blooming.

著者

長谷場 徹也

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.32, no.1, pp.27-31, 1976-06-15 (Released:2010-07-01)

参考文献数

14

被引用文献数

1 1

著者

蔵田 憲次 大原 源二

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.44, no.1, pp.33-36, 1988-06-10 (Released:2010-02-25)

参考文献数

2

著者

蔵田 憲次

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.44, no.3, pp.181-186, 1988-12-10 (Released:2010-02-25)

参考文献数

6

被引用文献数

1 3

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Computers have been applied to crop management in protected cultivation and have proved to be of great use. However, in the present computer systems, control algorithm is fixed and users can only change the setpoints of the controlled variables. Crop management is strongly influenced by the local conditions of climate, soil, etc. and well trained and eager growers manage their crops in the way which is suitable under the given local conditions and is obtained through the long period experience.This study aims at developing a system which learns grower's managing methods (rules, hereafter) through measuring environmental factors, crop status, if possible, and grower's behavior.After learning the grower's rules, the learned rules will be applied to the automatic management.Thus, the grower will be released from the management labor without losing their own personal preference and principles in crop management. This system can also be applied to the rule aquisition and analysis of well trained growers. This report presents considerations on the characteristics of the growers' rules and the possibilities and problems of the simple learning algorism developed (K-algorithm, hereafter), which will be the framework of the system we aim at. Details of K-algorithm are given in another report (Kurata, 1988).Considerations on the grower's rules revealed that there are many difficult aspects for the computer in learning, for examples, the problem of fuzziness associated with the human feelings, the problem of noise and how to find out a function which the grower's rule has but not directly measurable. All these points are omitted in the present study and left for the future study.A simple simulation revealed that K-algorithm is very powerful in imitating the grower's behavior but the learned rules are somewhat longer than the assumed grower's rules, examples of which are listed Table 1. This redundant expression of the learned rule is due to some correlations among environmental factors, crops status and time. If we assume stochastic stationary state of these functions and their correlations, this brings about no problem in applying the learned rules to the automatic management.

著者

小中原 実

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.39, no.4, pp.315-322, 1984-03-10 (Released:2010-02-25)

参考文献数

69

被引用文献数

2 2

著者

孫 禎翼 高倉 直

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.44, no.4, pp.253-258, 1989-03-10 (Released:2010-02-25)

参考文献数

14

被引用文献数

9 10

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For investigation of the relationship between plant growth and environmental factors in a plant factory, an experimental plant factory has been built and some experiments have been carried out. Leaf lettuce was grown in a hydroponic system under artificial light condition. Arial environment such as air temperature, humidity and CO2 concentration were controlled. Root environment such as EC and pH were monitored and controlled by a microcomputer.In the first experiment, EC level was maintained at a constant set-point and the difference between the set-point and the actual value was summed up when the latter value was corrected. Transpiration was also calculated from the water depression in the tank. Then it was summed up through the growing period.Following results were obtained:(1) The EC decrement showed high correlation with the transpiration, regardless of light intensity and (2) the transpiration rate per EC decrement decreased as the EC of nutrient solution became higher.In the second experiment, the effects of light intensity, lighting cycle and EC of nutrient solution on tipburn injury were examined.Following results were obtained: (3) The tipburn occurrence became later under the conditions that the EC was low and the duration of a lighting cycle was short and (4) the tipburn occurrence became later under the conditions that the light intensity was low and the duration of a lighting cycle was short.Effect of the duration of a lighting cycle on the tipburn occurrence showed larger as the light intensity increased. From the results of Tibbitts et al (1985), it is, therefore, considered that the pressure of laticifer or the Ca concentration in the wall of laticifer increases with the increase of the duration of lighting cycle and this could cause the tipburn.

著者

Akihiko ITO Shimpei INOUE Motoko INATOMI

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.78, no.2, pp.56-65, 2022 (Released:2022-04-10)

参考文献数

62

被引用文献数

8

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Evaluating regional budgets of methane (CH4), a potent greenhouse gas and short-lived climate forcer, is an important task for future climate management. This study estimated historical CH4 emissions from paddy fields in East Asia by using a process-based terrestrial biogeochemical model driven by climate and land-use data. To capture the range of estimation uncertainty, this study used two CH4 emission schemes, four paddy field maps, and two seasonal inundation methods for a total of 16 simulations. The mean CH4 emission rate during 2000-2015 was estimated to be 5.7 Tg CH4 yr-1, which is similar to statistical inventories and other estimates. However, the large standard deviation (± 3.2 Tg CH4 yr-1) among the simulations implies that serious estimation uncertainties remain. Three factors - CH4 emission scheme, paddy field map, and inundation seasonality - were responsible for the disparity of the estimates. Because of the lack of historical management data, the model simulation did not show a decreasing trend in the agricultural CH4 emissions. A sensitivity analysis for temperature indicated that a 1-2 °C temperature rise (typical warming in mitigation-oriented scenarios) would substantially enhance CH4 emissions. However, a sensitivity analysis for water management indicated that a lower water-table depth would largely mitigate the emission increase. Additional studies to improve agricultural datasets and models for better paddy field management are still needed.

著者

宮本 硬一

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.16, no.4, pp.145-148, 1961-03-30 (Released:2010-02-25)

参考文献数

15

被引用文献数

1 1

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This investigation was made in 1958 to estimate the amount of damages to be done by the prevailing easterlies to the rice yield in the area at the leeward of the windbreak on the seashore near Yamoto Town, Miyagi Prefecture, as a result of the cutting-down of the forest for the purpose of enlarging the landing strip of Matsushima military air depot.The outline of the information I have obtained on the effective limits of the windbreak and the estimated distance distribution of decrease in rice crop, will be given below.(1) On the map I drew two lines (A) and (B), one on the paddy fields exposed to the breeze and the other on the paddy fields at the leeward of the shelter-belt of trees. The measuring spots were placed at every 100 meters on the lines. The comparison was made between the rice yields at the corresponding spots of each line, and the difference between them was considered being made by the shelter-belt of trees. The same comparison was made at the area on the other side of the air depot. For comparison at the measuring spots I used the average rice yield per 10 a figured out by the Yamoto Agricultural Insurance Association.(2) The effective zone of the windbreak on rice yield was found out having a radius of about 400 meters from the forest, in other words, a screen of trees gives useful shelter to about a distance of thirty times its height. This finding was in accord with the calming effect of the forest measured by the Sendai Meteorological Observatory.(3) In case when the windbreak is cut down, it can safely be guessed that between the distance of the forest and the rice yield will be formulated by the following equation (see Fig. 3):Y=0.07x+68 (σ=2.2)Therefore, after the windbreak has been destroyed, the paddy fields near the forest are supposed to show about 30 percent decrease in production as compared with the non-effective site. The decrease percentage increases with the distance—about 7 percent every 100 meters—and at a point 400 meters from the screen of trees, the rice production comes to be free from the influence of the forest.

著者

久保木 光熙

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.43, no.1, pp.53-57, 1987-06-10 (Released:2010-02-25)

著者

重原 好次

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.44, no.1, pp.37-43, 1988-06-10 (Released:2010-02-25)

著者

吉野 正敏 宮内 誠司 岩間 敏彦

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.43, no.3, pp.239-246, 1987-12-10 (Released:2010-02-25)

参考文献数

14

被引用文献数

1 2

著者

星野 和生

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.51, no.1, pp.61-68, 1995-03-10 (Released:2010-02-25)

参考文献数

3

著者

長谷場 徹也 伊藤 代次郎

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.38, no.3, pp.269-277, 1982-12-10 (Released:2010-02-25)

参考文献数

28

被引用文献数

2 2

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葉の熱収支式を解いて, 葉温と気温もしくは相対湿度との関係を求めた。この際, 熱及び水蒸気の葉面境界層輸送係数には, 浮力, 葉面温度分布, 群落内気流の乱れ及び葉の揺れの効果を考慮した。また, 気孔開度は, 日射量, 気温及び相対湿度の関数として与えた。気孔開度が日射量によるとともに気温の上昇に伴って飽和曲線的に大きくなる場合に, 気温が低いと葉温は比較的高いが, 湿度が一定で気温が上昇すると, 葉気温差はほぼ直線的に小さくなって, ある気温で葉温は気温と等しくなり, それ以上の気温で葉温は気温より低くなる。この“equality ternperature”は日射が強く相対湿度が高くまた風が弱いほど高くなる。さらに, equality temperature は作物の生まれた土地の温度条件に関連する遺伝的特性としてきまること, ならびに, equality ternperature は光合成の適温に重要な意味を持つことが示唆された。気孔開度は日射量と気温とに依存するが, 相対湿度に対しては一定の場合, 高湿になるに従い, 葉温は直線的に上昇する。次に, 気孔が低湿時に開く場合も, 葉温は湿度の上昇に伴ってほぼ直線的に上昇するが, 高湿時には気孔が相対的に閉じて葉温はやや高くなる。低湿時に, 気孔が閉じる場合には, 葉温は相対的に高くなる。実測値から得られた葉温と各気象要素とのそれぞれの関係は葉の熱収支のシミュレーションの結果とほぼ一致した。

著者

向井 利明

出版者

養賢堂

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.58, no.3, pp.157-164, 2002-09-10

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*平均気温は東・西日本と南西諸島で高く、北日本で平均並 *北日本の冬の低温 *春の少雨 *夏は東日本以西で高温 *早い梅雨明け(東日本、東北南部)、7月の記録的な高温と少雨、8月は北冷西暑 *秋は東・西日本太平洋側などで多雨 冬には北日本は1987/88年冬以来13年ぶりの低温となり、北日本日本海側の降雪量も多くなった。春は気温の変動が大きかったが、南西諸島を除き高温となった。また、北・東・西日本では高気圧におおわれることが多く、少雨となった。南西諸島では多雨・寡照だった。夏の気温は北日本で平年並、東日本以西で高くなった。梅雨明けは東日本と東北南部で平年より2週間以上早く、7月は東日本などで記録的な高温と少雨になった。8月にはオホーツク海高気圧などの影響で北日本で低温となる一方、西日本・南西諸島では高温が続いた。秋には台風や低気圧の影響で東日本以西で多雨となった。年平均気温は北海道や東北の一部で平年を下回り、そのほかの地方では平年を上回った。東日本以西では平年を0.5℃以上、上回るところがあった。年降水量は南西諸島と西日本、関東甲信、北海道の一部で平年を上回り、そのほかの地方では平年を下回るところが多かった。年日照時間は東日本と西日本では平年を上回り、北日本と南西諸島では平均を下回るところが多かった。

著者

丸山 篤志 大場 和彦 黒瀬 義孝

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.56, no.4, pp.275-282, 2000-12-10 (Released:2010-02-25)

参考文献数

9

被引用文献数

2 1

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Effects of wind and salt water exposure on yield of paddy rice were investigated by using a wind tunnel and sprinkler. Rice plants were exposed to seventy-two different treatment combinations of salt concentration, wind duration, cultivar (Hinohikari and Yumehikari) and growth stage. Photosynthesis on the day after treatment was decreased by wind and salt water exposure. Percentage and weight of filled grain at harvesting, and consequently yield were also decreased by wind and salt water exposure. Yield reduction in Hinohikari was more than Yumehikari due to a difference in wind tolerance between the two cultivars. The amount of adhered salt on the rice plants grown outdoors decreased after treatment due to rainfall, but the yield reduction was the same as cropping under cover (no rainfall) after treatment.The amount of adhered salt on the panicle after treatment was directly proportional to salt concentration in the sprayed water. Using the proportional coefficient, relationships between the amount of adhered salt on the panicle and relative yield of paddy rice were determined. Relative yield of paddy rice decreased from 1.0 to 0.2 when treated at heading time and 8-12 days after heading as the amount of adhered salt increased from 0 to 6mg per panicle. In the same way, relative yield decreased from 1.0 to 0.7 when treated at 21-25 days after heading. These relationships will be useful in predicting the yield of paddy rice affected by strong wind and salt from the sea caused by typhoons.

著者

清野 豁 甲斐 啓子 太田 俊二 菅野 洋光 山川 修治

出版者

日本農業気象学会

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.54, no.2, pp.179-186, 1998

被引用文献数

1

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In this paper, new knowledge of global warming is briefly described on the basis of the 1st and 2nd Working Group of IPCC (Intergovernmental Panel of Climate Change) published in 1996. The contents of this paper are arranged according to the oral reports in the 7th gathering of the Researching Group for Impacts of Climate Change (ICC) in the Society of Agricultural Meteorology of Japan on June 7, 1997. The main authors are as follows: Seino is §1 and §4, Kai in §2, Ohta in §3, Kanno and Yamakawa in §5. Observed climate change, its variability and uncertainty are discussed in §2. Assessment of impacts of climate change on terrestrial ecosystem is presented in §3. Agriculture under changing climate is introduced in §4. In §5, some problems as to the IPCC reports are mentioned including the discussions in the meeting.

著者

原薗 芳信 矢吹 万寿

出版者

日本農業気象学会

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.37, no.2, pp.p103-110, 1981-09

被引用文献数

2

著者

Yasushi ISHIGOOKA Toshihiro HASEGAWA Tsuneo KUWAGATA Motoki NISHIMORI Hitomi WAKATSUKI

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.77, no.2, pp.139-149, 2021 (Released:2021-04-10)

参考文献数

44

被引用文献数

16

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Rice is the most important cereal crop in Japan, and therefore the impact of projected climate change on its production and quality has been assessed using rice growth models accounting for the effects of rising temperature and atmospheric CO2 concentration ([CO2]) on important growth processes. Recent experimental studies, however, have shown some negative effects of interactions between [CO2] and temperature on yield and quality of rice which were not accounted for by previous impact assessments. This study examined the importance of [CO2]×temperature interactions in the nationwide impacts of climate change on grain yield and quality of rice in Japan by 2100. We introduced new functions accounting for the effects of interactions on yield. Then we adopted the acceleration by elevated [CO2] in the estimation of the occurrence of chalky grains, an indicator of appearance quality of rice. We applied the modified model to Japan at a spatial resolution of 1 km using 10 climate scenarios (5 Global Circulation Models×2 representative concentration pathways [RCPs]) from 1981 to 2100. The effects of the newly introduced negative effects of [CO2]×temperature were evaluated by comparing simulations with and without the interaction in each scenario. Nationwide production was estimated to decrease by up to 28% and the percentage of white chalky grains to increase up to 16% relative to the previous assessment results, especially in RCP8.5, in which larger increases were projected in both temperature and [CO2]. The result suggests that the positive effect of elevated [CO2], which had been expected to offset the negative effect of increased temperature on rice productivity, may be limited in the future, and rice quality degradation may be more severe than predicted previously.